FLU EPIDEMIC

Family of Orthomyxoviridae

2011-12-20T19:12:00.000-08:00

Only a few pathogens viruses have a potential for invasion of lower respiratory tract. Among these the Orthomyxoviridae are the most prominent in terms of numbers of young and elderly people infected, disabled or dying.

Three genera of Orthomyxoviridae are Influenzavirus A, Influenzavirus B; Influenzavirus C. Thogoto-like viruses, a tickborne virus of mammals, forms a fourth genus, Thogotovirus.

In Greek arthos means prosper and myxa means mucos.

Influenza virus A and B are closely related, but influenza A infects a wide spectrum of birds and mammals including humans, with bird being the reservoir, whereas influenza B infects primarily humans and humans are the reservoir.

The Orthomyxoviridae is a family of single strained RNA viruses. They are ubiquitous enveloped virus, approximately 90-120 nm in diameter with helical symmetry and segmented, negative sense, ssRNA genome.

The envelope, which is derived from host cell membrane lipids, contains glycosylated and non-glycosylated viral proteins.

They are extremely stable in small droplet aerosols and are shed in large numbers, both characteristically adding in their efficient spread among immunologically naïve individuals and young schoolchildren.

Surface projections of glycoproteins form ‘spike’ or peplomers which, in influenza A and B viruses, are of two types a haemagglutinin (H) responsible for virus attachment and envelope fusion, and a neuraminidase (N) capable of cleaving viral receptors., degrading mucos and promoting both entry of virus into cells and release of virions from infected cells.

Family of Orthomyxoviridae

Flu Virus contagious

2011-10-09T22:26:00.000-07:00

Influenza virus is contagious and spreading from human to human. Human will start feeling sick from one to four days after exposing to the flu virus.

Adults generally can spread the virus to others starting one day before they fell sick, and up to seven days after the symptom start.

Flu virus, transmitted by coughs, sneezes, laughs and even normal conversation, are extraordinarily contagious, particularly in the first three days.

The person will be contacted by aerosolized droplets and also with objects contaminated by mucus from an infected person.

The virus enters the body through the respiratory tract. Incubation is one to three days. The person is most contagious one day before the onset of symptoms and for up to seven days the symptoms begin. Most people will be sick from two to five days.

Fever, headache, extreme tiredness, dry cough, sore throat runny or stuffy nose and muscle are the symptoms of flu.

However, fatigue and resultant cough can last for several weeks.

Children can infect others for much longer. They are infectious for several days before they start to feel sick. They can pass the virus on for more than seven days after showing flu symptoms.

On average each year 20,000 Americans die of the flu. Because these virus are highly contagious, it is thought that public transportation is a main conduit for transmission.
Flu Virus contagious

Influenza Virus

2011-09-05T00:33:00.000-07:00

Influenza viruses are enveloped RNA viruses, segmented and single-stranded belonging to the family Orthomyxoviridae.

The orthomyxoviruses differ from the paramyxoviruses primarily in that the former have a segmented RNA genome, whereas the RNA genome of the latter consist of a single piece.

There are three influenza virus genera, or virus types, within this family, influenza A, B and C distinguishable on the basis of antigenic differences between their matrix and nucleoproteins.

Influenza A, B and C viruses also differ with respect to host range, variability of the surface glycoprotein, genome organization and morphology.

Influenza A viruses are primarily avian viruses but also infected a wide variety of animals, including pigs, horses and seals.

These viruses also most commonly infect poultry as well as many types of wild birds.

On the other hand, influenza B and C viruses are essentially human viruses.

However, influenza C virus, is of little importance for human influenza infections, causing only a mild common cold like disease.

Influenza C viruses are very rare but can infect humans, dogs and swine.

Influenza virus causes worldwide epidemics of influenza; influenza B virus causes major outbreaks of influenza; and influenza C causes mild respiratory tract infections but does not cause outbreaks of influenza.

Pandemics of influenza A have in the past had a tremendous impact on human health and have paralyzed the communities worldwide.

Similar scenarios would have to be expected to occur in case of pandemic spread of a new influenza virus in the human population.
Influenza Virus

Sneezing

2011-07-10T04:48:00.000-07:00

People can’t spread the virus until they start to have symptoms, such as coughing and sneezing.

Cold virus usually gets to the body via nose. They moved in, take over the cells lining of the nostril, and begin reproducing.

When the body nerves detect a virus, they contact the lungs and get them to send a blast to air through the body.

When the infected person coughs or sneezes, he or she release tiny droplets of water from the mouth and nose.

These droplets are loaded with the flu virus. The tiny water packages carry the virus through the air and can travel several feet away from the person who sneezed or coughed.

They spew out millions of viruses that float on tiny mucous droplets.

If the virus-containing droplets lands on someone’s mouth or nose, that person may also get sick.

Therefore if the person feels sick, cover nose and mouth with disposable tissues when cough or sneeze and wash the hands after coughing or sneezing.

The flu virus’s ability to turn normal human or animal host cells into flu-copying machines is another reason influenza can take over immune system.

Adults are generally contagious for about six days, from the day before the onset of symptoms to about five days after they get sick.
Sneezing

Influenza A

2011-06-08T01:31:00.000-07:00

Influenza viruses are enveloped RNA viruses, belonging to the family Orthomyxoviridae.

They are divided into three general, influenza A, B and C viruses, distinguishable on the basis of antigenic differences between their matrix and nucleoproteins.

The influenza A viruses are responsible for pandemic outbreaks of influenza and for most of the well known annual epidemics.

Influenza viruses primarily avian viruses, but also infect a wide variety of animals, including pigs, horses and seals.

The A viruses contain two major envelope glycoprotein, hemagglutinin and neurominidase.

Subtypes are classified by the surface proteins of the virus called hemagglutinin – H and neuraminidase – N.

H1N1 influenza A virus appeared in 2009. It is very important veterinary and human health pathogens around the world.

Influenza A virus infection begins in the nasal and tracheal airways and can spread throughout the upper and lower respiratory tract.

Clinical symptoms of an acute human influenza A virus infection can range from mild to severe and typically include fever, cough, headache and malaise.
Influenza A

Complication of Flu

2011-04-10T19:22:00.000-07:00

Most of annual deaths form seasonal influenza A are die to pneumonia caused by the virus spreading into the lungs.

The person with the flu may suffer complications of pneumonia if care is not properly given and without medical attention.

Secondary complications in unvaccinated individuals, especially those over 65 years infants or with underlying medical conditions, may lead to bacterial pneumonia if S. aureus or H. influenza invade the danged respiratory tissue.

Most deaths occur from viral pneumonia because the body creates such as dramatic immune response to the virus that it floods the lungs with fluids in its attempts to attack the multiplying viruses.

Viral pneumonia can be deadly force, killing forty-eight hours of disease onset. The influenza virus can disable and over whelm the immune system.

The early symptoms of viral pneumonia may resemble those of influenza a dry cough, fever headache muscle pain and weakness.

Twelve to 36 hours later, however people with viral pneumonia may experience increased breathlessness, worsening cough with mucous, high fever and possibly blueness of the lips.

Immunizing a person is the most effective protective measure for those who are so susceptible by increasing though the body’s defense mechanism.

Older people should be sure to receive immunization for flu, as well as for pneumonia, a very serous disorder for anyone who has chronic illness or a compromise immune system.
Complication of Flu

Viral Infection

2011-01-19T16:59:00.000-08:00

Influenza viruses have special features that can over power a body’s immune system. It affects respiratory tract – nose, throat, bronchial tubes and lungs.

First, influenza virus are efficient travelers.

Second, they have an amazing ability to copy themselves.

And third, flu viruses are unique in that once a strain has spread in a population, its structure changes and it then is capable of causing a new form of flu because the antibodies produces to combat the original virus are not effective against the new form.

An entirely new strain appears about every 10 years.

Not only do influenza viruses travel easily from person to person, they do so secretly for part of the time.

A person with the flu may be contagious for several days before he or she know it.

When an infected person coughs or sneezes, he or she releases tiny droplets of water from the mouth and nose.

The most common way to catch the flu is by inhaling that tiny droplets. Less often it is spread when the person touch a surface such as a faucet handle or phone that has the virus on it and then touch his own mouth, nose, or eyes.

The virus’s ability to turn normal human or animal host cells into flu-copying machines is another reason influenza can take over immune systems.

After an incubation period of 1 to 4 days, people infected with influenza virus develop an abrupt fever, headache, sore throat and dry cough that can in some cases progress to viral pneumonia, respiratory failure and death.
Viral Infection

Antivirals for Influenza

2010-08-27T08:25:00.000-07:00

Antivirals for Influenza
While vaccination is the method of choice for influenza prophylaxis, under specific conditions where the individual has not been or cannot be vaccinated, or is not fully protected by vaccination, the use of drugs should be considered for treatment or prevention of influenza infection.

Physician needs to know whether influenza is circulating in the community and how to diagnose influenza illness for the purpose of appropriate prescription of influenza antiviral drugs.

Antiviral drugs approved for treatment or prophylaxis of influenza include M2 channel inhibitor amantidine and rimantidine and the neuraminidase inhibitors zanamivir and oseltamivir.

The application of these drugs to clinical may be limited buy issues of efficacy with respect to the type of influenza virus (influenza A vs B), drug resistance, adverse effects and cost.

In the case of the M2 ion channel blockers, these drugs are only effective against influenza A, the induction of drug resistance is well documented and side effects can be significant, especially in older people.

M2 channel blockers of influenza virus destruct the virus’ ability to penetrate the cells and to release ribonucleoprotein.

While for Neuraminidase inhibitors destruct the ability of A and B influenza virus to penetrate the epithelial cells, break the virions’ outlet from the infected cell, reduce the virions’ resistance to the action of secretary factors.

While these issues have not been apparent with the more recent neuraminidase inhibitors, high cost may be prohibitive for broad use of these drugs, while for the inhaled zanamivir there is a caution against its use incases of airways hypersensitivity.

These issues not only limit the use of antivirals for individual treatment but also present major challenges to their potential use in future pandemics.
Antivirals for Influenza

What is Tamiflu?

2010-07-14T20:18:00.000-07:00

What is Tamiflu?
This medicine contains as active ingredient oxeltamivir phosphate used in the treatment of symptoms of influenza (flu).

Tamiflu is one of the classes of antiviral drugs called neuraminidase inhibitors.

This medicine speeds recovery from the flu. When started during the first 2 days of the illness, it hastens improvement by at least a day.

It also can prevent the flu of treatment is started within 2 days after exposure to a flu victim.

As the flu virus takes hold in the body, it forms new copies of itself and spreads form cell to cell.

Neuraminidase inhibitors fight the virus by preventing the release of new copies from infected cells

Tamiflu is taken in liquid or capsule form.

Tamiflu can prevent the flu as long as continue taking this medication but getting a yearly flu shot is still the best way of avoiding the disease entirely.

For older adult, those in high risk situations such as health-care work, and people with an immune deficiency or respiratory disease, vaccination remains a must.

To provide any benefit, Tamiflu must be started within two days of the onset of symptoms or exposure to the flu.

If have the flu, continue taking it twice daily for 5 days, even of started to feel better.

To prevent the flu take it once a day for at least 7 days. Protection lasts as the medicine taken.

Unless otherwise directed by doctor or pharmacist, take this medication as directed. Do not take more of them and do not take them more often then recommended on the label.
What is Tamiflu?

Death Flu 1918

2010-07-04T18:20:00.001-07:00

Death Flu 1918
During the month of October 1918 in America, 195,000 people died of the flu, many of them, within eighteen hours of disease onset.

The worldwide flu pandemic claimed an estimated 40 million lives.

No one knows exactly what that particular virus was so deadly, but the gruesome description of cases rival any medical accounts of the Black Plaque, smallpox, or ebola virus.

Physicians described patients who literally bled to dead before their eyes in 1918, spurting blood from nosebleeds, oozing blood from the eyes or ears, and hemorrhaging from the lungs, intestines and uterus.

Pneumonia usually began within a day or two after exposure followed by high fever and convulsions.

The lungs were literally destroyed and laid waste by the flu bug. The skin turned purple to death from lack of oxygen in the bloodstream, a certain sign of impending doom.

The total death toll from the flu in America in 1918-1919 was 675,000. A proportion of the population that in the current era would total 1,750,000.
Death Flu 1918

Lymphatic System

2010-06-01T18:42:00.000-07:00

Lymphatic System
The lymphatic system works with the immune system to fight attacking pathogens. The entire lymphatic system shares many organs and cell types with the immune system.

It consist of lymph vessels, lymph nodes and lymph fluids.

Lymph vessels; are similar to veins that carry blood except that they carry a clear fluid instead of blood.

This lymph fluid contains waste products from cell activity, proteins, fats and many white blood cells, especially lymphocytes. These watchful and helpful lymphocytes continually travel through lymph tissue, lymph fluid and blood.

At certain points in the body, the lymph vessels have check points called lymph nodes. These nodes filter lymph fluid and remove foreign material.

White blood cells also gather in the lymph nodes, the way they do on the spleen.

Lymph nodes are good places for white blood cells to monitor and destroy germs floating in the lymph fluid.

Everyone has lymph nodes in the sides of the neck, behind the ears, in the back of the head, under the chin and jaw and in the groins and armpits.

When your body is healthy, your lymph nodes are soft and difficult to feel. But when body is actively fighting an infection, your lymph nods can become swollen , tender and more solid. When your infection is over, your lymph nodes return to normal size and feel soft again.
Lymphatic System

Impact of Influenza Epidemics and Pandemics

2010-05-04T23:42:00.001-07:00

Impact of Influenza Epidemics and Pandemics
Influenza epidemics have been recognized as a major cause of morbidity and increase mortality, especially in the very young, the very old people with chronic cardiopulmonary conditions, pregnant women and immunocompromised individuals.

Each year, influenza results in 3-5 millions cases of severe illness and kills between 0.25 and 0.5 million people worldwide.

The WHO estimates that there are currently 1 billion people worldwide who are at high risk of suffering or dying from influenza and its complications.

Furthermore, as the elderly population increases, future influenza epidemics would be associated with ever increasing hospitalization rates and excess mortality unless adequate prophylactic measures are taken.

In developed countries, about 100 people per million population die annually from influenza.

Public health policy needs to address the interrelated issues of optimizing both the effectiveness of annual vaccination programmes and the preparedness for future pandemic outbreaks of influenza.

Health-care professional play a key role in this regard by participating in influenza surveillance and by providing appropriate preventative and treatment regiments for their patients.
Impact of Influenza Epidemics and Pandemics

Symptoms of flu

2010-04-05T05:32:00.001-07:00

Symptoms of flu
You’ve probably had the flu sometimes in the past and know how it feels from personal experience.

In case you have forgotten the feeling, here are the typical symptoms.

A day or two after exposure to someone with the flu, you feel a bit out of sort for a day.

Then the next day or that night, you are knocked flat with unmistakable muscle aching, chills, a dreadful headache, and dry cough.

You languish in bed, taking painkillers for the headache, drinking fluids and awaiting for the ordeal to end.

In a few days it does. You have lost a few pounds and five days of work.

You feel weak for another four days, then after ten to fourteen days back to normal. If you are lucky.

Some people develop pneumonia, the most common complication of the flu. Since the pneumonia is usually viral, antibiotics are useless.

Sometimes people will recover from the flu and then another high fever develops with typical pneumonia symptoms of coughing, chest tightness, difficulty breathing and weakness.

This secondary infection is often bacterial, Deaths typically occur as a result of pneumonia.
Symptoms of flu

B-cells and T-cells

2010-03-07T07:10:00.000-08:00

B-cells and T-cells
B-cells and T –cells have amazing memories and remember an old infection for a long time. These cells are like soldiers facing an enemy they have fought before. They know the enemy’s old tricks and weapon and how to fight them.

The T-cells quickly launch and attack, using effective antibodies that worked in the past.

Phagocytes another kind of white blood cells, work with lymphocytes to destroy germs. But phagocytes play a different role. After leukocytes mark antigens for destruction, phagocytes actually destroy them.

They do this by surrounding these harmful invaders, then “eating” them. They digest the invaders and turn them unto harmless fragments.

White blood cells work with two important organs in the body: the spleen and the thymus. Spleen is located in the upper side of abdomen between ribs and hips.

One of the spleen’s major jobs is to filter blood. This filtering process removes unwanted material like infection-causing pathogens as well as old or damaged blood cells.

The hard-working spleen is also a place where lymphocytes get activated so that they can destroy invading pathogens.

The thymus is located in the center of the upper chest, and its job is to produce T-cells.

T-cells develop in the thymus. The T-cells learn to distinguish between substances that belong in the body and those that do not. T-cells must recognized their immune system teammates to communicate with them.

T-cells die when they fail to recognize other immune cells. T-cells also die if they mistakenly target normal body cells for destruction.

Another white blood cells producer is bone marrow. This spongy material in the bones plays an important role in the immune system.

Blood vessels that run though bone marrow transport blood loaded with white blood cells.

Plus, the bone marrow itself produce a variety of blood cells: red blood cells that carry oxygen, platelets that help blood clot, and infection fighting white blood cells.

Bone marrow also produces B-cells. B-cells stay in the bone marrow to complete development, once they are fully formed. B-cells can produce antibodies against many invaders that try to attack the human body.
B-cells and T-cells

Colds and Flu

2010-02-23T23:19:00.000-08:00

Colds and Flu
All of us have experienced the sore throat, runny nose, aching and general sense of misery that announce the onset of the common cold.

Other familiar signals include a cough headache, and dry sore or sensitive breathing passages.

The symptom of both common cold and the flu are often the same, because both are caused by the same family of respiratory viruses.

The distinction between the two depends on how severe the infection is and the range of symptoms.

The flu is usually more severe develops quickly and involves more of the body than a cold.

A cold also occurs at any time of year, while the flu usually in epidemics normally in late fall and winter.

Beyond respiratory inflammation, the flu produces a moderate to high fever, aching muscles and acute fatigue.

Vomiting and diarrhea may also develop and in extreme cases, the flu may lead to pneumonia in particularly susceptible individuals.

Other complications of the flu, although rare, include inflammation of the brain (encephalitis) or heart (myocarditis), R eye’s syndrome (an illness primarily affecting children, involving abnormal brain and liver function), and croup.

As the body attempts to fight the invading pathogens that can cause colds and flu, white blood cells are rapidly transported to the sites of infection.

The chemically mediated inflammatory response of white blood cells causes swelling, which can result in stiffed sinuses and swollen nose of throat.

Mucus is also secreted to trap the pathogens. Such reactions are signs of a normally functioning immune system. As are a runny nose, sneezing, and coughing which serve to expel toxins and infectious organisms in the form of phlegm.
Colds and Flu

The Influenza Virus

2010-02-07T04:21:00.000-08:00

The Influenza Virus
Influenza virus are enveloped particles of spherical or elongated shape, measuring 80-120 nm in diameter and containing a segmented single stranded RNA genome.

The influenza virus belongs to the family of the Orthomyxoviridae.

There are three influenza genera, or virus types within this family influenza A, B and C.

Influenza A virus have been responsible for the major pandemics of influenza in the last century and are also the causative agents for most of the annual outbreaks of epidemic influenza.

A characteristic feature of the virus is its outermost layer of spike-like projections.

These are the two viral surface glycoprotein, hemagglutinin (HA)and neuraminidase (NA), which are embedded in the lipid membrane of the viral envelope.

Hemagglutinin, the major spike protein, is responsible for attachment of the virus to specific receptors on the host cell surface.

Hemagglutinin also mediates a fusion reaction between the viral envelope and the cell membrane, through which the viral genome gains access to the interior of the cell.

One inside the cell, the viral RNA is replicated and viral proteins are synthesized leading to the production of many thousand of new virus particles.

Ultimately, the cell dies as a result of the infection.

In the lungs and airways this process of cell lysis leads to desquamation of the respiratory epithelium as one aspect of influenza pathogenesis.
The Influenza Virus

Flu Virus by the Numbers

2010-01-20T17:34:00.001-08:00

Flu Virus by the Numbers
The flu virus are named and numbered. The 1918 Spanish flu was an H1N1 A flu virus.

Influenza viruses come in three varieties – A, B and C – each with different nucleoproteins encoded by the nucleoprotein gene.

A viruses are more virulent and responsible for the major flu epidemics.

B viruses typically cause milder symptoms and more sporadic disease spread.

C viruses seldom cause symptoms. Flu vaccine contains A viruses and a B virus.

Two types of protein (hemagglutinin and neuraminidase) sit in the outer membrane of the virus, and serve to identify the virus in the H and N coding system.

The HA gene encodes the hemagglutinin protein responsible for the spikes that bind to cell membranes.

Three types of hemagglutinin affect humans: H1, H2 and H3. Nine others have been identified that affect animals.

The NA gene encodes the neuraminidase protein, which is the part of the viral membrane that protects it from the cell’s defenses.

There are two N1 and N2. The most worrisome flu viruses currently in circulation are different strains of the H3N2 line, the A/Panama, A/Fujian and A/Wellington, each named for the place where it was first discovered. Bird flu is an H5 virus, H5N1.
Flu Virus by the Numbers

Immune System

2010-01-03T17:37:00.000-08:00

Immune System
The first defender in immune system is white blood cells.

Just as an army has soldiers with different jobs, body has different types of white blood cells to defend against invaders.

All white blood cells are known as leukocytes. They travel swiftly though human body to challenge intruding pathogens.

Two kinds of white blood cells, or leukocytes, are called lymphocytes. These are either B-cells or T-cells.

These are either B-cells or T-cells. Each one has a special job.

B-cells produce protective proteins called antibodies. These antibodies attach themselves to certain substance on pathogens celled antigens and mark them so that other cells will destroy them later.

Antibodies also block flu virus from moving from one cell to another. This limits the spread of infection within the body.

B-cells can produce up to 10 millions copies of the needed antibody in one hour.

The job of T-cells is to coordinate the attack on pathogens. T-cells do this by giving instructions to other immune cells on when and how to attack.

These immune cells then produce different kinds of molecules that carry information and instructions form one group of immune cells to another.

These messenger molecules tell other cells when to change their behavior and coordinate the immune response.
Immune System

Aetiology of the flu

2009-12-01T09:44:00.001-08:00

Aetiology of the flu
Influenza, or simply “flu”, is caused by a virus. It occurs not only in occasional major pandemic outbreaks, but also in epidemics of variable severity almost every winter.

The term “influenza” in the m id 1300s, indicating that, at the time, the illness was believed to result from astrological influences.

Yet, the aetiology of the disease and the explanation for this peculiar behavior remained elusive.

At the turn of the 19th century, influenza was thought to be due to a bacterial infection with Haemophilus influenzae.

It was not until 1931 that Richard Shope showed that swine influenza could be transmitted with filtered mucus, indicating that causative agent was a virus.

A few years later, Smith and co workers isolated the influences virus from humans with respiratory illness.

The burden of influenza for a society, not only from a clinical but also from an economics perspective, is often underestimated.

This relates particularly to the recurring annual winter epidemics.

Fortunately, since the virus was first discovered, efficient means to contain the infection have been developed.

Vaccination is the cornerstone of influenza prevention and control.

Accordingly, the WHO has issued guidelines or the implementation of influenza vaccination programmes in individual countries.

As a result,. many thousands of live are saved worldwide each year. Yet in many places, implementation of vacation programmes remains woefully deficient.

This implies that significant numbers of people at risk of the complications of influenza remain vulnerable to infection and possibly death.
Aetiology of the flu

Viral Attack

2009-11-05T15:58:00.000-08:00

Viral Attack
The influenza virus is a bit of protein, a membrane surrounding eight genes.

It is a simple but sophisticated killing machine with a mission to multiply.

The flu virus takes the shape of a sphere with spikes protruding from its surface.

The spikes are primarily invaders that attach epithelial cells on the surface of mucous membranes in the airways of animals.

The spikes, composed of a glycoprotein called hemagglutunin, bind to a cell and hold the virus tightly to the cell’s wall while the virus creates a hole in the cell.

Then the virus simply slips through this hole in the cell.

Once the influenza virus hides inside the cell, the body’s immune system cannot find it and destroy it.

The virus then has all the time it needs to do its work.

Thus sneak attach is a special trick of the influenza virus, and account s for its great success.
Viral Attack

The Flu season

2009-10-15T20:00:00.000-07:00

The Flu season
People are more likely to get flu between October and April. The worst months for infection in the northern hemisphere are December though March.

Scientists are not completely sure why this flu “flu season” exists every year but they have a few ideas.

First, the flu virus survives better in cool and wet weather.

It is possible that the viruses can survive longer outside a person’s body, as when they are sneezed out, when the weather is cool.

Also, the people tend to crowd together during the colder months.

Flu viruses have short distances to travel because windows are tightly shut. Many holidays also take place during the colder months of the year.

Wherever people gather to celebrate, the festivity can become a party for viruses, too.

They can easily move from person to person in a crowded space.

But people can get the flu any time of year especially due to the number of people who travel around the world.

Influenza viruses exist around the world. People may carry the viruses with them when they travel, exposing fellow travelers regardless of the time of year.
The Flu season

Influenza - aetiology and history

2009-09-20T04:07:00.000-07:00

Influenza - aetiology and history
Influenza or simply “flu”, is caused by virus. It occurs no only in occasional major pandemic outbreaks but also in epidemics of variables severity almost every winter.

The term “influenza” has been derived from the Italian influential in the mind-1300s, indicating that, at the time, the illness was believed to result from astrological influences.

Yet, the aetiology of the disease and the explanation for its peculiar behavior remained elusive.

At the turn of the 19th century, influenza was thought to be to a bacterial infection with Haemophilus influenzae.

It was not until 1931 that Richard Shope showed that swine influenza could be transmitted with filtered mucus, indicating that causative agent was a virus.

A few years later, Smith and co-workers isolated the influenza virus from humans with respiratory illness.

The burden of influenza for society, not only from a clinical but also from an economic perspective is often underestimated.

This related particularly to the recurring annual winter epidemics.

Fortunately since the virus was first discovered, efficient means to contain the infection have been developed.

Vaccination is the cornerstone of influenza prevention and control.
Influenza - aetiology and history

Sign and Symptoms of Influenza Infection

2009-09-02T09:38:00.000-07:00

Sign and Symptoms of Influenza Infection
There are no specific physical examination findings associated with influenza.

The patient usually appears ill and has fever. A clear nasal discharge is common.

A typical uncomplicated case of influenza illness begins abruptly and is manifested by sore throat, headache, fever, chills, myalgias, anorexia and extreme fatigue.

Fever is usually between 38 and 40 degree C but may be higher and usually lasts for -3 days (but < 5 days).

Other respiratory tract manifestations include cough, which is usually non productive, and a runny or stuffy nose.

Substernal tenderness, photophobia, abdominal pain, and diarrhea occur less frequently.

Despite severe sore throat, the mucous membranes of the pharynx may be unremarkable or hyperemic without exudates.

Small tender cervical lymph nodes may palpable and the lungs are usually clear, although scattered rhonchi and crackles can be heard in as many as a quarter of patients.

In elderly, fever may be absent and the presenting signs may be anorexia, lassitude confusion and rhinitis.

In children, fevers are often higher and can lead to febrile seizure.

Gastrointestinal manifestations, such as vomiting, abdominal pain, and diarrhea and other complications such as myositis, croup (tracheobronchitis), and otitis media also occur more frequently in children.

Unexplained fever may be the primary manifestation in neonates.
Sign and Symptoms of Influenza Infection

Avian Influenza

2009-08-10T02:38:00.000-07:00

Avian Influenza
The normal hosts for avian influenza viruses are birds and occasionally pigs. A highly pathogenic influenza A subtype (H5N1) was found in poultry in East and South Asian countries.

In 1997, an outbreak of H5N1 influenza occurred in poultry in Hong Kong, resulting in the first recognized human cases.

A massive slaughter of poultry was attempted to contain the disease.

New outbreaks of H5N1 influenza on poultry emerged however, in 2003 and continue to spread to different nations.

At least 20 countries reported poultry outbreaks as of early 2006, largely in Asia but also in Nigeria, Greece, Turkey and Italy.

Although the H5N1 strain of avian influenza is highly contagious from one bird to another, the transmission from human to human is relatively inefficient and not sustained.

Most human cases occur after exposure to infected poultry or surfaces contaminated with poultry droppings.

Because infection in humans is associated with mortality rate greater than 50% (most patient die of respiratory failure), there exists considerable concert that H5N1 strains might widely disseminate and initiate a pandemic.

The worldwide concern that the avian H5N1 subtype of influenza may transform, by generic re -assortment and mutation, developing greater human-human transmissibility, is the basis for fear of a global avian influenza pandemic.

The risk of these events appears more realistic as avian influenza continues to spread among birds with many parts of Southeast Asia now considered endemics for virus.

Careful surveillance of new human cases and continued development of a commercially available vaccine are important aspects of influenza control.
Avian Influenza

H1N1 Swine Influenza Virus

2009-06-29T17:06:00.000-07:00

H1N1 Swine Influenza Virus
Viruses of the classical H1N1 lineage were the dominant cause of influenza among pigs in North America from their first isolation.

Classical H1N1 viruses have also been isolated from pigs in South America, Europe and Asia.

There is only limited evidence of maintenance of human H1N1 influenza viruses after natural introduction into swine populations but human H3N2 viruses have been recovered frequently from pigs in Asia and Europe.

Experimental infection studies have shown that pigs can be infected with a wide range of avian influenza virus (AIVs) and naturally acquired infections of pigs with AIVs have also been documented from multiple areas of the world.

In particular, an avian H1N1 virus introduction into pigs Europe in late 1970s spread throughput much of the European continent and United Kingdom and ultimately became a dominant cause of swine flu in these areas.

These avian-like H1N1 viruses have also undergone genetic/antigenic drift and have spread from pigs to domestic turkeys.

The occurrence of influenza virus infections in pigs poses two important public health issues: zoonotic infections of people with swine influenza viruses and the potential for pigs to serve as hosts for the creation of novel viruses of pandemic potential for the human population.

Infections with swine influenza viruses is generally limited to the respiratory tract, with virus replication demonstrated in epithelial cells of the nasal mucosa, tonsils, trachea, lungs and tracheobronchial lymph nodes.

Swine flu is an acute infections and virus clearance is extremely rapid. In most experimental studies, nasal virus shedding begins on day 1 postinoculation (P1) and ceases within 7 days.

Likewise, swine influenza virus could not be isolated from lungs or other respiratory tract tissues after day 7.

Infections with H1N1, H1N2 and H3N2 subtype viruses are clinically similar, and viruses of all subtypes have been associated with acute respiratory episodes in most European countries.

Disease onset is sudden, after an incubation period of 1 – 3 days. Disease signs typically appear in a large percentage of animals of all ages within a herd or epidemiological unit.
H1N1 Swine Influenza Virus

Swine Flu - Occurrence

2009-05-31T05:34:00.001-07:00

Swine Flu - Occurrence
Classical swine influenza is caused by influenza A virus subtypes H1N1, H1N2 and H3N2.

Swine influenza first appeared in the United States immediately following the 1918 pandemic of human influenza, and it was generally believed that it was caused by adaptation of the human influenza virus to swine.

Nucleotide sequencing of the gens coding for the internal virus proteins indicates that the human pandemics H1N1 strain and the classic swine strain H1N1 have a common avian ancestor.

It is suggested that a virulent avian strain H1N1 entered the human population in 1918 causing the pandemic.

The pandemic virus was then introduced into swine population where it has persisted unchanged. In contrast, influenza was not observed in swine in Europe until 1979, caused by a virus antigenetically related to contemporary avian H1N1 strains found in ducks.

In 1992, many outbreaks of classical swine influenza occurred in England, caused by a group of H1N1 viruses that were distinguishable from classical swine viruses, the European viruses, and human H1N1 viruses, all of which are known to be circulating in pigs.

Influenza A virus subtypes H1N1 and H3N2 are endemic in pigs in Great Britain.

Two distinct antigenic variants of H1N1 viruses have been associated with the outbreaks of swine influenza, one of which was probably transmitted from birds to pigs in the early 1990s.

The disease usually affects young pigs but all ages may be affected. Typically, sudden onset epidemics occur with a high morbidity rate but with a low case fatality rate of less than 5%. Loss body condition in marked, which is usually the important cause of financial loss, although occasionally death losses may be extensive if the pigs are kept under inadequate conditions or if secondary bacterial infection occur.
Swine Flu - Occurrence

The 1976 Swine Flu Fiasco

2009-05-09T19:34:00.000-07:00

The 1976 Swine Flu Fiasco
Shortly after new army recruit and soldiers returning form the Christmas holidays arrived at Fort Dix, New Jersey, in January 1976, an outbreak of influenza ensued.

Most of the illness remained mild with only a few hospitalized victims. One sick recruit refuse to answer sick call died from influenza related pneumonia.

Tests showed that he and three others had been infected with and H1N1 swine virus, while all the others had been infected with a variant of the H3N2 virus hat had been circulating every year since it was introduced to human population in 1968.

There had been a few reported cases of human infection by the swine flu since 1974, but the virus had grown so adapted to pigs that it no longer adjusts well enough in the human host to be transmitted from person to person.

Fearful that the H1N1 subtype of 1918 had begun to resurface within the human population, with the prospect of a similar pandemic, scientist debated the issue and considered what should be done to prevent such a disaster.

Some scientists believed this was not the same type variant of 1918, while many others feared it could be.

President Ford at that time, following recommendations coming out of the debate announced in March the federal government’s intent to immunize the entire population of the United States against the swine flu to prevent a disastrous outbreak expected in the fall of 1976, similar to the 1918 pandemic.

Congress appropriated $135 million for the vaccination program.

Ten days after the vaccinations began, three elderly individuals with the heart conditions died shortly after receiving their shots. The news media jumped on this to create fear of the vaccine.

This prompted President Ford and his family to encourage people to take the shots by televising their own vaccinations.

Over 40 million people did receive the vaccine before the program ended in December.
The 1976 Swine Flu Fiasco

White Blood Cells: B-cells and T-cells

2009-04-12T22:33:00.000-07:00

White Blood Cells: B-cells and T-cells
The “first defenders” in immune system are white blood cells.

Just as an army has soldiers with different jobs, human body has different types of white blood cells to defends against invaders.

All white blood cells are known as leukocytes.

These travel swiftly through human body to challenger intruding pathogens.

Two kinds of white blood cells, or leukocytes, are called lymphocytes.

These are either B-cells or T cells; each one has a special job.

B-cells produce protective proteins called antibodies. These antibodies attach themselves to certain substance on pathogens called antigens and mark them so that other cells will destroy them later.

Antibodies also block the flu virus form moving form one cell to another.

This limits the spread of infection within the body. B cells can produce up to 10 million copies of the needed antibody in one hour.

The job of T-cells is to coordinate the attack on pathogens. T-cells do this by giving instructions to other immune cells on when and how to attack.

These immune cells then produce different kinds of molecules that carry information and instructions from one group of immune cells to another.

These messenger molecules tell other cells when to change their behaviors and coordinate the immune response.

Some special B-cells and T0cells also have amazing memories and remember an old infection for a long time.

These cells are like soldiers facing an enemy they have fought before. They know the enemy’s old tricks and weapon and how to fight them. The T-cells quickly launch an attack, using effective antibodies that worked in the past.
White Blood Cells: B-cells and T-cells

Influenza – Major Occasional Pandemic Outbreaks

2009-03-22T23:15:00.000-07:00

Influenza – Major Occasional Pandemic Outbreaks
Influenza or simply “flu” is caused by a virus. It occurs not only in occasionally major pandemic outbreaks, but also in epidemics of variable severity almost every winter.

The term “influenza” has been derived from the Italian ‘influentia’ in the mid-1300s, indicating that, at the time, the illness was believed to result from astrological influences.

Yet, the aetiloogy of the disease and the explanation for its peculiar behavior remained elusive.

At the turn of the 19th century, influenza was thought to be due to a bacteria infection with Haemophilus influenzae.

It was not until 1931 that Richard Shope showed that swine influenza could be transmitted with filtered mucus, indicating that the causative agent was a virus.

A few years later, Smith and co-workers isolated the influenza virus from humans with respiratory illness.

The burden of influenza for the society, not only from a clinical but also from an economic perspective, is often underestimated.

This relates particularly to the recurring annual winter epidemics. Fortunately, since the virus was first discovered, efficient means to contain the infection have been developed.

Vaccination is the cornerstone of influenza prevention and control. Accordingly, the WHO (World Health Organization) has issued guidelines for implementation of influenza vaccination programs in individual countries.

Yet, in many places, implementation of vaccination programs remains woefully deficient. This implies that significant numbers of people at risk of the complications of influenza remain vulnerable to infection and possibly death.
Influenza – Major Occasional Pandemic Outbreaks

Short History of Influenza

2009-02-22T17:54:00.000-08:00

Short History of Influenza
Hippocrates recorded an epidemic of a flu-like infection in 412 B.C that wiped out the Athenian army.

The sixteenth century saw two flu pandemics that spread throughout Europe. The first, in 1510, infected nearly the entire population of Europe, but claimed few lives.

The second, in 1580, devastated cities and spread through the whole of Western Europe. The city of Rome, for example, had 9,000 fatalities.

At least pandemics of flu spread throughout Europe in the seventeenth century. In the past of 200 years eight great flu pandemics seized the world prior to the devastation wrought by the 1918 flu.

During a period of fourteen months beginning in the spring of 1918, half of the entire world’s population was infected with the influenza virus and nearly 41 million people died.

Every country in the world was affected, no matter how remote, and this occurred in an era before air travel and a global community existed.

Victims who died during the 1918 flu were typically healthy young adults. Among the 20 to 40 year old age group, the fatality rate from the 1918 flu was 50 percent.

The virus of 1918 was so effective at killing its host that within a short period of time it rendered itself extinct, people either immune to the virus or dead.

Since that time several other lesser pandemics have occurred across the globe, but health officials anxiously await the next deadly flu pandemic, which they predict as inevitable.

When it occurs, experts foresee millions of death, hospitals quickly flooded with cases of pneumonia, and every health care system in the world over whelmed by the volume of flu victims.
Short History of Influenza

The Spread of Influenza

2009-01-29T16:21:00.000-08:00

The Spread of Influenza
The spread of bird flu across Asia and parts of Europe and the Middle East, as well as the occasional infections of humans with disconcertingly high number of deaths, have cause concern about potential new global epidemic of influenza.

Literally for ages influenza has been with mankind and it would be naive to think that as of the 21st century there will be no further influenza pandemics.

Now we may have the opportunity to follow the emergence of a potential new influenza pandemic and to prepare ourselves, so that we may ameliorate the burden of the outbreaks or perhaps even avert it together at the start.

Influenza or simply “flu” is caused by a virus. It occurs not only in occasional major pandemic outbreaks but also in epidemics or variable severity almost every winter.

The term “influenza” has been derived from the Italian influential in the mid 1300s, indicating that, at the time, the illness was believed to result from astrological influences. Yet, the aetiology of the disease and the explanation for its peculiar behaviors remained elusive.

At the turn of the 19th century, influenza was thought to be due to a bacterial infection with Haemophilus influenzae.

It was it until 1931 that Richard Shope showed that swine influenza should be transmitted with filtered mucus, indicating that the causative agent was a virus. A few years later, Smith and co-workers isolated the influenza virus from humans with respiratory illness.

Richard Shope, American animal pathologist and virologist who was the first to isolate an influenza virus, first to vaccinate animals against influenza and first to identify the causative agent as a virus in the 1918 – 19 Spanish influenza pandemic.
The Spread of Influenza

The word of Influenza

2009-01-07T04:31:00.000-08:00

The word of Influenza
The word influenza is Italian for influence, as in the astral or occult influence of a visitation or outbreak that affects many people at the same time. First used in 1504, the word signified any disease epidemics.

In a severe flu outbreak of 1743 the word influenza was applied to the epidemic that began in Italy and spread throughout Europe.

Since then, the influenza, shortened to flu, means a serious infectious disease characterized by muscle and joint aching, prostration, and respiratory congestion with fever and headache.

It was not until 1931 that an influenza virus was identified in pigs, and finally in 1933 a human influenza virus was discovered by three researchers: Smith, Andrewes, and Laidlaw.

Both of these viruses were closely related to the Spanish flu virus of 1918. During the time of the 1918 flu pandemic, however, the suspected culprit was a bacterium named Hemophilus influenza. Viruses had not yet been discovered.

Although most people consider the flu simply and annoyance, and possibly a danger to seniors in poor health, influenza has been responsible for repeated, devastating worldwide pandemics capable of bringing entire nations to their knees.

It is hard to imagine today, but in 1918 the entire world was in the clutches of a deadly flu virus. The 1918 flu still remains the greatest plague the world has ever seen.
The word of Influenza

Bird Flu Virus

2008-12-25T07:36:00.000-08:00

Bird Flu Virus
Influenza cause many American deaths each year. Bird flu (influenza) is one of the latest emerging diseases. Bird flu is known also as Asian flu or avian flu. Bird flu is caused by one of 15 avian flu viruses. The virus is worrisome for several reasons. It mutates rapidly and obtains genetic information from other flu viruses that infect other animals and humans. The virus is dangerous to human and spread quickly.

The virus has a potential for rapid spread among humans. The rapid spread may result in an influenza pandemic. Influenza pandemics usually occur three to four times each century. The worst pandemic in the twentieth century was the 1918 – 19 Spanish flu. This pandemic resulted in an estimated 50 million deaths world wide and is considered to be the deadliest plague in history. The flu appeared to have an avian origin. The critical change that made the influenza virus so infectious in people appears to have been change in a single amino acid in the structure of the virus.

In 1918 and avian infected humans, and within months it adapted to its new host. The first of its new hosts were soldiers in World War 1. The virus spread rapidly from person to person and killed more than any other plaque in history. In six months it killed over 30 million people.

There are two avenues for a new influenza pandemic to emerge. First, a dormant human flu virus may resurface. Because of the relatively long time period since the last outbreak of the virus, no natural defense mechanism would be available to protect against infection. Second, a nonhuman virus, such as the bird flu virus, may acquire the ability to infect humans and spread rapidly.

If the bird flu virus infected a human who is infected with a human flu virus, these two viruses might recombine into a new mutant, part human and part bird virus. Once established, the new flu virus would spread rapidly. If the bird flu virus spread to pigs, the virus would probably transfer more quickly and more easily to humans. This is because of the genetic similarities between humans and pigs.
Bird Flu Virus

The Immune System

2008-12-18T19:34:00.000-08:00

The Immune System
The immune system is always in the job, observing all types of cells and materials traveling though your body. Certain cells, chemicals called proteins, and organs in your immune system identify foreign invaders like flu viruses that can make you sick.

Your immune system can tell the difference between substances that belong in the body and those that do not. When it detects a “nonself,” such as a flu virus or other harmful outsider, from a “self,” the immune system’s defenses kick in, they treat anything unfamiliar as a threat.

These outside threats to our bodies are called pathogens, pathogens which can also be called microbes or germs, may be bacteria or viruses such as influenza. Sometimes the immune system succeeds in keeping out harmful invaders and sometimes it does not.

When your immune system is not able to prevent an influenza virus from infecting you, you may come down with the flu. However, even when you do get the flu, you begin to feel better when your immune system is able to destroy the virus. And if you received a flu shot, your immune system will respond to a viral infection more quickly so you do not become sick at all or you are only sick for a short time.
The Immune System

Types of Flu Shot Vaccines

2008-12-04T08:00:00.000-08:00

Types of Flu Shot Vaccines
Anybody who has ever had the flu can tell you it is no picnic, and in some situations it can happen to be life-threatening. Medical professionals want to protect society against such a sickness, so there is little case against flu shots. Every year, almost 40,000 people die of flu in the U.S. alone. Flu cases also cause about 200,000 hospitalizations, not counting the many more that stay at home sick.

Two kinds of flu vaccines exist. The traditional vaccine, which we know as the flu shot, is classified as an inactivated vaccine. Inactive vaccines contain a virus which is not alive; it is typically administered via a hypodermic needle. Flu shots can be given to anyone over six months of age in reasonable health.

The other type of vaccine is called a Live Attenuated Influenza Vaccine (LAIV). LAIVs contain weakened, live viruses. The Attenuated flu shot is administered by nasal-spray; it is only approved for use in healthy people between the age of 5 and 49.

The flu shot and the flu nasal-spray vaccine both work to develop the body's antibody defenses against the influenza strain. Antibodies are exposed to the virus in the vaccines; the antibodies then specialize themselves to attacking the invading flu. As a result, the antibodies become efficient fighting machines, lying in wait for future attacks of that influenza strain.

People are recommended by medical professionals to get a flu vaccine at least once a year. For those living in North America, the flu season generally lasts from November to April. Most people get the virus during this period, which means infections within the general populace are at its height.

Flu vaccines don't work immediately, so it is recommended that the flu vaccine is taken prior to November. Antibodies take two weeks minimum to improve their power against a flu virus; meanwhile the individual remains at risk from the illness. Getting vaccinated during the months of September, October, and November is a good idea because of this. Don't forget flu viruses mutate each year, so to prevent the flu, you need to get a shot of the latest vaccine at least once a year.
Types of Flu Shot Vaccines

Learn more about flu immunization and treating bird flu at Medopedia.com
Article Source: http://EzineArticles.com/?expert=Antoinette_Boulay

The Beginning of Bird Flu

2008-10-30T18:12:00.000-07:00

The Beginning of Bird Flu
Before 1997, no evidence had indicated that H5 influenza viruses could infect humans and cause fatal disease. The precursor of the H5N1 influenza virus that spread to humans in 1997 was first detected in China, in 1996, when it caused a moderate number of deaths in geese. However, it attracted very little attention at the time.

The goose virus acquired internal gene segments from influenza viruses later found in quail. It also acquired the neuraminidase gene segment from a duck virus. This all took place before goose virus became widespread in live poultry markets in Hong Kong and killed 6 of 18 infected persons.

The H5N1 viruses is continued to change and in late 2002 a single genotype was responsible for killing most waterfowl in Hong Kong nature parks. This genotype of H5N1 s spread to humans in Hong Kong in 2002, killing 1 of 2 infected persons, and was the precursor to the current strain of bird flu, which has become dominant.

The recent H5N1 influenza viruses have acquired the unprecedented and disturbing capability to infect humans. These incremental changes intensify concern about this bird flu virus potential to cause a global pandemic.

These genes were presumably acquired from virus found in waterfowl in Southeast Asia, but the actual gene donors have not yet been identified. While most H5N1 influenza viruses that have been isolated from avian species in Asia since 1997 are highly pathogenic in certain poultry, they show varied pathogenicity in other species.

There is evidence that swine also may be involved in the interspecies transmission by providing an environment where human influenza viruses originate, pandemic subtypes rarely occur, yet when they do emerge it happens suddenly.

Many of these subtypes first appeared in China. It is believed that this is because China’s cultural heritage allows considerable domestic exposure to aquatic fowl, such as ducks as well as a close domestic association with pigs. Influenza viruses can use a process known as genetic reassortment to create new pandemic strains that represent a combination of avian, human, and possibly even swine genomes.

In reassortment, parts of individual genomes between closely related strains of virus are exchanges creating a viral strain that is capable of infecting a different host, such as humans.
The Beginning of Bird Flu

Cold and Flu

2008-10-14T23:02:00.000-07:00

Cold and Flu
Most people get a cold or flu from time to time. School children are especially vulnerable – it is not unusual for them to get up to eight colds a year. Adults usually catch only two or three colds every year. While it might be fun to have a day off from school every now and again, colds and flu can be a serious problem as they are the main reason why people all over the world miss work.

Cold and flu are viral infections. Up to 50% of all colds are caused by a large family of viruses called rhinoviruses. There are over 100 different rhinoviruses, which usually case colds in the spring, summer and fall. Symptoms in the winter are caused by another family of viruses. This family includes the influenza virus. Influenza is the full medical name for flu.

Colds and flu are not the same thing, although both can make people fell very unwell. Colds take one to three days to develop. They usually begin with a sore throat, followed by sneezing, sometimes a fever, a runny or stuffy nose, and cough. The flu can be much more severe, it usually starts suddenly and can affect the whole body.
Cold and Flu

What is the Flu?

2008-09-16T15:59:00.000-07:00

What is the Flu?
The flu is an infection of the airways, throat, and lungs caused by the influenza. Like all viruses, influenza viruses are microscopic parasites. That means they are completely dependent on living organisms called hosts. Viruses reproduce by infecting hosts such as animals, birds, insects, plants and human.

The virus infects between 5 and 20 percent of the population in the United Sates every year. If the flu breaks out in school or neighborhood, one or two people out of every ten people will probably get sick. Adult with the flu miss approximately 70 million days of work.

People do not just miss school and work because they get the flu, more than 200,000 flu victims need to be hospitalized each year in United States alone. And each year, approximately 36,000 of them die from the effects of the flu. Around the world, influenza affects about three to five million people each year. Between a quarter-million and half a million of them die form flu complications.

Despite so many flu victims, most people do not get the flu each year, there are several reason for this. Some people do not come into contact with flu virus. Others get protection with flu shots. Still others can fight off some flu infections thanks to their hard working immune systems, which defend the body form harmful invaders like flu virus.
What is the Flu?

1918 Influenza

2008-09-02T21:37:00.000-07:00

1918 Influenza
The influenza pandemic of 1918-1919 killed at 20 to 40 million people. It may have killed as many as 25 million people in its first 25 weeks. It was the most devastating epidemic in the world history. It was a global disaster known as Spanish Flu. The flu was first found in the United States, appeared in Sierra Leone and France, and then spread to nearly ever part of the world. It was caused by an unusually severe and deadly Influenza A virus strain of subtype H1N1.

An estimated 675,000 Americans died of influenza during the pandemic. An estimated 43,000 serviceman mobilized for World War I died of influenza. The effect pf the influenza epidemic was so severe that the average life span in the US was depressed by 10 years. In Britain as many as 250,000 died; in France more than 400,000 people died.

The pandemic affected everyone. With one quarter of the US and one-fifth of the world infected with the influenza, it was impossible to escape from the illness.

The Allies of World War I came to call it the Spanish flu, primarily because the pandemic received greater press attention after it moved from France to Spain in November 1918.
1918 Influenza

Overview of Bird Flu

2008-07-28T23:19:00.000-07:00

Overview of Bird
Flu Bird Flu, also called avian Influenza, is caused by the Influenza viruses strain A. The most contagious group is H5N1 that produces epidemics and deaths in birds and humans. The disease was first identified over 100 years ago in Italy and since that time cases have appeared all over the world.

The most susceptible of Bird Flu are domestic poultry but all species of birds are believed to be sensitive to the disease. Wild birds though are more resistant to H5N1. Chickens and turkeys are most susceptible.

The infection caused by the Influenza triggers a large spectrum of symptoms in birds, leading from middle illness signs to a fatal ending. Bird flu is a very dangerous condition as it produces wide spreading epidemics in birds and the direct contact is highly contagious to human. The symptoms usually appear sudden and the mortality rate is almost in all cases 100%.

There are few known cases of illness transmission in man, in 1997 in Hong Kong 6 persons died of Bird Flu after a number of 16 got infected. Also susceptible to the disease are pigs. After those cases, the entire poultry population is Hong Kong was destroyed in order to prevent a catastrophic pandemic.

There are 15 species of Influenza virus known, but the most dangerous of all is H5N1 as it can trigger deadly diseases in human and can rapidly mutate producing uncontrollable new types. After they have survived the infection, birds still carry the active virus for 10 days and are able to transmit it on live poultry markets and by wild migratory birds. An increased number of sick human would trigger the risk of an infection with both bird and human infecting virus types. This would represent an opportunity for a pandemic flu transmitted also from human to human not only from sick birds to man.

The first occurring symptoms of the Bird Flu are fever, sore throat and cough. On an Influenza field, other dangerous complications like respiratory distress and multi-organ failure can appear causing a certain death. Different types of viral pneumonia have also been found complicating the Influenza infection.

Bird Flu can affect previously healthy children and adults, but the most susceptible are persons with different chronic conditions. All strains of the virus, of human and animal origin, can now be rapidly and surely be diagnosed with specifically testing. Today, very efficient antiviral drugs have been discovered; they can be used both in treatment and in the prevention of the infection with influenza virus type A. The antiviral grigs have their limitations, as they are expected to be more helpful in previous healthy persons.

The appearance of a new genetic mutation would require at least four months to detect an efficient vaccine for the entire affected area population.
Overview of Bird Flu
By Groshan Fabiola
Article Source: http://EzineArticles.com

Influenza A Virus H5N1

2008-07-08T16:10:00.000-07:00

Influenza A Virus H5N1
Influenza A (H5N1) virus is an influenza A virus subtype that occurs mainly in birds, is highly contagious among birds, and can be deadly to them. H5N1 virus does not usually infect people, but infections with these viruses have occurred in humans. Most of these cases have resulted from people having direct or close contact with infected poultry or contaminated surfaces.

Historically, human infections with avian influenza have been extremely rare. Most caused only mild illness followed by full recovery. H5N1 however has been exception. The first documented was that caused 18 cases and 6 deaths in Hong Kong in 1977.

Following the Hong Kong eradication, H5N1 did not appear again until the end 2003. In 2004, 7 had died and 2 were critical condition was reported in Vietnam due to respiratory disease. WHO then confirmed that 3 of the children died in Hanoi were infected with H5N1.

H5N1 is of greatest present for human health. The H5N1 has caused far the greatest number of human cases of severe disease. If the virus given enough opportunities it will develop the characteristics it needs to start influenza pandemic. H5N1 can mutates rapidly and acquire genes from virus infecting other animal species. Its ability to cause severe disease and death in humans has been known. The increasing incidence of H5N1 in birds and the accompanying increase for direct infection of humans pose the likehoods that humans concurrently infected with avian influenza strains could become “mixing vessels” for the emergence of a novel subtype with sufficient human genes to be transmitted easily from person to person.

The H5N1 virus that has caused human illness and death in Asia is resistant to amantadine and rimantadine, two antiviral medications commonly used for influenza. Two other antiviral medications, oseltamivir and zanamivir, would probably work to treat influenza caused by H5N1 virus, but additional studies still need to be done to demonstrate their effectiveness.
Influenza A Virus H5N1

Flu and Genes

2008-06-09T17:11:00.000-07:00

Flu and Genes
A new study of flu-infected mice found that certain genes spurred a strong immune response in the lungs that led to much more severe illness. Mice that didn't exhibit such an immune response were more likely to recover, the researchers found.

The findings may help humans not only survive the annual flu season but also an avian flu pandemic, should it ever arise.

The long-term implications would fit into the idea of genetically based preventive medicine. To know that some people are predisposed to any kind of disease, it would be able to better monitor those people so as to limit their health risk.

This knowledge might also help public health officials allocate precious resources. In the case of influenza, viral treatments and vaccine are in limited availability and if this kind of information, it could potentially be used to target the resources to those most at risk. It brings up the question of whether anti-inflammatories have a role in treating flu with a lot of inflammation.

It also brings up the question of 'Does genetics allow to anticipate which group is going to have a more deleterious inflammatory response?' That would be very helpful epidemiologically. The question of who dies of influenza has been a hot topic since at least the 1918 pandemic, which killed millions of people around the world. At the time, doctors noted that the immune systems of young, robust adults often "overreacted," resulting in a severe and often deadly inflammation of the lungs.

The 1918 pandemic and the current avian flu -- which has so far killed only a small number of humans -- have some similarities: Both cause an intense inflammatory and immune response in the lungs of mice and people. With the current avian influenza as well as the influenza from the 1918 pandemic, the influenza caused a really enhanced and intense inflammatory and immune response in the lungs which killed the mice.
Flu and Genes

Learning From The Influenza Virus' Tricks

2008-05-05T19:24:00.000-07:00

Learning From The Influenza Virus' Tricks
Influenza is currently a grave concern for governments and health organizations around the world. The worry is the potential for highly virulent bird flu strains, such as H5N1, to develop the ability to infect humans easily. New drugs and vaccines to halt the spread of the virus are badly needed. Now one of the tactics used by influenza virus to take over the machinery of infected cells has been laid bare by structural biologists at the European Molecular Biology Laboratory (EMBL) and the joint Unit of Virus Host-Cell Interaction of EMBL, the University Joseph Fourier and National Centre for Scientific Research (CNRS), in Grenoble, France. In the current issue of Nature Structural and Molecular Biology they publish a high-resolution image of a key protein domain whose function is to allow the virus to multiply by hijacking the host cell protein production machinery. The findings open the way for the design of new drugs to combat future influenza pandemics.

Upon infection the influenza virus starts multiplying in the cells of its host. One protein that is crucial in this process is the viral polymerase - the enzyme that copies its genetic material and helps to produce more viruses. One component of the polymerase, called PB2, plays a key role in stealing an important tag from host cell RNA molecules to direct the protein production machinery towards the synthesis of viral proteins. Researchers of the groups of Stephen Cusack and Darren Hart at EMBL Grenoble have identified the PB2 domain responsible for binding the tag, produced crystals of it and examined them with the powerful X-ray beams of the European Synchrotron Radiation Facility (ESRF).

"Viruses are masters of cunning when it comes to hijacking the normal functioning of the host cell. The influenza virus steals a password from host messenger RNAs, molecules that carry the instructions for protein production, and uses it to gain access to the cell's protein-making machinery for its own purposes," says Cusack.

The password is a short extra piece of RNA, a modified RNA base called a 'cap', which must be present at the beginning of all messenger RNAs (mRNAs) to direct the cell's protein-synthesis machinery to the starting point. The viral polymerase binds to host cell mRNA via its cap, cuts the cap off and adds it to the beginning of its own mRNA - a process known as 'cap snatching'. The capped viral mRNA can then be recognized by the host cell machinery allowing viral proteins to be made, at the expense of host cell proteins.

The atomic resolution image the EMBL scientists generated of a PB2 domain bound to a cap reveals for the first time the individual amino acids responsible for recognizing this special structure. The central interaction is a sandwich with two PB2 amino acids stacking either side of the cap. Whilst this recognition mechanism is similar to other cap-binding proteins, its structural details are distinct. Collaborators at the Centro Nacional de Biotecnologia in Madrid showed that disruption of the PB2 cap-binding site prevents the influenza virus from replicating.

"These findings suggest that the PB2 cap-binding site is a very promising target for anti-influenza drugs," Hart says. "Our new structural insights will help us design mimics of the cap that would inhibit viral replication and hence reduce the spread of virus and the severity of the infection."
Learning From The Influenza Virus' Tricks
Article by: Medical News Today

Live-Saving Flu And Pneumonia Shots Not Reaching Cancer Patients

2008-04-08T16:41:00.000-07:00

Live-Saving Flu And Pneumonia Shots Not Reaching Cancer Patients
Although flu and pneumonia can be lethal for cancer patients, more than one quarter of patients undergoing radiation therapy are not complying with national guidelines to be vaccinated against these potentially life-threatening yet preventable illnesses, according to a study presented at the American Society for Therapeutic Radiology and Oncology's 49th Annual Meeting in Los Angeles.

While Centers for Disease Control and Prevention guidelines and the Joint Commission recommend an annual flu (influenza) vaccine for cancer patients aged 50 years or older, 25 percent of patients 50 years or older reported never having received the flu vaccine. Similarly, the pneumonia (pneumococcus) vaccine is recommended to all cancer patients 65 year or older; however, over one-third (36 percent) of cancer patients in this age range reported never having received the vaccine. Cancer patients are at a higher risk of acquiring and dying from these illnesses due to a weaker immune system, among other factors.

Three reasons accounted for almost 80 percent of why patients didn't receive either vaccine: Patients either believed they didn't need the vaccines, they didn't know about the recommended vaccination guidelines or their physicians didn't recommend the vaccines.

While 44 percent of patients who received either vaccine reported that they were asked or informed about these vaccines by their family physicians or internists, only seven percent reported being asked or informed by their oncologists.

"People undergoing cancer treatment and their loved ones should ask their oncologists about these vaccines. They are a very simple, yet very effective, way for people living with cancer to extend their lives," said Neha Vapiwala, M.D., a study author and a radiation oncologist at the Hospital of the University of Pennsylvania in Philadelphia. "Oncologists have the opportunity to talk to patients about recommended vaccines during their frequent interactions with patients, whether it be before, during, or after cancer therapy. This discussion could result in better cancer care and ultimately save lives."

This was the first study done to find out whether cancer patients receiving radiation therapy complied with national vaccination guidelines. The anonymous study asked 207 patients from August 2006 to January 2007 about whether they received the flu and pneumococcus vaccines. Those who reported receiving neither vaccine were asked further questions about the reasons why they didn't receive them.
Live-Saving Flu And Pneumonia Shots Not Reaching Cancer Patients
Source: www.medicalnewstoday.com

Facts of flu or cold

2008-02-03T03:34:00.000-08:00

Influenza, or the flu, is a viral disease of the respiratory tract-the nose, throat, bronchial tubes and lungs. It's similar to a cold in that both are caused by viruses that infect the respiratory tract, mainly in the winter season, and both can cause symptoms such as coughing and sore throat. A cold is a minor viral infection of the nose and throat, and its primary symptoms are nasal stuffiness, sneezing, runny nose, sore throat and cough. Influenza is a more serious infection, and its major symptoms are high fever, severe aches and pains, cough with mucus production, tiredness and weakness. The flu symptoms appear within one to four days of exposure and are much more severe than those of a cold.

The flu is highly contagious and is spread though airborne droplets of moisture produced when someone with the flu coughs or sneezes. When you breathe in these germs, you may come down with the flu, generally within one to four days of being exposed.

Influenza outbreaks sweep quickly through a community, affecting approximately five to 20 percent of Americans annually, although rates of infection vary among age groups and from one season to another, according to the U.S. Centers for Disease Control and Prevention (CDC).

On average, approximately 36,000 Americans die from the flu each year, according to the CDC.

The CDC recommends that the following groups of people be given top priority for receiving a flu vaccine, should vaccine supplies become limited, which is not expected to happen this year:

*children from age two to adults 50 years and older

*People of any age who have chronic medical conditions, especially respiratory conditions such as asthma, chronic bronchitis or emphysema

*all women who are or will be pregnant during the influenza season

*nursing home and long-term care facility populations

*children age six to 59 months

*health care workers involved in direct patient care

*household contact and out-of-home caregivers of children younger than six months

*Ask your health care professional for more information about restrictions and availability of flu vaccine or visit the CDC's Web site: http://www.cdc.gov for the most up-to-date flu information.
Smoking can increase your risk for the flu and complications from the flu because smoking injures your airways and damages the cilia, tiny hair-like structures that help keep the airways clear.

The most serious, often life-threatening complication of the flu is pneumonia. Other complications include ear infection, bronchitis, dehydration, and worsening of chronic conditions, such as congestive heart failure, asthma or diabetes. Croup and a lung disease called bronchiolitis can develop as complications in infants and young children.

The influenza virus changes its genetic make-up from year to year, which means that each year you're likely exposed to a new virus. That's why you can get the flu every year, and why a flu vaccine is recommended every year. Vaccines, which are made with killed or inactivated virus or viral fragments of those strains, work by forcing the immune system to make antibodies that fight circulating strains of influenza.

A flu vaccination is your best chance to protect yourself against the flu; it has a 70 percent to 90 percent success rate in healthy adults and children, according to the CDC.

The nasal mist flu vaccine, FluMist, is now available from your health care professional. It is recommended for children at least age two and adults up to the age of 49. It is effective in preventing influenza types A and B.

There is something you can do about the flu. Prescription antiviral medications, such as oseltamivir (Tamiflu) and zanamivir (Relenza) can be used to treat and prevent the flu if used within 12-48 hours of symptom onset or exposure to the virus.
Source: findarticles.com

Bird Flu

2007-11-07T11:12:00.000-08:00

Birds, just like people, get the flu. Bird flu viruses infect birds, including chickens, other poultry and wild birds such as ducks. Most bird flu viruses can only infect other birds. However, bird flu can pose health risks to people. The first case of a bird flu virus infecting a person directly, H5N1, was in Hong Kong in 1997.

Since then, the bird flu virus has spread to birds in countries in Asia, Africa and Europe. Human infection is still very rare, but the virus that causes the infection in birds might change, or mutate, to more easily infect humans. This could lead to a pandemic, or a worldwide outbreak of the illness.

During an outbreak of bird flu, people who have contact with infected birds can become sick. It may also be possible to catch bird flu by eating poultry that is not well cooked or through contact with a person who has it. Bird flu can make people very sick or even cause death. There is currently no vaccine.

Symptoms of Common Cold

2007-05-26T06:57:00.000-07:00

The Flu
The common cold, also known as a viral upper respiratory tract infection, is a contagious illness that can be caused by a number of different types of viruses. Because of the great number of viruses that can cause a cold and because new cold viruses develop, the body never builds up resistance against all of them.

Symptoms of a common cold include nasal stuffiness and drainage, sore throat, hoarseness, cough, and perhaps a fever and headache. Many people with a cold feel tired and achy. These symptoms typically last from three to 10 days. The common cold is caused by a different type of virus and usually does not result in a significantly higher body temperature—a high fever is a very reliable indicator of the flu.

After a common cold, a sufferer develops immunity to the particular virus. This immunity offers only limited protection against the many other cold viruses. The person, therefore, can easily be infected by a different cold virus. In most cases, something called a "rhinovirus" is the cause of the common cold, while a variety of other viruses are responsible for the remaining cases of the cold. However, bacterial infections are rarely the cause of upper respiratory symptoms so antibiotics won't help most colds. Almost all cases of the common cold are caused by VIRUSES, and antibiotics do not work against viral infections. In spite of this fact, an amazing 60% of colds are treated with antibiotics.
The Flu

Fujian Flu

2007-04-30T23:55:00.000-07:00

The Flu
There is a flu outbreak every year and there is a new flu vaccine being introduced every year. The reason is this - the flu virus changes or mutate a little every year, making it impossible to create a vaccine that is permanently effective year after year. Instead, each year a new flu vaccine needs to be introduced that is effective for that particular year.

Fujian flu is what scientists call a "drift variant." It's nearly the same virus as the Panama flu included in this year's vaccine, but it's not exactly the same, notes the expert.

According to data from Center for Disease Control, Atlanta, USA, this year's flu outbreak that is happening in USA is mainly due to flu virus of the Fujian variant (79%) and the Panama variant (21%). So, is flu vaccine effective? No vaccine is 100% effective. For the flu vaccine to be effective for this outbreak, ideally the vaccine needs to contain both the Fujian and Panama variants. Unfortunately, the present available flu vaccine isn't.

However, that is not to say that the vaccine is totally useless. It would still afford a certain degree of protection as there is cross- immunity. In other words, the immunity that you get from one particular variant provides you with partial protection against other variants. Some protection is better than no protection, particularly for the immuno-compromised, such as: -those above 65 years old
-children below 2
-people undergoing treatment for terminal illness
-those traveling to affected areas in USA
The Flu

Symptoms of Bird Flu

2007-04-07T10:41:00.000-07:00

The Flu
The virus is found in the bird's intestines. Even in the birds,the symptoms are not severe. But it can be seen in poultry farms the way in which the birds are handled—they are packed closely together with chicken and turkeys—thus man helps the cause of rapid spread of the latest disease called bird flu—to give it a more trendy name, avian influenza!

A general alert was sounded in health circles all over the world, when the mutated variety of the bird flu virus, H5N1 showed its teeth. That was in the year 2003. The infected poultry led to several human infections. About 50% of the affected died. The other 50%, turned temporary vegetarians, and inspired many others to follow suit!

The mode of infection is simple. Come into contact with the bird's saliva, faces or nasal secretions—and certainly have the infection instantly. The other birds which come into similar contacts have no chance of survival. As for human beings, if protective measure are not taken, become some of the symptoms are identified. As regards the other symptoms the usual guess work is going on. In birds, the virus H5N1 causes diarrhea, excessive shedding, a swollen head and difficulty in breathing.

Some more symptoms are, fever sore throat, muscle ache, chest pain, lethargy, cough and headache. If the infection has taken a serious turn in, the following symptoms would indicate that state: eye infections, acute respiratory problems, pneumonia, inflammation of the heart and inflammation in the brain.

Immediate hospitalization in the case of severe symptoms is not only advisable but absolutely necessary. Human to human help is most welcome, but not at this time when your H5N1 virus is waiting for the opportune moment to take hold of the person who is coming to help you. So, avoid all contacts and let a trained health worker handle the precious cargo!
The Flu

Flu in Adults Symptoms

2007-02-12T21:19:00.000-08:00

The Flu
A sudden increase in the number of school-aged children sick at home with flulike illness may indicate arrival of flu season. This outbreak is soon followed by similar infection in other age groups, especially among adults.
Symptoms usually come on suddenly.

*Fever (usually high)

*Severe aches and pains in the joints and muscles and around the eyes

*Generalized weakness

*Ill appearance with warm, flushed skin and red, watery eyes

*Headache

*Dry cough

*Sore throat and watery discharge from the nose
The Flu

Preparing For Pandemic Influenza

2007-01-12T21:45:00.002-08:00

The Flu
A pandemic is a global disease outbreak. An influenza pandemic occurs when a new influenza A virus emerges for which there is little or no immunity in the human population, begins to cause serious illness and then spreads easily person-to-person worldwide. The federal government, states, communities and industry are taking steps to prepare for and respond to an influenza pandemic.

A pandemic is likely to be a prolonged and widespread outbreak that could require temporary changes in many areas of society, such as schools, work, transportation and other public services. An informed and prepared public can take appropriate actions to decrease their risk during a pandemic.
Communities, Businesses and Individuals Should:

· Develop preparedness plans as you would for other public health emergencies.

· Participate and promote public health efforts in your state and community.

· Talk with your local public health officials and health care providers; they can supply information about the signs and symptoms of a specific disease outbreak.

· Implement prevention and control actions recommended by your public health officials and providers.

· Adopt business/school practices that encourage sick employees/students to stay home.

· Anticipate how to function with a significant portion of the workforce/school population absent due to illness or caring for ill family members.

· Practice good health habits, including eating a balanced diet, exercising daily, and getting sufficient rest and take these common-sense steps to stop the spread of germs.
o Wash hands frequently with soap and water.
o Cover coughs and sneezes with tissues.
o Stay away from others as much as possible if you are sick.

· Stay informed about pandemic influenza and be prepared to respond.
o Consult www.pandemicflu.gov frequently for updates on national and international information on pandemic influenza.
o Use national and local pandemic hotlines that will be established in the eventuality of a global influenza outbreak.
o Listen to radio and television and read media stories about pandemic flu.

The Flu

Avian Influenza

2006-12-10T16:46:00.000-08:00

The Flu
The bird flu virus, known as A(H5N1), belongs to a group of influenza viruses known as Type A, which are the only ones that have caused pandemics. It has been steadily advancing around the world, first appearing in Asia, then Europe and Africa.

The apparent lethality of A(H5N1), combined with its inexorable spread, are what have made scientists take it seriously. The virus lacks just one trait that could turn it into a pandemic: transmissibility, the ability to spread easily from person to person. If the virus acquires that ability, a worldwide epidemic could erupt.

The A(H5N1) strains circulating now are quite different from the A(H5N1) strain detected in Hong Kong in 1997, which killed 6 of 18 human victims. Over time, A(H5N1) seems to have developed the ability to infect more and more species of birds, and has found its way into mammals -- specifically, cats that have eaten infected birds.
The Flu

The Flu

2006-11-20T06:36:00.000-08:00

The Flu
flu, is an infectious disease of birds and mammals caused by an RNA virus of the family Orthomyxoviridae (the influenza viruses). In people, common symptoms of influenza are fever, sore throat, muscle pains, severe headache, coughing, and weakness and fatigue. In more serious cases, influenza causes pneumonia, which can be fatal, particularly in young children and the elderly.

Although the common cold is sometimes confused with influenza, it is a much less severe disease and caused by a different virus. Similarly, gastroenteritis is sometimes called "stomach flu" or "24-hour flu", but is unrelated to influenza.

Typically, influenza is transmitted from infected mammals through the air by coughs or sneezes creating aerosols containing the virus, and from infected birds through their droppings. Influenza can also be transmitted by saliva, nasal secretions, feces and blood. Infections either occur through direct contact with these bodily fluids, or by contact with contaminated surfaces.

Flu viruses can remain infectious for over 30 days at 0°C (32°F) and about one week at human body temperature, although they are rapidly inactivated by disinfectants and detergents.

Flu spreads around the world in seasonal epidemics, killing millions of people in pandemic years and hundreds of thousands in non-pandemic years.

Three influenza pandemics occurred in the 20th century—each following a major genetic change in the virus—and killed tens of millions of people. Often, these pandemics result from the spread of a flu virus between animal species. Since it first killed humans in Asia in the 1990s a deadly avian strain of H5N1 has posed the greatest influenza pandemic threat. However, this virus has not yet mutated to spread easily between people.
The Flu