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
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
