Bird Flu

Bird flu is a highly contagious disease that is caused by Type A influenza virus.

Type A virus can infect both animals and humans and can change its genetic code. All known Type A virus are carried by wild migratory birds (mainly wild ducks). Generally the ducks are immune to its effects but chickens have little resistance to it. The virus causes high mortalities among chickens - it can kill an entire flock within hours!

Infected poultry can show signs such as:

• sudden death
  
• lack of energy and appetite
  
• decreased egg production
  
• soft-shelled or misshapen eggs
  
• swelling of the head, eyelids, combs, wattles and legs
  
• purple discolouration of the wattles and combs
  
• nasal discharge
  
• coughing and sneezing
  
• diarrhoea

If you notice any of the above signs, call the relevant authorities in your country.

It is rare for the bird flu virus to be transmitted from chickens to humans. Of all the bird flu virus strains, only the H5N1, H9N2 and H7N7 strains have been known to pass from chickens to humans. The virus is transmitted to humans through close contact with infected chickens. Transmission may occur through

• inhalation of dried faeces of infected chicken,
  
• inhalation of droplets of nasal and respiratory secretions from the infected chickens,
  
• consuming duck's blood and
  
• eating undercooked poultry.

Poultry farmers and those who rear chickens in their backyards are at risk in catching bird flu.

There are three ways through which bird flu can spread to humans:

1. Directly from birds to humans
   
   
2. Indirectly from birds to intermediate hosts (e.g., pigs) then to humans
   
   
3. Bird strain and human strain of influenza infect the same intermediate host to spawn a new strain that can spread among humans

Though there have been a few cluster cases of members of the same family infected with the virus, human-to-human transmissions had not been conclusively proved. Nevertheless, there is a fear of the virus mutating into one that is capable of spreading from human to human. If that happens and with no vaccine available yet¹ to protect people from catching it, then there is a potential of a global pandemic developing!

Because the virus is carried by wild migratory birds (who know no boundary), there is no way to prevent bird flu from spreading from country to country. However, keeping poultry indoors and preventing wild birds getting in to poultry houses is a safeguard against bird flu infecting domestic flocks. Countries with bird flu outbreaks have adopted culling (i.e., killing of all or a large number of poultry within the infected area) to control the spread of the virus among birds.

«« Bird Flu Crossword

---

¹ Vaccines have to be made specifically for a particular type of virus and will take some time to be manufactured after a new strain of virus is confirmed.

Fears of a global pandemic | Bird Flu Scare

Information compiled in February 2006 by "Parenting the Next Generation"
Mad Cow Disease   |   SARS   |   Bird Flu