THE DEADLY VIRUS

It is just one among 15 types of avian influenza, or bird flu, viruses. Some scientists believe that ducks in mainland China may be ‘reservoirs’ of H5N1. The first human outbreak caused by the H5N1 virus occurred in Hong Kong in 1997. Until then it was believed that birds gave the virus to pigs and pigs gave it to humans. The 1997 outbreak showed that birds can give influenza directly to people.

SOURCES OF HUMAN INFECTION

The only way humans can contract the H5N1 virus is through close contact with infected poultry. Birds that have survived the infection continue to secrete massive quantities of the virus in their faeces. People who touch birds or inadvertently come into contact with or ingest tiny and invisible faecal particles are at risk. The H5N1 cannot be transmitted from person to person.

DIFFERENCE BETWEEN HUMAN FLU AND AVIAN FLU

Countless people around the world may be infected with the predominant human influenza virus named H3N2. It causes a mild flu, which can, in some cases, become life-threatening. The illness caused by H5N1 in humans is far more severe and early data suggests that mortality may be as high as 60 per cent. So far, eight out of 10 people infected with H5N1 in the current outbreak have died.

DRUGS AGAINST H5N1

Antibiotics do not work against viruses. The traditional, relatively inexpensive, anti-viral drugs are amantidine and rimantidine. But early results indicate that the H5N1 virus in this outbreak does not respond to these drugs. However, another anti-viral drug called oseltamivir is believed to work against this strain of H5N1, but this drug is expensive and not available in many countries.