Exposure to bird flu through animal markets

Femke van den Bos, Jakarta

With the threat of Avian Influenza (bird flu) increasing daily, some decisive measures need to be taken.

Exotic birds, water birds, poultry and some mammal species are susceptible to the bird flu. After infection with Avian Influenza, it can take anything up to three days before the animal shows symptoms. During this period, shedding of the virus has already started.

Some species of water birds carry the virus without becoming ill. These species form a great risk because they are able to spread the disease without being detected.

Transmission of the virus to other animals or humans occurs through the respiratory tract, the conjunctivae and feces. Infected feces can stay contagious for a long period.

In animal markets, wild mammals, birds, and reptiles are in transit daily. In these markets they are in contact with people and with dozens of other species before they are shipped to other markets, sold locally, or even freed and sent back into the wild as part of religious customs.

Pramuka Market in East Jakarta is likely one of the world's largest animal markets (unfortunately endangered animals are traded here as well) followed by Jakarta's Jatinegara, Barito and Surabaya's Bratang and Semarang's Karimata bird markets.

Hunters, middle men, and consumers all experience some type of contact as each animal is traded. Other wildlife in the trade is temporarily exposed, and domestic animals and wild scavengers in villages and market areas consume the remnants and wastes from the traded wildlife.

The free ranging chickens in Indonesia can be easily exposed to the virus in this way, and spread it even further. This trade, coupled with rapid modern transportation and the fact that markets serve as network hubs rather than as product endpoints, dramatically increases the movement and potential cross-species transmission of infectious agents like avian influenza.

Besides the obvious economic threat to the poultry industry, a possible pandemic is a great threat to public health. The moment the avian virus mutates into a new strain which is transmissible from human to human, a pandemic is likely to occur. Pandemics are different from seasonal outbreaks or "epidemics" of influenza.

Seasonal outbreaks are caused by subtypes of influenza viruses that are already in existence among people, whereas pandemic outbreaks are caused by new subtypes or by subtypes that have never circulated among people or that have not circulated among people for a long time. The worst known pandemic of influenza (the "Spanish flu") occurred in 1918-1919, killing approximately 40 million people around the world.

In several Western countries a limited amount of antiviral drugs (amantadine, rimantadine, oseltamivir, and zanamivir) are available for influenza patients. For example, Oseltamivir, administered in the first 48 hours after symptoms occur, shortens the disease period to two days, and decreases the chance of sometimes-deadly viral pneumonia.

Unfortunately, these drugs are not available in Indonesia. The World Health Organization will receive one million doses by the end of 2005.

Avoiding infection with bird flu is not difficult:

* Don't go to markets where birds are being traded

* Only eat well-cooked chicken meat

* Avoid close contact with birds, poultry and their excrement

Prevention of further spread of influenza is extremely important. Closing the animal markets is a relatively easy measure with a very clear result. So, what are the authorities waiting for?

Femke van den Bos is a veterinarian at the Wildlife Rescue Centre in Tegal Alur, Jakarta and can be reached at femkevandenbos@hotmail.com.