2005-02-10-More warnings of bird fluUnderstanding Avian Influenza
2005-02-10-More warnings of bird flu
Rising numbers of cases of avian flu in Asia are fueling fears of a global outbreak. The disease appears to be resurfacing in the region, and health officials worry that they do not have the tools to fight it. A mutation that allows the disease to pass from person to person could be the spark that sets off a worldwide pandemic. Only a concerted and speedy international response can provide the protection needed.
According to the World Health Organization (WHO), there have been 58 human cases of avian flu since January 2004, with 44 fatalities. In Vietnam, 13 of 14 people infected in the last two months have died. In Thailand, 12 of 17 infected people died last winter, before warm weather stopped the spread of the disease. A Cambodian woman died of the disease in early February.
Although the number of human cases has been limited thus far, it is far more widespread in birds. Infected fowl have been found in nine Asian nations, including Japan, resulting in the slaughter of hundreds of millions of birds and ducks. About half of Vietnam's provinces have infected animals. Following the most recent cases, Vietnamese officials have ordered the culling of another 210,000 ducks and banned live ducks from the city. Recent studies have showed that ducks, both domestic and wild, are reservoirs, and the animals do not show signs of the disease. Thus, the Vietnamese government is reportedly considering halting all duck breeding -- a key poultry industry in southern Vietnam -- to stop the spread of the flu.
Mass slaughter is unlikely to solve the problem. The U.N. Food and Agriculture Organization has warned that the disease will be present for several years in the countries that experienced outbreaks during 2004. More worrying still are concerns that the disease is mutating and becoming stronger and more virulent.
Mutations make treatment more difficult. Vaccines must target particular strains -- that is why each year we all need another flu shot. For developing countries, acquiring any vaccine is difficult; keeping pace with a rapidly changing threat is virtually impossible.
Health officials' greatest fear is that the disease will become more communicable. Earlier strains could only be passed from a bird to a human; the density of urban populations in Southeast Asia and frequent contact between fowl and humans made that all too easy. More recently, there are cases of human-to-human transmission, but only after sustained contact, such as when caring for a sick or dying person. Now, there are reports of transmission after casual contact. If that is established, human susceptibility to the disease means that a global pandemic, with the possibility of tens of millions of deaths is a real possibility.
While health officials caution that we cannot know the likelihood of such a mutation, there is no point in waiting. We already know where the disease is. The international community must move quickly to cut off the source of infection; that means helping slaughter the millions of ducks and birds that might be infected and providing governments with funds to help replace the lost income. Merely recommending massive culls without compensating for the losses will guarantee that farmers will fail to take action for fear of losing their livelihood.
At the same time, there must be increased effort to coordinate programs to identify cases when they break out, isolate the strains and develop vaccines for them. Lab tests require specialized skills and equipment, which can be expensive, and tests take time. All too often, national pride or fear of the economic consequences obliges governments to cover up rather than reach out when disease hits. To its credit, the Vietnamese government has recognized its weaknesses and asked for help.
So far, donors have provided $18 million for emergency activities in response to the outbreak over the last year, but that is not enough. We know too little about this disease; most especially how it is transmitted and what makes people vulnerable to it. Real time responses are essential, even though -- or, especially because -- the hardest hit countries are the least developed. Networks have to be established that permit the identification of the disease, patients real and suspected must be isolated, and medicines made available both for treatment and prevention. By one estimate, the only producer of vaccine for the current strain of bird flu would need six months to prepare enough medicine to treat 1 million people for five weeks.
That is a potential catastrophe in the making. Given its intention to play a leading role in the region, Japan should be heading up the effort to raise more money and help develop the infrastructure that is needed to contain avian flu. That would be a critical contribution to regional security and could save countless lives.