Why the Avian Influenza Might be the Next Pandemic

Scientists believe that parts of the three types of human flu viruses originated from birds. Widespread human influenza outbreaks occur with regularity, on average three to four times a century. It’s estimated that the pandemic of the Spanish flu (H1N1) in 1918-1919 caused an estimated 40 to 50 million deaths worldwide, but killing only about 2.5% of those infected. Scientists say that these pandemics are inevitable, and that the next one might be imminent.

Scientists from the World Heath Organization (WHO) have warned that the bird flu might be the next worldwide influenza pandemic. They are particularly concerned about the H5N1 subtype of virus, the one responsible for the Hong Kong outbreak, for several reasons. First, H5N1 mutates very quickly and can latch onto genes from diseases affecting other animals. Second, it’s already proved highly harmful to humans. (Compare the Spanish flu mortality rate of 2.5% to the H5N1 rate of 70% and you’ll see why scientists are so worried.) Finally, birds that survive the influenza can excrete virus-laden material for up to ten days, increasing the chances of infection among other bird populations.

H5N1 has shown up in bird populations in nine Asian nations - Cambodia, China, Indonesia, Japan, Laos, Malaysia, South Korea, Thailand, and Vietnam. The spread of bird infections to larger geographic areas increases the chances of human infection. Since H5N1 is so easily mutated, scientists worry that an increased number of infections in humans will lead to a virus which transforms into one more easily transmitted from person to person, resulting in a regional or even worldwide pandemic.

In an alarming outbreak in Vietnam, Cambodia and Thailand, H5N1 has resulted in 55 human infections since 2004, of which 42 victims died. To complicate the problem, “a diagnostic test designed by Canadian researchers and used in Vietnam to detect H5N1 avian flu is out of date, scientists from the National Microbiology Laboratory admit — raising the possibility some human cases may have been dismissed in error.” (Source: The Associated Press, May 8, 2005) Additionally, traditional mistrust between Vietnam and the West means that Vietnam has not fully agreed to help from international agencies like the World Health Organization, making quick diagnosis and analysis of new cases much more difficult.