Influence of Words as Determinants of U.S. International and Domestic Health Policy: Part I, The

Journal of Allied Health, Fall 2005 by Elwood, Thomas W

Type A flu can swap its genes with those from other strains. If mixed with a human strain, the result might be a new and highly deadly virus. The prospect of having a virus jump from one species to the next increases when animals and humans are in close contact. That situation prevails in nations such as Cambodia, Vietnam, and Thailand, where it is common for households to have pigs, chickens, and ducks roaming around the yard. The popularity of cockfighting places humans in even more direct and dangerous contact with infected fowl because blood is sprayed on spectators at these events. Owners also tend to the lacerations of combatants either by sucking the blood from wounds or wiping blood from feathers and eyes using only their bare hands.

On April 14, 2005, Indonesian scientists found the H5N1 bird flu virus in a pig. As of April 21, 2005, the strain has infected poultry across East Asia and killed at least 51 humans. The case fatality rate is high, which also is quite worrisome because it means that once the disease is contracted, death is a probable outcome.

Meanwhile, World Health Organization (WHO) officials began noticing a change in the mortality rate in northern Vietnam, when it plummeted from 70% to 20% between January and April 2005. One theory is that for the virus to thrive in humans, it should not be such an effective killer because its victims are less able to transmit the disease once they are dead. The higher the number of persons infected who survive means that they will be able to infect many other individuals. Thus, while lower mortality sounds reassuring, a decrease in the fatality rate still would have enormous implications because the reduced percentage would be applied to hundreds of millions of infected persons in a pandemic. Currently, infectious disease specialists from the United States and other countries are in Vietnam to provide advice on public health strategies.6

Scientists fear pigs could act as a "mixing vessel" in which a human pandemic strain could evolve because the animals can harbor both human and avian flu viruses. A hybrid bird-human virus could have hemagglutinin from birds that human immune systems will not recognize and genes from humanadapted flu that will make the hybrid highly contagious in humans.

Complicating the dimensions of the peril is that countries such as Laos and Cambodia lack the public health infrastructure in the form of laboratories and reporting systems to investigate and record outbreaks of disease. Given the importance of domestic fowl in the economy of such places, there also may be a much greater reluctance to undertake large-scale culling of bird flocks to prevent the spread of influenza.

Many factors present in the world today serve to accelerate the spead of infectious diseases. Both human and farm animal populations are increasing. The entire globe continues to experience urban growth, with many cities having populations in excess of 15 million individuals. Increasing amounts of food are being shipped across wide borders, including oceans. More and more humans are moving to wilderness areas that previouly were unpopulated. Air travel can result in the transmission of disease by passengers from one end of the globe to the other in less than 24 hours.