Wednesday, March 29, 2006
Five Bird Flu Human Cases In Egypt Now
On the brighter side, the WHO staffers mostly left Azerbaijan (where seven cases in humans were confirmed). They say they believe the outbreak there is under control, and they believe that some of the cases occurred when people plucked feathers from dead birds who had presumably died of or contacted the virus. Fomite transmission might be the main route of human infection.
Turkey's situation appears to be largely controlled. Another man is supposed to have died in Baghdad from H5N1 and the virus has been found in poultry in Baghdad.
India keeps culling, but now the labs are saying they aren't getting good samples for testing and they can't handle the volume of samples they're getting regardless.
An interesting article reporting on a Chinese scientist's viewpoint:
A recent rise in the number of human cases of avian influenza reported in cities is a dangerous sign of things to come, said Zhong Nanshan, president of the Chinese Medical Association, Tuesday in Beijing.
In Vietnam, Thailand and Indonesia, the main source of the virus is spreading through dead poultry, said Zhong at an international conference.
However, in China, some 16 human cases of bird flu were not caused by direct contact with ill or dead poultry, he noted.
Is it sub-clinical infections that are resulting in infection? China has been vaccinating poultry, so that might be the case. If so, we in the west should think carefully about the implications. Do we really want people exposed to birds that are capable of transmitting the infection but show no signs of illness? According to Zhong, there have been eleven human fatalities in China caused by H5N1. Most people think there are far more cases that have not been reported, but recent studies say that does not seem to be true. However there are several distinct strains of highly pathogenic H5N1 circulating in birds, and this ignores the evidence in Turkey, where mild sub-clinical cases were detected. The more of it there is the more it mutates.
Swab-testing seems to be far less effective in detecting H5N1 than regular flu strains, so it is very possible that many cases aren't being detected. Antibodies from blood tests can be detected, but usually it takes a while for them to develop. Several studies have been released surveying populations
Indonesia seems to be in a peck of trouble, but they have not been actively culling. Like Egypt, they have a population intermixed with birds.
It does seem that if a population has been alerted and then changes its ways, it is possible to control human exposures until and unless the virus goes human-to-human. That is not very helpful for very poor rural populations dependent on local chicken flocks for protein who find it difficult to change their ways without starving, but it is good news for developed countries in which exposures can be controlled. I think there are going to be an awful lot of hungry people in the world before this is all over. Unfortunately the countries that are the poorest seem to have the most uncontrollable risks.
This is an ill wind that blows absolutely no good to anyone. Most people are concerned about the possibility of H5N1 becoming easily transmittable to humans. I think it is a scourge even as an avian virus.