Monday, March 02, 2009

Bird Flu Obsession

Around the time that I started this blog, bird flu (specifically the deadly H5N1 strain) was a major news topic due to a series of outbreaks among domestic poultry in Asia and elsewhere. Unfortunately, the coverage encouraged fears that birds were about to fly into the U.S. and start a massive pandemic on the scale of the Spanish Flu of 1918 – a threat that so far has not materialized. It appears that there is now some movement towards reconsidering how bird flu was represented.

"We continue to be aroused and some nearly panicked by the threat of a flu pandemic caused by the avian influenza virus, H5N1. Is this anxiety justified? In the more than 15 years since it was first recognized, this bird flu virus has yet cause very much mortality in humans or evolve to be readily transmitted between people," says Bruce Levin, the Samuel Candler Dobbs Professor of Biology at Emory University.

Nevertheless, because of the high case mortality of humans infected with H5N1 (sometimes exceeding 90%), pandemic influenza caused by this avian virus has appropriately stimulated a great deal of research on the microbiology, immunology, pathology, virulence, epidemiology and evolution of influenza. It has also contributed to a renaissance of interest in the great influenza of 1918, says Levin.
He also notes some differences between now and 1918:
  • It was not clear that a virus was responsible for the pandemic
  • There were no vaccines or even ways to develop vaccines to prevent the disease
  • There were no antiviral drugs to mitigate the course of this disease and reduce the rate of transmission
  • There were no antibiotics to treat, or vaccines to prevent, secondary bacterial infections that evidence suggests were the major cause of mortality in influenza patients.
I would also add that in 1918, the most medically advanced countries had just spent four years pummeling each other and destroying each other's infrastructure, millions of soldiers were either living in unsanitary trenches or in transit between the battlefields and their home countries, and medical facilities and staff were already overburdened with caring for the war's casualties. Even with contemporary medical knowledge and pharmaceuticals, it is questionable whether medical systems could have prevented a pandemic from occurring in the aftermath of World War I.