Shades of 1918? New study compares avian flu with a notorious killer fro...( In the waning months of the First Wo...)

In the waning months of the First World War, a lethal virus known as the Spanish flu (influenza A, subtype H1N1), swept the United States, Europe and Asia in three convulsive waves. The year was 1918. The ensuing pandemic claimed up to 100 million victims, most of whom succumbed to severe respiratory complications associated with rapidly progressing pneumonia. Many died within days of the first symptoms.

In a new study, Carole Baskin, formerly assistant research professor at Arizona's Biodesign Institute, currently with Science Foundation Arizona, and an interdisciplinary team of collaborators, compared the recent avian strain known in the scientific community as H5N1, with genetic ressortants of the 1918 virussource of the most severe influenza pandemic in recorded history. The results, which appear in the latest issue of the Proceedings of the National Academy of Science, are sobering. H5N1 was found to replicate profusely within the first 24 hours, causing severe damage to respiratory tissues while sending the host's innate immune response into a lethal overdrive, reminiscent of the trajectory of the original 1918 virus.

The threat of an avian flu pandemic hasn't gone away and emergency preparedness efforts may be inadequate to deal with the scope of such a pandemic, were one to occur. "In order to come up with vaccines and therapies, you have to understand the disease," Baskin stresses. "That's why I think this type of pathogenesis study is so important."

Although H5N1 is not readily communicable between humans, it has nevertheless killed over 400 people to date as a result of human-avian interactions, primarily in Vietnam, Thailand, China, Egypt and Indonesia, according to the World Health Organization. The mortality rate for those stricken with highly pathogenic avian influenza (HPAI) H5N1 is 63 percent. Should a series of modifications allow the virus to pass from person to person, the consequences for humankind
'/>"/>