Experts call for close monitoring of H1N1 changes

By Tan Ee Lyn

HONG KONG (Reuters) - Experts have called for close monitoring of how the new H1N1 flu virus evolves in coming months in the southern hemisphere as that may help answer questions that have eluded scientists for decades.

In an article published in Nature, the scientists from Japan and the United States reviewed literature on the three most recent pandemics -- Spanish flu of 1918-1919, Asian flu of 1957 and Hong Kong flu of 1968 -- as well as skirmishes against the H5N1 bird flu virus in the past 10 years.

"Although much has been learned about influenza viruses, key questions still remain unanswered: for example, what factors determine interspecies transmission, reassortment and human-to-human transmission -- factors that have accounted for past pandemics and will be critical in the emergence of new pandemic viruses," they wrote.

Led by Yoshihiro Kawaoka at the University of Tokyo's International Research Center for Infectious Diseases, the team recalled how the first mild wave in the Spanish flu pandemic was followed by two deadly waves.

Therefore, watching how this new H1N1 virus evolves in coming months may shed light on what accompanying genetic changes need to take place for it to become more virulent or even more efficient in transmitting between humans, if these adaptations occur.

"Careful monitoring of the (H1N1) during the upcoming winter season in the southern hemisphere is of critical importance to detect more virulent variants, should they arise," they wrote.

"From a scientific perspective, the opportunity to watch virus evolution in real time may provide us with invaluable information on the factors that determine pathogenicity and/or transmissibility."

"These factors accounted for past pandemics and will be critical in the emergence of new pandemic viruses," they added.