July 17, 2007 Researchers from the U.S. and abroad used a
contact ferret model to evaluate transmissibility of influenza
viruses in humans and found that some strains currently
circulating throughout the world may transmit better than others
in mammals. The researchers report their findings in the July
2007 issue of the Journal of Virology. Transmission of H5N1
influenza viruses is of great concern worldwide as their
geographic and host ranges continue to expand. Currently
transmission to humans has been inefficient. Although there is
limited knowledge of potential routes and determinants required
for transmission, researchers predict genetic reassortment and
mutation during adaptation in the host to be the two most likely
avenues. In the study experimental groups consisting of one
inoculated ferret and two contact ferrets were used to monitor
the transmissibility of four human H5N1 viruses isolates
collected in Hong Kong (A/Hong Kong/213/03), Vietnam
(A/Vietnam/1203/04 and A/Vietnam/JP36-2/05) and Turkey (A/