THURSDAY, May 28 (HealthDay News) -- Officials must decide what actions to take before the severity and scale of the H1N1 virus are certain, and geography plays an important role in the incidence of the virus, according to perspectives published online May 27 in the New England Journal of Medicine.
Marc Lipsitch, of the Harvard School of Public Health in Boston, and colleagues write that in the early stages of an epidemic, decision makers face a trade-off between harm caused by an intervention and harm caused by a potentially wider outbreak if they delay action. A lack of reliable incidence measures makes it impossible to track the epidemic's growth rate. Therefore, the authors note, decisions about dealing with the virus must be made without definitive severity estimates.
Vladimir Trifonov, Ph.D., of Columbia University in New York City, and colleagues write that the 2009 H1N1 virus is likely closely related to common reassortant swine influenza A viruses isolated in North America, Europe and Asia. The authors note that human influenza A viruses travel around the globe with their hosts, but swine viruses in different parts of the world have distinct lineages.
"Given both the dependence of the distribution of swine influenza A viruses on geographic location and the lack of sampling in certain parts of the world, it is perhaps not surprising that the ancestors of the new human influenza A (H1N1) virus have gone unnoticed for almost two decades. Only more efficient surveillance could prevent such an event from happening in the future," Trifonov and colleagues conclude.
Lipsitch reported receiving consulting fees from the Avian/Pandemic Flu Registry, and a co-author received them from Sanofi Pasteur.
Full Text - Lipsitch
Full Text - Trifonov