General
MIT and CDC find a genetic explanation for the less effectively spread of H1N1 virus
A team from MIT (Massachusetts Institute of Technology) and the Centers for Disease Control USA has found a genetic explanation for why the new H1N1 "swine flu" virus has spread from person to person less effectively than other flu viruses. The H1N1 strain, which circled the globe this spring, has a form of surface protein that binds inefficiently to receptors found in the human respiratory tract, the team reports in the July 2 online edition of Science. "While the virus is able to bind human receptors, it clearly appears to be restricted," says Ram Sasisekharan, the Edward Hood Taplin Professor and director of the Harvard-MIT Division of Health Sciences and Technology (HST) and the lead MIT author of the paper. Sasisekharan and his laboratory co-workers have been actively investigating influenza viruses.That restricted, or weak, binding, along with a genetic variation in an H1N1 polymerase enzyme, which MIT researchers first reported three weeks ago in Nature Biotechnology, explains why the virus has not spread as efficiently as seasonal flu, says Sasisekharan. However, flu viruses are known to mutate rapidly, so there is cause for concern if H1N1 undergoes mutations that improve its binding affinity. "We need to pay careful attention to the evolution of this virus," says Sasisekharan. Read more...
Influenza A(H1N1): WHO announces pandemic alert phase 6
On June 11th, based on assessment of all available information and following expert consultations, WHO raised the pandemic influenza A(H1N1) alert level from phase 5 to phase 6. WHO stresses that this is not a statement about the severity of the virus, but means there is clear evidence of community-level transmission in multiple countries in regions of the world outside the Americas, where the disease started in April this year.
At present, WHO assesses the severity of this pandemic to be moderate. It advises countries to adapt plans and interventions to the current moderate severity of the pandemic strain and to local conditions of severity and spread.
WHO poised to declare first flu pandemic since 1968
The World Health Organization was poised on Thursday to declare that the new H1N1 virus has caused the first influenza pandemic in more than 40 years, health sources said on Thursday.
The move will trigger heightened health measures in the WHO's 193 member states as authorities brace for the worldwide spread of the virus that has so far caused mainly mild illness.
Flu experts advising WHO Director-General Dr Margaret Chan, who convened at 1000 GMT, were expected to recommend moving to the top phase 6 on the WHO's six-point scale, the sources said.
Influenza A(H1N1) cases reported in over half of European countries
5 June 2009
Since the update of 29 May, Bulgaria, Cyprus, Hungary and Luxembourg have reported new laboratory-confirmed cases of influenza A(H1N1). As of 09:00 Greenwich Mean Time (GMT) on 5 June, 29 of the 53 countries in the WHO European Region had reported a total of 954 cases to WHO/Europe. The number of reported cases nearly doubled between 29 May and 5 June.
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