Nov 23, 2011
Study finds flu viruses don't survive long on surfaces
Neither seasonal H1N1 nor pandemic 2009 H1N1 (pH1N1) flu viruses survive on common porous and nonporous surfaces after 24 hours, according to a study by UK scientists. The group applied seasonal H1N1 viruses and pH1N1 viruses to a wide range of surfaces common at home or in the workplace, from fabric to wood to plastics to glass to metal. They found that the genetic material of either virus as determined by polymerase chain reaction could be detected on most surfaces, except for unsealed wood, 24 hours after inoculation with little decline in quantity. In contrast, live virus—as tested by plaque assay (for seasonal H1N1) or fluorescent focus formation (for pH1N1)—was recovered from most surfaces after 4 hours and from some nonporous materials after 9 hours, but by 24 hours it had fallen below detection levels. The team also found that, contrary to previously published data, nonporous materials were not consistently more conducive to virus survival than were porous ones. They conclude that "influenza A transmission via fomites is possible but unlikely to occur for long periods after surface contamination (unless re-inoculation occurs)."
Nov 22 PLoS One study
Birds may be more prone to H5N1 just before migration
Wild birds may be most prone to shedding highly pathogenic avian influenza H5N1 (HPAIV H5N1) virus just before migration but not be more prone to clinical disease at that time, potentially raising the risk of spreading the disease over long distances, according to a study in PLoS One by an international team of researchers. The group studied a subspecies of red knot (Calidris canutus islandica), a shorebird that migrates from the Arctic Circle to Europe. They measured the birds' levels of corticosterone, a hormone that regulates physiologic changes as birds prepare for migration, and inoculated them with HPAIV H5N1 before migration, during fueling (as they prepare for migration), just before migration departure, and after migrating. They inoculated five to nine birds at each stage. They found that, of the birds inoculated just before migration, those that had higher plasma corticosterone levels and thus were more ready for take-off, shed more virus but did not tend to develop clinical disease. "Therefore," they write, "assuming no effect of sub-clinical infection on the likelihood of migratory take-off, [these findings] may favor the spread of HPAIV H5N1 by migratory birds over long distances."
Nov 22 PLoS One study
Measles cases in Europe top 30,000
More than 1,000 new cases of measles have been confirmed in Europe in the past month, bringing the continent's total cases in 2011 to more than 30,200, according to a monthly update today from the European Centre for Disease Prevention and Control (ECDC). The report said, though, that no cases in October were linked to outbreaks of the disease. The agency also reported two cases of subacute sclerosing panencephalitis, a late, often fatal, complication of measles. One of those patients died. The ECDC also noted that it now monitors surveillance across Europe for measles and other vaccine-preventable diseases, a function that used to be performed at the Statens Serum Institut in Denmark.
Nov 23 ECDC press release
Nov 23 ECDC report
Bangladesh reports chikungunya outbreak
Bangladesh has confirmed 46 cases of chikungunya, according to the country's online news service, bdnews24, today. The cases—31 in Dohar, 12 in Chapai Nawabganj, and 3 in Dhaka city—were confirmed using laboratory testing. Health officials warned people to protect themselves from Aedes aegypti mosquitoes, which transmit the virus that causes the disease, manifested by fever and crippling joint pain. Bangladesh reported its first case of chikungunya in 2008, according to the story.