Nov 10, 2010
Second 2009 pandemic flu wave saw single viral lineage dominate
A phylogeographic analysis of the two waves of pandemic 2009 H1N1 influenza showed that the second wave was dominated by a single viral lineage in three US regions, whereas the first wave saw a more genomically diverse attack. Researchers analyzed genomic and epidemiologic data from the first pandemic wave (March through July 2009) and second wave (beginning in August 2009) in Houston, Milwaukee, and New York state. The found that no single viral lineage dominated in the spring in Houston, but that Texas was experiencing low flu activity at that time. Milwaukee and New York, however, were seeing widespread outbreaks, and each area was dominated by a different viral lineage. During the fall, which saw increased activity throughout the country, the scientists reported, "All three US localities were dominated by a single viral lineage, that which had been dominant in New York during wave 1." The authors attribute this effect to "extensive global migration and increased spatial mixing."
Nov 10 J Virol abstract
Study: Telephone triage helped clinics manage pandemic surge
In one of the first studies of its kind, researchers from the Mayo Clinic assessed the effect of telephone triage in a primary care setting during the 2009 H1N1 pandemic and found that it helped manage the surge during the fall illness peak without shifting the burden to emergency departments. The findings appeared Nov 8 in an early online release by Telemedicine and e-Health. The nurse-directed telephone triage system included computerized decision support and covered three primary care divisions at Mayo's Rochester, Minn., campus: internal medicine, pediatrics and adolescent medicine, and family medicine. Nurses were able to give callers information about pandemic flu and make recommendations, including oseltamivir for some patients, for those who fit the flu criteria. The researchers looked at all calls to the service from July 2009 through January 2010. They found that call volume during the peak pandemic flu months was 56% higher than nonpeak months. Nurses prescribed oseltamivir to 5.4% of callers. In October, the peak month, nurses advised about 3,200 callers to stay home, of whom only about 1,500 had intended to stay home before the telephone triage. During the peak pandemic months Mayo's primary care clinics were able preserve about 5% of their appointment capacity. The study group concluded that the phone triage system met the acute flu demands while preserving medical access for other patients.
Nov 8 Telemed e-Health abstract
WHO says overall global flu activity remains low
Influenza activity has remained low in most regions of the world in recent weeks, though Southeast Asia, tropical areas of the Americas, and parts of southern Africa continue to report cases, according to the World Health Organization's (WHO's) latest flu update. Flu activity has returned to near or below baseline in temperate areas of the Southern Hemisphere, following late winter and springtime epidemics, the WHO said. Thailand is the most active area for flu in Southeast Asia, with influenza A/H3N2, 2009 H1N1, and influenza B viruses all circulating. In tropical areas of the Americas, flu has declined substantially after epidemics in late summer and early fall. A post-season increase in 2009 H1N1 cases has been seen recently in parts of southern Africa, the WHO said. In Zimbabwe, the health ministry said 15,241 H1N1 cases have been reported since mid October, according to a report today from The Herald, a government-sponsored news site. A government epidemiologist said about 80% of the cases have been in children under age 5. Virologic testing shows that H3N2 viruses continue to be the predominant subtype globally, according to the WHO.
Nov 8 WHO flu update
Nov 10 Herald story
European findings show westward spread of H5N1 avian flu strain
The detection of highly pathogenic H5N1 influenza viruses in poultry and wild birds in Eastern Europe earlier this year marked the first European appearance of H5N1 clade 2.3.2, according to a report by an international team of researchers in Transboundary Emerging Diseases. Previous European detections of H5N1 viruses in birds have exclusively involved clade 2.2, the report says. Clade 2.3.2 viruses were found in March in hens from three flocks in Romania and in a buzzard on the Black Sea coast in Bulgaria. The clade appears to be spreading westward, having been found in wild waterfowl in Mongolia and eastern Russia in mid 2009, the researchers write. They say the level of threat posed by the clade is uncertain.
Nov 5 Transbound Emerg Dis study abstract