May 10, 2012
Study finds few subclinical H5N1 cases in poultry workers
Only 9 of 2,512 poultry workers (0.4%) exposed to H5N1 avian influenza during a 2003-04 outbreak in South Korea had antibodies to the virus, according to a study published yesterday in Emerging Infectious Diseases. From December 2003 through March 2004, workers culled about 5 million chickens and ducks after 19 H5N1 outbreaks in seven provinces. As reported in the study, South Korean and US investigators analyzed serology samples from 2,512 workers who culled poultry or worked on the affected farms, both high-risk groups. Using laboratory tests and case definitions recommended by the World Health Organization, the team found that nine workers—all cullers—had antibodies to H5N1. Although the authors list study limitations, including limited epidemiologic data, they conclude, "We determined that the risk for poultry-to-human transmission of the influenza (H5N1) virus is small. Other studies have also shown low frequencies of poultry-to-human (H5N1) virus transmission."
May 9 Emerg Infect Dis study
H5N2 strikes another South African ostrich farm
Agriculture officials in South Africa today reported that highly pathogenic H5N2 avian influenza has turned up on another commercial ostrich farm. At first, no clinical signs were found, but the report said 98 cases with no deaths were detected among 310 susceptible birds. Culling operations at the farm, located in Western Cape province, are under way. Yearlong culling activities prompted by H5N2 outbreaks have decimated South Africa's ostrich flocks over the past year, according to a report today in Business Day, a national daily newspaper based in Johannesburg. The area where the outbreaks have occurred supplies about 70% of the world's ostrich meat, according to the report.
May 9 OIE report
May 10 Business Day story
In Norwegian study, 40% had antibodies to H3N2 variant
Seroprevalence to variant H3N2 flu (H3N2v) was 40% overall in Norwegians but much lower in young children and those 45 to 54 years old, according to a report today in Eurosurveillance. Last year and this year 13 US cases of H3N2v have been confirmed, primarily in children who had contact with pigs, but the strain has not been identified in Europe. To assess the risk of H3N2v in Norway, researchers analyzed 253 serum samples taken last August in three different areas of the country. They found the overall seroprevalence (based on a hemagglutinin inhibition titer of 40 or higher) to be 40%, but it ranged from 0% in children 12 and younger to 71% in adults 18 to 34. The breakdown by age-group was: 0-12, 0%; 13-17, 16%; 18-24, 71%; 25-34, 71%; 35-44, 28%; 45-54, 14%; 55-64, 41%; 65-74, 50%; 75-97, 53%. The size of the subgroups varied from 17 to 47 samples. The investigators said their findings are similar to those reported by a Canadian team in Eurosurvillance on Jan 26 and by US researchers in Morbidity and Mortality Weekly Report (MMWR) last month. They write, "More research is needed to explain the poor immunity in 45- to 54-year-olds."
May 10 Eurosurveillance study
Jan 26 Eurosurveillance Canadian report
Apr 12 CIDRAP News story on MMWR report
Study profiles 2009 H1N1 neurologic complications
An analysis of neurologic complications in California patients who had severe or fatal 2009 H1N1 infections found that the conditions were more common in children and Asian/Pacific Islanders than in the state's general population, according to a report yesterday in Clinical Infectious Diseases. The study team included researchers from the California Department of Public Health and the US Centers for Disease Control and Prevention. Of 2,069 severe or fatal cases reported in California from April through December 2009, 3.7% were classified as having one of four primary influenza-related neurologic complications: encephalopathy/encephalitis, seizures, meningitis, and other, such as Guillain-Barre syndrome. The frequency was consistent with smaller published case studies. However, no California children with 2009 H1N1 died from encephalopathy, which was the leading cause of death in Japanese children with the disease. Most patients who had encephalopathy recovered and returned to baseline. The group noted that the higher rates in Asian/Pacific Islanders hasn't been reported in the United States before, and factors such as genetic predisposition should be explored.
May 9 Clin Infect Dis abstract
Haiti still ill-prepared to deal with cholera, aid group says
With Haiti's rainy season under way and cholera on the rise again, the medical aid group Medecins Sans Frontieres (MSF) says the country remains inadequately prepared to fight the disease. Health facilities in many regions are still incapable of responding to the seasonal fluctuations of cholera, although the Haitian Ministry of Health and Populations claims the situation is under control, MSF said in a statement today. The group said it treated 1,600 cases in Port-au-Prince in April, marking a fourfold increase in less than a month. An MSF study in the Artibonite region showed a clear reduction in cholera prevention activities since 2011, with more than half of the organizations that were working in the region last year now gone and with some health centers short of drugs and some staff members unpaid since January, the group said. Maya Allan, an MSF epidemiologist, said that as soon as the rainy season ends and cholera levels subside, funding dries up, even though sustained funding is needed for long-term prevention efforts. "The majority of Haitians do not have access to latrines, and obtaining clean water is a daily challenge," MSF said. "Of the half-million survivors of the January 2010 earthquake who continue to live in camps, less than one third are provided with clean drinking water and only 1% recently received soap." Since cholera emerged in Haiti in October 2010, the country has had about 535,000 cases and more than 7,000 deaths, the statement said.
May 10 MSF statement