Man dies of H5N1 in Vietnam
A 52-year-old man in the southern province of Binh Phuoc has died of H5N1 avian flu, the first case in Vietnam in 9 months, Than Nien News reported today.
The man was hospitalized at Bu Dang District's General Hospital with a fever, cough, and difficulty breathing on Jan 11, the country's health ministry reported. As his situation deteriorated, he was transferred to the Hospital for Tropical Diseases in Ho Chi Minh City on Jan 18 and died the same day. His samples later tested positive for H5N1.
Officials said the man's family had killed and eaten duck recently and that chickens in a nearby home had recently died suddenly. His case, if confirmed by the World Health Organization, would bring the country's official H5N1 total to 126 cases and 63 deaths since the disease was first detected there in 2003.
Jan 21 Than Nien report
Study suggests match of flu vaccine to circulating virus is important
Canadian researchers who studied influenza vaccine effectiveness (VE) for the 2011-12 season found that the vaccine was much more effective against circulating flu strains closely matched to those in the vaccine than against those not so well matched, according to a recent report in the Journal of Infectious Diseases.
Influenza experts try to predict each year which flu strains will be most common during the winter flu seasons and endeavor to pick the vaccine strains accordingly. But the evidence for the importance of a close match between vaccine and circulating strains has not been entirely consistent.
A team from across Canada conducted the test-negative case-control study, which involves assessing vaccination coverage and infection prevalence in patients who seek treatment for a flu-like illness and are tested for the virus. Danuta Skowronski, MD, of the British Columbia Centre for Disease Control and Prevention served as lead author.
The report notes that the trivalent inactivated vaccine (TIV) used in the 2011-12 season targeted the same three flu strains as the 2010-11 vaccine. The authors used hemagglutination inhibition and sequencing of parts of the hemagglutinin gene to characterize the circulating flu strains. The study included 1,507 patients.
The authors calculated that VE against the circulating 2009 H1N1 virus—which had only two amino acid (AA) differences from the vaccine strain—was 80% (95% confidence interval [CI], 52%-92%). In contrast, VE against circulating H3N2 strains, which had 11 or more AA differences from the vaccine strain, was 51% (95% CI, 10%-73%)
Overall VE against influenza B was 51% (95% CI, 26%-67%), but it differed according to the B lineage. The vaccine was 71% effective (95% CI, 40%-86%) against the Victoria lineage, which was contained in the vaccine, but only 27% effective (95% CI, 21%-56%) against the Yamagata lineage, which was not in the vaccine.
The team also found that VE was similar among recipients of either the 2010-11 or 2011-12 vaccine alone but was higher in those who were vaccinated in both seasons.
Jan 19 J Infect Dis report
H5N8 outbreak spreads on South Korea duck farms
Ducks on a farm in the South Korean city of Jeoneup in the southwestern province of Jeollabuk-do are suspected of being infected with the highly pathogenic H5N8 strain of avian influenza, as a recent outbreak spreads, according to a story from Arirang News today. This would represent the fifth farm infected recently and the first one outside of Gochang and Buan counties in the province.
In Gochang county, a poultry farm identified 10 cases, including 3 deaths, of H5N8 in ducks and has destroyed 21,180 susceptible birds, according to a World Organization for Animal Health (OIE) notice late last week. An epidemiologic survey is being implemented. Control measures include quarantine and disinfection of the infected premises.
The virus is thought to be spread by wild migratory birds from Russia that typically visit South Korea from October through March. An article yesterday in the Wall Street Journal (WSJ) Asia says H5N8 was found in the remains of 100 dead migratory birds in a reservoir near the Gochang farm. The wild ducks are Baikal teals.
The Korean Ministry of Agriculture, Food and Rural Affairs announced today that all ducks within a 3-kilometer radius of infected farms are to be destroyed, a far larger area than had been declared earlier, says the Arirang story; chickens are excluded from the order.
Jan 21 Arirang News story and video
Jan 18 OIE notice of latest Gochang outbreak
Jan 20 WSJ article