Vietnam reports H5N1, H5N6 outbreaks; Hong Kong finds H5 in songbird
Vietnam reported small outbreaks of H5N1 and H5N6 avian flu in backyard poultry flocks, according to reports posted yesterday by the World Organization for Animal Health (OIE), while Hong Kong officials said they had detected an H5 avian flu virus in a dead Oriental magpie robin.
The H5N1 outbreak in Vietnam began Nov 11 in Ca Mau province in the south. Of 600 susceptible birds, 94 died from the virus, and the rest were culled to contain the outbreak.
The H5N6 outbreak began Nov 16 in Son La province in the north. That backyard flock had 100 deaths among 326 poultry, and the rest were euthanized. Response steps like disinfection and control of bird movement have begun in response to both outbreaks.
In Hong Kong, meanwhile, the Agriculture, Fisheries and Conservation Department (AFCD) said preliminary testing revealed that the dead magpie robin was infected with an H5 strain of avian flu, and confirmatory tests are under way.
The bird was found on the second floor of a public housing development in Hong Kong's Kwai Chung area of Kwai Tsing district. An AFCD spokesman said the area where the dead bird was found has been disinfected, and area farmers notified. The agency said there are no farms within 3 kilometers of the housing complex.
Nov 18 Hong Kong press release
Study: 4-strain nasal-spray flu vaccine 82% effective against 1 'B' strain
Quadrivalent (four-strain) live attenuated influenza vaccine (LAIV, which is administered via nasal spray) showed 82% protection against flu B/Yamagata strains in children but none against 2009 H1N1 in the 2013-14 flu season, while cases of H3N2 and B/Victoria flu were too few for determining effectiveness for those strains, according to a Nov 14 study in Vaccine.
US investigators analyzed data on 1,033 children and adolescents, among whom 145 (14%) developed lab-confirmed influenza. Of those cases, 108 (74%) were caused by 2009 H1N1, 31 (21%) by B/Yamagata, and 6 (4%) by H3N2, which, like H1N1, is an "A" strain.
LAIV showed no protection against 2009 H1N1 but 82% effectiveness against B/Yamagata, though numbers of cases for that strain were fairly small. The study also found that inactivated flu vaccine—the flu shot—was 70% effective against the Yamagata strains and 74% effective against 2009 H1N1.
The authors recommended a different H1N1 strain be used for subsequent LAIV compositions.
Nov 15 Vaccine study