Nov 30, 2010
H5N1 suspected in Japanese poultry outbreak
Animal health officials in Japan suspect an H5N1 outbreak at a poultry farm in Shimane prefecture, located in the western part of the country, Agence France-Presse (AFP) reported today. Preliminary tests, conducted after five chickens were found dead, revealed the H5 subtype. Veterinary authorities have begun culling the farm's remaining 23,000 birds to control the spread of the virus, according to the report. The H5N1 virus was last detected in Japan in 2009 in a small number of swans found sick or dead on the shores of Lake Towada in Akita prefecture, according to reports from the World Organization for Animal Health (OIE).
Flu activity increases in Southeastern US
US flu activity remained low but showed an increase in the Southeast, according to the latest report from the Centers for Disease Control and Prevention (CDC). Data showed that, for the week ending Nov 20, Georgia became the first state this flu season to report regional flu activity, while Alabama, Hawaii, Mississippi, Oklahoma, Pennsylvania, Puerto Rico, South Carolina, and Texas reported local activity. Thirty-four states or territories reported sporadic activity, and 11 states reported no activity. Two flu-related deaths were reported nationwide, but the proportion of deaths attributed to pneumonia and influenza remained below the epidemic threshold. Likewise, the proportion of outpatient visits for flu-like illness was 1.4%, below the national baseline of 2.5%. Of 2,896 respiratory samples tested, 284 (9.8%) were positive for influenza. Of those, 169 (59.5%) were influenza B and 115 (40.5%) were influenza A. Of the 30 influenza A samples that were subtyped, 9 were determined to be 2009 pandemic H1N1, and 21 to be an H3 subtype, presumably H3N2. Circulating strains appear to be well-matched to the vaccine strains.
Latest CDC FluView report
CDC weekly flu map
Theater chain pulls anti–flu vaccine ad
AMC Theatres turned away an advertisement produced by anti-vaccine groups before it aired during the holidays after an outcry from two science blogs and their readers, Forbes reported yesterday. The ad, sponsored by the anti-vaccine groups Safe Minds and Age of Autism, was intended to warn moviegoers about flu vaccines that contain thimerosal, which they believe is linked to autism. Studies published in the medical literature have revealed no link between the vaccine preservative and autism. Science blogs SkepChick and Respectful Insolence drew attention to the group's plans and rallied readers to voice their objections to AMC.
Nov 29 Forbes story
Researchers report transmission of pandemic H1N1 to dogs
Writing in Emerging Infectious Diseases, Italian scientists reported finding evidence of pandemic 2009 H1N1 influenza infection in dogs. They studied serum specimens from 964 dogs and 97 cats that were submitted from October through December 2009 for assessment of rabies vaccine efficacy. An average of 70 samples were tested per week; the highest number of samples (n = 106) was tested for week 51 and the lowest (n = 25) for week 53. Of the canine samples, 7 (0.7%) tested positive for pandemic 2009 H1N1, while none of the feline samples did. All positive samples were collected during weeks of high human transmission of the virus, which suggests transmission from owners to dogs via aerosol or close contact, the authors write. They conclude that, while it is unrealistic to infer that dogs are "particularly susceptible" to novel H1N1, "Influenza A viruses are quite capable of evolving and becoming more host specific. This factor alone would justify the continued surveillance of influenza A viruses in domestic dogs."
Dec Emerg Infect Dis letter
Study maps pandemic Twitter traffic
Toronto researchers who analyzed the volume and content of Twitter traffic during the 2009 H1N1 pandemic found that news and information were the most common tweet topics and that patterns varied over the course of the pandemic. Their report appeared yesterday in Public Library of Science (PLoS) One. Using both automated and manual systems, they looked at a random sample of about 5,400 tweets from more than 2 million that appeared between May 1 and Dec 31, 2009. They found that the posts' wording evolved from "swine flu" to the preferred "H1N1" terminology and that public health events such as the World Health Organization's pandemic declaration and major news stories prompted spikes in tweets. Information on protective behaviors peaked as the outbreak threat increased, and reports of personal experiences with the flu rose during the two pandemic waves. News Web sites were the most popular sources cited (23.2%), and only 4.5% of tweets were identified as misinformation. The investigators concluded that social media such as Twitter are useful for gauging knowledge during public health events.
Nov 29 PLoS One study