Dec 22, 2011
Bangladesh confirms four recent H5N1 outbreaks
Bangladesh has confirmed four H5N1 avian flu outbreaks in November and December that killed 1,257 poultry and led to culling 13,727 others, according to a report filed with the World Organization for Animal Health (OIE) yesterday. All the outbreaks were on commercial farms. The first, in the Rajbari district of Dhaka division, began Nov 12 and killed 270 birds. The remaining 11,230 of the flock of 11,500 were culled to prevent disease spread. The second outbreak began Nov 23 and led to 572 poultry deaths, with the remaining 1,532 birds destroyed in Manikganj district of Dhaka division, which borders Rajbari district to the east. The most recent two outbreaks were in Khulna division, which adjoins Dhaka to the southwest. In those, H5N1 killed 95 birds with 565 culled in Khulna district starting Dec 10 and killed 320 birds with 400 culled in the adjacent Bagerhat district starting Dec 18. Officials have applied infection-control measures such as disinfection on the affected farms, the OIE report said.
Dec 21 OIE report
Ethicists suggest framework for considering vaccine evidence
Vaccine policymaking in the United States could benefit from a more systematic ethical foundation when evidence-based medicine tools are used to make decisions about vaccines, according to a report in Vaccine yesterday by two medical ethics experts. The authors are Dr Robert Field, with Drexel University's schools of law and public health, and Dr Arthur Caplan, with the University of Pennsylvania. They noted that ethical considerations that typically assist with making evidence-based medical decisions don't always fit well with prevention goals. Rule-utilitarianism often underpins evidence-based medicine, which can ignore other considerations that carry ethical weight, they wrote, such as fair allocation of resources and autonomy. Vaccine consideration requires weighing social norms and values in a way that treatment issues don't, and Field and Caplan emphasized that an evidence-based medicine framework doesn't always consider the suffering caused by a condition. Though ethical-based considerations are difficult to quantify, a better foundation that uses a multifaceted set of outputs, rather than a single number such as a cost-benefit ratio, might be useful, they argued. They wrote that one approach could be a graphical analysis that incorporates different relevant considerations, similar to what Britain's health ministry uses for its evidence-based policies for medications.
Dec 21 Vaccine abstract
Group proposes vaccine failure definitions
A working group with the Council for International Organizations of Medical Sciences and the World Health Organization yesterday proposed general definitions for different types of vaccine failure that they said could be used to assess and compare the benefits of vaccines in different populations. The group discussed the difference between vaccine failure and failure to vaccinate and suggested different definitions for confirmed vaccine failure, suspected vaccine failure, confirmed immunologic vaccine failure, and suspected immunologic vaccine failure. They wrote that the definitions could be a starting point and that more specific definitions are needed for difference vaccines.
Dec 21 Vaccine abstract