The World Health Organization have announced that a further four patients in China have been diagnosed with new avian influenza A strain H7N9. This brings the total number of WHO-confirmed cases in China to 11, including 5 deaths. However, the WHO report that there is so far no evidence of human-to-human transmission.
The virus appears to infect some birds without causing any noticeable symptoms. As such, the source of infection could be difficult to track. “We speculate that when this virus is maintained in poultry the disease will not appear, and similar in pigs, if they are infected, so nobody recognizes the infection in animals around them, then the transmission from animal to human may occur,” said Dr. Masato Tashiro, director of the World Health Organization’s influenza research centre in Tokyo. “In terms of this phenomenon, it’s more problematic.”
Influenza A H7 viruses normally circulate among birds. While other H7 viruses (H7N2, N7N3 and H7N7) viruses have occasionally infected humans, these recent cases in China are the first reports of human infection with the H7N9 subgroup.
No vaccine is currently available for the prevention of influenza A (H7N9), but the CDC have announced that they are following the situation closely and gathering information to develop a candidate vaccine virus. Production of a vaccine against the virus may however mean sacrificing production of the seasonal flu vaccine, potentially leading to a shortage of normal seasonal flu vaccine stocks. Sanofi Pasteur are reportedly in contact with the WHO but say it is too soon to know the significant of the Chinese cases.
Reuters report that Chinese authorities have slaughtered over 20,000 birds at a poultry market in Shanghai after the H7N9 virus was detected in samples from pigeons in the market.
What do you think? Do you think that H7N9 is likely to pose a serious health threat? Do you think we are ready to develop a vaccine rapidly enough in the event of a pandemic? Or do you think there's too much concern being placed on these new case reports?
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Watch the video > Preventing epidemics, the virus hunt continues – Joseph Fair to hear about discovery of new viruses â new technologies and how they prevent global pandemic outbreaks, new approaches to epidemiology research, and early warning systems and the crucial role of preventative vaccines.
If you'd like to hear more about strategy and innovation in vaccines, including several talks on the influenza vaccine landscape and influenza vaccine development, you might be interested in attending the World Vaccine Congress & Expo 2013, 16-18 April 2013, at the Gaylord National Hotel and Convention Center, Washington DC.