Live poultry market closures also remove a traditional dish of fresh cooked chicken. One can be certain that no-one will die because of the substitution of frozen or factory prepared chicken for a fresh chicken, even if chefs don't succumb to the tantrums of last year and refuse to prepare dishes made from anything but fresh market-selected poultry. One can be equally certain that if the markets remain operating during the peak season for influenza virus circulation as they have been, that human infections, and deaths, due to H7N9 infections, will also continue
Guangdong province has been a major source of human H7N9 cases in 2015. |
Why does this closure in Guangdong matter?
Guangdong province has been a major source of human H7N9 cases this year, as it was in 2014. If we look at the activity under the outbreak curves, we can see the brown line of Guangdong cases has been prominent in both years, only brought under control last year after the closure of the poultry markets...although their temporary closure may have been the reason for the long tail on Outbreak #2's epidemic curve compared to Outbreak #1. Will that tailing happen again in 2015 because Guangdong's markets are only being closed for a short period? Time will tell.
Occurring at a similar time is the change in seasons. Seasonal change towards summer, makes the survival of influenza viruses in the environment more difficult. It's hard to tease out any one main cause of the precipitous case decline; the market closures or the seasons changing or both. Because most H7N9 human cases have exposure to poultry listed among their details when they are passed along and posted by the World Health Organization, live poultry markets clearly are one major factor for human acquisition of infection. There is literature that agrees.[3,4,5]
The activity under the epidemic curves for each of the three outbreaks. Guangdong province-acquired human cases are indicated by the brown line and features in 2014 and 2015. |
References...
- http://news.xinhuanet.com/english/china/2014-02/15/c_126138118.htm
- http://www.thepoultrysite.com/poultrynews/33938/guangdong-restricts-poultry-markets-over-bird-flu-fears
- http://www.ncbi.nlm.nih.gov/pubmed/25340354
- http://wwwnc.cdc.gov/eid/article/20/12/14-0765_article
- http://jvi.asm.org/content/88/6/3423.long