Avian influenza A(H7N9) and the closure of live bird markets

Manoj Murhekar,Peter Horby,Katejin Vandemaele,Chin-Kei Lee,Yuzo Arima,Sirenda Vong,Feng Zijian,Ailan Li

doi:10.5365/wpsar.2013.4.2.008

Abstract

WPSAR Vol 4, No 2, 2013 | doi: 10.5365/wpsar.2013.4.2.008 www.wpro.who.int/wpsar 1 a Division of Health Securities and Emergencies, World Health Organization Regional Offi ce for Western Pacifi c, Manila, Philippines. b World Health Organization, Geneva, Switzerland. c Emerging Diseases Surveillance and Response, World Health Organization, China Offi ce, Beijing, China. d Chinese Center for Disease Control and Prevention, Beijing, China. * Members of the World Health Organization Regional Offi ce for the Western Pacifi c Event Management Team: Nyka Alexander, Steve Bice, Joy Rivaca Caminade, Xavier Dufrenot, Emily Jane Fearnley, Alice Ruth Foxwell, Nori Isoda, Michelle McPherson, Zu Rongqiang, Tomoe Shimada. Submitted: 8 May 2013; Published: 21 May 2013 doi: 10.5365/wpsar.2013.4.2.008 On 31 March 2013, the National Health and Family Planning Commission, China notified the World Health Organization of three cases of human infection with avian influenza A(H7N9) from Shanghai and Anhui.1 By 8 May, 131 cases, including 26 deaths, had been notified from 11 provinces/ municipalities.1,2 The majority (81%) of reported cases were from Shanghai municipality and Zhejiang and Jiangsu provinces. Available data indicate that more than three quarters of cases (59/77, 76%) had recent exposure to animals. Among these, 58% (34/59) had direct contact with chickens and 64% (38/59) visited a live bird market (LBM).3 Provincial and national authorities in China have collected more than 80 000 samples from LBMs, poultry slaughter houses, poultry farms, wild bird habitats, pig slaughter houses and their environments. As of 7 May, 50 samples were positive for avian influenza A(H7N9): 39 samples from poultry from LBMs in Anhui, Jiangsu, Jiangxi, Guangdong, Shanghai and Zhejiang provinces (26 chickens, three ducks, four pigeons, six unknown) and 11 environmental samples from LBMs in Shanghai, Henan and Shandong provinces.4 None of the samples from poultry farms or pigs were positive.5

Highlights

Data on the background rate of exposure to live bird market (LBM) among the general population in the affected areas are not available
LBMs play a crucial role in the maintenance, amplification and dissemination of avian influenza viruses and are considered high risk locations for potential zoonotic transmission of influenza viruses to humans.[6,7,8]
Following the detection of avian influenza A(H7N9) virus infection in poultry in LBMs in Shanghai on 4 and 5 April 2013, authorities initiated a series of public health measures including: closure of all three LBMs and sale spots on 6 April; culling of all live birds in wholesale markets; safely disposing of culled birds, excreta, polluted feed and water; and disinfection of the materials, transportation and tools in contact with live birds and the market environment.[11]

Summary

Introduction

Data on the background rate of exposure to LBMs among the general population in the affected areas are not available. Following the detection of avian influenza A(H7N9) virus infection in poultry in LBMs in Shanghai on 4 and 5 April 2013, authorities initiated a series of public health measures including: closure of all three LBMs and sale spots on 6 April; culling of all live birds in wholesale markets; safely disposing of culled birds, excreta, polluted feed and water; and disinfection of the materials, transportation and tools in contact with live birds and the market environment.[11] The last case from Shanghai had its onset on 13 April, and since no new cases have been reported from this municipality (Figure 1).

Results

Conclusion