Rural villagers and urban residents exposure to poultry in China.

Zhibin Peng,Jianhua Lu,Lei Zhou,Hang Zhou,Qiaohong Liao,Xiaomin Wu,Weike Su,Leilei Li,Peng Wu,Zhangda Yu,Min Ye,Shunxiang Zhang,Hongjie Yu,Jiabing Wu,Benjamin J Cowling,Ying Shi,R Fielding ,Xin Cheng ,Гэ Ли ,Hongxia Ma

doi:10.1371/journal.pone.0095430

Abstract

Patterns of poultry exposure in rural and urban areas in China have not been systematically evaluated and compared. The objective of our study is to investigate patterns in human exposure to poultry in rural and urban China. We conducted a two-stage household-based clustered survey on population exposure to live/sick/dead poultry in Xiuning and Shenzhen. Half of the rural households (51%) in Xiuning raised poultry, mostly (78%) free-range. Around half of those households (40%) allowed poultry to stay in their living areas. One quarter of villagers reported having contact with sick or dead poultry. In Shenzhen, 37% urban residents visited live poultry markets. Among these, 40% purchased live poultry and 16% touched the poultry or cages during purchase. Our findings indicated that human exposure to poultry was different in rural and urban areas in China. This discrepancy could contribute to the observed differences in epidemiologic characteristics between urban and rural cases of influenza A(H7N9) and A(H5N1) virus infection.

Highlights

The highly pathogenic avian influenza (HPAI) virus, A (H5N1) [1], caused 630 confirmed human cases and 375 deaths in 15 countries as of June 4, 2013 [2]
Case-control studies and case investigations conducted during the 1997 outbreak in Hong Kong Special Administrative Region (SAR) of China [10], Thailand [11], Vietnam [12], Indonesia [5], [7], [9], Egypt [13] and Mainland China [14] during 2004–2009 revealed that visiting a live poultry market and direct contact with sick or dead poultry one week before illness onset were risk factors for H5N1 virus infection
In China, two patterns of exposure to birds were identified among the human cases: in rural environments, villagers raise backyard poultry for food production and income and exposure is primarily associated with the backyard poultry, whereas in urban areas exposure primarily occurs in live poultry markets where poultry is purchased alive or freshly slaughtered [14], [18]

Summary

Introduction

The highly pathogenic avian influenza (HPAI) virus, A (H5N1) [1], caused 630 confirmed human cases and 375 deaths in 15 countries as of June 4, 2013 [2]. Environment-to-human transmission remains a possibility for some human H5N1 cases without an identified exposure source [5], [9]. Of the 37 confirmed human H5N1 cases reported in China, 36 were identified through surveillance systems [15] from October 2005 [16] through August 2009 [2]. In China, two patterns of exposure to birds were identified among the human cases: in rural environments, villagers raise backyard poultry for food production and income and exposure is primarily associated with the backyard poultry, whereas in urban areas exposure primarily occurs in live poultry markets where poultry is purchased alive or freshly slaughtered [14], [18]

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