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. 2014 Sep 12;9(9):e107266.
doi: 10.1371/journal.pone.0107266. eCollection 2014.

Detection of avian influenza A(H7N9) virus from live poultry markets in Guangzhou, China: a surveillance report

Zongqiu Chen  1 , Kuibiao Li  1 , Lei Luo  1 , Enjie Lu  1 , Jun Yuan  1 , Hui Liu  1 , Jianyun Lu  1 , Biao Di  1 , Xincai Xiao  1 , Zhicong Yang  1
Affiliations

Detection of avian influenza A(H7N9) virus from live poultry markets in Guangzhou, China: a surveillance report

Zongqiu Chen et al. PLoS One. .

Abstract

Purpose: A virologic surveillance program for A(H7N9) virus was conducted from April 15, 2013 to February 14, 2014 in Guangzhou, aiming to clarify the geographical distribution of A(H7N9) viruses among live poultry markets (LPMs) and poultry farms in Guangzhou. Virological and serological surveys of poultry workers were also conducted to evaluate the risk of poultry-to-human transmission of the A(H7N9) virus.

Methods: 36 retail LPMs, 6 wholesale LPMs and 8 poultry farms were involved in our surveillance program. About 20 live poultry and environmental samples were obtained from each surveillance site at every sampling time. Different environmental samples were collected to represent different poultry-related work activities. RT-PCR and virus culture were performed to identify the A(H7N9) virus. Hemagglutinin inhibition assay and RT-PCR were conducted to detect possible A(H7N9) infection among poultry workers.

Results: A total of 8900 live poultry and environmental samples were collected, of which 131(1.5%) were tested positive for A(H7N9) virus. 44.4% (16/36) of retail LPMs and 50.0% (3/6) of wholesale LPMs were confirmed to be contaminated. No positive samples was detected from poultry farms. A significant higher positive sample rate was found in environmental samples related to poultry selling (2.6%) and slaughtering (2.4%), compared to poultry holding (0.9%). Correspondingly, A(H7N9) viruses were isolated most frequently from slaughter zone. In addition, 316 poultry workers associated with the 19 contaminated-LPMs were recruited and a low seroprevalence (1.6%) of antibody against A(H7N9) virus was detected. An asymptomatic A(H7N9) infection was also identified by RT-PCR.

Conclusions: Our study highlights the importance of conducting effective surveillance for A(H7N9) virus and provides evidence to support the assumption that slaughtering is the key process for the propagation of A(H7N9) virus in retail LPMs. Moreover, the ability of A(H7N9) virus to cross species barrier is proved to be still limited.

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Conflict of interest statement

Competing Interests: The authors have declared that no competing interests exist.

Figures

Figure 1
Figure 1. Enrollment of surveillance sites of the virologic surveillance program for A(H7N9) in Guangzhou, China.
Figure 2
Figure 2. The general routes of live poultry transmission in Guangzhou, China.
Figure 3
Figure 3. Geographic distribution of surveillance sites of the virologic surveillance program for A(H7N9) in Guangzhou, China, April 15, 2013 to February 14, 2014.
See this image and copyright information in PMC

References

    1. Yu H, Cowling BJ, Feng L, Lau EH, Liao Q, et al. (2013) Human infection with avian influenza A H7N9 virus: an assessment of clinical severity. Lancet 382: 138–145. - PMC - PubMed
    1. Gao R, Cao B, Hu Y, Feng Z, Wang D, et al. (2013) Human infection with a novel avian-origin influenza A (H7N9) virus. N Engl J Med 368: 1888–1897. - PubMed
    1. WHO Risk assessment: Human infections with avian influenza A(H7N9) virus. Available: http://www.who.int/influenza/human_animal_interface/RiskAssessment_H7N9_.... Accessed 2014 Jan 21.
    1. Li Q, Zhou L, Zhou M, Chen Z, Li F, et al. (2014) Epidemiology of human infections with avian influenza A(H7N9) virus in China. N Engl J Med 370: 520–532. - PMC - PubMed
    1. Shortridge KF, Stuart-Harris CH (1982) An influenza epicentre? Lancet 2: 812–813. - PubMed

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