Zoonoses and wet markets: beyond technical interventions
Authors: Tony Barnett, Guillaume Fournié
Journal: The Lancet Planetary Health (2021)

Following initial suspicions that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) might have emerged in a wet market in Wuhan, China, calls have been made to ban wet markets1The Lion CoalitionOpen letter to the World Health Organization.https://lioncoalition.org/2020/04/04/open-letter-to-world-health-organisation/Date: April 4, 2020Date accessed: October 20, 2020Google Scholar or implement technical interventions mitigating disease risk while minimising business disruptions.2Nadimpalli ML Pickering AJ A call for global monitoring of WASH in wet markets.Lancet Planet Health. 2020; 4: e439-e440Summary Full Text Full Text PDF PubMed Scopus (15) Google Scholar Regardless of the role of wet markets in the emergence of SARS-CoV-2, they do pose public health threats and should be targeted by disease control interventions. A recent Comment in The Lancet Planetary Health2Nadimpalli ML Pickering AJ A call for global monitoring of WASH in wet markets.Lancet Planet Health. 2020; 4: e439-e440Summary Full Text Full Text PDF PubMed Scopus (15) Google Scholar called for "standardised global monitoring of water, sanitation, and hygiene (WASH) conditions" in such markets. Monitoring is one thing, but the way forward to sustainable change does not lie with standardised interventions in isolation. As shown with the response to the threat of avian influenza virus (AIV), local context and detailed understandings are crucial in effective responses.3Fournié G Høg E Barnett T Pfeiffer DU Mangtani P A systematic review and meta-analysis of practices exposing humans to avian influenza viruses, their prevalence, and rationale.Am J Trop Med Hyg. 2017; 97: 376-388Crossref PubMed Scopus (17) Google Scholar Novel disinfection programmes, separating poultry species, and limiting the length of poultry stay successfully reduced AIV prevalence in the specific political circumstances of Hong Kong live bird markets. Yet, the transfer of those interventions to other lower income and quite different political settings was less effective. Although WHO guidelines4WHOA guide to healthy food markets. World Health Organization, Geneva2006Google Scholar recommended desirable practices in food markets and their promotion through awareness and education programmes, an evaluation of these interventions did not find substantial changes.5UNICEF BangladeshEvaluation of avian influenza communications for development initiative: improving biosecurity in live bird market. Lessons learned report. Centre for Communicable Diseases, Dhaka2014Google Scholar Our and others' recent studies in Bangladesh revealed that there was no difference in the prevalence of AIVs in poultry6Biswas PK Giasuddin M Nahar N Islam MZ Yamage M Biosecurity and circulation of influenza A(H5N1) virus in live-bird markets in Bangladesh, 2012.Transbound Emerg Dis. 2017; 64: 883-891Crossref PubMed Scopus (25) Google Scholar or in the practices of workers for food markets that had or had not benefitted from UN-funded biosecurity-upgrading programmes. The needs of retailers and butchers to assure income in the immediate term and show confidence to consumers about their stock, as well as long standing practices of workers, all contributed to risky behaviours. Together, these factors resulted in low uptake of personal protective equipment, disinfection programmes, and desirable poultry management practices. Similar observations were made on backyard farms.7Rimi NA Sultana R Ishtiak-Ahmed K et al.Understanding the failure of a behavior change intervention to reduce risk behaviors for avian influenza transmission among backyard poultry raisers in rural Bangladesh: a focused ethnography.BMC Public Health. 2016; 16: 858Crossref PubMed Scopus (13) Google Scholar Of course, hand washing, toilet facilities, and water supplies are important parts of the response, but perhaps not the most important parts. Behaviour change can only be enforced through regulation if national and local social, cultural, and financial factors—the social and economic structures constraining behaviours—are understood and addressed. If this is not done, interventions will probably fail. The key to the problem lies in structural interventions that are informed by detailed knowledge of local situations, of what is happening on the ground—however wet and slippery that ground may be! Zoonotic disease emergence and transmission will not be stopped by one-size-fits-all interventions across a diverse range of settings and, in any given setting, across a diverse range of actors. Beliefs and practices along poultry trading networks are heterogeneous.8Høg E Fournié G Hoque MA Mahmud R Pfeiffer DU Barnett T Competing biosecurity and risk rationalities in the Chittagong poultry commodity chain, Bangladesh.BioSocieties. 2019; 14: 368-392Crossref Scopus (27) Google Scholar The paths and transaction nodes whereby hazards become risks are also diverse. Even in a single market, large-scale slaughterers on the edge of a wet market might do business differently, work within different financial structures, and have a different perception of risk compared with somebody in a small booth with slow throughput. Actors behave in relation to their position in the trading structures and consequently have distinct sociocultural perspectives on risk, depending on the contexts in which they experience it.8Høg E Fournié G Hoque MA Mahmud R Pfeiffer DU Barnett T Competing biosecurity and risk rationalities in the Chittagong poultry commodity chain, Bangladesh.BioSocieties. 2019; 14: 368-392Crossref Scopus (27) Google Scholar, 9Barnett T Pfeiffer DU Ahasanul Hoque M et al.Practising co-production and interdisciplinarity: challenges and implications for one health research.Prev Vet Med. 2020; 177104949Crossref PubMed Scopus (16) Google Scholar, 10Ebata A MacGregor H Loevinsohn M Win KS Why behaviours do not change: structural constraints that influence household decisions to control pig diseases in Myanmar.Prev Vet Med. 2020; 183105138Crossref PubMed Scopus (15) Google Scholar People's risk calculations have to be understood within those contexts: people's social interactions, how they make sense of their situation, and how these reflect the convergence of constraints and individuals' aspirations.8Høg E Fournié G Hoque MA Mahmud R Pfeiffer DU Barnett T Competing biosecurity and risk rationalities in the Chittagong poultry commodity chain, Bangladesh.BioSocieties. 2019; 14: 368-392Crossref Scopus (27) Google Scholar That this is the case should be at the forefront of thought when considering how to mitigate the zoonotic disease risk generated by wet markets. Policy homogeneity is certainly cheaper and often politically appealing in the short term. The question of whether it is cost-effective or merely cheap is something to be borne in mind when developing policy. Heterogeneity, localism, and consultation might be more expensive, but are also more cost-effective in both the short and longer term. We declare no competing interests. TB and GF are supported by the UK Research and Innovation Global Challenges Research Fund One Health Poultry Hub (BB/S011269/1), one of 12 interdisciplinary research hubs funded under the UK government's Grand Challenge Research Fund Interdisciplinary Research Hub initiative.