A scoping review of approaches for the surveillance of swine influenza viruses at human-swine interfaces.

14 July 2025
Departmental update
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New insights from a recent IHM Unit supported study highlights urgent gaps and opportunities in swine influenza surveillance across Southeast Asia. The study, published in BMJ Public Health, reviews global practices in monitoring influenza A viruses (IAVs) among swine and at human–animal interfaces—providing vital direction for preventing future pandemics in the region.

Southeast Asia’s densely populated settings with cohabiting humans, pigs, and poultry create ideal conditions for zoonotic influenza to emerge. Swine are considered “mixing vessels” for influenza strains from multiple species, potentially generating novel viruses capable of human-to-human transmission. Despite these risks, most surveillance efforts in the region remain fragmented, short-term, and heavily focused on virological detection—often missing early warning signals at critical animal–human contact points.

The study systematically reviewed 42 global studies, finding that:

• Over 90% used active surveillance methods, mostly in commercial swine farms.

• Nearly 70% prioritized identifying virological changes (e.g., new mutations), but very few combined swine and human sampling or any other species, such as poultry.

• Only 19% included combined animal sampling with some form of human sampling, limiting the anticipation and rapid recognition of spillover events.

In the SEAR context, backyard farms, live animal markets, and agricultural fairs pose significant but under-monitored risks. The review calls for standardised, objective-driven surveillance protocols tailored to the region’s diverse epidemiological and production settings.

Importantly, the findings will inform WHO’s next steps in developing operational guidance for influenza A surveillance at the human–swine interface, grounded in the realities of SEAR countries. This includes identifying high-risk interfaces, supporting cost-effective, cross-sectoral surveillance, and enhancing coordination between public health and veterinary systems.

These findings offer critical inputs for national policymakers to prioritize One Health-based surveillance investments, expand surveillance to underrepresented settings such as backyard farms, and align pandemic preparedness plans with the realities of zoonotic risk in SEAR. They also underscore the need to institutionalize swine IAV surveillance as part of routine national zoonotic disease surveillance frameworks.

This initiative aligns closely with the IHM Unit’s broader mission to mitigate risks of emerging infectious threats. It strengthens One Health integration, supports early detection of high-threat pathogens, and enhances regional readiness for future pandemics.

Reference:

Subarna Roy, Mohammad Mahmudul Hassan, Gulam Mohd, Abdulkader Suliankatchi Rizwan, Muthappan Sendhilkumar, Jasmine Beryl Lydia, Janana Priya, Manickam Ponnaiah, Pushpa Ranjan Wijesinghe, Edwin Ceniza Salvador, Nilesh Buddha, Ricardo Soares Magalhaes, Manish Kakkar, Manoj Murhekar - Implications for influenza A virus surveillance in Southeast Asian Region countries: a scoping review of approaches for the surveillance of swine influenza viruses at human-swine interfaces: BMJ Public Health 2025;3:e002330. https://bmjpublichealth.bmj.com/content/3/1/e002330