A Systematic Review of New, Enhanced Surveillance Systems and Methodologies for Zoonotic Influenza Viruses in Animals and Human–Animal Interface

In 2009, the World Health Organization (WHO) developed a public health research agenda for influenza to guide researchers and outline directions and priority areas for research on influenza aiming at reducing the burden of seasonal epidemic influenza and the risk and impact of pandemic influenza. The agenda was updated in 2017, but since then, important research has been conducted, and major changes have occurred to the global health landscape impacted mainly by the COVID-19 pandemic. Therefore, there is a need to assess advances in zoonotic influenza surveillance methods reported between 2017 and 2024 in order to highlight key achievements and identify remaining gaps that limit their broader implementation, hence informing an update of the research agenda. We conducted a comprehensive literature review of zoonotic influenza surveillance and monitoring, focusing on novel and enhanced methodologies reported globally between 2017 and 2024. A systematic analysis was performed following PRISMA guidelines on 7490 peer-reviewed manuscripts from 2017 to 2024 retrieved from PubMed, of which 164 records were included in this review. Analysis of the information collected indicated several advances and gaps at different levels of surveillance and unmet public health needs. Most countries do not have active and comprehensive surveillance programs for zoonotic influenza at the human-animal interface, which underestimates the true burden of zoonotic influenza diseases. The review concludes with a set of high-priority research recommendations focused on filling gaps in One Health data integration, validation, and field deployment of novel diagnostic technologies, wider adoption of noninvasive and environmental surveillance approaches, and stronger linkage of methodological innovations to risk assessment and policy action. In light of the recent upsurge in H5N1 activity and cross-species transmission, the WHO has convened multiple R&D Blueprint consultations over the past year to prioritize research and development for H5N1 candidate vaccines, diagnostics, and pandemic preparedness. These ongoing initiatives underscore the critical importance of strengthening surveillance at the human-animal interface.