Abattoirs as sentinel sites for Lassa fever surveillance: A One Health perspective in West Africa

Abstract

Lassa fever (LF), an acute viral haemorrhagic disease caused by Lassa virus (LASV), remains a significant public health concern in West Africa. The multimammate rat (Mastomys natalensis) is the principal reservoir, with humans primarily exposed through contact with infected rodent excreta and contaminated materials. Although healthcare workers are widely recognized as an occupationally vulnerable group, abattoir workers may represent an under-recognized population at risk because of frequent contact with animal blood and tissues, compounded by poor sanitation, inadequate rodent control, and inconsistent use of personal protective equipment (PPE). This review synthesizes available evidence on the occupational risk of Lassa virus exposure among abattoir workers and examines the broader public health implications, with emphasis on strengthening surveillance, biosafety, and integrated One Health interventions within abattoir settings. This is a narrative review that consolidates existing findings and literature on the epidemiology of Lassa fever, its virology and transmission pathways, the link between abattoirs and zoonotic disease exposure, rodent activity and biosecurity in abattoirs, and public health implications. Abattoirs, characterized by abundant organic waste and inadequate sanitation, offer ideal conditions for rodents like Mastomys natalensis to thrive and contaminate surfaces and meat products. Abattoir workers face a severe, under-recognized occupational health hazard due to routine and unprotected exposure to animal tissues, blood, and bioaerosols. Infected workers, serving as an entry point, can inadvertently act as vectors, introducing the virus into households and communities, fueling outbreaks. Abattoirs represent critical sentinel sites for early detection, as they centralize large animal populations and waste streams, allowing for detection of spillover events earlier than hospital-based systems. Abattoirs represent important yet addressable points of Lassa fever risk. Recognizing their potential as sentinel sites and integrating coordinated One Health interventions could help policymakers detect and disrupt hidden Lassa virus transmission pathways, protect at-risk population.