Title : Urban monkeypox transmission and One Health response: Lessons from a household cluster outbreak in Lagos, Nigeria
Abstract:
Background: Monkeypox, an emerging Orthopoxvirus, is transitioning from zoonotic spillovers to sustained human-to-human transmission in dense urban environments, posing threats to global health. In 2019, Lagos State—Africa’s largest megacity—experienced a monkeypox outbreak in Mushin Local Government Area. Despite limited resources, public health teams activated a rapid One Health response to contain the outbreak within a high-risk setting. We aimed to characterize the epidemiological features of an urban MPX outbreak and identify scalable containment strategies in tropical megacities.
Methods: A descriptive cross-sectional investigation was conducted using data from case-based surveillance, contact tracing, environmental assessments, and semi-structured community interviews. Ten suspected cases and five contacts were line-listed based on WHO and national case definitions. Biological samples were collected via lesion swabs and tested by PCR at the national virology reference laboratory. Field teams-initiated door-to-door risk communication, isolation protocols, and IPC training for 34 frontline health workers across two wards.
Results: Four cases were PCR-confirmed. All originated from a single household with no reported animal contact, indicating sustained human-to-human transmission. The mean age was 29 years; 50% were male. Symptoms included fever, vesiculopustular rash, and lymphadenopathy. One case had recent travel history from a neighboring state. No fatalities occurred. The outbreak was swiftly contained within 10 days through early case identification, isolation, intensive contact monitoring, and high community compliance. Environmental inspections revealed substandard housing, poor sanitation, and no zoonotic vectors.
Conclusion: This outbreak illustrates the changing landscape of monkeypox transmission in urban Africa. The Lagos response demonstrated how decentralized surveillance, cross-sectoral coordination, and community mobilization can halt MPX outbreaks in resource-constrained urban settings. Building on this experience, Lagos has launched ongoing surveillance in high-risk districts and initiated MPX vaccine readiness, including cold chain mapping, risk stratification, and public engagement. This integrated model offers a replicable framework for urban outbreak preparedness globally.
Key words: Monkeypox, urban outbreak, one Health, surveillance, vaccine readiness, community engagement.
