Lassa fever in Nigeria: Social and Ecological Risk Factors Exacerbating Transmission and Sustainable Management Strategies

With the advent of COVID-19, infectious diseases are increasingly a cause of concern to both national and international governments as well as non-governmental organizations. This review focusses on Lassa fever incidence, prevalence, and socioecological factors influencing the spread and management of the disease in Nigeria using data mined from the Nigeria Centre for Disease Control and other public databases. Lassa fever and the causative agent Lassa virus (LASV) and vector, Mastomys natalensis is becoming a topical issue despite the neglected tropical disease status. The primary transmission mode of LASV has not been fully comprehended but several social and environmental factors have been implicated to either play a major role in determining the rate of transmission or exacerbating transmission risks. Nonetheless, some transmission route includes faeco-oral, rodent bites, and the consumption of rodent meat. From epidemiolocal studies and surveillance, it is glaring that LASV is a West African phenomenon. In West Africa, about 100,000 to 300,000 new cases of Lassa fever have been reported with a mortality rate of 5,000 persons per year. In Nigeria, Lassa fever has occurred in several states across the six geopolitical zones and the federal capital territory. However, Edo State in the Southsouth geopolitical zone and Ondo State in the Southwest geopolitical zone is the core epicentre of the virus since December 2016 in Nigeria. Some environmental conditions that contribute to exacerbating the incidence of Lassa fever include weak environmental hygiene laws, poor housing, and regional planning, indiscriminate disposal of wastes, poor food handling, and storage, absence of a law against eating Mastomys natalensis , deforestation, and poor agricultural practices as well as climate change.