Understanding One Health through biological and behavioral risk surveillance in Liberia: a cross-sectional study

Abstract

BackgroundThe 2014 Ebola crisis in West Africa mainly affected Guinea, Liberia, and Sierra Leone, claiming the lives of over 11 000 people, including health-care workers. Following this crisis, the Ebola Host Project worked to identify the wildlife reservoir for the virus that started the epidemic, to detect other related filoviruses, and to better understand ecological and human behavioral dynamics that could inform future risk reduction and prevention strategies. Here, we report key ecological and behavioral results for Liberia. MethodsIn Liberia, this cross-sectional study was conducted in 13 sites throughout eight counties. The project used a One Health biological-behavioral surveillance approach that included catch-and-release wildlife sampling and behavioral risk surveys. These sites were chosen from counties with forested areas inhabited by bats and rodents and included counties that were both severely and minimally impacted by the Ebola crisis. The analysis included 5000 bat and rodent biological samples, and the behavioural risk survey included 585 enrolled human participants from eight counties. Participants were selected from villages within a 5 km range of the 18 sampling sites, and they provided writteninformed consent. In addition to US based approvals, the Liberian National Ethical and Review Board, the Liberian Forest Development Authority and local government authorities approved the study and community work. FindingsThis sampling effort led to the first-time discovery of an Ebolavirus in a west African bat (Miniopterus inflatus) in January 2019. Across five of the eight counties, including Nimba County where the infected Miniopterus inflatus was sampled, mosquitos and tsetse flies were also identified as present vectors. Respondents reported the ways in which they interfaced with taxa of interest such as rodents. These interactions included wildlife consumption and proximity to human dwellings—interactions that present the risk of zoonotic infections that may go misdiagnosed as fevers of unknown origin. Respondents additionally described gaps in knowledge around topics such as the aetiology of Ebola in Liberia, as well as changes in the level of concern towards Ebola risk, which rose during the crisis but later returned to pre-crisis levels. InterpretationOur results highlight how, against the backdrop of human-wildlife interactions in these Liberian communities that present spillover risk, there exist opportunities to bridge knowledge gaps and create cues to encourage continued vigilance against transmission. FundingThis project was funded by USAID, and analysis with regard to the risk of acute febrile illnesses continues with funding from the US Defense Threat Reduction Agency.