Two major public health issues facing Nigeria in 2017 and 2018 were the terrorist activity by the Boko Haram Islamist group and an unprecedented outbreak of Lassa fever.

To determine if Boko Haram activity was temporally or spatially related to the incidence of Lassa fever in Nigeria and if so, to identify potential concurrent causes and mitigation measures.

The study was a mixed-methods design. First, we conducted a secondary analysis of the Armed Conflict Location and Event Data (ACLED) Project for all known Boko Haram activity and of the weekly Nigeria Centre for Disease Control reports for suspected Lassa fever cases. Data were analyzed for January 2017 through June 2018. The ACLED data were spatially overlaid with suspected Lassa cases for each of Nigeria’s 36 states. Secondly, we conducted interviews with six aid workers in Nigeria regarding Boko Haram activities and Lassa fever cases.

In the study period, 596 Boko Haram activities occurred in 13 states (36.1%): 416 in 2017 and 180 between January and June of 2018. During the same period, 3,137 suspected Lassa cases were reported from 21 states (58.3%): 1,022 in 2017 and 2,115 in January through June 2018. Only one state, Sokoto, was unaffected by either issue. Aid workers reported a positive relationship between Boko Haram activity and increased negative health outcomes.

The investigation found little geographic overlap in Nigeria between Boko Haram activity and the 2018 Lassa fever outbreak, suggesting independence of these two issues. However, unmeasured factors, such as public fear and mistrust of governmental activities, may affect both issues. It is also critical to note that widespread co-occurrence (97.2% of 36 states) of these two issues presents significant public health, medical, and security challenges for Nigeria, calling for overarching solutions such as governmental stability and economic stimulus.