Descriptive epidemiology of Lassa fever in Nigeria, 2012-2017.

Introduction: Lassa fever, an acute viral hemorrhagic zoonotic disease is endemic in some parts of Nigeria. The disease alert and outbreak threshold are known; however, there has been a shift from the previous seasonal transmission pattern to an all year-round transmission. We described data on Lassa fever and highlighted the magnitude of the disease over a six-year period.