We reviewed data pertaining to the massive wave of Lassa fever cases that occurred in Nigeria in 2018. No new virus strains were detected, but in 2018, the outbreak response was intensified, additional diagnostic support was available, and surveillance sensitivity increased. These factors probably contributed to the high case count.
Keywords: Ebonyi; Edo; Lassa fever; Lassa virus; Nigeria; Ondo; epidemiology; hemorrhagic fever; outbreak; surveillance; surveillance capacity; viruses; zoonoses.