An ecologist extracts a sample of blood from a Mastomys Natalensis rodent in the village of Jormu in southeastern Sierra Leone February 8, 2011. Lassa fever, named after the Nigerian town where it was first identified in 1969, is among a U.S. list of "category A" diseases -- deemed to have the potential for major public health impact -- alongside anthrax and botulism. The disease is carried by the Mastomys Natalensis rodent, found across sub-Saharan Africa and often eaten as a source of protein. It infects an estimated 300,000-500,000 people each year, and kills about 5,000. Picture taken February 8, 2011. To match Reuters-Feature BIOTERROR-AFRICA/ REUTERS/Simon Akam (SIERRA LEONE - Tags: HEALTH SOCIETY ANIMALS) - GM1E72F07HC01
Nigeria has recorded 1,086 confirmed cases of Lassa fever and 259 deaths across 24 states and 118 Local Government Areas since the start of 2026, according to the Nigeria Centre for Disease Control and Prevention (NCDC).
The figures were contained in the agency’s latest Lassa Fever Situation Report for epidemiological week 36, covering August 31 to September 6, 2026.
Weekly Infection Trends
During the reporting week, 12 new confirmed cases were recorded nationwide—a decline from the 18 cases reported in week 35 and 21 cases in week 34. The new infections were identified across Ondo, Edo, and Kogi states.
Despite the weekly decline in new infections, the national cumulative Case Fatality Rate (CFR) stands at 23.9%, marking a notable increase compared to the 18.6% recorded during the corresponding period in 2025.
Hotspot States and Affected Demographics
The NCDC report highlighted that 87% of all confirmed Lassa fever cases in 2026 are heavily concentrated in five states: Bauchi, Ondo, Taraba, Benue and Edo.
The disease continues to disproportionately impact young adults, with the 21-to-30 age bracket remaining the most affected group nationwide.
Response and Healthcare Worker Safety
No new infections were reported among healthcare workers during week 36, keeping frontline infection rates stable for the reporting period.
The NCDC reaffirmed its commitment to maintaining active surveillance, case management, and vector control measures across all affected communities. Public health authorities continue to emphasize early detection, hygienic food storage to prevent rodent contact, and rapid clinical presentation as critical measures to reduce mortality.
