Lassa Fever Claims 155 Lives in Nigeria as Case Fatality Rate Rises

The Nigeria Centre for Disease Control and Prevention (NCDC) has revealed that Lassa fever has killed 155 people across the country between January 1 and July 20, 2025.

This marks a rise in the Case Fatality Rate (CFR) to 18.9%, up from 17.1% during the same period in 2024.

In its latest update covering epidemiological Week 29, the NCDC said Nigeria recorded 6,640 suspected cases and 822 confirmed infections of the viral disease across 21 states and 105 Local Government Areas.

According to the World Health Organisation, Lassa fever is an acute viral illness endemic in parts of West Africa, including Nigeria, Benin, Ghana, and Sierra Leone. It is primarily transmitted to humans through contact with food or household items contaminated with rodent urine or faeces. Person-to-person transmission, particularly in healthcare settings with poor infection control, is also possible.

For Week 29, the NCDC noted that the number of new confirmed cases remained unchanged from the previous week, with new infections recorded in Ondo and Edo states.

“Cumulatively, as of Week 29, a total of 155 deaths have been reported, with a CFR of 18.9%. This is higher than the CFR for the same period in 2024, which stood at 17.1%,” the NCDC stated.

Five states accounted for 89% of all confirmed cases in 2025: Ondo (32%), Bauchi (23%), Edo (17%), Taraba (14%), and Ebonyi (3%). The remaining 11% came from 16 other states.

The most affected age group is 21–30 years, with patients ranging from 1 to 96 years old. The median age of confirmed cases is 30, and the male-to-female ratio is 1:0.8.

The NCDC also reported that there were no new infections among healthcare workers during the week under review. Meanwhile, a national multi-partner, multi-sectoral Technical Working Group continues to coordinate the Lassa fever response across all levels.