Ondo, Bauchi, Edo top list as Lassa fever cases rise to over 800

Nigeria has recorded 822 confirmed cases of Lassa fever and 155 deaths within the first seven months of 2025, according to new figures released by the Nigeria Centre for Disease Control and Prevention (NCDC).

The data, which covers the period from January 1 to July 20, 2025 (epidemiological week 29), highlights a concerning increase in the Case Fatality Rate (CFR), now at 18.9%, compared to 17.1% during the same period last year.

“In Week 29, the number of new confirmed cases is the same as epi Week 28 of 2025. These were reported in Ondo and Edo States,” the NCDC reported.

Since the start of the year, Nigeria has seen a total of 6,640 suspected cases of the disease, with 21 states and 105 Local Government Areas reporting at least one confirmed case.

The majority of infections—89%—have come from five states: Ondo (32%), Bauchi (23%), Edo (17%), Taraba (14%), and Ebonyi (3%). The remaining 11% of cases were spread across 16 other states.

The NCDC also noted: “Cumulatively as at Week 29, 2025, 155 deaths have been reported with a Case Fatality Rate of 18.9 per cent, which is higher than the CFR for the same period in 2024 (17.1 per cent).”

Lassa fever, an acute viral illness caused by the Lassa virus, remains a major public health concern in Nigeria and other West African countries. According to the World Health Organisation, the virus is endemic in Nigeria, Benin, Ghana, Guinea, Liberia, Mali, and Sierra Leone — and likely exists in more West African nations.

WHO explains that: “The Lassa virus is primarily transmitted to humans via contact with food or household items contaminated with rodent urine or faeces. Person-to-person transmission can also occur, particularly in health care settings lacking adequate infection prevention and control measures.”

Demographic analysis shows that the age group most affected by Lassa fever in Nigeria this year is 21–30 years, with patients ranging in age from 1 to 96 years. The median age is 30, and the male-to-female ratio among confirmed cases is 1:0.8.

Encouragingly, the NCDC noted a decline in both suspected and confirmed cases compared to the same period in 2024 and confirmed that: “No new healthcare worker was affected in the reporting week 29.”

The agency said the National Lassa Fever Multi-partner, Multi-sectoral Technical Working Group continues to coordinate response efforts across all levels to manage the outbreak.