The Nigeria Centre for Disease Control and Prevention has listed 1,277 persons for follow-up over the possibility of being infected with Lassa fever. This follows the centre recording 659 confirmed cases out of 3,779 suspected cases and 122 deaths in 13 weeks (from January to March 30, 2025).
A report obtained from the NCDC on Friday indicated that no fewer than 18 states across the country have recorded Lassa fever cases, with Ondo, Bauchi, and Edo being the most affected.
The report partly reads, “Cumulatively, in week 13 of 2025, 122 deaths have been reported, with a Case Fatality Rate of 18.5%, which is lower than the CFR for the same period in 2024 (18.7%).
“In total for 2025, 18 states have recorded at least one confirmed case across 93 Local Government Areas. Seventy-one per cent of all confirmed Lassa fever cases were reported from these three states (Ondo, Bauchi, and Edo), while 29% were reported from 15 other states with confirmed Lassa fever cases. Of the 71% of confirmed cases, Ondo reported 30%, Bauchi 25%, and Edo 16%.
“The predominant age group affected is 21-30 years (Range: 1 to 94 years, Median Age: 30 years). The male-to-female ratio for confirmed cases is 1:0.8. The number of suspected cases increased compared to that reported for the same period in 2024. No new healthcare worker was affected in week 13. The National Lassa fever multi-partner, multi-sectoral Incident Management System (IMS) was activated to coordinate the response activities at all levels.”
The report shows that the contacts under follow-up number 1,277, while the contacts that have completed follow-up total 1,448.
According to the NCDC, the disease has affected 20 healthcare workers in eight states so far this year.
Lassa fever is an acute viral haemorrhagic fever caused by the Lassa virus. The natural reservoir for the virus is the multimammate rat (also known as the African rat), although other rodents can also act as carriers.
The public health institute stated that Lassa fever cases occur year-round, with peak transmission periods typically from October to May.