The Nigeria Centre for Disease Control and Prevention is currently monitoring 357 individuals who may have been exposed to Lassa fever following the death of a 31-year-old physician, The PUNCH reports.
The doctor, who had recently returned from the United Kingdom on February 27, 2025, passed away on March 1, 2025, after being treated at a private hospital in Ondo State.
“Laboratory investigation confirmed the result as Lassa fever-positive through PCR testing on Tuesday, 04/03/2025. The patient was reported to have visited his fiancée in Edo State, as well as family and friends, before travelling,” the NCDC stated.
According to data released by the agency on Wednesday, a total of 535 individuals have been infected out of 2,728 suspected cases spread across 13 states and 75 local government areas.
The outbreak has resulted in over 100 deaths as of March 2, 2025, with a case fatality rate (CFR) of 18.7%.
Lassa fever, a viral haemorrhagic disease, is caused by the Lassa virus, which is primarily transmitted by multimammate rats, though other rodents may also be carriers.
The NCDC noted that while Lassa fever is present year-round, peak transmission typically occurs between October and May.
Decline in New Cases
Recent surveillance data for week nine of 2025 indicate a decrease in newly confirmed cases, dropping from 54 in week eight to 29.
The affected states include Ondo, Bauchi, Edo, Taraba, Ebonyi, Plateau, Cross River, Nasarawa, and Enugu.
Providing further insight, the NCDC reported, “Cumulatively in Week 9, 2025, 100 deaths have been reported with a CRF of 18.7 per cent which is marginally lower than the CFR for the same period in 2024 (18.8 per cent).”
The agency disclosed that Lassa fever has been confirmed in at least 75 local government areas across 13 states this year. The majority of cases, 72%, have been recorded in Ondo, Bauchi, and Edo states. Of this, Ondo accounts for 31%, Bauchi 24%, and Edo 17%.
Individuals between the ages of 21 and 30 remain the most affected demographic, with a median age of 30. The infection rate among males is slightly higher than among females, with a male-to-female ratio of 1:0.8. Suspected cases have also declined compared to the same period in 2024.
Healthcare Workers Among Those Infected
The NCDC further revealed that 17 healthcare workers have been infected in 2025, with cases reported in Ondo (eight), Bauchi (four), Edo (one), Taraba (two), and Gombe (two).
A breakdown of confirmed cases across affected states is as follows: Ondo (168), Bauchi (128), Edo (93), Taraba (83), Ebonyi (17), Kogi (14), Gombe (11), Plateau (nine), Benue (five), Nasarawa (three), Cross River (two), Delta (one), and Enugu (one).
The 100 recorded fatalities were distributed among Ondo (21), Bauchi (10), Edo (15), Taraba (26), Ebonyi (eight), Kogi (four), Gombe (six), Plateau (three), Benue (three), Nasarawa (three), and Cross River (one).
To manage the outbreak, the NCDC has activated the National Lassa Fever Multi-Partner, Multi-Sectoral Incident Management System, ensuring coordinated response efforts at all levels.
