The Nigeria Centre for Disease Control and Prevention has listed 357 persons for follow-up over the possibility of being infected with Lassa fever.

This came after the death of an undisclosed 31-year-old physician who returned from the United Kingdom on February 27, 2025, and died of Lassa fever on March 1, 2025.

The late physician was said to have been managed at a private health facility in Ondo State after returning from a trip abroad.

In a statement, NCDC explained: “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 natural reservoir for the virus is the multimammate rat (also known as the African rat), although other rodents can also act as carriers.

The agency’s Director General (DG), Jide Idris has emphasised the growing urgency for Nigerians to maintain rodent-free environments and enhance personal hygiene amid the ongoing Lassa fever outbreak. He stated that Lassa fever cases occur year-round, with peak transmission periods typically from October to May.

Idris revealed that with the disease spreading and already claiming 98 lives in 2025, including a medical doctor, the agency stressed the need for preventive measures such as proper waste disposal, sealing food in airtight containers, and blocking rodent entry points.

Adding that: “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 decreased compared to that reported for the same period in 2024.”

Meanwhile, so far in 2025, 17 healthcare workers have been infected with the disease in Ondo (eight), Bauchi (four), Edo (one), Taraba (two), and Gombe (two).