Nigeria health officials have reported 53 deaths due to Lassa fever during the first four weeks of 2025, a 10 percent increase compared to the same period last year (48).
Taraba state has reported the most deaths with 15, followed by Ondo and Edo states with 10 each.
In total for 2025, 10 Nigerian States have recorded at least one confirmed case across 54 Local Government Areas.
To date, 290 confirmed cases, 1171 suspected and one probable Lassa fever case has been reported. Seventy-five (75%) of all confirmed Lassa fever cases were reported from these three states (Ondo- 107, Edo- 61, and Bauchi-49) while 25% were reported from 7 states with confirmed Lassa fever cases. Of the 75% confirmed cases, Ondo reported 37%, Edo 21%, and Bauchi 17%.
Two healthcare workers have been infected in 2025 to date.
Lassa fever is an acute viral hemorrhagic fever (VHF) caused by the Lassa virus. The natural reservoir for the virus is the Mastomys natalensis rodent (commonly known as the multimammate rat or the African rat). Other rodents can also be carriers of the virus.
The virus spreads through:
• Direct contact with urine, feces, saliva, or blood of infected rats.
• Contact with objects, household items, and surfaces contaminated with the urine, feces, saliva, or blood of infected rats.
• Consuming food or water contaminated with the urine, feces, saliva, or blood of infected rats.
• Person-to-person transmission can also occur through direct contact with blood, urine, feces, vomitus, and other body fluids of an infected person.
Lassa fever initially presents like other common illnesses accompanied by a fever, such as malaria. Other symptoms include headache, general body weakness, cough, nausea, vomiting, diarrhea, muscle pains, chest pain, sore throat, and, in severe cases, bleeding from ears, eyes, nose, mouth, and other body openings. The time between infection and the appearance of symptoms of the disease is 3 to 21 days. Early diagnosis and treatment of the diseases greatly increase the chances of patient survival.
Lassa fever with Dr Judy Stone
People most at risk for Lassa fever are:
• People of all age groups who come in contact with the urine, feces, saliva, or blood of infected rats.
• People living in rat-infested environments.
• People who consume potentially contaminated foodstuff, especially those left open overnight or dried outside in the open.
• People who handle or process rodents for consumption.
• People who do not perform hand hygiene at appropriate times.
• Caretakers of infected persons with poor infection prevention and control measures.
Healthcare workers including:
• Doctors, nurses, and other health workers who provide direct patient care in the absence of standard precautions.
• Hospital staff who clean and disinfect contaminated surfaces, materials, and supplies without adequate protective gear.
• Laboratory staff who handle blood samples of suspected Lassa fever patients without appropriate precautions.
• Persons who prepare and/or handle bodies of deceased Lassa fever cases without appropriate precautions.
The NCDC-led National Lassa Fever TWG offers the following advice to reduce the risk of Lassa fever infection:
ADVICE TO THE PUBLIC
• Always keep your environment clean.
• Block all holes in your house to prevent the entry of rats and other rodents.
• Cover your dustbins and dispose of refuse properly. Communities should set up dump sites far from their homes to reduce the chances of the entry of rodents into their homes.
• Safely store food items such as rice, garri, beans, corn/maize, etc., in tightly sealed or well-covered containers.
• Avoid drying food stuff outside on the ground or roadside, where it is at risk of contamination.
• Discourage bush burning. This destroys the homes and food sources of rodents and drives them to migrate from the bushes to human residences to find food.
• Eliminate rats in homes and communities by setting rat traps and other appropriate and safe means.
• Practice good personal and hand hygiene by frequently washing hands with soap under running water or using hand sanitizers when necessary.
• Visit the nearest health facility if you notice any of the signs and symptoms associated with Lassa fever mentioned earlier or call the State Ministry of Health hotline and 6232 (NCDC). This is essential because early identification and treatment of cases appear to be more effective and can save lives.
• Avoid self-medication to ensure proper diagnosis and early treatment.