• Killer virus goes viral, ravaging, rampaging
By Doris Obinna
Lassa fever is an acute viral haemorrhagic fever (VHF) caused by the Lassa virus. The natural reservoir for the virus is the multimammate rat (also known as the African rat). Other rodents can also act as carriers of the virus.
Nigeria is currently battling with the virus as cases are recorded across states all year round with peak transmission periods within October to May every year. According to Nigeria Centre for Disease Control and Prevention (NCDC) report, in 2025, from February 17 to 23, 95 deaths have been reported with a case fatality rate (CFR) of 18.8 per cent, which is the same CFR for the same period in 2024 (18.8 per cent).
It further disclosed that in total for 2025, 12 states have recorded at least one confirmed case across 70 Local Government Areas (LGAs). While 73 per cent of all confirmed lassa fever cases were reported from these three states; Ondo, Bauchi and Edo while 27 per cent were reported from nine states with confirmed lassa fever cases.
Of the 73 per cent confirmed cases, Ondo reported 32 per cent, Bauchi 24 per cent, and Edo 17 per cent. The predominant age group affected is 21-30 years (Range: 1 to 94 years, median age: 30years). The male-to-female ratio for confirmed cases is 1:0.8.
Also, February 24 to March 2, 2025, 2728 suspected cases; 535 confirmed cases and 98 deaths recorded across 14 states; CFR 3 per cent, five states account for 91 per cent of confirmed cases: Ondo: 31 per cent, Bauchi: 24 per cent, Edo: 17 per cent, Taraba: 16 per cent and Ebonyi: 3 per cent. Ten LGAs make up 68 per cent of confirmed cases, namely Owo, Akure South, Etsako West, Kirfi, Akoko South-West, Bali, Esan North-East, Bauchi, Toro and Jalingo.
Confirmed case with international travel
NCDC on March 5 was notified of a confirmed case of Lassa fever by the Ondo State Ministry of Health, in a 31yr old physician managed at a private health facility in Ondo State after returning from a trip abroad United Kingdom.
According to NCDC, the patient departed Nigeria February 19, and returned February 27. “Samples were taken late on February 28 on a suspicion of Lassa fever, but the patient unfortunately passed away in the early hours of Saturday, March 1. The laboratory investigation returned a result was Lassa fever positive on PCR on Tuesday, March 4. The patient was said to have visited his fiancée in Edo state, as well as family and friends before traveling.”
How virus is transmitted
In view of the above, the NCDC in its advisory stated that Lassa fever can be transmitted through: direct contact with urine, faeces, saliva or blood of infected rodents; ingesting food and drinks contaminated with urine, faeces, saliva or blood of infected rats.
“Also, contact with objects, household items or surfaces contaminated with urine, faeces, saliva or blood of infected rats should not be overlooked.
“While person-to-person transmission can also occur through contact with blood, urine, faeces, vomits and other body fluids of an infected person, particularly in hospital environment where infection prevention and control practices are not optimal.
How it presents
According to NCDC, 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.
“Early presentations to ensure diagnosis and treatment of the diseases can greatly increase the chances of patient survival. Early reporting of symptoms helps ensure timely diagnosis and treatment, thereby improving the chances of patient survival.”
People most at risk
It further disclosed that people of all age groups, who come in contact with the urine, faeces, 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 and caretakers of infected persons with poor infection prevention and control measures.
“Also, 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 as well as persons who prepare and/or handle bodies of deceased Lassa fever cases without appropriate precautions.”
Advice to the public
It added: “Preventing the spread of Lassa fever and other infectious diseases is a collective responsibility. While the NCDC and the state governments are actively responding to these threats, every Nigerian has a crucial role to play in reducing the spread of this disease. Key actions to prevent the spread of Lassa fever include: keeping your environment rodent-free.
“Regularly clean your homes, markets, and surroundings to eliminate conditions that encourage rat infestation or reduce breeding grounds for rats, store food items such as rice, garri, beans, and maize in sealed containers to prevent contamination.
“Block all holes in your house, including walls, floors, and roofs, to prevent rats and other rodents from entering homes. Cover your dustbins and properly dispose of refuse or waste to limit rodent access and safely store food items such as rice, garri, beans, corn/maize, etc., in tightly sealed or well-covered containers and avoid open drying of food stuff outside or on roadsides, where it is at risk of contamination.
“Properly process or prepare rats (bushmeat) before consumption, discourage bush burning and Deforestation as these can destroy the homes and food sources of rodents, driving 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 mean;
Maintain personal hygiene, safe food practices
NCDC cautions: “Wash hands frequently with soap and running water, especially after handling food or waste or using hand sanitizers when necessary.
“Avoid overcrowded living areas as overcrowding leads to poor sanitation, avoid direct contact with body fluids or secretions from infected persons, avoid self-medication and seek early medical attention if you experience symptoms such as fever, headache, body weakness, sore throat, or bleeding.”
For healthcare workers
“Remain vigilant and adhere to strict infection prevention and control (IPC) protocols, always practice standard IPC measures, including proper hand hygiene, PPE use, and safe waste disposal.
“Be on high alert for suspected Lassa fever cases and refer patients promptly for laboratory testing and case management and ensure strict isolation precautions for confirmed cases to prevent further transmission within healthcare facilities.”
