Rats scrambling around the home is considered common sight in most Nigerian homes. However, a grave health concern is rising around communities in Nigeria from this common sight. Its name? Lassa fever.

History and cause of Lassa fever

Lassa fever was first identified in 1969 in Lassa town, a small town located in Borno State, and has since become widespread in Nigeria, with seasonal outbreaks recorded every year. Despite increased awareness, Lassa fever remains a frequent threat, particularly in areas where sanitation and housing conditions make it easier for rodents carrying the disease to thrive.

Lassa fever is caused by the Lassa virus, primarily transmitted through contact with food or household items contaminated by the urine or faeces of infected rodents, particularly the multimammate rat, a common specie of rats in West Africa. They refer to rodents of the class Mastomys, characterized by having an unusually high number of mammary glands, typically 8 to 12 pairs, but sometimes as many as 18.

In some cases, it can also spread from person to person, especially in healthcare settings where infection prevention measures are poor or insufficient.

One of the biggest challenges in managing the disease is its similarity to common illnesses like malaria. Early symptoms like fever, weakness, headache, and sore throat are often overlooked or misdiagnosed, allowing the infection to progress to more severe stages. In severe cases, it escalates to bleeding from body openings, respiratory distress and organ failure. The similarity in early symptoms is one of the reasons Lassa fever is so dangerous and often detected late.

 

Lassa Fever Prevalence in Nigeria

According to the Nigeria Centre for Disease Control (NCDC), the country records thousands of suspected cases annually, with outbreaks climaxing during the dry season. Lassa fever remains a stubborn public health challenge, particularly in states like Edo, Ondo, and Ebonyi, but the risk is far from out of the way. With increasing movement, urban crowding, and gaps in sanitation, no region is entirely immune, including Osun and Lagos.

Nigeria has made progress in disease surveillance and response, but the outbreaks are being constantly fueled by several factors, including:

  • Poor sanitation and waste disposal, attracting rodents into homes
  • Limited awareness, especially in rural communities
  • Delayed diagnosis, due to symptom overlap with common illnesses
  • Healthcare gaps, including insufficient protective equipment in some facilities

The seasonal nature of the upsurge in outbreaks is naturally between November and April, and also contributes to a cycle of reaction rather than prevention.

Public health experts have consistently emphasized that Lassa fever is largely preventable, explaining that the risk can be considerably reduced with simple but consistent measures such as:

  • Storing food in rodent-proof containers
  • Maintaining clean homes and surroundings
  • Avoiding drying food items on the ground or roadside
  • Practicing good hand hygiene
  • Seeking medical attention early when symptoms persist

At the healthcare level, strict infection prevention and early detection remain critical to protecting both patients and workers. When detected early, Lassa fever can be treated with antiviral medication such as Ribavirin, which significantly improves survival rates. However, access to timely diagnosis and treatment remains uneven across the country. This makes awareness and early presentation to health facilities not just important but lifesaving.

Read Also: Self-Medication in Nigeria: A Dangerous Habit We Normalize

Expert Insight: A Doctor’s Perspective

Providing deeper insight into the disease, Dr. Obasanjo Adebiyi, a Consultant Cardiologist at Peacelife Medical Centre and Specialist Clinics in Osogbo, Osun State, explained that Lassa fever remains dangerous largely because of how easily it is misunderstood in its early stages.

According to him, its primary carrier, the multimammate rat, does not show signs of illness despite harbouring the virus for life.

“The real danger begins when these rodents come into contact with human food,” he explained. “They contaminate food through urine or droppings, especially when food is not properly stored. Once consumed, the virus gains entry into the human body.”

Dr. Obasanjo Adebiyi noted that after infection, symptoms may take between 7 and 21 days to appear, although some individuals may remain asymptomatic. For those who develop symptoms, the early signs: fever, headache, vomiting, weakness, and muscle pain, are easily mistaken for malaria or typhoid.

“As the disease progresses, more severe symptoms can develop, including sore throat, chest pain, hearing loss, and in some cases, bleeding,” he added.

He also highlighted the heightened risk for pregnant women, noting that infections often result in the loss of the unborn child and, in severe cases, maternal death. Among newborns, a rare but serious condition known as “swollen baby syndrome” may occur.

Beyond rodent transmission, Adebiyi warned that infected individuals can also spread the virus through bodily fluids, increasing the risk of human-to-human transmission, particularly in poorly managed healthcare environments.

On diagnosis and treatment, he stressed the importance of acting quickly.

“Early detection is critical. If a patient does not respond to malaria treatment within one or two days, they should immediately seek medical attention. Once diagnosed, treatment with Ribavirin and supportive care can significantly improve outcomes,” he said.

However, he pointed out that managing Lassa fever in Nigeria comes with major challenges, including late presentation of patients, limited access to diagnostic laboratories, and inadequate availability of personal protective equipment for healthcare workers. In many rural areas, essential drugs and isolation centres are also lacking.

He further noted that increased human mobility contributes to the spread, as infected individuals can travel across regions before symptoms become severe.

On prevention, Adebiyi emphasised the need for environmental hygiene and food safety.

“Keeping homes clean, blocking entry points for rodents, and storing food properly are key. Practices like drying food in open spaces increase the risk of contamination,” he said.

He concluded with a strong call for vigilance, saying “Anyone with persistent symptoms should seek medical care immediately. Communities must remain alert. Early presentation at a healthcare facility can make all the difference in saving lives.”

 

A Pharmacist’s Perspective

Offering a frontline view from the pharmaceutical sector, Pharm. Afolabi Aziz Omotayo, a pharmacist at the Obafemi Awolowo University Teaching Hospital Complex (OAUTHC), highlighted the critical role pharmacists play in early detection and response.

“Pharmacists are often the first point of contact, especially in community settings,” he explained. “This makes our role very important in identifying suspected cases.”

According to him, one of the key warning signs is when a patient presents with persistent fever that does not respond to antimalarial or antibiotic treatment.

“That raises suspicion because Lassa fever symptoms are often non-specific and can easily be mistaken for malaria or typhoid,” he said.

On treatment accessibility, Pharm. Afolabi clarified that Ribavirin, the primary antiviral drug used in managing Lassa fever, is not readily available everywhere.

“Ribavirin is not an antibiotic; it is an antiviral and is restricted. While it can be stocked in hospitals, it is not something every pharmacy carries. In most cases, it is only accessible within hospital settings,” he noted.

He also warned strongly against the dangers of self-medication, a common practice in Nigeria.

“Self-medication is very risky, especially where every fever is assumed to be malaria,” he said. “The dangers include delayed diagnosis, progression of the disease, increased risk of transmission, drug misuse, and even toxicity.”

For the public, his advice was clear and direct as he stated that people need to avoid assumptions and seek proper care early.

“We should not assume every fever is malaria. If a fever lasts between 24 to 48 hours without improvement, it is important to go to the nearest hospital. Any fever that persists beyond two to three days should be properly evaluated,” he advised.

 

Lassa Fever, A Shared Responsibility

Lassa fever may not always dominate headlines, but its impact is deeply felt in affected communities. Combating it requires more than government intervention, it also demands collective responsibility, from maintaining hygiene at home to strengthening healthcare systems nationwide.

As Nigeria continues to battle recurrent outbreaks, one message remains clear: awareness, prevention, and early action can save lives.