Lassa fever is a serious but often overlooked viral illness that affects thousands of people in West Africa each year. While it may not get as much global attention as Ebola or COVID-19, it can be deadly if left untreated.
In this guide, you’ll learn what is Lassa fever, what causes Lassa fever, the main Lassa fever symptoms, and why it’s such a concern in Nigeria.
What is Lassa Fever?
Lassa fever is an acute viral hemorrhagic illness caused by the Lassa virus, part of the Arenaviridae family. It was first identified in 1969 in the town of Lassa, Nigeria.
The disease is endemic in several West African countries — meaning it occurs regularly. Lassa fever in Nigeria remains a major public health issue, with thousands of cases reported annually. According to the World Health Organization (WHO), there are between 100,000 to 300,000 infections and around 5,000 deaths every year.
What Causes Lassa Fever?
The main cause of Lassa fever is infection with the Lassa virus, carried by Mastomys rats (multimammate rats). These rodents excrete the virus in their urine and droppings without becoming sick themselves.
Humans can become infected through:
- Eating or handling food contaminated with rodent urine or droppings.
- Inhaling tiny airborne particles contaminated with the virus.
- Direct contact with the blood, urine, or other body fluids of an infected person.
How Lassa Fever Spreads
- Rodent-to-Human: The most common route, through contaminated food or surfaces.
- Human-to-Human: Possible through direct contact with an infected person’s blood, tissue, or secretions, especially in healthcare settings.
- Not Casual Contact: The virus does not spread through casual touch or being near an infected person.
Lassa Fever Symptoms
The symptoms of Lassa fever typically appear 6 to 21 days after infection. Many cases are mild, but severe infections can lead to serious complications.
Mild symptoms include:
- Fever
- Weakness
- Headache
- Sore throat
- Muscle pain
Severe Lassa fever symptoms can include:
- Facial swelling
- Bleeding from the mouth, nose, or other openings
- Respiratory distress
- Vomiting blood
- Organ failure and shock
Diagnosis
Early diagnosis is crucial but challenging because early symptoms can mimic malaria or typhoid fever. Lab tests used include:
Prevention
With no vaccine available, prevention focuses on reducing exposure:
- Store food in rodent-proof containers.
- Keep homes and surroundings clean to discourage rodents.
- Dispose of waste far from living areas.
- Avoid direct contact with the bodily fluids of infected individuals.
Lassa Fever in Nigeria
Lassa fever in Nigeria occurs year-round but peaks during the dry season when rodents move closer to homes in search of food. Seasonal outbreaks put pressure on healthcare systems, especially in rural areas. Neighboring countries like Sierra Leone, Liberia, and Guinea also face similar challenges.
Myths vs Facts
| Myth | Fact |
|---|---|
| Lassa fever is airborne like COVID-19. | It mainly spreads through contaminated food or bodily fluids. |
| Only rural communities are affected. | Urban outbreaks have been recorded. |
| All cases are fatal. | Many infections are mild or symptom-free, but severe cases can be deadly. |
Final Thoughts
Lassa fever is a preventable but dangerous disease that continues to affect communities in West Africa, especially Nigeria. Knowing what is Lassa fever, what causes Lassa fever, and recognizing early Lassa fever symptoms can save lives.
By spreading awareness, practicing prevention, and supporting public health initiatives, we can reduce the impact of this often-overlooked virus.
