Lassa fever is a viral illness that has become a public health concern worldwide, particularly in West Africa. The disease causes severe and life-threatening symptoms, making understanding its causes, symptoms, and treatment options crucial.
In this article, we’ll explore the world of Lassa fever to keep you informed and help protect you and your loved ones from this dangerous disease.
What is Lassa Fever?
Lassa fever is a severe viral hemorrhagic illness caused by the Lassa virus, which belongs to the Arenaviridae family. The virus primarily affects West Africa, causing thousands of infections and hundreds of fatalities each year.
The disease, though first described in the 1950s, was first identified in 1969 after an outbreak occurred in the town of Lassa, Nigeria. Since then, it has been reported in various countries across the region, including Liberia, Guinea, and Sierra Leone.
Lassa fever can be contracted through direct contact with infected animals, contaminated food, or exposure to the bodily fluids of an infected person.
Signs and Symptoms of Lassa Fever
Lassa fever presents a wide range of symptoms that can vary in severity. Some of the common signs and symptoms include:
- Fever
- Headache
- Sore throat
- Muscle and joint pain
- Chest pain
- Nausea and vomiting
- Diarrhea
- Cough
- Abdominal pain
- Swelling in the face and neck
- Bleeding from the mouth, nose, or other body openings
Remember: not all infected individuals will exhibit symptoms, and some cases may be mild, making it challenging to identify the illness solely based on symptoms.

How is Lassa Fever Caused?
Lassa fever is caused by the Lassa virus, primarily transmitted to humans through contact with the urine or feces of infected Mastomys rats, a common rodent species found in West Africa.
These rodents often invade human homes and contaminate food sources, leading to the spread of the virus.
Additionally, the Lassa virus can be transmitted through direct contact with an infected person’s blood, tissue, or bodily fluids, making it a risk for healthcare workers and caregivers without proper protective equipment.
The virus can sometimes spread through the air when aerosolized particles, such as those produced during certain medical procedures, are inhaled. However, it’s important to note that person-to-person transmission through casual contact is relatively rare.
Epidemiology
Lassa fever infections are most common in West Africa, where the disease is endemic. The World Health Organization (WHO) estimates that Lassa fever affects around 100,000 to 300,000 individuals annually in the region.
The mortality rate of patients hospitalized for Lassa fever is approximately 15%-20%. However, the mortality rate of all Lassa virus infections is approximately 1-2%.
Lassa fever is also associated with occasional epidemics, during which the mortality rate can reach 50% in hospitalized patients.
The majority of Lassa fever cases occur in Nigeria, Liberia, Sierra Leone, and Guinea. However, occasional outbreaks have been reported in neighboring countries as well.
While the risk of Lassa fever infection is higher in rural areas where Mastomys rats are more prevalent, urban areas are not exempt from the disease.
Travelers to West Africa should be aware of the risk and take necessary precautions to avoid exposure to the virus, such as storing food in rodent-proof containers and avoiding contact with sick individuals.
Diagnosis and Treatment: Key to Tackling Lassa Fever
Here’s a rundown of the essential diagnostic tests and treatments for Lassa fever:
Diagnosing Lassa fever involves several tests, including reverse transcription-polymerase chain reaction (RT-PCR) to detect Lassa virus RNA in a patient’s blood or body fluids.
Antigen detection tests identify Lassa virus proteins in the blood, while antibody detection tests reveal antibodies against the virus, signifying a current or past infection.
Treating Lassa fever hinges on the timely administration of the antiviral drug ribavirin.
Supportive care is also vital for managing symptoms and complications, which involves rehydration, pain relief, and monitoring and addressing complications like shock, seizures, and bleeding as needed.
Prevention and Control Measures
To reduce the risk of Lassa fever infection, implement the following measures:
- Practice good hygiene: Wash hands regularly, keep living spaces clean, and store food in rodent-proof containers.
- Control rodents: Take steps to prevent rodents from entering homes and buildings.
- Use personal protective equipment (PPE): Healthcare workers and caregivers should wear gloves, masks, and gowns to minimize the risk of infection.

Summary
Lassa fever is a severe viral illness primarily affecting West Africa. Early diagnosis and treatment with ribavirin and supportive care are crucial for improved patient outcomes.
Practicing good hygiene, controlling rodents, and using personal protective equipment minimize the risk of infection and help protect yourself and your loved ones from this dangerous disease.
Disclaimer: This article is for informational purposes only and should not be used as a substitute for seeking medical attention. If you have any symptoms of Lassa fever, it is important to seek medical attention immediately.
Written by: Emmanuel J. Osemota