Lassa fever is a severe viral hemorrhagic illness caused by the Lassa virus, which belongs to the arenavirus family.
Humans typically contract the virus through contact with food or household items contaminated by the urine or feces of infected Mastomys rats, which are common in certain parts of West Africa.
The disease is endemic in several West African countries, including Benin, Ghana, Guinea, Liberia, Mali, Sierra Leone, Togo, and Nigeria, and likely present in others.
Read Also: Things You Don’t Know About Infertility
Infections can also spread from person to person or through laboratory exposure, especially in healthcare settings where infection control measures are lacking.
Early diagnosis and treatment are critical. The overall fatality rate is about 1%, but it can rise to around 15% for those hospitalized with severe symptoms. Early intervention with rehydration and supportive care increases the chances of survival.
Approximately 80% of people infected with the Lassa virus show no symptoms. However, in 20% of cases, the infection leads to severe disease, affecting major organs like the liver, spleen, and kidneys.
Symptoms
The incubation period of Lassa fever typically ranges from 2 to 21 days.
When symptoms appear, they usually begin gradually with fever, general weakness, and malaise.
Within a few days, additional symptoms may develop, including headache, sore throat, muscle and chest pain, nausea, vomiting, diarrhea, cough, and abdominal discomfort.
In more severe cases, facial swelling, fluid in the lungs, bleeding from the mouth, nose, vagina, or gastrointestinal tract, and low blood pressure may occur.
Read Also: Symptoms Of Diabetes
Protein can sometimes be detected in the urine.
As the disease progresses, more serious complications like shock, seizures, tremors, disorientation, and coma may emerge.
About 25% of survivors experience deafness, though in half of these cases, hearing improves partially within 1–3 months. Recovery can also include temporary hair loss and difficulty with coordination.
In fatal cases, death usually occurs within 14 days.
The disease is especially dangerous late in pregnancy, where maternal death or fetal loss occurs in over 80% of third-trimester cases.
Due to the wide range of symptoms and their non-specific nature, diagnosing Lassa fever clinically is challenging, particularly in the early stages.
It is also difficult to distinguish from other viral hemorrhagic fevers such as Ebola, or from diseases like malaria, shigellosis, typhoid fever, and yellow fever.
Treatment
There is currently no approved vaccine for Lassa fever, though several candidates are in development.
While the antiviral drug ribavirin has been used as a treatment for Lassa fever in some countries, it is not officially licensed for this purpose, and its effectiveness remains unproven.
There is still a need for a safe and effective treatment, and various options, including immune and drug therapies, are under evaluation.
Read Also: Treatment Of Hypertension
Preventing Lassa fever primarily involves promoting good community hygiene to keep rodents out of homes.
This includes storing food in rodent-proof containers, disposing of waste away from living areas, keeping homes clean, and keeping cats to control rodents.
Due to the abundance of Mastomys rats in affected areas, complete eradication is not feasible.
Additionally, family members caring for sick individuals should avoid direct contact with blood and bodily fluids.
Lassa fever is endemic in certain regions. Health workers treating suspected cases should immediately consult local and national experts for guidance and arrange for laboratory testing.
Standard infection prevention and control measures should be strictly followed by healthcare personnel.