Lassa fever history and symptoms

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Ammu Susheela, M.D. [2]

Overview

Common symptoms of Lassa fever typically include persistent, high-grade fever and other non-specific symptoms, such as headache, myalgia/arthralgia, cough, conjunctival injection, and vomiting. Less commonly, patients may present with more severe symptoms, such as GI bleeding, deafness, confusion, seizures, and coma.

Diagnosis

The current case definition for suspecting Lassa fever is as follows:^[1]

Unexplained fever at least 38 °C or 100.4 °F for ≥ 1 week
And 1 of the following:
▸ No response to standard treatment with the choice of regimen for most likely cause of fever (malaria, typhoid fever)
▸ Readmitted within 3 weeks of inpatient care for an illness with fever
And 1 of the following
▸ Edema or bleeding
▸ Sore throat and retrosternal pain/vomiting
▸ Spontaneous abortion following fever
▸ Hearing loss following fever

Common Symptoms

Common symptoms of Lassa fever are often non-specific symptoms that resemble symptoms of other viral infections:

The following table lists the common symptoms of Lassa fever and their corresponding prevalence among infected patients:

Symptom of Lassa Fever	Prevalence Among Infected Patients (%)
Fever	≈100
Headache	80-90
Arthralgia/Myalgia	80-90
Retrosternal Chest Pain	80-90
Weakness	70-80
Dizziness	70-80
Sore Throat/Pharyngitis	60-80
Cough	60-70
Vomiting	60-70
Abdominal Pain	50-60
Diarrhea	30-50
Conjunctivitis/Subconjunctival Hemorrhage	30-40
Chills	20-40
Deafness	20-30
Bleeding	20-30
Confusion	10-20
Swollen Neck or Face	10-20

Less Common Symptoms

Less common symptoms of Lassa fever usually develop late and are often associated with a more severe course of disease.

References

Overview