infectious diseases
Lassa Fever
Symptoms and Signs of Lassa Fever
The incubation period for Lassa fever is 5 to 16 days. Symptoms of Lassa fever begin with gradually progressive fever, weakness, malaise, and gastrointestinal symptoms (eg, nausea, vomiting, diarrhea, dysphagia, stomach ache); Symptoms and Signs may occur. Over the subsequent 4 to 5 days, symptoms progress to prostration with sore throat, cough, chest pain, and vomiting. The sore throat becomes more severe during the first week; patches of white or yellow exudate may appear on the tonsils, often coalescing into a pseudomembrane. In severe cases, facial swelling, fluid in the lung cavity, bleeding from the mouth, nose, vagina or gastrointestinal tract, and low blood pressure may develop (see World Health Organization [WHO]:Lassa fever). Occasionally, patients have tinnitus, epistaxis, maculopapular rash, cough, and dizziness. Sensorineural hearing loss develops in 20 to 30% ( Symptoms and signs reference ); it is often permanent. Patients who recover defervesce in 4 to 7 days. Progression to severe illness results in shock, delirium, rales, pleural effusion, and, occasionally, generalized seizures. Pericarditis occasionally occurs. Degree of fever and aminotransferase levels correlate with disease severity. Late sequelae include alopecia, iridocyclitis, and transient blindness. 1.Cummins D, McCormick JB, Bennett D, et al. Acute sensorineural deafness in Lassa fever.JAMA264(16):2093-2096, 1990 