infections
Lassa Fever and South American Hemorrhagic Fevers
Symptoms
Symptoms of Lassa fever and South American arenavirus hemorrhagic fevers usually start about 5 to 16 days after people are exposed to the virus. These infections cause fever, a general feeling of illness (malaise), weakness, diffuse body aches, diarrhea, and vomiting. Over the next 4 to 5 days, chest pain, a sore throat, cough, and vomiting may develop. About 80% of cases of Lassa fever are mild and are often not diagnosed. But symptoms are severe in about 20% of people. If severe, Lassa fever may cause the face and neck to swell, fluid to build up in the lungs, bleeding from the mouth, nose, vagina or digestive tract, and low blood pressure (see World Health Organization [WHO]:Lassa fever). About 20 to 30% of people with Lassa fever lose their hearing. Loss may be permanent. Bleeding from the mouth, nose, stomach, and intestinal tract is common in South American hemorrhagic fevers. Obvious bleeding is less common in Lassa fever. But bleeding sometimes occurs from puncture wounds, the gums, or the nose and under the skin (seen as small purplish spots). When death occurs, it usually results from shock caused by widespread leakage of fluid from blood vessels. Recovery or death usually occurs 7 to 31 days after symptoms begin. Approximately 15 to 20% of people hospitalized for severe Lassa fever die from the illness (Centers for Disease Control and Prevention [CDC]:Lassa Fever Signs and Symptoms). Disease is severe during pregnancy, especially during the 3rd trimester. Most infected pregnant women lose the fetus (CDC:Lassa Fever Signs and Symptoms). 