Viral Diseases - OTHER HEMORRHAGIC FEVERS

(Arenaviruses) All have natural persistent infection in rodents with humans being accidental hosts. Route of transmission to humans is generally thought to occur thru contamination of food, water, or air by rodent feces or urine or by inoculation of skin abrasions. Humans are infected primarily through infected rodents invading human habitats. Contact with infected rodent feces has produced disease in laboratory personnel. 

DIAGNOSIS:

Is by serology or virus isolation. Control is to reduce opportunity for exposure to infected rodents.

1. JUNIN VIRUS: produces Argentinian hemorrhagic fever There is an illness of 1-2 weeks with insidious onset of fever, malaise, rigors, fatigue, headache, vomiting, constipation or diarrhea, conjunctival congestion, retro-orbital pain, epistaxis, petechial hemorrhages beneath skin, palate and gums. Edema of the upper body is possible. In severe cases hematemesis and melena, encephalopathy, bradycardia and hypertension occur. Case fatality rate 5-30%. Several hundred cases reported each year in Argentina. Associated with at least 3 different cricetine rodent species in Argentina.

2. MACHUPO VIRUS: produces Bolivian Hemorrhagic fever.  Signs and case fatality rate like Junin virus. Case numbers have been decreasing rapidly since initiation of rodent control programs in 1975. Associated with Calomys callosus (a mouse-like South American wild rodent) (Bolivia).

3. LASSA FEVER: Serologically related to Lymphocytic Choriomeningitis, Machupo, and Junin virus. Fever has insidious onset over 2-3 days and may persist for up to 4 weeks, with malaise, headache and generalized aching and sore throat. Vomiting and diarrhea, possibly edema of face and neck, lymphadenopathy with hemorrhages and renal failure occurs in the second week. The prostration is out of proportion to fever. Often there is a maculopapular rash. Occurs in large areas in West Africa. Documented man to man transmission. Found in common rodent Mastomys natalensis, multimammate rat (West Africa).