Lassa Fever

Epidemics occur in dry seasons in West Africa, Nigeria, Sierre Leonne, and Democratic Republic of Congo. This virus is transmitted to humans by infected rat body fluids, and then highly contagious between people. Up to 30% of those infected have no symptoms.

Others have symptoms beginning after an incubation period of 1-3 weeks.
Symptoms are high fever, vomiting, diarrhea, cough, pains and generalized weakness. Inflammation of eyes, throat, face and neck may occur.

After 3-6 days bleeding occurs.

Survivors may be left with hair loss, deafness, and loss of coordination.

Diagnosis is initially difficult to differentiate.

White patches are present on the tousle.

A blood test helps confirm cases. IV treatment, with anti-viral helps.

Since there may be some time before people exhibit symptoms a strong suspicion should be kept in returning travelers with high fever, who have been to endemic areas, no matter how short their stay.

Lassa fever is an arena virus and is transmitted to people by contact with infected rat urine and also by person -to- person contact. It can cause severe illness including bleeding and meningo-encephalitis with lack of effective therapy, but the vast majority of people infected exhibit minimal symptoms

Risk to travelers is very small but exists for health care workers. Usually infected people will exhibit symptoms within 21 days of return.
Differential diagnosis includes other viruses caught from mosquitoes or other insects (Dengue fever, Yellow fever, O'nyong-nyong, Chikungunya, Rift valley fever, Crimean-Congo fever and Hanta fevers.

Lassa Fever links:
WHO http://www.who.int/mediacentre/factsheets/fs179/en/

travelhealth.co.uh http://www.travelhealth.co.uk/diseases/lassa.htm

TKH Virology: http://www.tarakharper.com/v_lassa.htm

CDC site: http://www.cdc.gov/ncidod/dvrd/spb/mnpages/dispages/lassaf.htm

CDC slide set: http://www.cdc.gov/ncidod/dvrd/spb/mnpages/lassaslides.htm

Adoption.com http://library.adoption.com/Health-Issues/Lassa-Fever/article/1319/1.html


eurosurveillance.org http://www.eurosurveillance.org/em/v07n03/0703-226.asp