Lassa fever is one of the four forms of viral haemorrhagic fever transmitted from person to person (see Ebola haemorrhagic fever). It was first recognized in 1970 in Nigeria and is known to have a rodent reservoir, with person to person spread following human ingestion of contaminated food. The pathogenesis involves viral interaction with and damage to endothelial cells and platelets, giving rise to a generalized capillary leak.
The incubation period is 6—21 days, which provides sufficient time nowadays for travel anywhere in the world.
The illness presents initially as influenza-like, with a sore throat, rash and gastrointestinal symptoms. In the second week, encephalopathy, hepatitis and pleurisy are seen. Haemorrhage, renal failure and shock may occur in some patients.
The diagnosis is made by viral culture and serology.
The differential diagnosis includes many other infective diseases, including:
Was this article helpful?