English: The male Lassa fever patient depicted here, in this 1977 image, was lying in a hospital bed in Segbwema, Sierra Leone, while recuperating from his viral illness. Note his dazed, somnolent facial expression due to his weakness, and exhaustion from fighting this illness. The pathogen was the Lassa virus, which is transmitted to humans who come into contact with urine of the viral host animal, which in this case, was a rodent known as the Natal multimammate rat, Mastomys natalensis.