Clinical Virology of Lassa Fever in Hospitalized Patients

Publisher Website
Google Scholar
Abstract
We measured levels of virus in sequential specimens from 137 patients with Lassa fever. The probability of fatal disease increased significantly with the level of viremia measured either on admission or during the course of illness. The odds ratio of death in patients with viremia >103.0TCID50/ml was 3.7 (90% confidence interval, 1.9–7.2). The same ratio in patients with viremia >103.0TCID50/ml and with levels of aspartate aminotransferase ⩾150 IU/liter was 21.5 (95% confidence interval, 5.2–99.0). Virus was found in throat cultures from 39% of viremic patients, compared with 14% of nonviremic patients (P < .002); however, the level of virus was usually ⩽101.0TCID50/ml. Fewer than 3% of patients were viruric during acute illness, and virus was isolated from three of three samples of cerebrospinal fluid. On admission, 53% of patients had IgG antibodies, and 67% had IgM antibodies. Recovery was not associated with the presence of either IgG or IgM. Virus was isolated from >100 serum specimens that also contained high titers of IgG. Clinical Lassa fever was shown to be a disseminated systemic, primary viral infection, with an outcome highly associated with viremia but not with development of antibody.