Lassa Fever Virus

Abstract

Abstract Lassa virus, a member of the Arenaviridae family, is an enveloped virus with a bisegmented, linear, single‐stranded ribonucleic acid genome. Infection with Lassa virus can result in a range of outcomes from a mild or asymptomatic infection to Lassa fever, a severe and often fatal viral haemorrhagic fever. Human infection with Lassa virus occurs through contact with the reservoir Mastomys natalensis or infected humans. There are an estimated 300 000–500 000 cases of Lassa fever in West Africa each year, with most recorded cases occurring in Sierra Leone and Nigeria. Presently, there is no licensed vaccine or immunotherapy available for preventing or treating this disease. Although the antiviral drug ribavirin can be beneficial, it must be administered at an early stage of infection to successfully alter the disease outcome, thereby limiting its utility. Key Concepts: Lassa virus, a member of the Arenaviridae family, is the aetiologic agent of Lassa fever. Infection with Lassa virus can result in a range of outcomes from a mild or asymptomatic infection to severe and often fatal viral haemorrhagic fever. Signs and symptoms of Lassa fever are highly variable, which challenges early diagnosis. Lassa virus has an enveloped virion with a bisegmented, linear, single‐stranded ribonucleic acid genome. The Lassa virus virion contains nucleoprotein NP, zinc protein Z, glycoproteins GP1 and GP2 and an unusually long and stable signal peptide SSP. Human infection with Lassa virus occurs through contact with its reservoir Mastomys natalensis or infected humans. An estimated 300 000–500 000 cases of Lassa fever occur in West Africa each year, with most recorded cases occurring in Sierra Leone and Nigeria. No licensed vaccine or immunotherapy is presently available for preventing or treating Lassa fever. The antiviral drug ribavirin can be beneficial, but must be administered early, limiting its utility.