Lassa fever: A comprehensive review of virology, clinical management, and global health implications.

Abstract

Lassa fever (LF) is a serious acute viral hemorrhagic illness that is endemic to West Africa where it affects an estimated two million people and results in up to 10000 deaths each year. The disease is caused by the Lassa virus (LASV), part of the Arenaviridae family, and is primarily transmitted through contact with urine or feces of infected Mastomys natalensis rodents. Human-to-human transmission, particularly in healthcare and community settings, further amplifies the risk of spread. Since its discovery in 1969, LF continues to be a neglected tropical disease with significant health impacts, especially in vulnerable populations such as pregnant females and those with weakened immune systems. The clinical spectrum of LF varies from mild, flu-like symptoms to severe complications including bleeding, brain inflammation, and multiple organ dysfunction with neonates and pregnant female showing the highest fatality rates. Accurate diagnosis is hindered by symptom overlap with common regional illnesses such as malaria and typhoid, underlining the urgent need for strengthened diagnostic infrastructure and rapid testing methods. While ribavirin remains the main antiviral treatment, its effectiveness depends heavily on early administration. Currently, no approved vaccine exists; however, promising candidates like vesicular stomatitis virus (VSV)ΔG-LASVGPC, INO-4500, and measles virus-based (MV)-LASV are undergoing preclinical and early-phase clinical evaluation, exhibiting encouraging immune responses in animal and human studies. A comprehensive strategy combining public health education, rodent control measures, robust infection prevention in clinical settings, and international cooperation in vaccine and drug research is essential to curb the impact of LF.