What is Lassa fever?
Lassa fever is a deadly acute viral hemorrhagic fever that kills thousands of people every year in West Africa.
Over 900,000 people are infected annually in Benin, Guinea, Liberia, Nigeria, Sierra Leone and Togo*.
Fever, diarrhea, hemorrhaging, and death in severe cases, is what follows after a person is infected by the Lassa virus through food or material contaminated by rodents. It can be transmitted from person to person through contact with infected body fluids.
Lassa fever is often difficult to diagnose, and acts with devastating speed, killing people within 14 days of their first symptoms. During Lassa fever outbreaks, the mortality rate ranges from 10 to 30%, with in-hospital mortality at 12%.
Loss of life could be avoided if Lassa fever is diagnosed and treated in time. However, the current recommended treatment drug, ribavirin, is associated with worrying toxicity and is of questionable efficacy*. New, more effective, Lassa fever treatment drugs are urgently required.
Lassa fever is one of the most dangerous threats to public health in the region given its epidemic potential, and the WHO has listed it as a priority disease for urgent research and development.
* Source: (2021) Basinski AJ, Fichet-Calvet E, Sjodin AR, Varrelman TJ, Remien CH, Layman NC, Bird BH, Wolking DJ, Monagin C, Ghersi BM, Barry PA, Jarvis MA, Gessler PE, Nuismer SL. Bridging the gap: Using reservoir ecology and human serosurveys to estimate Lassa virus spillover in West Africa. PLoS Comput Biol. 2021 Mar 3;17(3):e1008811. doi: 10.1371/journal.pcbi.1008811. PMID: 33657095; PMCID: PMC7959400.