Lassa fever outbreak in West Africa: Rising regional cases with global implications

<p dir="ltr">Guinea confirmed its first fatal Lassa fever case since February 2024 in September 2024; moreover, a total of 10,121 cases have been reported in Liberia and Nigeria as of epidemiological week 45, highlighting the increasing threat posed by this viral hemorrhagic fever and its global health implications. Lassa virus (LASV), first identified in 1969 in a nurse who contracted the disease in Lassa, Nigeria, has since become endemic in Nigeria (with yearly outbreaks from 2018 to 2023), Guinea, Liberia and Sierra Leone. On October 3, 2024, WHO was notified about the Guinea case, involving a 63-year-old man from Guéckédou prefecture. He presented on September 19 with symptoms including fever, headache, and fatigue, was confirmed with Lassa fever three days later, and passed away on September 23. This case forms part of a broader 2024 outbreak across West Africa, with Nigeria reporting 1115, Liberia 39 and Guinea 3 confirmed cases, among a total of 10,747 reported, and a case fatality rate (CFR) ranging from 17 % to 33 % across these countries between epidemiological weeks 1 and 49. In late October 2024, a U.S. citizen reportedly died from suspected Lassa fever after returning from West Africa, highlighting the virus’s potential for cross-border spread and the importance of global surveillance.</p>