Lassa Fever Nigeria 2026: 663 Confirmed Cases, 167 Deaths, 25 Percent Fatality Rate as US Healthcare Experts Issue Urgent Warning to Travelers

Nigeria’s 2026 Lassa fever outbreak: 663 confirmed cases, 167 deaths, 25.2% case fatality rate — up from 18.5% last year — across 22 states. 39 healthcare workers infected. NETEC warns U.S. clinicians to increase suspicion in returning travelers. Here is what patients and providers need to know.