As of epidemiological week 40 of 2026, the Nigeria Center for Disease Control and Prevention (NCDC) reported 1,138 confirmed cases of Lassa fever and 268 fatalities across 24 states and 119 local government units in Nigeria.
The case fatality rate increased to 23.6% from 18.6% in the similar period of 2025, according to the most recent situation report from the NCDC, which covered the period from September 28 to October 4.
With the largest proportion at 36%, Ondo was the most affected state among Bauchi, Taraba, Edo, and Benue, which together accounted for 88% of the confirmed cases. The reviewed week saw the reporting of three new cases along with one fatality.
The number of confirmed cases decreased from 13 the week before to three in week 40, as reported by the NCDC.
Factors such as inadequate environmental sanitation, poor health-seeking behaviour, high treatment expenses, and late presentation at health facilities were cited by the agency as contributing to the high death rate. Additionally, 54 healthcare professionals were reported to have contracted the virus in 2026.
The National Center for Epidemiology and Community Health (NCDC) announced that it had stepped up its efforts to prevent infections by increasing monitoring, contact tracing, outreach to the public, and safeguards for healthcare workers.
It stressed the importance of healthcare providers to “keep a high index of suspicion for Lassa fever,” act quickly to refer and treat suspected cases, and follow all protocols for preventing and controlling infections.