According to the Nigeria Center for Disease Control and Prevention, Lassa fever has killed 214 people in Nigeria, increasing the case fatality rate to 25%. The NCDC's Lassa Fever Situation Report for Week 23 (June 1–June 7, 2026) included this information.
According to the government, the death rate is significantly higher than the 18.9% that was noted during the same time in 2025. Additionally, compared to the same period last year, there has been an increase in both suspected and confirmed cases.
"The number of newly confirmed cases in Week 23 was consistent with that of Week 22. States of Edo, Ondo, Bauchi, and Ebonyi reported cases of infection. During the week, no new infections were reported among healthcare workers.
According to the report, "since January 2026, the outbreak has spread across 23 states and 109 Local Government Areas."
Eighty-four percent of all verified cases are found in five states, according to the government.
With 28%, Ondo leads, followed by Bauchi at 25%, Taraba at 15%, Edo at 10%, and Benue at 6%. It further stated that 18 additional states with confirmed infections account for the remaining 16% of cases.
Young adults continue to be the most impacted group, according to the government.
The NCDC reports that cases range from 1 to 93 years, with a median age of 30 years, and that the most common age group is 21–30 years.
According to the government, the National Lassa Fever Multi-Partner, Multi-Sectoral Incident Management System remains operational to coordinate the response.
It clarified that response efforts at the federal, state, and local government levels are supported by the IMS.
The NCDC stated that the increased death rate and broader geographic dissemination suggest ongoing transmission even if no new infections among healthcare workers were detected in Week 23.
The government claims that case management and surveillance activities are still underway in all 23 impacted states.
