Nigeria’s Lassa fever outbreak has recorded another increase in confirmed infections, with the Nigeria Centre for Disease Control and Prevention (NCDC) reporting 14 new cases during epidemiological Week 33.
The latest figures bring the cumulative number of confirmed Lassa fever infections to 1,035, according to the NCDC’s Week 33 situation report released in Abuja on Tuesday. The agency said the new infections were recorded between August 10 and August 16 across four states.
Bauchi, Benue, Ondo and Edo accounted for the 14 cases reported during the period, while the number of recorded deaths rose to 252. The corresponding case fatality rate (CFR) increased to 24.4 per cent, compared with 18.6 per cent recorded over the same period in 2025.
The latest weekly figures also show an increase in transmission compared with the immediately preceding reporting period. In epidemiological Week 32, the country recorded four confirmed cases from Ondo and Edo states, taking the cumulative infection figure at the time to 1,021, with 240 deaths and a case fatality rate of 23.5 per cent.
The NCDC said the 14 cases reported in Week 33 represented a rise from the four cases recorded one week earlier. However, the agency noted that weekly transmission has continued to fluctuate, pointing out that the Week 32 figure itself represented a decline from the 17 confirmed cases recorded during Week 31.
The changing weekly figures underscore the continuing transmission of Lassa fever across affected areas, even as the number of newly confirmed infections varies from one epidemiological period to another.
By the end of Week 33, the disease had been reported in 23 states, with confirmed infections recorded across 117 local government areas. The geographical spread highlights the continued presence of Lassa fever as a public health concern in different parts of the country.
The increase in the case fatality rate is also a notable feature of the latest situation report. With 252 deaths among the 1,035 cumulative confirmed cases, the reported CFR of 24.4 per cent is considerably higher than the 18.6 per cent recorded in 2025.
The NCDC continues to monitor the situation through its surveillance and response systems as new cases are identified. The agency has maintained that surveillance remains essential to detecting infections, tracking their spread and supporting the response to outbreaks across affected states.
The Week 33 report therefore presents a mixed picture of Lassa fever transmission: new infections increased sharply from the previous week’s four cases, but the pattern of transmission remains uneven, with the NCDC noting fluctuations in weekly case numbers.
The latest infections were identified in Bauchi, Benue, Ondo and Edo, adding to the cumulative burden already recorded across the 23 states affected by the disease. The concentration of new cases in four states also demonstrates that continued monitoring is required at the state and local government levels.
In Week 32, only Ondo and Edo recorded confirmed cases, with four infections reported between the relevant reporting dates. The subsequent increase to 14 cases in Week 33 means that 10 additional confirmed infections were recorded compared with the preceding week.
The NCDC’s comparison with Week 31 further shows why individual weekly increases need to be viewed within the wider surveillance trend. Although Week 33 recorded 14 cases, the figure remained below the 17 cases reported during Week 31, illustrating the fluctuations highlighted by the agency.
Despite those variations, the cumulative figures remain significant. More than 1,000 confirmed infections have now been recorded, while the death toll has reached 252. The agency’s latest report places the current case fatality rate at 24.4 per cent.
The continued spread across 117 local government areas also means that Lassa fever remains a national surveillance priority rather than an isolated outbreak restricted to a single location. The involvement of 23 states reflects the breadth of the areas where confirmed infections have been detected.
The NCDC has assured that surveillance and response activities remain ongoing as authorities monitor the disease in affected states. The agency continues to follow reported infections and assess developments through its epidemiological reporting system.
The latest report covers infections recorded from August 10 to August 16, meaning the figures provide a snapshot of confirmed cases during that reporting window rather than a final assessment of transmission across the country.
With the cumulative figure now standing at 1,035 confirmed cases and the death toll at 252, the Week 33 report provides the latest indication of the continuing Lassa fever burden in Nigeria. The rise from four cases in Week 32 to 14 in Week 33 has placed renewed attention on the need for sustained surveillance and response efforts.
The NCDC said it would continue its surveillance and response activities as the country monitors the situation across affected states and local government areas.
Lassa Fever: NCDC Confirms 14 New Cases as Death Toll Rises to 252
