Nigeria has recorded 1,035 confirmed cases of Lassa fever and 252 deaths across 23 states and 117 local government areas in the first 33 epidemiological weeks of 2026, according to the latest situation report from the Nigeria Centre for Disease Control and Prevention.
The case fatality rate stands at 24.4 per cent, higher than the 18.6 per cent recorded during the corresponding period in 2025, when 854 confirmed cases and 159 deaths were reported.
In epidemiological week 33, covering 10 to 16 August, the country recorded 14 new confirmed cases and two deaths. The new cases were reported in Ondo, Edo, Bauchi and Benue states, a sharp rise from the four cases recorded in week 32.
Five states continue to account for the overwhelming majority of infections. Ondo, Bauchi, Taraba, Edo and Benue together reported 87 per cent of all confirmed cases. Ondo accounted for 33 per cent, Bauchi 25 per cent, Taraba 13 per cent, Edo 10 per cent and Benue six per cent. The remaining 13 per cent of cases were distributed across 18 other states.
People aged 21 to 30 years constituted the predominant age group affected, although confirmed cases ranged from one to 93 years, with a median age of 30 years. The male-to-female ratio among confirmed cases was 1:0.9.
Fifty-four healthcare workers have been affected by Lassa fever in 2026, although no new healthcare worker infection was recorded during week 33. Twelve patients were being managed at treatment centres during the reporting week, bringing the cumulative number of cases managed at treatment centres in 2026 to 783.
On contact tracing, 2,007 contacts had been listed cumulatively, with 168 still under follow-up. A total of 1,836 contacts had completed follow-up, while 110 symptomatic contacts had been identified and 49 tested positive.
The NCDC said it had intensified interventions to contain the outbreak. These include training healthcare workers, strengthening infection prevention and control measures, supporting active case search and contact tracing, and pre-positioning personal protective equipment and other supplies in health facilities.
A 30-day Healthcare Worker Protection Plan has been developed to reduce infections among frontline health workers in endemic states, with support from the World Health Organisation and the United States Centers for Disease Control and Prevention. National Rapid Response Teams have been deployed across seven high-burden states, while Incident Management Systems for Lassa fever have been activated in Benue, Plateau, Kebbi, Kano and Gombe states.
Despite these efforts, the agency identified several major challenges. These include late presentation of cases, poor health-seeking behaviour linked to the high cost of treatment, poor environmental sanitation, low awareness in high-burden communities and infections among healthcare workers.
The NCDC urged states to sustain community engagement on Lassa fever prevention throughout the year. It advised healthcare workers to maintain a high index of suspicion, make timely referrals, commence treatment promptly and adhere strictly to infection prevention and control procedures. The agency also called for stronger state capacity to prevent, detect and respond promptly to outbreaks.
Lassa fever is an acute viral haemorrhagic illness endemic in parts of West Africa. It is primarily transmitted to humans through contact with food or household items contaminated with urine or faeces of infected multimammate rats. Person-to-person transmission can also occur, particularly in healthcare settings without adequate infection control.
Nigeria bears a significant share of the regional burden. Seasonal peaks typically occur during the dry season, although cases are reported year-round. The elevated case fatality rate in 2026 compared with the previous year underscores ongoing difficulties in early detection, timely access to care and consistent application of infection prevention measures.
The concentration of cases in a limited number of states highlights the importance of targeted interventions in high-burden areas while maintaining vigilance nationwide. Continued surveillance, community sensitisation, improved environmental hygiene and protection of healthcare workers remain central to efforts aimed at reducing transmission and mortality.
As of epidemiological week 33 of 2026, the cumulative figures of 1,035 confirmed cases and 252 deaths reflect both the persistent challenge posed by the disease and the scale of the public health response required to mitigate its impact.