Nigeria's Lassa fever year: 1,056 cases and a quarter of them fatal
What happened
Nigeria's Lassa fever season has continued through the year, and the national figures are now substantial. According to the UK's National Travel Health Network and Centre, NaTHNaC, whose entry was updated on 3 September 2026, Nigeria has reported 1,056 confirmed cases of Lassa fever so far in 2026, along with 7,580 suspected cases, six probable cases and 253 deaths, across 24 states. Nigerian reporting drawn from the Nigeria Centre for Disease Control put the case fatality rate at around 24 per cent as of epidemiological week 33, noticeably higher than the 18.6 per cent recorded over the same period in 2025. Cases are concentrated. Five states, Ondo, Bauchi, Taraba, Edo and Benue, account for around 87 per cent of confirmed cases, with Ondo alone accounting for roughly a third. One detail stands out in the reporting: health workers continue to be infected, with dozens affected over the course of the year. Lassa fever is not new in Nigeria. It has a season, typically peaking in the dry months, and this year's outbreak has been unusually persistent.
Why this matters
Lassa fever is a viral illness spread mainly by a rodent, the multimammate rat, which lives in and around homes across much of West Africa. People usually catch it by breathing in dust or eating food contaminated with the rat's urine or droppings, or by handling the animal. It can also pass between people through direct contact with blood or body fluids, which is why health workers are at particular risk. Most people who are infected have a mild illness, or none at all. But when it turns severe it is dangerous, and a case fatality rate of around a quarter among confirmed cases is high. For UK travellers, the honest framing is important. NaTHNaC states that tourists face minimal risk, and that imported cases are rare outside people working in high-risk occupations. A holiday, a business trip or a family visit does not put you in the same position as a nurse on a Lassa ward. But the UK has close and constant links with Nigeria, and people travel in both directions to visit family all the time. So this is not a distant story. It is worth knowing what the risk actually depends on, which is where you stay and what you do, not simply which country you are in.
What the evidence actually says
A few things are worth reading carefully in these numbers. The case fatality rate of around 24 per cent applies to confirmed cases. It is not the proportion of everyone infected who dies. Many mild infections are never tested, never confirmed and never counted, which pushes the measured rate upwards. The true fatality rate across all infections is considerably lower. The gap between 7,580 suspected cases and 1,056 confirmed cases also tells you something. Lassa fever starts with fever, headache and general aches, symptoms shared with malaria and many other illnesses, so a great many suspected cases turn out to be something else. The rise in the case fatality rate compared with last year is a genuine concern, and there are several plausible explanations: people arriving at hospital later, pressure on treatment centres, or differences in which cases are being tested. The published figures do not settle which. There is an antiviral, ribavirin, which is used in treatment, and evidence suggests earlier treatment gives better outcomes. There is no licensed vaccine, though candidates are in development. The strongest and least ambiguous point in the data is the geography. This is not an evenly spread national outbreak. It is heavily concentrated in a handful of states.
Practical advice
If you are travelling to Nigeria, particularly to rural areas or to the states most affected, the precautions are practical rather than dramatic. Store food in sealed, rodent-proof containers, and do not leave food out. Keep rubbish covered and away from the house. Do not sweep dry dust in a room where rodents may have been. Damp-cleaning avoids raising contaminated dust into the air. Do not catch, handle or eat rodents. Block holes and gaps where rodents can get into buildings, and keep the area around accommodation clear. Avoid close contact with anyone who is seriously unwell with a fever, and avoid contact with blood and body fluids. If you are working in healthcare, follow full infection control precautions, because health workers are among the most affected group in this outbreak. And this is the one that matters most: if you develop a fever within three weeks of returning from West Africa, seek medical advice straight away and tell them where you have been. Ring ahead rather than turning up unannounced. The most likely cause is malaria, which itself needs urgent treatment, so this is worth doing regardless. Before you travel, get destination-specific advice from a travel clinic, your GP practice or a pharmacist offering travel services, and check the FCDO travel advice for Nigeria.
What to know
Nigeria has recorded 1,056 confirmed Lassa fever cases and 253 deaths across 24 states so far in 2026, with a case fatality rate among confirmed cases of around 24 per cent, up from 18.6 per cent at the same point last year. Cases are heavily concentrated in five states, led by Ondo. The risk to ordinary travellers is described by NaTHNaC as minimal, with imported cases rare outside high-risk occupations. The precautions that matter are about food storage, rodents and avoiding contact with body fluids. If you develop a fever within three weeks of returning from West Africa, get medical advice quickly and say where you have been. Sources: NaTHNaC (TravelHealthPro), 'Lassa fever', updated 3 September 2026, figures as at 23 August 2026, https://travelhealthpro.org.uk/diseases/lassa-fever ; Vanguard News, 'Lassa fever deaths hit 252 as Nigeria records 14 new cases', September 2026, https://www.vanguardngr.com/2026/09/lassa-fever-deaths-hit-252-as-nigeria-records-14-new-cases/ ; Tribune Online, '2026: Nigeria records 252 Lassa fever deaths, 1,035 confirmed cases', September 2026, https://tribuneonlineng.com/2026-nigeria-records-252-lassa-fever-deaths-1035-confirmed-cases/ This article is for general information and does not replace advice from a doctor, pharmacist or other qualified healthcare professional. Case numbers change week by week; check NaTHNaC and FCDO advice close to your travel date.
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