A reverse-chronological feed of official reports and media coverage — scan what happened, in order, and link to any update.
NCDC situation report, epi week 29: 6 new confirmed cases and 1 death in Edo State, the current low-transmission endemic tail. Cumulatively the 2026 season stands at 807 cases and 207 deaths nationally (CFR 25.6%).
NCDC situation report, epi week 27: 8 new confirmed cases and 2 deaths in Ondo State. WHO's Lassa fever fact sheet notes Nigeria records cases year-round, with the dry-season peak now well past.
NCDC situation report, epi week 25: 12 new confirmed cases and 2 deaths in Edo State, the persistent endemic baseline at ISTH between seasons.
NCDC situation report, epi week 24: 14 new confirmed cases and 3 deaths in Ondo State. National weekly incidence is now a fraction of the February–March peak.
Nigerian media report a renewed Lassa fever cluster in Plateau State (Lineage III), with 13 confirmed cases and 4 deaths around Jos, keeping the north-central focus active into June.
NCDC situation report, epi week 23: 14 new confirmed cases and 3 deaths in Bauchi State as the outbreak settles into the mid-year endemic tail.
NCDC situation report, epi week 22: 18 new confirmed cases and 5 deaths in Benue State, one of the last north-central states to decline as the dry season ends.
NCDC situation report, epi week 21: 20 new confirmed cases and 5 deaths in Edo State as the season eases toward the wet-season low-transmission baseline.
NCDC situation report, epi week 20: 22 new confirmed cases and 4 deaths in Ondo State. The improving case fatality ratio reflects earlier presentation and ribavirin treatment at the Owo and Akure centres.
NCDC situation report, epi week 19: 12 new confirmed cases and 4 deaths in Taraba State as national incidence continues its post-peak decline into May.
NCDC situation report, epi week 18: 20 new confirmed cases and 5 deaths in Bauchi State as the north-eastern cluster winds down toward the wet-season transition.
NCDC situation report, epi week 17: 16 new confirmed cases and 5 deaths in Ebonyi State (Lineage III), managed at AE-FUTHA Abakaliki as the south-eastern focus continues at a lower level.
NCDC situation report, epi week 17: 34 new confirmed cases and 9 deaths in Edo State. ISTH admissions ease from the peak but Edo stays among the two highest-burden states of the season.
NCDC situation report, epi week 16: 12 new confirmed cases and 4 deaths in the Federal Capital Territory, several linked to travel from endemic states. Lineage assignment is pending sequencing at the NCDC National Reference Laboratory in Abuja.
NCDC situation report, epi week 15: 38 new confirmed cases and 8 deaths in Ondo State. Incidence is declining from the February–March peak but Ondo continues to lead the national count.
NCDC situation report, epi week 15: 16 new confirmed cases and 6 deaths in Nasarawa State, centred on Lafia. The north-central cluster is genotyped as Lassa virus Lineage III.
NCDC situation report, epi week 14: 22 new confirmed cases and 7 deaths in Taraba State as the peak eases; case fatality remains elevated in the north-east.
NCDC situation report, epi week 13: 28 new confirmed cases and 8 deaths in Benue State, the last week of the season's peak before national incidence begins to decline.
Nigerian media (The Guardian Nigeria) reports a Lassa fever cluster in Kogi State, with 14 confirmed cases and 4 deaths around Lokoja, ahead of the corresponding NCDC weekly report. State health authorities activate contact tracing in the affected LGAs.
NCDC situation report, epi week 12: 30 new confirmed cases and 8 deaths in Bauchi State as the dry-season peak begins to plateau nationally.
NCDC situation report, epi week 11: 40 new confirmed cases and 10 deaths in Edo State, with transmission broadening from Irrua toward Benin City and the Oredo and Esan Central LGAs.
NCDC situation report, epi week 10: 18 new confirmed cases and 5 deaths in Plateau State, centred on Jos. The north-central Plateau cluster is genotyped as Lassa virus Lineage III.
A returning traveller from Nigeria is confirmed with Lassa fever in England and transferred to a high-consequence-infectious-disease (HCID) unit at the Royal Free Hospital, London. UKHSA traces contacts as a precaution and reports no secondary transmission; imported Lassa cases in Europe historically remain isolated.
NCDC situation report, epi week 10: 46 new confirmed cases and 9 deaths in Ondo State, with the burden shifting toward Akure and Akure South LGAs. Ondo remains the highest-cumulative-burden state of the season.
NCDC situation report, epi week 9: 24 new confirmed cases and 7 deaths in Ebonyi State, managed at the Alex Ekwueme Federal University Teaching Hospital Abakaliki (AE-FUTHA). Sequencing assigns the Ebonyi cluster to Lassa virus Lineage III.
NCDC situation report, epi week 9: 30 new confirmed cases and 9 deaths in Taraba State, which continues to record one of the season's highest case fatality ratios.
NCDC situation report, epi week 8: 20 new confirmed cases and 6 deaths in Gombe State, extending the north-eastern cluster beyond Bauchi.
NCDC situation report, epi week 8: 34 new confirmed cases and 9 deaths in Bauchi State as the north-eastern focus intensifies through the dry-season peak.
ECDC communicable-disease threats report: a traveller returning to Germany from eastern Nigeria is confirmed with Lassa fever and treated in the high-level-isolation unit at Frankfurt University Hospital. Contact tracing of flight and household contacts finds no secondary cases; ECDC assesses the risk to the EU/EEA as very low.
NCDC situation report, epi week 7: 44 new confirmed cases and 11 deaths in Edo State. Two healthcare workers at ISTH are among the confirmed cases, prompting a review of infection-prevention-and-control practices; WHO AFRO notes Edo and Ondo remain the twin epicentres.
NCDC situation report, epi week 6: 24 new confirmed cases and 7 deaths in Benue State, centred on Makurdi. Benue joins the five highest-burden states as the north-central focus widens.
NCDC situation report, epi week 6: Ondo peaks at 52 new confirmed cases and 10 deaths as the dry-season transmission crests, the single largest weekly state increment of the season. NCDC deploys a rapid response team and additional ribavirin stocks to Owo.
NCDC situation report, epi week 5: 26 new confirmed cases and 8 deaths in Taraba State, centred on Jalingo. Taraba's case fatality ratio runs above the national average, straining the Federal Medical Centre Jalingo treatment capacity.
NCDC situation report, epi week 4: 22 new confirmed cases and 5 deaths in Bauchi State, extending the outbreak into the north-east. Abubakar Tafawa Balewa University Teaching Hospital activates its Lassa isolation ward.
NCDC situation report, epi week 3: 30 new confirmed cases and 8 deaths in Edo State, the bulk admitted to the Irrua Specialist Teaching Hospital Lassa treatment centre — confirming the late-December ISTH signal. Edo and Ondo together account for over half of national cases this week.
NCDC Lassa fever situation report, epi week 2: 28 new confirmed cases and 6 deaths in Ondo State, most in Owo and Ose LGAs, managed at the Federal Medical Centre Owo isolation ward. Ondo opens the season as one of the highest-burden states.