Noma (Cancrum Oris), the newest neglected tropical disease, is a severe, rapidly progressing necrotizing disease of the oral cavity and facial complex with a case fatality rate of 90% if untreated. It often affects children between two and six years in Sub-Saharan Africa (Noma Belt region), with most cases reported in northern Nigeria. However, little research is available on the incidence of noma and its clinical presentation in this region using comprehensive data. Therefore, this study aims to determine the incidence of noma and its clinical presentation in northern Nigeria among different age groups. We collected retrospective data of 1,383 consecutive patients managed at Noma Children’s Hospital, Nigeria between 1999 and 2024 for incidence estimation and description of the clinical presentation of noma. Incidence calculation was done using the WHO Oral Health Unit strategy designed with the Delphi method. Our results showed that patients were between 8 months and 80 years old with a median age (IQR) of 6 years (3-15). More patients presented with acute noma than arrested noma (67.3% vs 32.7%). The estimated incidence of noma in northern Nigeria during the study period was 114.5 cases per 100,000, with Sokoto state having the highest incidence of 921.9 cases per 100,000, while Adamawa state had the lowest incidence of 6.3 cases per 100,000. The annual average and median incidence of noma across all years was 4.4 and 2.2 cases per 100,000 (range: 0.2-21.3 cases per 100,000), although between 2020 and 2024, the annual average and median incidence estimates were 15.5 and 15.6 cases per 100,000. Also, this study found the incidence of noma cases with gangrene to be higher than cases with oedema or acute necrotizing ulcerative gingivitis. These findings confirm the high incidence and impact of noma in northern Nigeria in the last two and half decades and highlight the need to intensify awareness of risk factors and early signs of noma within communities in the region and to conduct community-based screening to promote the identification and cost-effective treatment of reversible early noma disease.

The authors have declared no competing interest.

The author(s) received no specific funding for this work.

I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.

Not Applicable

The details of the IRB/oversight body that provided approval or exemption for the research described are given below:

Approval to conduct this study was granted by the Sokoto State Ministry of Health Ethics Research Committee (Registration no: SKHREC/037/2024). Informed consent was waived due to the retrospective nature of this study. All potential patient identifiers were removed from the data collected, and anonymized data was used for analyses.

I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals.

Not Applicable

I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).

Not Applicable

I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable.

Not Applicable

Data used for this study is not publicly available due to the need to maintain patient confidentiality. However, anonymized data may be obtained from the corresponding authors upon reasonable request.