Study maps noma risk hotspots in northern Nigeria

Iveta Ramonaite, Dental Tribune International

Tue. 11. August 2026

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HONG KONG: Noma is a severe, rapidly progressing and generally non-contagious gangrenous disease that destroys the soft and hard tissue of the mouth and face. Nigeria is believed to have one of the heaviest burdens of noma globally, but its local geographical distribution has remained poorly understood. A recent study has now mapped estimated incidence risk across parts of northern Nigeria and identified previously unrecognised high-risk areas, providing evidence that could help guide prevention and early detection programmes.

According to noma researcher Dr John Adeoye, noma has been largely neglected in research and in public health efforts. (Image: Dr John Adeoye)

Senior author Dr John Adeoye, assistant professor in digital and precision dentistry at the University of Hong Kong, said that his interest in noma epidemiology and mapping began in 2018, when he encountered patients with the disease during a surgical outreach in Nigeria. “Before then, my knowledge of noma was largely limited to textbook descriptions of it as a historical disease associated with poverty and malnutrition,” he told Dental Tribune International. “I was deeply troubled to see how a condition that may begin with gingival inflammation could rapidly destroy large portions of the face and, if untreated, lead to death in 80% to 90% of affected individuals.”

In 2023, the World Health Organization formally recognised noma as a neglected tropical disease. “For many years, noma has received little research attention, limited funding and inadequate public health action. These experiences motivated me to contribute to research that identifies communities with a high incidence of noma so that government agencies, health workers and non-governmental organisations can target awareness, prevention and early detection programmes more effectively,” Dr Adeoye explained.

In the study, the researchers analysed 25 years of clinical data collected at the Noma Children’s Hospital in Sokoto in Nigeria and mapped estimated noma incidence risk at local government level in 12 northern Nigerian states. They identified 64 local government areas with modelled incidence risk significantly above the regional average, including a high-risk cluster encompassing 23 local government areas in north-western Nigeria. Dr Adeoye explained that these areas should be prioritised for activities aimed at raising awareness of noma, preventing the disease, promoting early detection and facilitating referral.

Additionally, the researchers created colour-coded maps showing the geographical distribution of estimated noma incidence risk overall and by age group, sex and time period. According to Dr Adeoye, these maps could help policymakers, health authorities and non-governmental organisations prioritise awareness, case finding, early referral and prevention programmes in areas with the greatest estimated need. The modelling framework could also be adapted for other countries in which noma remains under-reported and poorly mapped, he said.

For oral healthcare professionals, the maps could help connect geographical risk with clinical vigilance. Dr Adeoye emphasised that, because noma initially presents in the oral cavity, dentists, dental therapists and other oral health workers are well placed to recognise possible early disease and arrange urgent referral.

“Our findings provide a more precise geographical guide for where oral health interventions should be prioritised. Dental outreach programmes, oral health education, screening activities and training of primary healthcare workers can now be directed towards local government areas with the highest estimated risk,” he noted.

The maps are already being translated into practical action. Supported by the University of Hong Kong, the researchers are working with the ZeroNoma Initiative in north-western Nigeria to train volunteers and use the hotspot data to guide screening and case finding activities. The project illustrates how spatial modelling could help turn hospital records into more focused community prevention and referral strategies.

The study builds on earlier research involving members of the team. Research published in 2019 estimated noma incidence and prevalence in north-central Nigeria, and a study published in 2025 estimated noma incidence and described the clinical presentation of cases in northern Nigeria.

The study, titled “Spatial distribution of noma incidence in Nigeria, 1999–2024: A modelling study”, was published in the July 2026 issue of the Lancet Global Health.