Introduction

Noma is a severely debilitating oro-facial gangrenous disease, mostly affecting children aged 2–6 years [1]. Thus far, no specific causative agent of noma has been identified [2]. Yet, a large variety of risk factors linked to poverty and inequity have been reported, such as chronic malnutrition, having previously suffered from an infectious disease, poor oral hygiene, and no or very limited access to water, sanitation, and hygiene (WASH) infrastructure [3]. Noma may develop if an individual’s immune system is weakened, the oral microbiome is altered, and bacteria commonly present in the mouth shift to a pathogenic profile. Noma can be categorized into five stages: 1, acute necrotizing gingivitis (ANG); 2, edema; 3, gangrene; 4, scarring; and 5, sequelae [4] (Fig 1). Up to stage 2, noma is reversible with timely broad-spectrum antibiotic treatment, nutritional support, and oral hygiene. From stage 3 onward, functional impairment and facial disfigurement become permanent. According to the gravity of the sequela, noma survivors require access to reconstructive surgery to facilitate a functional restoration allowing them to drink, eat, speak, and breathe more easily and to support re-integration into society by reducing stigmatization linked to the disfigurement [1]. However, access to reconstructive surgery remains challenging, either not available or not affordable, in most settings where noma occurs.

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Fig 1. The five stages of noma (1–5), characterized in four localization types [

4,5]. Figure drawn by Chloé Fournier/Inediz.

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Current epidemiologic data about the global incidence, mortality, and geographic distribution of noma is scarce [6]. Due to the rapid progression of the disease, which often results in undocumented deaths outside of health facilities, stigmatization in the community, limited access to health care, and poor identification of noma by health workers, noma is not accurately reported. The mortality of untreated cases is believed to be very high, though evidence is scarce to ascertain figures [2]. Among patients receiving timely antibiotic treatment, mortality has been reported to range between 0% and 38% (including patients with immunodeficiency) [3]. The most widely cited global incidence estimate of noma stems from a World Health Organization (WHO) Delphi consultation dating back to 1998, suggesting 140,000 new cases per year [7]. The same consultation put forth a global prevalence of 770,000 people living with sequelae of the disease. Newer studies reporting noma prevalence or incidence vary greatly in their conclusions and are limited by poor study designs. The latest estimate on global incidence published in 2003 reported 30,000-40,000 noma cases annually [8]. Contrary to common belief, noma is not confined to the African continent, but occurs in most low- and middle-income countries and sporadic cases continue to occur worldwide [2,6].

Interest in noma has increased since December 2023 when WHO officially declared it a neglected tropical disease (NTD) [9]. Additionally, two noma survivors, Mulikat Okanlawon (co-author) and Fidel Strub, were recognized internationally as two strong health advocates of the impact of noma by the TIME 100 Health 2024 list [10]. In order to build on this unprecedented momentum, the Swiss Tropical and Public Health Institute (Swiss TPH) and Elysium, Noma Survivors’ Association, joined forces and convened a 1-day symposium. The event brought together more than 100 people with lived experience of the disease, donors, noma and NTDs experts, and other public health specialists, including researchers, health advocates, and clinicians with first-hand experience in the treatment and management of noma. The aim of the symposium was two-fold. First, to review the current understanding of noma and to define a research agenda to generate new evidence and shape a strategy to prevent, control, and eliminate noma as a public health problem. Second, to reflect on how the identified research priorities fit into a broader framework of NTDs, highlighting potential synergies in advocacy, research and development (R&D), prevention, control, and elimination of noma and other NTDs.

Methods

The symposium “Defining the Noma Research Agenda” took place on 20 September 2024 at Swiss TPH in Allschwil, Switzerland, and was open to interested individuals and organizations in a hybrid format for plenary sessions (Fig 2). During the morning, experts introduced noma to the audience, including the latest clinical and epidemiologic research, while a panel discussion with noma survivors set the stage for sharing the realities of surviving noma and living with its life-long consequences. In the afternoon, participants split into four thematic breakout groups, accompanied by a note taker and rapporteur to (i) brainstorm; (ii) condense the discussion into specific research questions; and (iii) develop concepts for research projects or programs (e.g., setting, size, funding, and partners). The focal areas of the breakout groups were:

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Fig 2. Structure and content covered in the 1-day symposium Defining the Noma Research Agenda, held on 20 September 2024 at Swiss TPH in Allschwil, Switzerland.

Created with Biorender.

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• surveillance and prevention of noma
• physical and mental well-being of persons affected by noma
• noma stages and reconstructive surgery
• microbiologic and therapeutic aspects of noma

A fifth breakout group was open to participants who were new to the topic and interested in receiving an in-depth introduction on current knowledge of noma. Once reunited in the plenary, the rapporteurs summarized the discussion outcomes, followed by reactions in the plenary, identification of cross-cutting themes, discussion on overall priorities, and exploring potential synergies to the broader group of NTDs.

Results

Symposium participants

Participants at the 1-day symposium were affiliated with academia, non-governmental organizations (NGOs), public health institutions, government and private sector, donor community, WHO, and product development partnerships (Fig 3). Overall, 77 people participated physically and 30 were present online, including speakers and moderators.

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Fig 3. Characteristics of noma symposium participants who have participated in-person (blue) or for online attendance (green).

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Discussion and way forward

Much of the challenges that were discussed in the symposium pertain to the severe neglect of noma and the affected and highly vulnerable populations. First, the five noma stages defined by WHO are only used sparsely by stakeholders in reporting, rendering comparability of noma-related data challenging [4]. Consequently, we advise emphasizing their relevance, so that a unified nomenclature is used across disciplines and communities. Second, the lack of knowledge about noma among clinicians, nurses, and other public health professionals is limiting the feasibility of broad-based consultations, early case detection, and surveillance activities. Noma diagnosis, clinical presentations, and treatment need to be integrated into health curricula and educational campaigns, with a focus on differential diagnosis and prompt interventions to reduce the risk of irreversible damage and premature death. Third, the absence of even basic epidemiologic data on noma is simply unacceptable. It is paramount to establish active and passive surveillance on a global scale and to integrate noma into (national) health information systems and campaigns that include the most marginalized and vulnerable populations. To start addressing the neglect, noma research should be pragmatic and not over-medicalized to strengthen early case detection, thus averting the disease’s progression to an irreversible stage.

A major asset of the symposium was the active participation of noma survivors. Efforts should be made to facilitate their permanent presence in research and advocacy as pioneered for other conditions. Survivors' priorities were not always aligned with what academics thought to be necessary. Discussions concluded on the importance of considering the socio-economic and mental health needs of people affected by noma and their families. Having mentors and support from a community of like-minded peers or people with similar experiences, such as the pilot program Experts by Experience by Médecins sans Frontières, proved extremely valuable for survivors. Hence, associations of people with lived experience of noma need to be strengthened locally and globally. A potential guide for such collaborations could be the WHO guidelines for meaningful engagement of people with lived experience [11], the fact sheet of the Swiss Clinical Trial Organisation about patient and public involvement [12], or the 11 principles of the Commission for Research Partnerships with Developing Countries (KFPE) [13].

Finally, in line with its recent addition to the WHO list of NTDs, noma should be fully integrated into the NTD research, control, and elimination agenda. The integrated skin NTDs framework, for example, provides a promising fit for noma, and elaborates on how resources for diagnosis, wound care, detection and preventive campaigns, support groups, and advocacy with people affected should be used [14]. Addressing NTDs together offers specific opportunities for funding bodies and policymakers through reduced fragmentation and improved cost structures. While basic research will be instrumental in elucidating some of the pressing knowledge gaps around noma, control and care will be boosted with a step-up in operational research, and data to improve access to health care and prevention. This focus is in line with the effort to achieve Universal Health Coverage and realize the Sustainable Development Goal 3 pertaining to health. Recognized by the Human Rights Council in 2012 as “the most brutal face of poverty and malnutrition” [15], noma truly is an indicator for inequities.

Acknowledgments

We are grateful for the support by the Swiss TPH communications team, the travel desk, and the administrative officer for all their work during the planning of the symposium. In addition, we thank the Noma Survivors Association, Elysium, for inspiring us to organize the symposium and all of the helpers. Finally, we acknowledge all of the participants for their time and active participation in the symposium.

The opinions expressed in this paper are those of the authors and may not reflect those of their employing organizations. The authors alone are responsible for the views expressed in this publication which does not necessarily represent the decisions, policy, or views of their organizations.