Brazzaville, Republic of Congo — 21 November 2025 — The World Health Organization published a Disease Outbreak News report revealing that from 1 January to 2 November 2025, a total of 20,412 suspected diphtheria cases, including 1,252 deaths, have been reported across eight Member States in the WHO African Region. The average case fatality ratio stands at approximately 6%, but varies dramatically between countries — from 1.1% in Chad to 25.8% in Guinea.
The affected countries are Algeria, Chad, Guinea, Mali, Mauritania, Niger, Nigeria, and South Africa. Several of these nations have been experiencing ongoing outbreaks since 2023, signalling a persistent and widening public health crisis driven by immunisation gaps, fragile health systems, and complex humanitarian contexts.
Country-by-Country Breakdown
| Country | Suspected Cases | Deaths | CFR | Key Features |
|---|---|---|---|---|
| Nigeria | 12,150 | 884 | 7.2% | Highest burden; 240 LGAs across 30 states affected |
| Chad | 4,462 | 47 | 1.1% | 27 of 215 health districts affected; hosts 1.4M refugees |
| Niger | 1,926 | 122 | 6.3% | 34 of 72 health districts affected; 765 lab-confirmed |
| Mauritania | 849 | 33 | 4.0% | Declared 25 September 2025; rapid expansion across 11 departments |
| Guinea | 476 | 123 | 25.8% | Highest CFR; concentrated in gold mining areas of Kankan region |
| Mali | 430 | 29 | 6.7% | Rapid geographic expansion: 3 to 30 districts in under 6 weeks |
| South Africa | 106 | 12 | 18.0% | 5 of 9 provinces affected; clusters in correctional facilities |
| Algeria | 13 | 2 | 15.4% | Outbreak in Skikda province; linked to refugee displacement |
Nigeria: The Epicentre
Nigeria continues to report the highest number of diphtheria cases in the African Region. From 1 January to 2 November 2025, 12,150 suspected cases were reported, with 8,587 confirmed and 884 deaths. Confirmed cases span 240 Local Government Areas across 30 states. The outbreak has disproportionately affected children and adolescents, with low vaccination coverage contributing to spread. More than 2 million children in Nigeria are under-immunised, including zero-dose children.
Reactive vaccination campaigns have been conducted in Imo, Kaduna, and Lagos, targeting health workers and priority populations. However, challenges include delayed laboratory confirmation, poor infection prevention and control practices, and vaccine shortages. According to WHO/UNICEF estimates of national immunization coverage (WUENIC) for 2024, Nigeria's DTP coverage stands at 71% for the first dose and 67% for the third.
Guinea: The Highest Death Rate
Guinea has experienced a resurgence of diphtheria since June 2025, with 476 suspected cases and 123 deaths — a case fatality ratio of 25.8%, the highest among affected countries. The outbreak is concentrated in the Kankan region, particularly in Siguiri district, which accounts for over 80% of reported cases and fatalities. The outbreak is occurring in gold mining areas with high population mobility, increasing transmission risk.
Guinea's immunisation coverage remains critically low: 77% for the first DTP dose and 63% for the third, according to WUENIC 2024 data. The response is hampered by delayed presentation to health facilities and insufficient resources for clinical management.
The Diphtheria Antitoxin Crisis
A critical challenge across all affected countries is the global shortage of diphtheria antitoxin (DAT). DAT is the primary life-saving treatment for diphtheria, dramatically reducing mortality when administered early. In settings with poor access to DAT, the case fatality ratio can reach as high as 40%.
The shortage, combined with uneven clinical capacity to administer the treatment, poses a significant barrier to effective case management. WHO has recommended the establishment of contingency stockpiles of DAT, antibiotics, and laboratory supplies at regional hubs in Dakar and Nairobi to enable rapid deployment.
Who Is Most Affected
Women, children aged 5–18 years, and young adults under 30 years are the most affected demographic groups. This confirms that the immunity gap extends well beyond early childhood — a pattern consistent with disrupted vaccination programmes and incomplete booster coverage.
The situation has deteriorated most rapidly in Mali, Mauritania, and Niger in recent weeks, with increasing case numbers and geographic spread. In Mali, the number of affected districts increased from three to 30 in less than six weeks, representing a rapid expansion that has overwhelmed already stretched health services.
The Humanitarian Context
Many of the affected countries are fragile, conflict-affected, or have system vulnerabilities where health systems are overstretched, routine services are disrupted, and access to essential services is limited. These settings are characterised by:
- High population mobility and crowded living conditions, especially among displaced populations
- Concurrent disease outbreaks (yellow fever, measles, cholera, hepatitis E, Rift Valley fever)
- Food insecurity and economic crisis
- Large refugee populations (Chad hosts over 1.4 million refugees; Mauritania hosts over 118,000 Malian refugees)
Response and Recommendations
WHO, together with partners, continues to support national authorities through:
- Enhanced surveillance through active case finding and timely reporting
- Clinical management support, including appropriate use of antitoxin and antibiotics
- Risk communication and community engagement
- Capacity-building through training and dissemination of evidence-based guidelines
- Supplementary immunisation activities to close immunity gaps
WHO has graded the multi-country diphtheria outbreak as a grade 2 emergency under its Emergency Response Framework. The organisation emphasises that preventing recurrence will require strengthened health systems, particularly through robust routine immunisation coverage — a long-term challenge in the fragile contexts where diphtheria has taken hold.
Sources
- World Health Organization, Disease Outbreak News: Diphtheria – African Region (AFRO) (21 November 2025). Available at:
- WHO Regional Office for Africa: Member states renew commitments on diphtheria response across Africa. Available at:
- WHO: Clinical management of diphtheria – guideline (2024). Available at:
- WHO/UNICEF estimates of national immunization coverage (WUENIC). Available at:
- Bita Fouda AA, et al. Resurgence of diphtheria outbreaks in the African Region 2023–2024. Pan Afr Med J. 2025;51(1). Available at:
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Institutional Research Desk · Foresight Institute of Research and Translation
The collective editorial and research translation board of FIRAT, synthesising peer-reviewed evidence, policy briefs, and division milestones across our seven foundational research pillars.
