Diphtheria - African Region (AFRO)

Diphtheria is a major public health problem in the African region despite substantial efforts on immunization activities over the past three decades. Between 2000 and 2024, 75 789 diphtheria suspected cases were reported in the Region with the majority being reported from 2023 to 2024. In 2023-2024, Algeria, Chad, Gabon, Guinea, Mali, Mauritania, Niger, Nigeria and South Africa reported resurgence of diphtheria outbreaks with approximately 57 000 suspected cases and 2000 deaths (CFR of 3.5%) recorded. The countries most affected were Guinea, Niger and Nigeria. Most cases reported were children under fifteen years and female. Over 50% of suspected cases were non-vaccinated or with unknown vaccination status.

Since the beginning of 2025 and as of 2 November 2025, eight countries in the Region have reported a total of 20 412 suspected diphtheria cases, including 1 252 deaths (with an average case fatality ratio [CFR] of 6%). Most cases are among children and young adults, with women slightly more affected than men. Laboratory confirmation remains low due to shortages of diagnostic supplies and limited testing capacity. The global shortage of DAT, and a variable clinical capacity to provide this essential treatment, poses an additional challenge to effective case management.

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 characterized by low routine immunization coverage, high population mobility, and crowded living conditions, especially among displaced populations. The resurgence of diphtheria in these countries is further compounded by disruptions caused by the COVID-19 pandemic, which led to significant declines in vaccine uptake and widened immunity gaps.

At the regional level, the public health risk is assessed as high due to the potential for further geographic expansion of outbreaks, high fatality rates, insufficient resources for outbreak control, and weak surveillance and laboratory systems. The humanitarian context in several affected countries, including Chad, Mali, Niger, and Nigeria, increases the likelihood of sustained transmission and complicates response efforts.

At the global level, the public health risk is considered low. Most countries outside the African Region have established immunization programs and adequate surveillance systems. However, the possibility of international spread through travel cannot be ruled out, particularly if susceptible individuals are exposed. Strengthened global surveillance and risk communication are therefore essential to mitigate this risk.

The confidence in the available information is assessed as moderate. While data collection and reporting have improved in some countries, gaps remain in laboratory confirmation, case classification, and timely sharing of epidemiological updates.