Diphtheria resurfaces in Morocco, as in Africa: What’s driving the comeback?

For decades, diphtheria was almost unheard of in Morocco, but in the past couple of days, the disease has resurfaced after two family clusters were reported in the Souss-Massa region.

So far, the Health Ministry has confirmed just one case through laboratory testing, while eight others are still under investigation and awaiting confirmation, including two people who died. 

The children had either not been vaccinated or had not finished their vaccination schedule, which has also been a key factor in the resurgence of diphtheria in several countries around the world, including Algeria, Mauritania, and Germany.

For years, vaccination had kept diphtheria at very low levels in Morocco and elsewhere. 

But then it started to resurface in places where vaccination rates have fallen, health systems have been disrupted, conflicts have displaced people, and the pandemic has interrupted routine vaccinations, including in Somalia, Sudan, Yemen, and Chad.

In the US, for example, childhood coverage for diphtheria, tetanus, and pertussis (DTP) vaccine among kindergartners fell from 95.2% in 2019/2020, the threshold needed to maintain herd immunity, to 92% in 2025/2026.

Morocco, meanwhile, kept vaccination rates relatively close to the recommended level between 2018 and 2024, according to the latest figures from the WHO immunization dataset.

But experts say the COVID-19 pandemic disrupted vaccination programs for several diseases, including measles, as lockdowns and restrictions made it harder for many children to get their vaccines and disrupted the follow-up needed to keep them on schedule.

Tayeb Hamdi, a health policy and systems researcher, told Hespress English that COVID-19 put enormous pressure on health systems, followed by a degree of “relaxation,” with some services failing to fully recover their previous level of follow-up.

The return of diphtheria is not new to the region. From January to November 2025, more than 20,000 suspected cases were reported across Africa, including 1,252 deaths.

Algeria reported 13 suspected cases in Skikda province in 2025, including two deaths, despite national DTP coverage reaching 98% for the first dose and 92% for the third in 2024.

None of the confirmed patients, however, had received the diphtheria vaccine.

Meanwhile, Mauritania saw a major diphtheria outbreak last year.

Between January and November 2025, the country reported 849 cases and 33 deaths, with 318 cases confirmed. 

Only 10% of cases had a documented vaccination history despite national DTP coverage of 95% for the first dose and 86% for the third dose in 2024.

Here are the key things to keep in mind about diphtheria:

Diphtheria is a contagious, vaccine-preventable bacterial infection that usually affects the throat and upper respiratory tract.

The bacteria can produce a toxin that makes it hard to breathe and can damage the heart and nerves.

How it spreads: The infection passes from one person to another through droplets released when an infected person coughs or sneezes, as well as through close contact with contaminated surfaces. 

Some people may carry the bacteria without showing clear symptoms and can still pass it to others.

Diphtheria can infect people of all ages, but it mainly affects unvaccinated children under 10 years old.