Understanding Diphtheria: A Threat to Public Health
Fatiha Smihrou from the Epidemiology and Disease Control Directorate (DELM) recently outlined the surveillance and response measures in place to combat diphtheria, a highly contagious toxico-infection caused primarily by the bacterium Corynebacterium diphtheriae. The basic reproduction rate (R0) of diphtheria ranges from 6 to 7, indicating its potential for rapid spread. With a mortality rate between 5% and 10%, diphtheria is classified as a notifiable disease, similar to other vaccine-preventable illnesses. Although vaccination efforts have effectively controlled diphtheria for decades, Smihrou noted a concerning rise in outbreaks, likely attributed to vaccine hesitancy. Reports of cases have emerged from neighboring countries including Mauritania, Senegal, and Mali.
In Morocco, the situation has escalated since the beginning of 2026, with two initial outbreaks detected. The first outbreak involved three confirmed cases, including one fatality, while the second was limited to a single confirmed case, which also resulted in death. Subsequently, sporadic cases were reported, including one imported case. As of yesterday, the current outbreak has identified 11 confirmed cases, leading to one death. A procedural manual has been developed since the alert in February to standardize surveillance and response activities.
Surveillance and Response Strategies
The ongoing surveillance program aims to achieve six key objectives: early detection of suspected cases, rapid confirmation of these cases, documentation of toxin production and antibiotic resistance, identification of transmission trends, at-risk zones and populations, monitoring the epidemic's progression, and evaluating the effectiveness of response measures. A suspected case is characterized by upper respiratory tract infections such as pharyngitis or laryngitis associated with a thick, adherent pseudomembrane. Probable cases are epidemiologically linked to confirmed cases, while confirmed cases are validated through laboratory testing.
When a suspected case arises, clinicians are advised to isolate the patient and provide them with a surgical mask to prevent panic. Immediate notification of local health authorities is critical, followed by validation of the case by local rapid response teams to minimize false reports during the peak winter season. Confirmed cases are then registered with the national epidemiological surveillance service, which assigns a tracking code to monitor the patient throughout their treatment.
Hospitalization is mandatory for all validated suspected cases, and testing is conducted promptly. The laboratory communicates results to regional and provincial teams without delay, allowing for proactive response measures. All data is centralized on a national platform for analysis, aiding in the understanding of the epidemic's evolution and the identification of at-risk populations.
Mouad Merabet, also from DELM, discussed contact management as a cornerstone of the response strategy. He emphasized the importance of understanding the epidemiological chain, which includes the reservoir, the pathogen, modes of transmission, and the susceptible host. Anyone who has had close exposure to a confirmed case during the contagious period is considered a contact, regardless of theoretical distance or duration. The contagious period starts with the onset of symptoms and can last from two to six weeks without effective antibiotics.
As the outbreak continues, vaccination remains a critical component of the response. Mohamed Benazzouz, a public health specialist and head of the National Immunization Program (PNI), explained that the vaccination strategy targets contacts of confirmed cases. Three vaccines within the national program contain the diphtheria component: the pentavalent vaccine, the DTC vaccine, and the Td vaccine. Specific guidelines adjust vaccination protocols during an epidemic, reducing the protection interval after the initial dose from ten years to five. Immediate vaccination is provided to individuals with an unknown or incomplete vaccination status, with subsequent doses administered according to age and previous vaccination history.
Effective management and communication are vital to controlling the diphtheria outbreak in Morocco. The health authorities are committed to minimizing the risk of transmission and protecting public health through comprehensive vaccination and monitoring strategies. For further details on the original report, you can visit fr.le360.ma.
