Thailand Reports 61 Suspected Diphtheria Cases and 8 Deaths in 2026, Steps Up Surveillance in Southern Border Provinces

Thailand's Department of Disease Control has reported 61 suspected diphtheria cases and eight deaths nationwide in 2026, prompting intensified surveillance in the southern border provinces and renewed calls for parents to ensure their children receive complete vaccinations.

Thailand's Department of Disease Control (DDC), Ministry of Public Health, is strengthening disease surveillance and prevention measures following reports of suspected diphtheria infections across several provinces, with most cases concentrated in the country's southern border region.

Dr. Jurai Wongsawat, senior medical expert and spokesperson for the DDC, said Thailand recorded 61 suspected diphtheria cases and eight deaths between January 1 and November 9, 2026, representing a reported case-fatality proportion of approximately 13% among suspected cases.

Patients ranged in age from eight months to 82 years, with a median age of 18 years. Children younger than four years accounted for the highest number of reported cases, while the male-to-female ratio was approximately 1.14 to 1.

Although cases have been reported sporadically across the country, health authorities identified a concentration of infections in the three southern border provinces and four districts of Songkhla Province. These areas recorded 21 cases and five deaths, including three laboratory-confirmed infections. Narathiwat Province reported the highest number of cases in the region, with 10 patients.

Dr. Jurai emphasized that there is currently no evidence of a widespread diphtheria outbreak across Thailand. However, she warned that additional cases could emerge, particularly in communities where children have not received vaccinations or have not completed the recommended immunization schedule.

The department is maintaining nationwide surveillance while strengthening disease prevention and control measures in higher-risk areas, particularly along the southern border.

Diphtheria is a potentially serious bacterial infection that commonly affects the respiratory tract. The disease generally has an incubation period of two to five days and can spread through coughing, sneezing, or contact with respiratory secretions from an infected person.

Common symptoms include fever, sore throat, difficulty swallowing, and the development of a thick grayish-white membrane in the throat. In severe cases, the membrane can obstruct the airway, while toxins produced by the bacteria may cause complications affecting the heart and nervous system, potentially leading to death.

Although diphtheria is more frequently associated with children, adults can also become infected, particularly if they are not adequately vaccinated.

The DDC advised individuals experiencing symptoms suggestive of diphtheria to wear a face mask and seek medical attention promptly. Patients should also inform healthcare professionals about any recent contact with infected individuals and provide their vaccination history to support accurate risk assessment and diagnosis.

As part of its response, the department has coordinated with provincial and local public health agencies to strengthen active case finding, epidemiological investigations, and contact tracing. Healthcare facilities are also preparing treatment resources, including diphtheria antitoxin, to ensure timely medical intervention and reduce the risk of severe complications and deaths.

In the southern border provinces, health authorities are working with local administrative organizations, schools, and community leaders to identify children who have missed routine vaccinations. Proactive immunization services are also being expanded to improve vaccine coverage among vulnerable populations.

Dr. Jurai stressed that diphtheria is a vaccine-preventable disease and urged parents to ensure their children receive all recommended doses under Thailand's national immunization program.

Children should receive five doses of diphtheria-containing vaccines during early childhood, beginning at two, four, and six months of age, followed by booster doses at 18 months and four years. Additional booster vaccinations are recommended during school age, while adults should also receive diphtheria and tetanus-containing boosters according to applicable immunization guidelines.

Parents who are uncertain about their children's vaccination status are encouraged to bring their immunization records to nearby healthcare facilities, where medical personnel can assess whether catch-up vaccinations are needed.

The department also urged the public to maintain good personal hygiene, wash hands regularly, and avoid sharing drinking glasses or personal belongings that may be contaminated with respiratory secretions.

People experiencing persistent sore throat, difficulty swallowing, or unusual membranes in the throat should seek medical care immediately, as early diagnosis and appropriate treatment are essential to preventing serious complications.

Dr. Jurai reiterated that parents should not wait for an outbreak before arranging missed vaccinations, emphasizing that maintaining high immunization coverage is critical to protecting children and preventing the spread of diphtheria.

While Thailand has not reported evidence of a nationwide outbreak, the DDC said it will continue monitoring the situation closely, particularly in communities with incomplete vaccination coverage, as part of ongoing efforts to prevent further infections and reduce the risk of deaths.

 

Source: Department of Disease Control, Ministry of Public Health, Thailand, November 11, 2026.