Situation of Pertussis in Thailand, 2025

Abstract

Highlight

- Pertussis is a vaccine-preventable disease of the respiratory tract infection caused by the bacterium Bordetella pertussis. Transmission occurs mostly via respiratory droplets expelled by infected individuals during coughing, sneezing, or speaking.

- During the past five years, pertussis surveillance data showed an overall increasing trend in reported cases. Since September 2023, the number of cases exceeded the five-year median (2020-2024), mostly due to outbreaks reported in the southern border provinces. In 2025, although the number of cases showed a declining trend compared with the previous year, however, case numbers remained higher than the five-year median. In 2025 (data as of 15 January 2026), a total of 243 cases were reported, corresponding to an incidence rate of 0.39 per 100,000 population. Two deaths were reported, resulting in a case fatality rate of 0.82%.

- Eight clustered outbreak events were reported, most commonly occurring within households, followed by educational settings. Mostly cases had a history of exposure through close contact, cohabitation, or participation in shared activities with infected individuals.

- Pertussis is a highly contagious disease that can spread rapidly. Prevention and control measures include administration of the combined diphtheria–tetanus–pertussis (DTP) vaccine according to the recommended age schedule. Pregnant women may receive the acellular pertussis (aP) vaccine from 20 weeks of gestation onward. In addition, adherence to proper personal hygiene practices plays an important role in disease prevention.