Taiwan: Taiwan has reported a total of 35 domestic whooping cough cases in the first half of 2025, the highest for the same period in a decade, the Centers for Disease Control CDC said Tuesday. Seventeen new cases were recorded in June alone, including one school cluster linked to a household and three separate household clusters, CDC officials said at a press conference.

According to Focus Taiwan, the school cluster involved five infected students, also making it the largest such outbreak in 12 years, said Lee Chia-lin, deputy director of the CDC’s Epidemic Intelligence Center. The three household clusters included two cases in central Taiwan, three in the north, and two in the south, Lee said, adding that contact tracing and health monitoring are set through mid to late July.

The school-linked outbreak began with a teenage student in northern Taiwan who had received a whooping cough-related vaccine. The student began showing symptoms such as coughing and a runny nose in late May. The student had no recent travel history and was mainly active at home and school. Four family members who also had cough symptoms from late May to early June were later confirmed to have whooping cough. Four classmates were also diagnosed, bringing the total to nine in the cluster.

CDC spokesperson Lo Yi-chun said the spike of 17 cases in one month and nine in a single cluster is highly unusual. The school outbreak, with five student cases, is the largest since 2013, when a similar outbreak involved eight students. Among the 35 cases so far this year, 37 percent were in the 11-18 age group, followed by 23 percent who were infants under six months old.