TAIPEI (Taiwan News) — Taiwan’s Centers for Disease Control on Thursday confirmed the country’s first pertussis case this year in a 5-month-old boy in northern Taiwan.

The infant began showing symptoms in late January and tested positive for pertussis on Tuesday. He has since been improving, according to CNA.

Of the infant’s four household contacts, two developed suspected symptoms. Both have been tested and evaluated for preventive treatment, and all four will remain under health monitoring until March 4.

Pertussis, also known as whooping cough, is a highly contagious respiratory infection spread through coughs or sneezes. Common symptoms include prolonged coughing lasting more than two weeks, flushed face, mild fever, vomiting, and a runny nose, according to the Hsinchu Health Bureau.

Children under 5 are most at risk. Infants younger than 6 months can face severe complications or death.

The CDC urged parents to seek medical care immediately if children experience intense coughing spells, wheezing, facial blueness, or vomiting after coughing.

From 2022 to 2026, Taiwan reported 2, 0, 34, 45, and 1 domestic pertussis cases, respectively. Most cases occurred among 11- to 18-year-olds (35.4%), followed by infants under 6 months (25.6%).

Pertussis has no seasonal pattern and can occur at any time. Early symptoms often resemble a common cold, which can delay diagnosis and increase the risk of spreading the disease to infants and other close contacts.

While recovering from pertussis generally provides longer-term immunity, it does not offer lifelong protection. Vaccination remains the most effective way to prevent infection, according to the CDC.