TAIPEI (Taiwan News) — Taiwan health authorities are warning of a continuing norovirus outbreak after more than 80,000 people sought medical attention for diarrhea during this year’s Lunar New Year holiday, per CNA.

According to the Centers for Disease Control, 80,308 outpatient and emergency room visits for diarrhea were recorded during Feb. 15–21, the second-highest figure for the same period in the past five years. Norovirus was detected in approximately 80% of cases.

CDC Director-General Lo Yi-chun (羅一鈞) said the number of visits was 37% of the figure recorded during the same period last year. He attributed the lower weekly total compared to the previous week’s 171,756 visits to most clinics being closed during the holiday.

Lo said the resumption of work and school, along with recent gatherings, could fuel additional cluster infections. As February and March are typically peak months for norovirus, he warned that more outbreaks are likely and urged the public to pay attention to food hygiene.

He said the higher number of outbreaks over the past two years is linked to the emergence of the GII.17 strain, which became the dominant circulating virus beginning in the spring and summer of 2024. The strain primarily affects adults and can cause vomiting, diarrhea, and fever.

Lo said the latter half of 2024 and all of 2025 were considered epidemic years for norovirus, with outpatient visits reaching as many as 200,000 per week at the peak last year. Several cluster infections were reported at restaurants.

The GII.17 strain was first identified in East Asia before spreading globally, Lo said. It has circulated in Taiwan for about a year and a half, and some level of population immunity has developed. He said the outbreak is nearing its end, but predicted February and March will remain peak periods, with a significant slowdown expected from mid- to late March.

Lee Chia-lin (李佳琳), deputy director of the CDC’s Epidemic Intelligence Center, said 122 diarrhea cluster cases were reported nationwide over the past four weeks, with norovirus detected in 83.8% of those cases.

Internationally, Lee said, norovirus infections continue to rise in South Korea, Japan, and the UK, reaching their highest levels in nearly five years. Diarrhea cases have also recently increased in China, and a norovirus cluster was reported during the Winter Olympics in Italy.

The CDC reminded the public to wash hands thoroughly with soap after using the toilet and before eating or preparing food. It also urged proper food-handling practices, including separating raw and cooked foods, avoiding raw or undercooked foods, and ensuring food, particularly shellfish such as oysters, is thoroughly cooked before consumption.