Influenza cases surge sixfold in September

The city’s Health Bureau (SSM) reported a 6.4-fold increase in influenza cases in September 2025, compared with the same month last year.

According to the SSM, a total of 1,358 cases of notifiable diseases were recorded in September. Influenza led the count with 1,073 cases, followed by enterovirus infections at 105, and varicella with 36.

The rise in influenza cases marks a 74.2% increase from August’s 616 cases. According to the bureau, the most common strains detected in Macau were influenza A (H1N1 and H3N2) and influenza B.

The bureau noted that while most individuals recover without complications, the elderly, infants, and people with chronic illnesses face an elevated risk of serious outcomes such as bronchitis or pneumonia. The Health Bureau continues to urge residents to receive annual influenza vaccinations, emphasizing that the shot remains the most effective way to prevent the illness during the ongoing peak flu season.

Meanwhile, scarlet fever cases rose by 66.7%, from 12 in August to 20 in September, although SSM highlighted that cases decreased 44.4% year-over-year.

Norovirus infections also increased by 66.7%, from six to 10 month over month, but showed a 63% decrease compared with the 27 cases recorded during the same period in 2024. The bureau noted that norovirus can affect all ages, with an onset pattern more common during the winter months.

In addition to local infections, there were four imported cases of dengue fever and 12 chikungunya cases, three locally transmitted and nine imported.

The SSM stated that it continues to monitor the situation closely.

Macau currently tracks 45 types of diseases under mandatory notification to protect public health.

Macau is experiencing an increase in influenza activity, according to recent monitoring data. Between October 5 and 11, the positivity rate of samples tested for the flu virus reached 12.2%, approaching the alert level of 13.1%.

At the same time, daily visits to the emergency departments of Conde de S. Januário and Kiang Wu hospitals have risen, suggesting the possibility of an early flu peak this season, according to SSM.