China’s National Disease Control and Prevention Administration warned Wednesday that cases of respiratory illnesses, including influenza and rhinovirus, have been increasing in recent weeks, raising concerns ahead of the country’s upcoming May Day travel period.

The agency said recent data show fluctuations in respiratory infections since early April, with higher transmission levels expected as travel and large gatherings increase during the holiday period. Authorities encouraged the public to take precautions, particularly when using transportation networks and attending crowded events.

The warning comes ahead of May Day, also known as International Workers’ Day, a major holiday in China marked by increased domestic travel, tourism, and family gatherings. The period is one of the busiest travel seasons of the year, with millions of citizens expected to move between cities and regions.

Health officials said influenza activity has increased since April, along with other respiratory viruses such as rhinovirus and human parainfluenza virus. Children under five have been identified as a higher-risk group for some of these infections, according to Chinese health data cited in state reporting.

The National Disease Control and Prevention Administration also warned about other seasonal health risks, including mosquito-borne diseases such as dengue fever and chikungunya, as well as gastrointestinal infections like norovirus. Officials advised increased hygiene measures, including handwashing, ventilation, and symptom monitoring, especially for elderly individuals and children.

In addition to respiratory concerns, Chinese authorities noted that travel demand is expected to rise sharply during the holiday period. Transportation hubs, including rail networks in major cities such as Shanghai, are preparing for increased passenger volume compared to previous years.

Chinese Foreign Ministry officials have also encouraged international tourism, highlighting visa-free travel policies and infrastructure improvements as part of efforts to attract foreign visitors during the broader spring and summer travel season.

Health officials emphasized that no new or novel pathogen has been detected, but stressed continued vigilance due to seasonal illness patterns and increased population mobility during the holiday period.