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Surveillance results showed that from December to January, the incidence of flu had seen a "rising trend", said Shu Yuelong with the National Center for Disease Control and Prevention (CDC).

The virus types spread at the same time the year before were slightly different from this year, he said.

However, a flu epidemic was unlikely at this time of the year, as "the types and sub-types of flu virus had no significant mutation," he said in an online interview.

The incidence of flu this year was lower than the average of previous years, both in the north and the south. The "rising trend" was noticed in a comparison between the current period with October last year, Shu said.

Vaccination was an effective way to avoid flu and was proven to be safe, he said.

However, people who were allergic to eggs or had other severe allergies and women less than three months pregnant could not take the vaccination, he said.

Shu also told people to wear masks, get exercise, keep warm and form hygienic habits to prevent flu, and those who had flu should rest at home.

Parts of China, including Beijing, have seen rising cases of flu recently, with some outpatient hospitals receiving up to 5,000 people, sparking worries that a flu epidemic might happen this winter.

Shu said China started monitoring flu in the 1950s. The country joined the international flu monitoring network set up by the World Health Organization in 1981.

So far, the government had established 63 surveillance laboratories and 197 national-level flu surveillance hospitals, covering 31 provinces and regions.

Last year, the Ministry of Health issued an emergency response guidance for flu pandemic, and strengthened surveillance and timely reporting of local authorities.