HONG KONG, Feb. 22 (Xinhua) -- The Center for Health Protection (CHP) of China's Hong Kong Special Administrative Region (HKSAR) government on Thursday warned schools to boost precautionary measures against seasonal influenza when classes resume after the Lunar New Year holiday.

The center noted that the overall seasonal influenza activity in Hong Kong has remained at a high level in the past few weeks, but it appears the trend is not increasing.

The seasonal influenza activity is expected to stay at a high level for some time, the CHP said.

It has issued letters to schools, kindergartens and childcare centers to remind them to reinforce preventive measures.

The HKSAR government's Education Bureau ordered earlier this month the closure of all kindergartens and primary schools in an effort to cut off the spread of seasonal influenza. Because of this decision, school children got an early start of the Lunar New Year holiday.

The CHP said it has recorded a significant drop in institutional influenza-like illness outbreaks since the start of the Lunar New Year holiday, from 115 cases in the week ending on Feb. 3 to 28 cases in the week ending on Feb. 17.