China will step up surveillance of the intestinal virus EV71 after an outbreak in east China killed 20 children, a health official said on Tuesday.

The virus, known as enterovirus 71, or EV71, has not yet been put on the mandatory reporting list of infectious diseases, Qi Xiaoqiu, director of the health ministry's disease control and prevention department, told a press conference here.

The ministry now considered it as an emergent public health incident that needed to be reported, Qi said.

"In accordance with the virus' outbreak in the past few years, we are considering how to further strengthen the management and surveillance of the disease," he said.

An outbreak in Fuyang City in eastern Anhui Province killed 20 children and sickened 1,500 others, the provincial health department said on Tuesday.

Of the sick, 585 have recovered, while 412 are still hospitalized. Of those, 26 are seriously ill.

Hospitals in Fuyang started to admit children with fever, blisters, mouth ulcers and hand and foot rashes in early March. Some were diagnosed with brain, heart and lung damage.

All were aged below six and the majority were under two.

Deng Haihua, director of the ministry's press office, said the ministry had sent two expert teams to Fuyang to help, and progress was being made in researching the virus and its treatment.

He urged the public to ward off intestinal infections by observing environmental, personal and food hygiene, as well as keeping children away from crowds.

EV71 can cause hand, foot and mouth disease. It usually starts with a slight fever followed by blisters and ulcers in the mouth and rashes on hands and feet.

It can also cause high fever, meningitis, encephalitis, pulmonary edema and paralysis in a small number of children. Infections can lead to high mortality rates in serious cases. No vaccine is available.

Editor: Yan