A cluster of EV71 cases in Fuyang in the central province of Anhui in March led to 22 deaths, official media reported.
About 104 patients remain in critical condition across the province.
The outbreak was not made public until late April, triggering memories of the deadly SARS epidemic that crippled China in 2003 and provoking calls for Fuyang officials to be sacked.
The World Health Organisation has said the delay was due to problems local doctors faced in trying to identify the illness.
China has since issued a nationwide alert, closing kindergartens and sending officials to visit nurseries and primary schools and educate staff on hygiene and prevention.
A US health official offered to assist China in curbing the outbreak, and Michael Leavitt, the US health secretary, is to visit Beijing next week, the state media said.
"We are willing to help China in any way possible with this issue," it quoted William Steiger, head of the office of global health affairs at the US department of health, as saying.
Praise for a doctor
State media was filled with praise on Friday for a doctor who called in experts after she was baffled by the deaths of several children who colleagues insisted were just suffering severe colds or flu.
The People's Daily carried a tribute with the headline "We salute you, Fuyang's Liu Xiaolin," comparing Liu to a doctor who helped lead the fight against the deadly SARS virus.
"We have no way to count how many children were treated and cured because of Liu Xiaolin's responsibility and steadfastness; there is also no way to calculate how many families avoided the epidemic because of her sharpness and courage," it said.
Liu had previously helped uncover a baby milk scandal, when fake formula made without key nutrients caused the death by malnutrition of several children.