A fast-spreading viral outbreak in China has killed 22 children, sickened nearly 3,600 others and caused panic among parents in an impoverished corner of Anhui Province, government health officials said Friday. All of the fatalities, from lung problems and other complications, have been in children younger than 6, with a majority of them under 2. The outbreak, caused by a particularly strong intestinal virus, enterovirus 71, or EV-71, has been spreading in the city of Fuyang, in east-central China, since early March. Provincial health officials, however, announced the outbreak only this week, raising questions about whether they had been trying to conceal it. In recent days the Chinese media have heavily criticized the local government response, offering comparisons to the SARS epidemic of 2003, which drew widespread attention to China's shaky public health system and official attempts to cover up the outbreak. Xinhua, the official news agency, published the latest figures on Friday. On Thursday, the World Health Organization warned that the disease, which thrives in warm weather and passes easily among children, could spread in the coming summer months. It advised child care centers and schools in the city and surrounding region to stay closed until the spread was curtailed. The virus begins with a fever and often leads to mouth ulcers and to blisters on the hands, feet and buttocks. Commonly known as hand, foot and mouth disease, it has no relation to the foot-and-mouth disease that infects livestock. There is no vaccine or cure, but most patients recover in a week without treatment. In severe cases, brain swelling can lead to paralysis or death. Cleaning surfaces with bleach and washing hands significantly reduces the spread of the pathogen. Health officials in Fuyang said more than 970 children remained hospitalized, 48 of them in critical condition. Health officials said the disease also spread to three adjacent provinces, with the bulk of them