BEIJING, China (CNN) -- The death toll from China's outbreak of hand-foot-mouth disease has climbed to 28 -- all of them children -- the state-run Xinhua news agency reported Wednesday.
The latest deaths were reported by the health bureaus in central China's Hunan province and the Guangxi Zhuang Autonomous Region in the southwest, according to Xinhua.
Authorities reported 15,799 cases of the disease on Tuesday.
The official count has increased dramatically in recent days, the result of an order issued late last week by the Ministry of Health mandating that all cases be reported.
Chinese health authorities have been dispatched to the worst-hit province, Anhui, in rural eastern China, where 22 of the fatalities have occurred. The deaths are blamed on enterovirus 71, or EV-71, one of the most common causes of HFMD. All of the deaths occurred in Fuyang City.
The provincial government has quarantined people exposed to the virus and limited movement into and out of Fuyang, where the outbreak was first reported in mid-March.
Authorities there have also closed schools and sprayed streets with disinfectant. Extra beds have been crowded into hospital corridors to accommodate the influx of patients attributed to the disease.
Fuyang officials have been accused of sitting on information of the outbreak last month even as children were dying. A World Health Organization official said weeks passed between the outbreak in mid-March and the first reports by local officials because they did not know what they were dealing with. Local officials say they are doing all they can.
HFMD is not related to foot-and-mouth disease, which affects farm animals. HFMD can be caused by a number of intestinal viruses, of which EV-71 and Coxsackie A16 are among the most common.
In mild cases, EV-71 causes cold-like symptoms, diarrhea, and sores on the hands, feet and mouth. Severe cases can cause fluid to accumulate on the brain, resulting in polio-like paralysis and death.
There is no treatment for severe EV-71 infections nor does a vaccine exist. Adults' well-developed immune systems usually can fend off the virus, but children are particularly vulnerable to it, according to the U.S. Centers for Disease Control and Prevention.
Across China, schools are on heightened alert as teachers and parents are being told to re-emphasize the fundamentals of basic hygiene with their children -- washing hands and not sharing food.
Public health officials expect the number of cases to peak in June or July, since the disease thrives in warm weather.
The virus is a concern for Chinese officials as the nation prepares to host the Summer Olympic Games starting August 8.
On Saturday, China's Ministry of Health issued a pamphlet urging health bureaus to step up prevention and control efforts, Xinhua reported.
A large outbreak of HFMD occurred in Taiwan in 1998 with 78 deaths, and smaller outbreaks recurred there in 2000 and 2001, according to the CDC.