The lethal intestinal virus that has killed 20 children and infected over 1,500 others in the east China province of Anhui has been identified as enterovirus 71, or EV71, that causes hand, foot and mouth disease.

Du Changzhi, Anhui Provincial Health Department deputy chief said that by early today, Tuesday 29th April, the virus, which is spreading in Fuyang City, in the northeast part of the province, will have claimed the lives of 20 children and infected 1,520 others, reported the Chinese state-run Xinhua news agency.

About one third of the sick children have recovered, while another third are in hospital and 26 are gravely ill.

The authorities have called in medical workers from other areas, who are joined by experts from the Ministry of Health, in an “all-out” effort to save the children, said the deputy chief.

Hand, foot and mouth disease is mainly a childhood disease, occuring rarely in adults, unless they have weak immune systems. It is not uncommon among infants and children, and it spreads easily through contact with mucus, saliva and feces. It is characterized by fever, sores in the mouth and a blistery skin rash.

It has an incubation period of 3 to 7 days and it usually starts with general listlessness, poor appetite, and a slight fever, often accompanied by a sore throat. One or two days later, painful mouth sores develop, starting as small red spots that blister and turn into ulcers. They usually appear on the tongue, gums and the inside of the cheeks.

The non-itchy skin rash usually breaks out on the palms of the hands and the soles of the feet and develops over 1 or 2 days, starting as red spots that can be flat or bumpy, sometimes with blisters. Some children also get the rash on their buttocks. In some cases no rash is present, only the mouth ulcers, and in other cases, the mouth ulcers occur with no rash.

In a few cases it can lead to high fever, meningitis, encephalitis, pulmonary edema and paralysis.

Paralysis is more common in infants under two years of age, while meningitis is more common among infected 2 to 5 year olds.

Unfortunately there is no vaccine and no cure, and there is a high rate of death among children seriously ill with the disease.

Hand, foot and mouth disease is not to be confused with foot-and-mouth disease, which affects cattle, sheep and pigs.

The outbreak started in early March when hospitals in Fuyang began admitting children suffering from fever, blisters, rashes on the hands and feet, and mouth ulcers. All the children were under six years old, and most of them were infants under two. Some of them also had suffered damage to the heart, brain and lungs.

Because there was an initial delay in identifying the cause of the illness, there was a rumour circulating in the area that the disease was a form of SARS (severe acute respiratory syndrome). An outbreak of SARS swept through China in 2002 and 2003 and eventually claimed hundreds of lives worldwide.

Sources: Xinhua news agency, CDC.

Written by: Catharine Paddock, PhD