In the latest health scare in China three children have died from hand, foot and mouth disease and another 110 are sick - this is China's second outbreak of the virus this year in young children.
Hand, foot, and mouth disease (HFMD) is a common illness among infants and children and begins with a fever and a rash with blisters.
Within one or two days of the fever appearing, painful sores develop in the mouth and other lesions form on the hands and feet.
HFMD is caused by a virus from the group called enteroviruses and the most common culprit is the coxsackievirus A16 virus - but sometimes, HFMD is caused by enterovirus 71 or other enteroviruses.
Those most at risk from HFMD are mainly children under 10, but it can also affect adults - infants, children and adolescents are more susceptible because they are less likely than adults to have antibodies and to be immune from previous exposures to them.
There is no vaccine or treatment for HFMD but its symptoms can be treated to provide relief from fever, aches or pain from the mouth ulcers.
HFMD is usually not dangerous and the infection caused by coxsackievirus A16 infection is as a rule a mild disease with most patients recovering without medical treatment - complications are rare.
However sometimes a patient with coxsackievirus A16 infection will also develop "aseptic" or viral meningitis, which is characterised by fever, headaches, and stiff neck or back pain, and may require hospital treatment for a few days.
The last outbreak in April and May in China which killed at least 42 people, was mainly linked with enterovirus 71 which can also cause viral meningitis and, rarely, more serious diseases, such as encephalitis, or a poliomyelitis-like paralysis which can be fatal; cases of fatal encephalitis occurred during HFMD outbreaks in Malaysia in 1997 and in Taiwan in 1998.