What is "hand, foot, and mouth disease?"

by Tara Smith     Department: Health & Life Sciences

The latest infectious disease outbreak in China is hand, foot, and mouth (HFM) disease, an infection that causes a rash to develop on the feet and hands and sores inside the mouth. (This is not to be confused with foot and mouth (or "hoof and mouth") disease of animals, caused by a different virus). Human HFM disease can be caused by several different viruses, but most commonly it is caused by coxsackie virus A or enterovirus-71, both picornaviruses (cousins of the polio virus, in fact). These viruses usually cause only mild disease, but they can occasionally cause outbreaks, and young children are particularly vulnerable:

The death toll rose to 43 from the hand, foot and mouth disease virus that has sickened tens of thousands of children across China, a report said Friday.

A 22-month-old girl from eastern Jiangxi province died Thursday in a local hospital, health officials told the state-run Xinhua News Agency.

As of Wednesday, the hand, foot and mouth disease virus had sickened more than 24,934 children in seven Chinese provinces plus Beijing, Xinhua reported.

As enteroviruses, these are spread via the fecal-oral route, so children are vulnerable not only because their immune systems have not been exposed to the virus previously, but also because they are less likely to keep their hands clean and therefore break the transmission cycle.

In addition to the outbreak in China, the virus is spreading. As I mentioned at Aetiology, I'm currently in Mongolia working to set up a research collaboration, and the capital city of Ulaanbaatar is where most of the cases have been diagnosed. Vietnam is also reporting an outbreak.

The good thing is that this is typically a mild, self-limiting disease. The bad thing is that even "typically mild" infectious diseases can sometimes be severe, as shown by China's death toll (43 as of this writing). For this particular virus, death is more likely when children suffer from encephalitis: inflammation of the brain due to viral infection.

There is no vaccine for this disease, and health officials in China are growing increasingly concerned. Typically enterovirus outbreaks peak later in the summer...just prior to the Beijing Olympics.

Tags: Asia, disease, Enterovirus, outbreak, public health