Hand foot and mouth disease (HFMD) is caused by a virus. The coxsackievirus A16 is usually the specific cause, although other coxsackieviruses can cause the disease too. Coxsackievirus is a type of enterovirus though, and sometimes it is another enterovirus, such as enterovirus 71, that causes a particular case of hand foot and mouth disease.
Coxsackievirus is fairly contagious, and it mostly affects young children. So it is fortunate that this disease that causes painful mouth blisters and a rash on the hands and feet is generally mild. Children will usually come down with it three to seven days after they are exposed. The first symptom may be fever, and a general under-the-weather feeling. The patient may get a sore throat next. Then blisters and a rash may appear one or two days later. Not everyone who gets HFMD shows all of these symptoms. Most people will recover completely in seven to ten days.
Most children who get this disease have ingested the virus orally. It spreads through mucus, saliva, popped blisters and the stool of infected children. So frequent hand-washing helps slow or prevent the spread of the disease. HFMD can also spread through an aerosol route, when an infected person doesn’t cover a cough or sneeze. No one can ever catch HFMD from any pet or farm animal.
It is especially important to wash hands after changing diapers, because this is one of the main routes of transmission of coxsackievirus and other enteroviruses. Also, common areas should be cleaned regularly, and disinfected with diluted bleach, because these viruses can live on surfaces. Children should be taught not to put their hands in their mouths (but they probably will anyway) because this is a prime transmission route for the disease. Children sick with this disease should stay home, so that they’re not spreading it, and so should adults who have it.
People infected with hand foot and mouth are most infectious during the first week they have the disease. However, on occasion they may still be carrying the virus and be somewhat contagious weeks later.
Children often pick up hand foot and mouth in childcare, with its sometimes crowded and busy conditions. It is most common in children under ten. However, teens and adults can get it too, and will usually get a milder case because they have built up some immunity. In some cases, these groups of people can be contagious for weeks without showing any symptoms. Coxsackievirus is most commonly caught in summer or fall.
After a child has had HFMD he or she is immune to the disease caused by that particular virus. However, he or she can still catch the disease again, if it is transmitted by another virus.