Hand-foot-mouth disease (HFMD) is a common infectious disease caused by many types of enteroviruses which include Enterovirus 71 (EV71), Coxsackievirus A (CoxA), and certain serotypes of echoviruses (Echo). Among these viruses, EV71 infection accounts for comparatively large proportion of the severe cases.

HFMD occurs very often in preschool children, and especially in children younger than 3 yrs, but may also occur in adults. Most patients exhibit mild syndrome and can recover, but complications such as myocarditis, lung edema, aseptic meningitis and circulatory collapse may develop and are fatal in serious cases.

EV71 infections are present all year round, predominantly between April and September. Major routes of transmission include body contact with those infected, contaminated towels, handkerchiefs, cups, toys, dining and milk utensils, beddings and underwear. Viruses in throat secretion and saliva of patients can be transmitted through the air (droplets); therefore close contact with sick children can bring about infection. Infections can also occur through consumption of contaminated water or food.

The latency period of HFMD is 2-7 days. Initial symptoms are mainly fever, often at 38°C, as well as rash in mouth, on hands, feet and buttocks or vesicular exanthema of the oral mucosa. Some patients experience flu symptoms such as cough. After 1 to 2 days of fever, a rash develops in hands and footplate, and may also in buttocks. Some infected children with mild symptoms do not have fever, but only rash on hands, feet and buttocks or herpangina. Most infected children experience temperature drop, deflorescence and recovery within a week.

The key to preventing HFMD is to maintain good hygiene practices in homes and surrounding environment, as well as personal hygiene. Wash hands thoroughly with soap before eating, after going out and after using bathrooms; avoid consuming raw water and raw food; maintain good ventilation in indoor areas; and frequently sun-dry clothing and bedding. During peak periods of the disease, avoid bringing children to crowded public areas with poor ventilation, and most importantly, avoid contact with infected children.
Lab diagnoses of the enteroviruses include:

1. Viral isolation: enteroviruses isolation from throat swabs or throat wash, stool or anal swabs, C.S.F. or vesicle fluid as well as from brain, lung, spleen, lymph nodes specimens, etc.;
2. Serological tests: specific IgM antibody positive in patients' sera or more than four times' increase of sera IgG in patients during acute stage and convalescent period;
3. Nucleic acid detection: viral nucleic acid detected from extractions of sera, throat swab or wash, stool or anal swab, C.S.F. or vesicle fluid as well as brain, lung, spleen, lymph nodes specimens, etc.