Hand, Foot, and Mouth Disease (HFMD) is a common viral illness, predominantly affecting infants and young children, though adults can also contract it. It is typically caused by enteroviruses, most frequently Coxsackievirus A16, but also Enterovirus 71 and other coxsackieviruses. Characteristic symptoms include a fever, sore throat, painful mouth sores, and a distinctive skin rash. This rash often appears as blister-like lesions on the hands and feet, but can also be found on the buttocks, legs, and arms.
When Contagiousness Begins and Ends
Contagiousness for Hand, Foot, and Mouth Disease begins even before symptoms appear, typically during the 3-7 day incubation period after exposure. Individuals are most infectious during the first week of illness, particularly when fever is present and mouth sores are active. Open blisters and active mouth lesions contribute significantly to transmission during this period.
While visible symptoms may resolve within 7 to 10 days, the virus can continue to shed from the body for an extended period. Viral particles can be found in respiratory secretions for one to three weeks and in stool for several weeks to months after symptoms have disappeared. This prolonged shedding means a person can still transmit the virus even if they appear well and have no active symptoms. However, the practical period of high contagiousness is generally considered shorter, primarily focusing on the initial symptomatic phase.
How the Virus Spreads
The viruses responsible for Hand, Foot, and Mouth Disease are present in various bodily fluids of an infected person. These include secretions from the nose and throat (saliva, sputum, nasal mucus), fluid from characteristic blisters, and feces.
Transmission primarily occurs through direct contact with an infected person, such as kissing, hugging, or sharing eating utensils. The virus also spreads through respiratory droplets from coughing or sneezing. Contact with contaminated objects or surfaces, known as fomites, is another common route; toys, doorknobs, and shared items can harbor the virus and facilitate its spread if hands then touch the mouth, nose, or eyes. The fecal-oral route is a significant contributor to spread, especially in environments where young children are in close contact, such as childcare centers.
Practical Measures to Prevent Spread
Good hygiene practices are important for minimizing the spread of Hand, Foot, and Mouth Disease. Frequent and thorough handwashing with soap and water for at least 20 seconds is a primary defense, especially after changing diapers, using the toilet, and before preparing or eating food. Teaching children proper handwashing techniques is also beneficial in communal settings.
Reducing close contact with infected individuals can help prevent transmission. This includes avoiding activities like kissing, hugging, or sharing eating utensils, cups, and towels. Disinfecting contaminated surfaces is another measure to disrupt the virus’s spread. Regularly clean and disinfect frequently touched items and shared surfaces, such as toys and doorknobs, using a bleach solution or household disinfectant.
Regarding isolation, most public health guidelines suggest that individuals, especially children, can return to school or daycare once their fever has subsided and they feel well enough to participate in activities. While the virus can still be shed in stool for weeks, the risk of transmission significantly decreases once active symptoms like fever and open mouth sores have resolved. Blisters should ideally be dry and scabbed over to further reduce the risk of spreading the virus through contact with blister fluid.