Babies get hand, foot, and mouth disease (HFMD) by coming into contact with a group of viruses called enteroviruses, most commonly through another person’s saliva, nasal secretions, blister fluid, or stool. The virus enters through the mouth or nose, and because babies constantly put their hands, toys, and other objects in their mouths, they’re especially vulnerable. Children under five account for the vast majority of cases.
The Viruses That Cause It
HFMD isn’t caused by a single virus. It’s caused by a family of enteroviruses, and the specific one your baby catches can affect how mild or severe the illness is. Coxsackievirus A16 is the most common cause in the United States. Coxsackievirus A6 also causes HFMD but tends to produce more severe symptoms, including larger blisters and more widespread rashes. In East and Southeast Asia, enterovirus 71 (EV-A71) is a more common culprit and is associated with rare but serious complications.
Your baby can catch HFMD more than once because infection with one type doesn’t protect against the others.
How the Virus Spreads to Babies
The virus travels between people through several routes, and babies are exposed to nearly all of them during normal daily life.
- Direct contact with saliva or nasal mucus. A kiss, a sneeze, or a cough from an infected person can transfer the virus directly. Babies in close physical contact with caregivers and siblings are constantly exposed this way.
- Blister fluid. The fluid inside HFMD blisters is packed with virus. If another child’s blister pops and your baby touches the fluid, then puts a hand in their mouth, the virus gets in.
- Fecal-oral route. The virus sheds heavily in stool. During diaper changes, traces of stool on hands or changing surfaces can transfer the virus. If those hands then touch a baby’s face, bottle, or pacifier, transmission happens easily.
- Contaminated surfaces and toys. Enteroviruses can survive on hard surfaces like plastic toys, crib rails, and doorknobs for several days. Shared toys in daycare settings are a major transmission point. A baby mouthing a toy that an infected child drooled on hours earlier is a classic way HFMD spreads.
Why Daycare Is a Hotspot
Group childcare settings are where HFMD spreads fastest. Babies and toddlers share toys, drool on surfaces, and have frequent diaper changes in close quarters. During one well-documented daycare outbreak in Spain, 25 out of 45 children in the center became infected before the virus even spread to the wider community. That’s an attack rate of nearly 56%. The close contact and shared environment made the daycare the epicenter, with community cases following afterward.
Outbreaks in the U.S. peak during summer and early fall, though cases can occur year-round. If your baby is in daycare during those months, the risk is highest.
Adults Can Spread It Without Knowing
Adults can carry enteroviruses and shed them without ever developing symptoms. This means a parent, grandparent, or daycare worker can unknowingly pass the virus to a baby through routine caregiving: wiping a nose, preparing food, or handling a diaper. Because adults rarely show obvious signs of HFMD, they don’t know to take extra precautions.
Older siblings are another common source. A school-age child might bring the virus home with a mild case that looks like nothing more than a few mouth sores, then pass it to a baby through shared cups, close play, or simply breathing nearby.
How Long the Virus Stays Contagious
The incubation period, the gap between catching the virus and showing symptoms, is typically three to six days. A child is most contagious during the first week of illness, particularly while blisters are present and fever is active. But that’s not where transmission ends.
The virus continues to shed in stool for weeks after symptoms clear up. Research on coxsackievirus A6 found that children shed the virus in their stool for up to five weeks after infection. Other strains, including coxsackievirus A16 and enterovirus 71, may shed for even longer. This means your baby can still pass the virus to others through diaper changes well after they seem completely recovered, and they can catch it from children who appear healthy.
Reducing Your Baby’s Exposure
There’s no vaccine for HFMD in the United States, so prevention comes down to reducing contact with the virus. Handwashing is the single most effective step. Wash your hands thoroughly after every diaper change, before preparing food or bottles, and after wiping your baby’s nose or mouth. If your baby is old enough to be washing their own hands, make it a habit after play and before eating.
Disinfecting surfaces matters because the virus survives on objects for days. A diluted bleach solution works well: mix 5 tablespoons (one-third cup) of standard household bleach per gallon of room-temperature water. Wipe down toys, highchair trays, and changing surfaces, and let the solution sit on the surface for at least one minute before wiping it off. Mix a fresh batch daily, since the solution loses effectiveness after 24 hours. Never mix bleach with other cleaning products.
At daycare, ask about their cleaning protocols for shared toys and surfaces. During an active outbreak, keeping your baby home if possible can reduce exposure significantly. Avoid sharing cups, utensils, and towels between siblings, and try to limit face-to-face contact between your baby and anyone showing symptoms like mouth sores, rash, or fever.