How long is hand, foot, and mouth disease (HFMD) contagious?

Hand, Foot, and Mouth Disease Contagiousness Period

Hand, foot, and mouth disease (HFMD) is contagious from 1-2 days before symptom onset until all lesions have dried and crusted, typically 7-10 days after the onset of symptoms.

Transmission and Contagious Period

Hand, foot, and mouth disease is a highly contagious viral illness primarily caused by enteroviruses, including coxsackieviruses A6, A10, A16, and enterovirus 71 1. The disease spreads through:

• Fecal-oral contact
• Oral-oral contact
• Respiratory droplets
• Contact with contaminated surfaces and objects (fomites)

The contagious period follows a specific timeline:

• Before symptoms appear: Infected individuals can transmit the virus 1-2 days before showing any symptoms
• During active infection: Highest contagiousness occurs during the first week of illness when fever and rash are present
• After symptoms resolve: Viral shedding can continue in stool for several weeks, though infectivity decreases significantly once lesions have dried

Duration of Contagiousness

The exact duration of contagiousness varies slightly based on clinical presentation and individual factors:

• Standard cases: Contagious until all lesions have dried and crusted, typically 7-10 days from symptom onset 2
• Children: May shed virus for longer periods, potentially up to 7-10 days after symptoms appear 3
• Asymptomatic cases: Can still transmit the virus despite showing no symptoms

Recommendations for Preventing Transmission

To prevent spreading HFMD to others, infected individuals should:

1. Self-isolate until all lesions have dried and no new lesions appear within a 24-hour period
2. Practice good hand hygiene with soap and water (alcohol-based sanitizers are less effective against enteroviruses)
3. Avoid close contact with others, especially pregnant women, immunocompromised individuals, and young children
4. Use separate towels and utensils
5. Clean and disinfect frequently touched surfaces and soiled items

Special Considerations

High-Risk Settings

Individuals in high-transmission settings should take extra precautions:

• Healthcare workers: Should not return to work until all lesions have dried
• Childcare providers: Should avoid contact with children until no longer contagious
• School-aged children: Should stay home from school until fever resolves and lesions dry

Complications and Severe Cases

While most HFMD cases are mild and self-limiting, severe complications can occur:

• In rare cases, HFMD can lead to neurological complications including encephalitis, meningitis, or acute flaccid paralysis 4
• Severe cases may require longer isolation periods and medical monitoring
• Coxsackievirus A6 has been associated with more severe presentations and can affect adults more frequently than other strains 1

Treatment Approach

Treatment is supportive as there is no specific antiviral therapy available for HFMD:

• Focus on hydration and pain relief with acetaminophen or ibuprofen as needed
• Oral lidocaine is not recommended
• Maintain good oral hygiene despite mouth sores
• Soft, cool foods may be better tolerated with oral lesions

Remember that even after symptoms improve, proper hand hygiene remains important as viral shedding in stool can continue for several weeks after clinical recovery.