Is hand, foot, and mouth disease (HFMD) contagious?

Hand, Foot, and Mouth Disease: Contagiousness and Transmission

Yes, hand, foot, and mouth disease (HFMD) is highly contagious and spreads easily from person to person through direct and indirect contact. 1, 2

Causative Agents

HFMD is caused by several enteroviruses, primarily:

• Coxsackievirus A16 (CV-A16) - traditionally most common
• Enterovirus 71 (EV-A71) - associated with more severe cases
• Coxsackievirus A6 (CV-A6) - increasingly common in recent outbreaks
• Coxsackievirus A10 (CV-A10) - emerging cause 3, 2

Transmission Mechanisms

HFMD spreads through multiple routes:

1. Direct contact transmission:

   • Person-to-person contact with saliva, respiratory secretions, fluid from blisters, or stool of infected persons
   • Direct contact with an infected person's skin lesions 4, 5

2. Indirect contact transmission:

   • Touching contaminated surfaces or objects (fomites)
   • Contact with toys, doorknobs, or other items that have been exposed to the virus 4, 5

3. Respiratory droplet transmission:

   • Close-range exposure to respiratory secretions from coughs or sneezes 4

Contagious Period

• Incubation period: 3-10 days after exposure 1
• Most contagious during the first week of illness
• Can remain contagious even after symptoms resolve, as the virus may be shed in stool for weeks 5

High-Risk Settings

HFMD spreads particularly easily in:

• Childcare centers and kindergartens
• Schools
• Households with multiple children
• Areas with close community contact 4, 5

Studies have documented familial transmission patterns, including child-to-adult transmission, even to immunocompetent adults 6, 7.

Prevention Measures

To reduce transmission:

1. Hand hygiene:

   • Frequent handwashing with soap and water, especially after diaper changes, using the toilet, and before eating
   • Alcohol-based hand sanitizers when soap and water aren't available 4

2. Environmental cleaning:

   • Disinfect frequently touched surfaces and shared toys
   • Avoid sharing utensils, cups, towels, and personal items 4

3. Respiratory etiquette:

   • Cover coughs and sneezes
   • Proper disposal of tissues 4

4. Isolation precautions:

   • Keep infected individuals home from school, daycare, or work until fever is gone and mouth sores have healed
   • Avoid close contact (hugging, kissing) with infected persons 4, 5

Special Considerations

• Asymptomatic carriers: Some infected individuals may show no symptoms but can still transmit the virus 5
• Outbreak management: In school settings, identification of multiple cases may warrant temporary closure to interrupt transmission chains 5
• Adult susceptibility: While primarily affecting children, adults (especially those with close contact with infected children) can contract HFMD 6, 7

Clinical Implications

Understanding the highly contagious nature of HFMD is essential for implementing effective control measures, especially in childcare settings where rapid spread can occur. The potential for asymptomatic transmission further complicates containment efforts and highlights the importance of maintaining good hygiene practices even when no obvious illness is present.