How does Hand, Foot, and Mouth Disease (HFMD) spread?

Transmission of Hand, Foot, and Mouth Disease (HFMD)

Hand, Foot, and Mouth Disease primarily spreads through fecal-oral transmission, direct contact with saliva or respiratory secretions, and contact with contaminated surfaces. 1

Primary Transmission Routes

HFMD is a highly contagious viral illness caused by enteroviruses (primarily coxsackieviruses and enteroviruses) that spreads through multiple routes:

• Fecal-oral transmission:

  • Research suggests this is the principal mode of transmission among children 2
  • Occurs when microscopic particles of fecal matter containing the virus enter the mouth

• Direct person-to-person contact:

  • Contact with saliva, respiratory secretions, or fluid from blisters of infected persons 1
  • Oral-oral contact (kissing, sharing utensils, cups)

• Respiratory droplet transmission:

  • Spread through coughing and sneezing of infected individuals 1
  • Droplets containing virus particles can travel short distances (within 1 meter) 3

• Contact with contaminated surfaces and objects (fomites):

  • The virus can survive on surfaces and objects touched by infected persons 1
  • Common in childcare settings where toys and surfaces may be contaminated

Incubation Period and Contagiousness

• Incubation period: 3-10 days from exposure to symptom onset 4
• Patients are most contagious during the first week of illness
• Virus can be shed in stool for weeks after symptoms resolve, allowing for continued transmission

High-Risk Groups and Settings

• Children under 10 years of age are most commonly affected 1
• Outbreaks frequently occur in:
  • Childcare centers
  • Schools
  • Households with young children
• Seasonal pattern: More common in spring to fall in North America 1

Prevention Strategies

Breaking the chain of transmission requires multiple approaches:

• Hand hygiene:

  • Thorough handwashing with soap and water, especially:
    • After using the toilet or changing diapers
    • Before preparing food or eating
    • After contact with an infected person
  • Hand hygiene is crucial for preventing transmission 3, 5

• Respiratory hygiene:

  • Cover mouth and nose when coughing or sneezing
  • Dispose of tissues properly

• Environmental cleaning:

  • Disinfect frequently touched surfaces and objects
  • Clean toys and other items that may have been contaminated 1

• Behavioral measures:

  • Avoid close contact with infected individuals
  • Do not share eating utensils, cups, or personal items
  • Isolate infected individuals, particularly during the acute phase of illness

Important Considerations for Healthcare Providers

• Unlike airborne diseases like measles, HFMD does not typically require special isolation precautions in healthcare settings beyond standard precautions 5
• Infected children should stay home from school or childcare until fever is gone and mouth sores have healed
• There is currently no specific antiviral treatment or vaccine widely available for HFMD 6
• An inactivated EV-A71 vaccine has been approved in China, but it doesn't protect against other common HFMD-causing viruses 6, 7

Pitfalls in HFMD Transmission Control

• Underestimating fecal-oral transmission: Focus exclusively on respiratory precautions while neglecting proper hand hygiene after toileting
• Inadequate disinfection: Failing to properly clean contaminated surfaces and objects
• Premature return to group settings: Allowing children to return to school/daycare while still contagious
• Overlooking asymptomatic carriers: Some infected individuals may spread the virus without showing symptoms

Understanding these transmission pathways is essential for implementing effective prevention strategies to reduce the spread of HFMD, especially in settings with young children.