Can You Contract Hand, Foot, and Mouth Disease If You've Had It Before?
Yes, you can absolutely contract Hand, Foot, and Mouth Disease (HFMD) again even after having it previously, because the disease is caused by multiple different enteroviruses, and immunity to one serotype does not protect against others.
Why Reinfection Occurs
Multiple Causative Agents
- HFMD is caused by various enteroviruses, with the most common being coxsackievirus A16, coxsackievirus A6, coxsackievirus A10, and enterovirus A71 (EV-A71) 1, 2
- Recent epidemiological shifts show that coxsackievirus A6 and A10 are causing more infections than previously recognized 1
- Having immunity to one enterovirus serotype (for example, coxsackievirus A16) provides no cross-protection against other serotypes (such as EV-A71 or coxsackievirus A6) 2, 3
Evolving Viral Strains
- Extensive recombination events occur among enterovirus strains, leading to faster evolution and extinction of dominant serotypes 1
- The molecular epidemiology of HFMD-causing pathogens is constantly changing, with different strains circulating in different geographic areas and time periods 3
Clinical Implications for Reinfection
Transmission Risk Remains High
- HFMD is highly contagious and can affect both children and adults, including immunocompetent individuals 4
- Intra-familial transmission between siblings and to parents has been well-documented 4
- The disease predominantly affects children under 5 years of age, but adults can contract it through close contact 2, 5
Prevention Strategies After Prior Infection
- Hand hygiene with soap and water remains the most important preventive measure and is more effective than alcohol-based hand sanitizers 6
- Avoid sharing utensils, cups, or food to prevent transmission 6
- Environmental cleaning of toys and objects that may be placed in children's mouths is crucial 6
- Children should avoid close contact with others until fever resolves and mouth sores heal 6
Important Caveats
Vaccine Limitations
- The EV-A71 vaccine approved in China provides protection only against EV-A71-related HFMD, not against other causative enteroviruses 2
- Simultaneous circulation of multiple pathogens makes single-agent vaccines relatively inadequate for complete protection 2, 3
Severity Considerations
- While most cases are mild and self-limiting, severe complications including brain stem encephalitis, meningoencephalitis, acute flaccid paralysis, and pulmonary edema can occur, particularly with EV-A71 infections 1, 2
- Increased mortality has been associated with brain stem encephalitis in children under 3 years of age 1