China reported over 1.4 million HFMD cases in 2024, with the seasonal peak running May through August. Vietnam, Singapore, Malaysia, and Thailand all hit five-year highs. For most kids the illness is a week of misery and a return to normal. For a small fraction (mostly under age 3 in Asia), HFMD caused by enterovirus A71 produces brainstem encephalitis, pulmonary edema, and death within 48 hours.
The Asian summer wave has clinical features US and European parents may not expect. Coxsackievirus A16, the dominant US strain, is milder. The Asian strain mix includes EV-A71 and coxsackievirus A6, both capable of more severe disease. This post sits inside the outbreak-aware travel guide and complements traveling with chronic conditions and the hand hygiene technique guide.
Key Takeaways
- HFMD is a viral illness causing oral ulcers and a rash on hands and feet, most often in children under 7.
- Coxsackievirus A16 and enterovirus A71 (EV-A71) cause most cases globally.
- EV-A71 causes around 10 to 30 percent of severe HFMD cases in Asia, with rare progression to brainstem encephalitis and pulmonary edema.
- Two licensed EV-A71 vaccines are available in mainland China, not in the US or Europe in 2026.
- Peak seasons: May to August in Asia, August to October in temperate Northern Hemisphere.
- Hand hygiene, surface disinfection, and avoiding infected playmates are the primary prevention.
What is HFMD?
Hand, foot, and mouth disease is a viral illness caused by enteroviruses, most commonly coxsackievirus A16 (in the US and Europe) and enterovirus A71 (in Asia). Coxsackievirus A6 has emerged as a third major cause globally since 2008, with more atypical and severe rash presentations.
The illness affects mainly children under 7, with peak attack rates in toddlers in daycare and preschool settings. Adults can be infected but usually have milder symptoms. Pregnant women can transmit the virus to newborns, with rare neonatal disease.
HFMD is different from foot-and-mouth disease (also called hoof-and-mouth) that affects cattle, sheep, and pigs. The two are unrelated despite the similar names.
What are the typical symptoms?
Symptoms appear 3 to 6 days after exposure (range 3 to 10).
- Prodrome: fever (usually 38 to 39 degrees C), sore throat, loss of appetite, malaise
- Day 1 to 2: painful mouth ulcers, particularly on the tongue, gums, inside cheeks
- Day 2 to 3: rash appears on palms, soles, and sometimes buttocks; can be macular, papular, or vesicular
- Day 4 to 7: rash resolves, ulcers heal, fever subsides
- Nail changes: onychomadesis (nail shedding) may occur 4 to 8 weeks later
Coxsackievirus A6 cases often have a more widespread rash extending to forearms, legs, and trunk, and can produce larger blisters that are sometimes confused with chickenpox. The differential diagnosis includes herpangina (which has oral ulcers without the rash), aphthous stomatitis, chickenpox, and atypical Stevens-Johnson reactions.
Most kids recover fully in 7 to 10 days. Hydration is the main concern because oral ulcers make eating and drinking painful. Cold drinks, soft foods, and topical anesthetic mouthwashes help.
What is severe HFMD?
The small fraction of severe HFMD cases involves neurologic and cardiopulmonary complications. EV-A71 causes most severe disease.
| Complication | Mechanism | Risk |
|---|---|---|
| Brainstem encephalitis | Direct viral CNS invasion | Higher in EV-A71 |
| Acute flaccid paralysis | Anterior horn cell damage | Polio-like, rare |
| Aseptic meningitis | Viral meningeal inflammation | Mild, usually self-limited |
| Pulmonary edema | Neurogenic, often fatal | Rare but catastrophic |
| Myocarditis | Direct cardiac invasion | Rare |
Severe disease almost always occurs in children under 3 and develops within the first 72 hours of fever. Warning signs include persistent high fever (over 39 degrees C for more than 48 hours), lethargy, tremor, ataxia, vomiting, tachycardia disproportionate to fever, and tachypnea. Any of these in a febrile child with HFMD warrants immediate hospital evaluation.
China, Taiwan, Vietnam, and Malaysia have developed standardized severity grading systems and surge response protocols during peak seasons. WHO published a HFMD case management guide in 2011 that remains current.
Where and when is HFMD active?
Asia sees the heaviest annual burden, with major peaks in mainland China, Taiwan, Hong Kong, Vietnam, Cambodia, Thailand, Singapore, and Malaysia from May through August. Singapore tracks HFMD weekly and posts public alerts when cases exceed seasonal averages.
US and European peaks come later (August to October) and are dominated by milder coxsackievirus A16 and A6 strains. EV-A71 cases occur occasionally in the West but rarely cluster.
| Region | Peak season | Dominant strain |
|---|---|---|
| Mainland China | May to August | EV-A71, CV-A16, CV-A6 |
| Singapore | March to July | CV-A6, EV-A71 |
| Taiwan | April to October | EV-A71 epidemics every 2 to 3 years |
| Vietnam | March to May, September to November | EV-A71 |
| United States | August to October | CV-A16, CV-A6 |
| Europe | September to November | CV-A6, CV-A16 |
Tropical regions can see year-round transmission with smaller seasonal fluctuations. The disease risks by region post covers broader regional patterns.
What should traveling parents do?
Most cases acquired during travel are mild and resolve at home. The pre-departure focus is on awareness, hygiene, and recognizing severe disease early.
Before travel:
- Note your destination's current HFMD activity (Singapore MOH, China NHC, Taiwan CDC publish weekly data)
- Pack pediatric paracetamol or ibuprofen for fever and pain
- Pack oral rehydration salts for kids who refuse fluids
- Verify travel insurance covers pediatric hospitalization in your destination
During travel:
- Wash kids' hands frequently, especially before meals and after toilet use (see the hand hygiene technique guide)
- Avoid splash pads, ball pits, and shared toys at indoor playgrounds during outbreaks
- Disinfect high-touch surfaces in hotel rooms (door handles, remote controls, table surfaces)
- Skip daycare and play group attendance for any child with fever or rash
If your child develops HFMD:
- Push fluids, treat fever with weight-appropriate analgesic
- Watch for severe disease signs (persistent fever, lethargy, breathing changes, neurological signs)
- Seek hospital evaluation for any worrying sign in a child under 3, especially in EV-A71 endemic areas
- Plan to delay return travel until rash resolves and child is fever-free for 24 hours
What about vaccination?
Two inactivated EV-A71 vaccines have been licensed in mainland China since 2015 (Sinovac, Vigoo). Efficacy against EV-A71-associated HFMD is around 90 percent. The vaccines are not licensed in the US, Europe, or most other countries.
The vaccines protect only against EV-A71. They do not prevent HFMD caused by coxsackievirus A6, A16, or other enteroviruses, which together cause most cases. For families relocating to mainland China or staying long-term, pediatricians at international clinics in Beijing, Shanghai, and Hong Kong can advise on the local vaccination calculus.
No oral or systemic antiviral has proven effective for HFMD or severe enterovirus disease. Management is supportive, with intensive care for severe complications.
FAQ
How long is HFMD contagious?
Most contagious during the first week of illness. The virus is shed in respiratory secretions, saliva, fluid from blisters, and stool. Stool shedding can continue for 4 to 8 weeks after recovery, which is why daycare exclusion alone does not stop spread. Hand hygiene matters even after recovery.
Can adults get HFMD?
Yes, though most adults have some immunity from childhood exposure. Adult cases are usually milder than pediatric cases. Parents and caregivers of infected children are most often the adults who become symptomatic. Pregnant women can transmit to newborns; if you have HFMD in late pregnancy, your obstetrician should know.
What is the difference between HFMD and herpangina?
Both are caused by enteroviruses. Herpangina has the painful mouth ulcers without the hand and foot rash. The same coxsackievirus strains cause both presentations. Treatment and isolation considerations are similar.
Are there long-term consequences after HFMD?
For uncomplicated cases, no. Severe EV-A71 disease with brainstem encephalitis can leave permanent neurological deficits in survivors. Onychomadesis (nail shedding) at 4 to 8 weeks post-infection is harmless; nails regrow normally over a few months.
Should daycares close during outbreaks?
CDC and most national authorities recommend exclusion of symptomatic children rather than facility-wide closure. Reinforcing hand hygiene, surface disinfection, and case identification controls outbreaks more reliably than closure. Some Asian countries do close daycares during severe epidemics; the threshold varies by jurisdiction.