Author(s): Eileen Yee

Infectious Agent

Hand, foot, and mouth disease (HFMD) is caused by nonpolio enteroviruses, a genus of the Picornaviridae family of nonenveloped RNA viruses (e.g., coxsackievirus A6, coxsackievirus A16, enterovirus A71). Enteroviruses that cause widespread outbreaks of HFMD worldwide can vary by type and region. In the Asia-Pacific region, enterovirus A71 (EV-A71) is the predominant etiologic agent, while in Europe and the United States, coxsackievirus viruses often are implicated in HFMD cases and outbreaks.

Transmission

Transmission occurs by direct person-to-person contact with the saliva, nose and throat secretions, vesicle fluid, or stool of an infected person and through contact with contaminated surfaces and objects (e.g., common diapering areas, shared toys, eating utensils).

Epidemiology

HFMD is a common infection among children worldwide and spreads quickly, causing large outbreaks that can lead to nursery, daycare, and school closures. Outbreaks often occur during summer and early fall in Australia and the United States, but seasonal patterns in the Asia-Pacific region can vary between climate zones. In the temperate climates, cases tend to peak during the early summer, whereas in tropical climates, including Hong Kong and Taiwan, outbreaks usually occur in late spring and fall.

Outbreaks also can happen sporadically throughout the year in other countries (e.g., Malaysia, Singapore, Thailand, Vietnam). Children <5 years old are most susceptible, but adults and adolescents also can become ill with HFMD. People traveling with young children should be aware of HFMD and any local outbreaks that might occur at their destinations and pay close attention to recommended preventive measures.

Clinical Presentation

Incubation period is 3–6 days, and illness usually is self-limited, with recovery within 7–10 days. Patients usually present with fever and malaise; then sore throat and painful vesicles (herpangina) appear in the mouth, involving the buccal mucosa, tongue, or hard palate, and a peripheral rash, usually papulovesicular, appears on the hands (palms), feet (soles), or less often on the buttocks, genitals, elbows, and knees.

In rare cases, patients can develop brainstem encephalitis, aseptic meningitis, myocarditis, or pulmonary edema and can die from complications. Additionally, HFMD can have an atypical presentation, often in adults, beginning with a rash or lesion that enlarges and coalesces to form bullae; a thorough travel history or history of recent exposure to others with the infection is critical to making the diagnosis. Onychomadesis (shedding of the nails) and desquamation of the palms or soles can occur during convalescence.

Diagnosis

Diagnosis is usually clinical, but confirmatory laboratory tests using reverse transcription PCR (RT-PCR) assays are available and performed for atypical or severe cases. Preferred samples for testing include vesicle fluid, throat or buccal swabs, or stool. Many commercial or reference laboratories can perform RT-PCR assays to detect enterovirus RNA.

The Centers for Disease Control and Prevention (CDC) Picornavirus Laboratory within the Division of Viral Diseases routinely performs qualitative pan-enterovirus molecular testing, after which the laboratory performs sequencing for enterovirus typing in consultation with state or local health departments in the United States. CDC can test nasopharyngeal or oropharyngeal swabs, nasal wash or aspirate samples, stool samples, rectal swabs, cerebrospinal fluid, serum, and tissue biopsy or autopsy specimens.

International laboratories seeking consultation can email the CDC laboratory, picornalab@cdc.gov. For information about specimen collection, storage, and shipping address, refer to CDC’s Non-Polio Enterovirus website and email the laboratory (picornalab@cdc.gov) prior to shipping.

Treatment

HFMD treatment mainly involves supportive care to treat symptoms of fever or pain caused by mouth sores, and to prevent dehydration, especially in young children.

Prevention

Travelers can prevent HFMD by avoiding close contact (e.g., hugging, kissing, sharing food utensils or drinking cups) with infected people. Travelers also should maintain good hand hygiene, and clean and disinfect potentially contaminated surfaces and soiled items, including diapering and child potty areas, doorknobs, eating areas, and toys. People traveling with infants and young children and those affected by local school or daycare outbreaks especially should follow these precautions.

Travelers should use frequent handwashing with soap and water rather than hand sanitizers, because alcohol-based sanitizers might be less effective against nonenveloped enteroviruses. Travelers should choose a US Environmental Protection Agency–registered disinfecting product or a comparable product that kills nonenveloped viruses (e.g., norovirus). The public health response to large outbreaks of HFMD, particularly in Asia, includes isolation of cases, social distancing, and closures of schools and daycare centers.

Licensed EV-A71 vaccines to prevent severe HFMD have been approved in China since 2015. This vaccine might not provide cross-protection against other enterovirus serotypes, however. The US Food and Drug Administration has not approved any enterovirus vaccines for use in the United States.

CDC website: Hand, foot, and mouth disease