How does hfmd start

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Last updated: April 8, 2026

Quick Answer: Hand, foot, and mouth disease (HFMD) typically starts when a person becomes infected with enteroviruses, most commonly coxsackievirus A16 or enterovirus 71. The virus spreads through direct contact with infected respiratory droplets, saliva, blister fluid, or feces, with an incubation period of 3-6 days before symptoms appear. Initial symptoms often include fever, sore throat, and reduced appetite, followed by the characteristic rash on hands, feet, and mouth within 1-2 days. Children under 5 years old account for approximately 90% of HFMD cases, with outbreaks peaking in summer and fall in temperate climates.

Key Facts

HFMD is caused primarily by coxsackievirus A16 (accounting for about 80% of cases) and enterovirus 71
The incubation period ranges from 3-6 days after exposure before symptoms begin
Children under 5 years old represent approximately 90% of all HFMD cases
Outbreaks typically peak in summer and fall months in temperate regions
The virus can remain in stool for several weeks after symptoms resolve

Overview

Hand, foot, and mouth disease (HFMD) is a common viral illness that primarily affects infants and young children, though adults can occasionally contract it. First described in 1957 during an outbreak in Toronto, Canada, HFMD has since been recognized worldwide, with significant outbreaks occurring in Asia-Pacific regions. The disease gained particular attention during the 1998 outbreak in Taiwan that affected over 1.5 million people and caused 78 deaths, primarily due to enterovirus 71 complications. In the United States, the CDC estimates 10-15 million symptomatic cases occur annually, with most being mild. The World Health Organization reports that Southeast Asia experiences the highest burden, with countries like China, Vietnam, and Malaysia reporting tens of thousands of cases yearly. HFMD is not related to foot-and-mouth disease that affects livestock, despite the similar name.

How It Works

HFMD begins when enteroviruses enter the body through the mouth or respiratory tract. The viruses initially replicate in the lymphoid tissues of the throat and intestines before spreading through the bloodstream. This viremia phase allows the virus to reach skin and mucous membrane tissues, where it causes the characteristic lesions. The viruses damage epithelial cells, leading to vesicle formation that appears as painful sores in the mouth and non-itchy blisters on hands and feet. The immune response to the infection causes fever and general malaise. Transmission occurs through multiple routes: direct contact with infected respiratory droplets from coughs or sneezes, contact with blister fluid, exposure to contaminated surfaces (where viruses can survive for days), and fecal-oral transmission. The viruses are shed in highest concentrations during the first week of illness but can persist in stool for several weeks.

Why It Matters

HFMD matters because it causes significant morbidity in young children worldwide, with economic impacts from medical costs and lost workdays for caregivers. Severe cases, particularly those caused by enterovirus 71, can lead to neurological complications like aseptic meningitis, encephalitis, or acute flaccid paralysis in approximately 1-2% of cases. In China alone, HFMD caused over 1.7 million reported cases and 27 deaths in 2019. The disease disrupts childcare and educational settings, with outbreaks often closing preschools and daycare centers. Research continues on vaccines, with China approving the first EV71 vaccine in 2015, which has reduced severe cases by approximately 90% in vaccinated populations. Understanding HFMD transmission helps implement effective hygiene measures to control outbreaks.