Hand, foot and mouth disease (HFMD) is a communicable disease mostly affects infants and children but can also occur in adolescents and adults. It is an acute viral infection caused by a group of enteroviruses, including Coxsackievirus A16 (CA16) and Enterovirus 71 (EV71). The disease is usually mild characterized by fever, painful sores in the mouth, and a rash with blisters on hands, feet and also buttocks. Infection with EV71 can cause severe disease in children, sometimes resulting in death.
Though the outbreaks of HFMD occur worldwide but in recent years these have occurred more in Asia including: China, Japan, Hong Kong (China), Republic of Korea, Malaysia, Singapore, Thailand, Taiwan (China) and Viet Nam.
HFMD is not to be confused with foot-and-mouth disease (also called hoof-and-mouth disease), which occurs in animals (cattle, sheep, and pigs) by a different virus and do not transmit to humans.
Symptoms
HFMD is usually a mild disease. Symptoms may appear in 3-7 days after getting infection (this period is termed as incubation period).
- The first symptom is fever lasting for 24-48 hours, with poor appetite, malaise and sore throat
- One or two days after fever onset, painful sores appear on the tongue, gums and inside the cheeks. Initially these are small red spots that blister and then ulcerate.
- A non-itchy rash develops over one to two days on the palms of the hands and soles of the feet; may appear on the buttocks and /or genitalia. Almost all patients recover in 7 to 10 days without any complications.
- Some persons with HFMD may not show any symptoms or may have only rash or only mouth ulcers.
- HFMD caused by EV71 has been associated with meningitis and encephalitis and may show mixed neurological (headache, stiff neck, or back pain) and respiratory symptoms. In HFMD due to EV71 complications may be serious with fatal outcome.
HFMD in pregnant women:
No adverse outcome of pregnancy (such as abortion, stillbirth or congenital defects) is observed when pregnant women are infected with HFMD; however pregnant women may pass the virus to the baby if they are infected shortly before delivery or have symptoms at the time of delivery.
Most newborns infected with an enterovirus have mild illness, but the risk of severe illness may be higher in newborns infected during the first two weeks of life.
Causes
HFMD is caused by group of viruses called enteroviruses. There are different types of viruses in this group that include polioviruses, coxsackieviruses, echoviruses and other enteroviruses. The common viruses causing HFMD are coxsackievirus A16 resulting in mild self limiting disease with few complications and enterovirus 71 (EV71) which has been associated with serious complication and is fatal.
Transmission of infection:
- HFMD virus is contagious.
- Nose and throat discharges, saliva, fluid from blisters, or the stool of infected persons are the infective materials.
- Infection spreads from person to person by direct contact with these infective materials.
- Infected persons are most contagious during the first week of the illness but can remain infectious up to several weeks (as the virus persists in stool).
- Children younger than 5 years of age are most commonly affected by the disease.
- Most adults are immune but cases in adolescents and adults may also occur. Immunity developed after an infection is virus specific and a second episode of HFMD may occur following infection with a different member of the enterovirus group.
HFMD is not transmitted to or from pets or other animals.
Diagnosis
The diagnosis of HFMD is based on clinical examination. Samples for virology investigation from the throat swabs, vesicles, rectal swab/ stool or cerebrospinal fluid (CSF) may be collected and sent to a laboratory to test for the virus.
- Reverse transcription by polymerase chain reaction (RT-PCR) is used to detect the virus in the samples.
- Four-fold rise in antibody titer in paired blood sample shows confirmation of the disease.
Management
In most cases, HFMD is a self-limiting illness, with the majority of children recovering spontaneously with symptomatic treatment as:
- Ensure adequate fluid intake to prevent dehydration. Cold liquids are generally preferable.
- Spicy or acidic substances may cause discomfort.
- Fever may be treated with antipyretics.
- Mouthwashes or sprays that numb pain can be used to lessen mouth pain.
- Seek prompt medical care for children showing severe symptoms.
Complications
Usually all patients recover within 7-10 days without any medical treatment and complications are uncommon.
- Dehydration may be seen in HFMD caused by coxsackieviruses; if intake of liquids is not sufficient due to painful sores in the mouth.
- Rarely aseptic or viral meningitis may develop with symptoms of fever, headache, stiff neck, or back pain and may require hospitalization for a few days.
Prevention
There is no vaccine to protect against the viruses that cause hand, foot and mouth disease. As HFMD is contagious disease further transmission of disease can be prevented by practicing good hygienic practices:
- Frequent hand washing with soap and water especially before preparing food and eating, before feeding young infants, after using the toilet and after changing diapers, after touching any blister or sore,
- avoiding close contact (kissing, hugging, sharing utensils, etc.) with children with HFMD
- covering mouth and nose when sneezing and coughing during illness;
- clean thoroughly toys or appliances which are contaminated by the child’s secretions first with soap and water and then disinfecting them by cleansing with a solution of chlorine bleach (made by adding 1 tablespoon of bleach to 4 cups of water; larger quantities can be made by adding ¼ cup of bleach to 1 gallon [16 cups] of water)
- do not let children attend nurseries/kindergartens/schools or gatherings until they are well;
- disposing properly of used tissues and nappies into waste bins that close properly;
- proper infection-control measures for child-care centers, pre-schools and schools to reduce disease transmission in these places.
- monitoring the sick child’s condition closely and seeking prompt medical care in following conditions:
- persistent high fever,
- decrease in alertness or
- deterioration in general condition
References :
www.wpro.who.int/topics/hand_foot_mouth/en/
www.wpro.who.int/mediacentre/factsheets/fs_
www.ncbi.nlm.nih.gov/pmc/articles/PMC4318054/