Parents must know: 5 points of knowledge about hand, foot and mouth disease and a case story

Regarding hand, foot and mouth disease, parents must understand these 5 points:

1. Pathogens: The pathogens of hand, foot and mouth disease include dozens of enteroviruses including Coxsackievirus (most common types 6, 10, and 16), enterovirus 71 (EV71), and echovirus. Mild cases account for 98% to 99%, severe cases account for 1% to 2%, and deaths account for 0.005%-0.02%.

However, more than 40% of the "morbidity", 70% of the "severe illness" and 90% of the "deaths" in our country are caused by EV71, and the incidence of meningitis, cerebrospinal meningitis, brainstem encephalitis, and pulmonary edema/pulmonary hemorrhage after EV71 infection is high.

2. Transmission route: Enterovirus is transmitted through the patient's feces (fecal-oral transmission), respiratory secretions and droplets, herpes fluid, and objects contaminated by their secretions and excrement. Therefore, children need to pay attention to hand hygiene and avoid close contact with children infected with enterovirus and their supplies to avoid infection.

However, even if children develop good hygiene habits themselves, they cannot necessarily prevent other family members from "bringing back" the virus. Studies in Guangdong Province and Taiwan Province in my country have found that siblings, parents, and grandparents can all bring enterovirus to children. Therefore, even if children do not go out, they may be infected by other family members.

Image source: Reference [1]

3. Clinical symptoms: Although it is a "self-limiting disease", the main symptoms include rashes on the hands, feet, and buttocks, oral herpes, and some children will experience "onychia" (nails falling off). Most children can get through it smoothly with symptomatic treatment.

However, a small number of severe cases can lead to complications such as neurological diseases or even "death"; and because EV71 and poliovirus have some similar characteristics, and a small number of cases may develop symptoms similar to polio (polio) after infection, some doctors even call EV71 infection "polio of the 21st century."

4. Diagnosis: The criteria are very clear. Clinical samples (throat swabs, stool or anal swabs, blood, etc.) have positive specific nucleic acid tests for enterovirus or have isolated enterovirus. Acute serum has positive IgM antibodies for related viruses. Neutralizing antibodies in the recovery serum are 4 times or more higher than those in the acute phase.

However, many parents and even medical staff use the results of "antibody testing" as the basis for diagnosis. Not only do they not understand the significance of IgM and IgG results in actual diagnosis, they also fail to consider the impact of vaccination on (EV71) antibodies, resulting in children using unnecessary drugs and parents increasing unnecessary energy and financial burden.

5. Vaccines: Since 2016, my country has approved a total of 5 inactivated enterovirus 71 vaccines (EV71 vaccines), including 3 in mainland China (1 each in Beijing, Hubei, and Yunnan), and 2 in Taiwan. The protective efficacy of all vaccines in Phase III clinical studies exceeded 90%. Since 2018, more than 15 million doses have been administered nationwide each year, and both safety and effectiveness have been verified. (Only 2 doses are required to provide more than 5 years of protection, allowing children to safely pass through the high-incidence period)

However, even with a vaccine, it can only prevent one pathogen, EV71. Therefore, in the future, a "polyvalent enterovirus vaccine" will still be needed to cover more pathogens including Coxsackie virus, so that it can truly be called a "hand, foot and mouth vaccine" rather than a single enterovirus vaccine. I once heard a story from a PICU director at a meeting: the department admitted a child with severe hand, foot and mouth disease infected with EV71. After treatment, although other functions of the body have recovered, serious sequelae have occurred- the child cannot breathe independently . Therefore, the child can only maintain life through a ventilator. Although irreversible brainstem damage has occurred, causing the child to be unable to breathe independently, the child's parents did not give up treatment and worked hard to treat the child for a year. During this year, the child has gradually grown up, has his own emotions, and is able to interact with medical staff.

Source: Reference [2] However, under the financial pressure of long-term treatment and knowing that the child could no longer breathe on his own, the parents had no choice but to give up treatment. After the parents signed a consent form to give up treatment, they told the child, "Dad has tried his best and I am sorry for you." Then the nurse stopped the ventilator and the child died. In fact, this is true for many diseases, including hand, foot and mouth disease. Most people will only have mild infections or recover quickly, but they are helpless when faced with severe illness, especially for some high-risk groups. Therefore, vaccines are needed for prevention . Ideally, it is to control the onset of the disease, but in fact, the greater value lies in reducing the risk of severe illness or even death.

A chart showing the changes in the incidence and mortality of hand, foot and mouth disease in my country. Therefore, no matter what disease you face, you don’t need to worry. You can take scientific measures to prevent it without affecting your life, such as developing good hygiene habits and getting vaccinated. As for the rest, let it be. I hope that a better and more comprehensive hand, foot and mouth disease vaccine can be developed as soon as possible, so that fewer children can be free from the invasion of enterovirus. Reference [1]: Digital Diagnosis of Hand, Foot, and Mouth Disease Using Hybrid Deep Neural Networks

Document [2]: Hand, Foot, and Mouth Disease Caused by Coxsackievirus A6

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=丸= **Disclaimer: **This article was created out of personal interest, only to allow more ordinary people to have a clearer understanding of vaccines. The content and views do not represent any organization, unit, or institution, and have not accepted any form of sponsorship. All pictures are from public online platforms. If the content is incorrect, everyone should do more self-criticism (not).