Viral Myocarditis

Viruses That Cause Various Diseases and Their Complications: Myocarditis and/or Encephalitis

Viruses that cause diseases can lead to significant complications, particularly inflammation of the heart muscle (myocarditis) or brain (encephalitis). Among these, enteroviruses are a common cause of myocarditis. Frequently encountered strains include Enterovirus A71, Coxsackie B, and Echo virus. The enterovirus group contains hundreds of types, including those responsible for hand, foot, and mouth disease (HFMD), which may lead to complications involving the brain and heart, though such occurrences are rare. These complications are more commonly seen in young children than in older ones.

In addition to enteroviruses, well-known viruses such as influenza, dengue, measles, and chickenpox can also lead to myocarditis or encephalitis. However, the chances of such complications are extremely rare, occurring in only one in tens or hundreds of thousands of cases.

Within the enterovirus group, strains like Enterovirus A71, Coxsackie B, and Echovirus are known to cause HFMD and may result in myocarditis or encephalitis. The risk of these complications is very low. For Enterovirus A71, the likelihood of encephalitis or myocarditis in children under 1 year old is approximately 1 in 100, while in children under 3 years old, it is 1 in 300. The probability decreases further as the child’s age increases. For other viruses, the risk is even lower, occurring in only one in tens or hundreds of thousands of cases.
 

Preventing Viral Infections
To prevent viral infections—whether they affect the respiratory or gastrointestinal systems—the best measures include:

  • Maintaining good hygiene
  • Keeping the body strong and healthy
  • Ensuring cleanliness, such as washing hands regularly
  • Consuming freshly cooked and clean food
  • Wearing masks in crowded places or hospitals
     

Dr. Yong Poovorawan
Academician, Academy of Science
Center of Excellence in Clinical Virology
Faculty of Medicine, Chulalongkorn University
January 9, 2025