Pathogen and epidemiology
The family Picornaviridae comprises small single-stranded RNA viruses lacking a supercapsid lipid envelope. The absence of a lipid layer makes them highly stable in the environment: they are not destroyed by fat solvents, detergents, or low temperatures. However, viruses are rapidly inactivated by boiling, ultraviolet (UV) radiation, chlorine-containing disinfectants, and hydrogen peroxide.
The source of infection is a sick person or an asymptomatic virus carrier (strict anthroponosis). Transmission occurs via several routes:
- Aerosol: in the early stages of the disease through coughing and sneezing.
- Fecal-oral: the virus can persist in the intestine and be excreted in feces for up to 5 months.
- Vertical: transplacental transmission to the fetus is possible.
The disease mainly affects children under 10 years of age, with maximum susceptibility observed in the first year of life. When introduced into childcare settings, an outbreak can affect up to 80% of contacts.
Pathogenesis and basic symptoms
Upon reaching the mucous membranes of the respiratory tract or gastrointestinal tract, the virus initially replicates in local lymphoid tissue. On the 3rd day, the pathogen breaks through the lymphatic barrier and enters the systemic circulation (primary viremia). Due to marked pantropism, the virus disseminates to various target organs: skin, muscles, central nervous system, myocardium, and liver.
Despite the polymorphism of forms, universal symptoms are frequently observed during the acute period:
- Persistent hyperemia of the upper torso and face.
- Scleral injection.
- Biphasic ("dromedary") fever.
- Pronounced hyperemia and characteristic granularity of the mucous membrane of the soft palate and posterior pharyngeal wall.
- Cervical lymphadenopathy.
Main clinical forms
The variety of clinical equivalents depends on the organ tropism of a specific strain (e.g., Coxsackie or ECHO viruses).
- Enteroviral fever (minor illness): The most frequent form. It presents with short-term febrile fever without pronounced symptoms of localized organ lesions.
- Hand, foot and mouth disease: Specific vesicular stomatitis with exanthema. Vesicles surrounded by a hyperemic halo appear on the palms and soles, and painful aphthas form in the oral cavity. Nail shedding (omychomadesis) is typical during the convalescent period.
- Herpangina: Characterized by the appearance of small papules on the palatine arches that rapidly transform into vesicles and superficial erosions. Accompanied by odynophagia and hypersalivation.
- Serous meningitis: One of the most common forms in preschoolers and school-age children. Manifests with febrile fever and meningeal syndrome; convulsions and hyperreflexia are possible in early childhood.
- Epidemic myalgia (Bornholm disease): Manifests with acute, paroxysmal pain in the abdominal and chest muscles, often mimicking the clinical picture of an "acute abdomen".
- Spinal form: Acute flaccid paralysis which, unlike classic poliomyelitis, is accompanied by marked muscle pain and is fully reversible.
Laboratory diagnostics
Due to clinical polymorphism, the diagnosis often requires laboratory confirmation. Four main groups of methods are used:
- Molecular biological: RT-PCR is the method of choice due to maximum sensitivity, specificity, and speed of detecting viral RNA.
- Serological: ELISA to search for acute phase markers (IgM and IgA) or neutralization assays (a 4-fold or greater rise in antibody titer in paired sera is diagnostically significant).
- Immunohistochemical: Direct detection of antigens in tissues.
- Virological: Isolation of the pathogen in cell cultures from blood, CSF, or feces.
To remember the triad of the most severe lesion in infants (neonatal encephalomyocarditis), use the mnemonic MMG: Meningoencephalitis, Myocarditis, Hepatitis.
Class and exam questions
How to distinguish enteroviral exanthema from the rash in other childhood infections?
Enteroviral exanthema lasts a short time (1–2 days) and resolves completely without a trace, leaving no pigmentation or skin desquamation.
What is the clinical feature of enteroviral mesadenitis?
It is accompanied by high fever and paroxysmal abdominal pain, which can mimic acute surgical pathology (e.g., appendicitis) and requires careful differential diagnosis.
What long-term autoimmune diseases are Coxsackie viruses associated with?
The role of enteroviruses as triggers in the pathogenesis of type 1 diabetes mellitus is being considered, and Coxsackie virus A9 is associated with the development of dermatomyositis.
What else to study on this topic
- Ophthalmological forms: epidemic hemorrhagic conjunctivitis and uveitis in infants
- Principles of differential diagnosis between enteroviral myalgia and "acute abdomen"
- Pathogenesis and outcomes of enteroviral myocarditis and coronaritis
- Reproductive system involvement (orchitis and epididymitis) in adolescent boys
- Symptomatic and nonspecific antiviral therapy for enteroviral infections
Master the entire topic in the Pediatrics course
This is a summary. The course covers everything tested in classes and exams.
- Complete study guide on "Enteroviral infections in children" and 3,738 more pages of the subject
- Assignments and quizzes after every topic — just like in a colloquium
- AI tutor answers questions on the topic anytime
- 71 video lessons on the subject
Other topics from the section «Chapter 12. Infectious and parasitic diseases»
Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.