Enterovirus infections

Enterovirus infections (Enterovirosis) are a large group of anthroponotic infectious diseases with a feco-oral mechanism of transmission of the pathogen, caused by enteroviruses of the Coxsackie and ECHO groups, which are characterized by polymorphism of the clinical picture (with damage to the central nervous system, muscles, mucous membranes and skin).

ICD-10 codes

• A85.0 (G05.1) Enteroviral encephalitis, enteroviral encephalomyelitis.
• A87.0 (G02.0) Enteroviral meningitis; Coxsackievirus meningitis/ECHOvirus meningitis.
• A88.0. Enterovirus exanthematous fever (Boston exanthema).
• B08.4. Enteroviral vesicular stomatitis with exanthema, viral pemphigus of the mouth and hands.
• B08.5. Enteroviral vesicular pharyngitis, herpetic sore throat.
• B08.8. Other specified infections characterized by lesions of the skin and mucous membranes; enteroviral lymphonodular pharyngitis.
• B34.1. Enterovirus infection, unspecified: Coxsackievirus infection, NEC; ECHOvirus infection, NEC.

What causes enterovirus infections?

Enterovirus infections are caused by enteroviruses, which together with rhinoviruses are picornaviruses (RNA viruses). Enteroviruses include polioviruses types 1-3, coxsackieviruses A1-A22 and A24, B1-B6, ECHO viruses 2-9, 11-21, 24-27, 29-33 and enteroviruses 68-71, 73. Coxsackieviruses and ECHO viruses (capital letters from the English combination of the words enteric cytopathic human orphan) differ in antigenic structure. They enter the environment with saliva, stool, blood, cerebrospinal fluid and are widespread in all geographic regions.

What are the symptoms of enterovirus infections?

Enterovirus infection has various symptoms. In the United States, the rise in infection occurs in the summer and fall. Epidemic pleurodynia, hand-foot-and-mouth disease, herpangina, and poliomyelitis are caused almost exclusively by enteroviruses. Other diseases associated with enteroviruses often have other etiologies.

Aseptic meningitis in young children is most often caused by coxsackieviruses A and B, ECHO viruses. In older children and adults, aseptic meningitis is caused by other enteroviruses and other viruses in general. The rash may be associated with enteroviral aseptic meningitis. Rarely, severe encephalitis may occur.

The incidence of hemorrhagic conjunctivitis in the United States is rarely epidemic. Outbreaks of the disease may be caused by the introduction of the virus from Africa, Asia, Mexico, and the Caribbean. The eyelids quickly swell, then subconjunctival hemorrhages and keratitis develop, causing pain, lacrimation, and photophobia. Systemic manifestations are uncommon, although transient lumbosacral radiculomyelopathies or poliomyelitis-like syndrome may occur (particularly if the cause of hemorrhagic conjunctivitis is enterovirus 70). Recovery usually occurs within 1-2 weeks from the onset of the disease. Hemorrhagic conjunctivitis can be caused by coxsackievirus A24, but in this case subconjunctival hemorrhages are less common.

Myopericarditis is caused by group B coxsackieviruses and some enteroviruses, and occurs in newborns (myocarditis of newborns and rarely in utero). Usually, a few days after birth, the newborn develops a picture resembling sepsis, lethargy, DIC syndrome, bleeding, and multiple intraorgan lesions. The central nervous system, liver, pancreas, and adrenal glands are simultaneously affected. Recovery occurs within a few weeks, but death may occur as a result of vascular collapse or liver failure. In older children and adults, myocarditis can be caused by group B coxsackieviruses, less often group A and ECHO viruses. These infections end in complete recovery.

A rash can appear as a result of infection with coxsackie and ECHO viruses, often during epidemics. It is usually non-itchy, non-flaky, and located on the face, neck, chest, and limbs.

It is usually maculopapular or morbilliform, rarely hemorrhagic, petechial or vesicular. Fever and aseptic meningitis may often develop.

Respiratory infection is caused by enteroviruses. Symptoms of enterovirus infection include fever, rhinorrhea, pharyngitis, and in some children (young children) vomiting and diarrhea. Bronchitis and interstitial pneumonia are rare in adults and children.

How are enterovirus infections diagnosed?

Diagnosis of enterovirus infections is clinical. Laboratory diagnosis of enterovirus infection is not of significant importance, but virus cultivation can be performed, seroconversion can be proven, and viral RNA can be detected in PCR. Enterovirus cultures that cause aseptic meningitis can be isolated from the nasopharynx, stool, blood, and cerebrospinal fluid.

How are enterovirus infections treated?

Treatment of enterovirus infection is symptomatic, although antiviral drugs are being developed. Detoxification treatment of enterovirus infection is carried out. In meningitis and meningoencephalitis, dehydration therapy is prescribed using saluretics (furosemide, acetazolamide), in severe cases, dexamethasone is used at 0.25 mg / kg per day for 2-4 days. It is recommended to prescribe human leukocyte interferon, ribonuclease, however, data on their effectiveness obtained by evidence-based medicine methods are absent.

What is the prognosis for enterovirus infections?

The overwhelming majority of patients with lesions of the skin and mucous membranes have a favorable prognosis. Enterovirus infection ends in complete recovery. A severe course with a fatal outcome is possible with neonatal encephalomyocarditis, encephalitis and meningoencephalitis, paralytic form of enterovirus infection, less often with epidemic myalgia. After encephalitis, in some cases, hemi- or monoparesis occurs; after the poliomyelitis form of the disease - decreased muscle tone and limb hypotrophy; with lesions of the visual organ - cataracts and bilateral blindness.