Enterovirus - EV

Enterovirus - EV

 

Enteroviral disease is a common, under-recognized childhood illness.

Epidemiology

  • Prevalence – Non-polio enteroviruses cause about 10-15 million symptomatic cases annually in the U.S.
  • Age – all ages; severity varies inversely with age
  • Occurrence
    • Infections occur throughout the year, but peak in July-October
  • Transmission – fecal oral

Organism

  • Enteroviruses (EV) are single-stranded RNA viruses in the Picornaviridae family
  • >70 recognized enteroviral serotypes
  • Wild type poliovirus 1-3 no longer in Western hemisphere due to effective vaccine strategies
  • Non-polio enteroviruses include:
    • Coxsackieviruses A 1-22 and 24
    • Coxsackieviruses B 1-6
    • Echoviruses 1-9, 11-27 and 29-31
    • Enteroviruses 68-71

Clinical Presentation

  • Nonspecific febrile illness with or without rash
  • Acute hemorrhagic conjunctivitis (coxsackie A24 & echovirus 70)
  • Hand-foot-mouth disease (echovirus 71)
  • Sepsis syndrome in neonates
  • Myocarditis (coxsackie B3)
  • Hepatitis
  • Central nervous system (CNS) infections
    • Aseptic meningitis (meningeal inflammation in absence of bacterial pathogen)
      • Enteroviruses are the most common cause
      • Account for 80-92% of all cases
      • Type of enterovirus varies
      • Clinical manifestations depend upon host
    • Enteroviral encephalitis is less common, but more severe, than aseptic meningitis
      • Global neurologic depression
      • Evidence of focal encephalitis, similar to herpes simplex encephalitis (enterovirus found on brain biopsy)
      • Immunocompromised adults and children with agammaglobulinemia are susceptible to chronic meningitis or meningoencephalitis
  • In the neonate, enterovirus may cause severe morbidity and mortality
    • Related to sepsis, meningoencephalitis, myocarditis or hepatitis
    • Complications associated with poor outcome generally occur 1-2 days after birth
      • Suggests prenatal origin of infection
    • Sudden onset of fever, irritability and poor feeding characterize infection
    • One-fourth of children have diarrhea, vomiting and rash (macular or maculopapular)
    • Meningeal involvement in febrile disease 70% of time
  • Meningitis beyond neonatal period characterized by sudden onset of fever (38°-40°C)
    • Meningeal irritation (>6 weeks) occurs in >50% of patients
    • Headache and photophobia are almost universally reported
    • Neurologic abnormalities rare
    • Both short and long term outcomes generally good for immunocompetent hosts
Manifestations Commonly Associated with Enterovirus Serotypes
  Serotype(s) of Indicated Virus
Manifestation Coxsackievirus Echovirus (E) and Enterovirus (Ent)
Acute hemorrhagic conjunctivitis A24 E70
Aseptic meningitis A2, 4, 7, 9, 10; B1-5 E4, 6, 7, 9, 11, 13, 16, 18, 19, 30, 33; Ent70, 71
Encephalitis A9; B1-5 E3, 4, 6, 9, 11, 25, 30; Ent71
Exanthem A4, 5, 9, 10, 16; B1, 3-5 E4-7, 9, 11, 16-19, 25, 30; Ent71
Generalized disease of the newborn B2-5 E4-6, 9, 11, 14, 16, 19
Hand-foot-and-mouth disease A5, 7, 9, 10, 16; B2-5 Ent71
Herpangina A1-10, 16, 22; B1-5 E6, 9, 11, 16, 17, 25; Ent71
Myocarditis, pericarditis A4, 9, 16; B1-5 E6, 9, 11, 22
Paralysis A4, 7, 9; B1-5 E2, 4, 6, 9, 11, 30; Ent70, 71
Pleurodynia A1, 2, 4, 6, 9, 10, 16; B1-6 E1-3, 6, 7, 9, 11, 12, 14, 16, 19, 24, 25, 30
Pneumonia A9, 16; B1-5 E6, 7, 9, 11, 12, 19, 20, 30; Ent68, 71
(Used with permission from Cohen, 2005, 1145)

Diagnosis

  • For mild to moderate disease (e.g., upper respiratory symptoms), diagnostic testing usually not indicated
  • For disseminated or organ-specific syndromes, laboratory testing is definitely indicated.
    • Culture – throat, stool, blood, CSF
    • Nucleic acid amplification testing (CSF, myocardium)
    • Serologic antibody titers

Treatment

  • Supportive

See Also