Enteroviruses 68, 70, 71, & Related Agents

Key Features

• Human enteroviruses are neurotropic and a potential role for these viruses in amyotropic lateral sclerosis is under investigation

• Household contacts, especially children under 6 months of age, are at particular risk for enterovirus 71 acquisition

• A number of nonpolio type C enteroviruses are associated with polio-like syndromes and surveillance for these is most active in China

• Enterovirus infection of the pancreas can trigger cell-mediated autoimmune destruction of beta cells resulting in diabetes

• Enterovirus myocarditis can be a serious infection in neonates, complicated by cardiac dysfunction and arrhythmias

Clinical Findings

• Enterovirus 68 (EV-D68)

  • Typically associated with respiratory illness

  • Has also been implicated in aseptic meningitis and encephalitis

  • Associated with acute flaccid myelitis but not definitively linked

• Enterovirus 70 (EV-70)

  • Responsible for abrupt bilateral eye discharge and subconjunctival hemorrhage with occasional systemic symptoms

  • Most commonly associated with acute hemorrhagic conjunctivitis

• Enterovirus 71 (EV-71)

  • Associated with hand, foot, and mouth disease (HFMD), herpangina as well as a form of epidemic encephalitis associated on occasion with pulmonary edema, and acute flaccid myelitis often mimicking poliomyelitis

  • Autonomic nervous system dysregulation, which may develop prior to the pulmonary edema, is a complication

  • Disease is usually more severe and sequelae more common than with other enteroviruses

Diagnosis

• Isolating EV-D68 in respiratory secretions

• Isolating EV-70 in conjunctival scraping

• Isolating EV-71 in vesicle swabs, body secretions, or cerebrospinal fluid

• Enzyme immunoassays and complement fixation tests show good specificity but poor sensitivity (< 80%)

• RT-PCR may increase the detection rate and is useful in analysis of cerebrospinal fluid samples among patients with meningitis and of blood samples among infants with a sepsis-like illness

Treatment

• EV-D68 requires supportive care with particular attention to respiratory support

• Largely symptomatic for EV-70 and -71