EV71

Enterovirus 71 is one of the viruses that causes hand-foot-and-mouth disease in children. It is an enterovirus, one of the picornaviruses.

Infection with enterovirus 71 predominantly results in a vesicular rash of the hands and feet that follows a prodrome of symptoms including fever, vomiting and oral mucosal ulceration.

In most cases, the initial infection wanes and symptoms and signs resolve. However in rare cases, it may be followed a by severe neurological infection resulting in aseptic meningitis, brainstem encephalitis and even acute flaccid paralysis akin to paralytic poliomyelitis.

Stages of disease

Shen et al.  described 5 symptomatic stages:

• grade 1:
  • fever, anorexia, erythema and skin manifestations;
  • resolution within a week for most patients
• grade 2:
  • fever, restlessness, vomiting, headache and abdominal pain;
  • most patients recover, some progress to grade 3 (those less than 2 years old may progress directly to grade 4)
• grade 3:
  • akin to grade 2 symptoms but with tachycardia and brainstem symptoms like cranial nerve palsy (6, 7, 9 - 12), auditory hallucinations, ocular disturbance, dyspnea and ataxia;
  • improvement in 3 - 4 days with recovery in 1 - 2 weeks (aside from those less than 2 years who tended to progress to grade 4)
• grade 4:
  • hypothermia, pulmonary edema, respiratory failure and neurogenic shock
• grade 5:
  • pulmonary hemorrhage, respiratory distress syndrome, circulatory collapse and death