Mild: fever +/- rash, hand/foot/mouth, herpangina, pleurodynia, pharyngitis, conjunctivitis, croup.

Serious: meningitis, encephalitis, acute paralysis, neonatal sepsis, myo/pericarditis, hepatitis, chronic infection (immunocompromised).

Meningo-encephalitis in neonates usually associated with other organ involvement. In adolescents headache can be severe and symptoms last several weeks! Early CSF can show around 1000 neutrophils! Prognosis good, although some subtypes with encephalitis highly aggressive eg EV-71 outbreak in Taiwan in assoc with hand/foot/mouth (78 deaths).

Acute flaccid paralysis can occur cf polio. Particularly Enterovirus EV-D68 (also associated with respiratory disease), some clusters.  Increased incidence across Europe including Wales since April 2016.

Neonatal disease can be severe, mimicking bacterial sepsis or HSV. Maternal history is often elusive.

Virus is shed in throat and stool (rectal swab quicker than stool!), can also be detected in CSF, blood and urine.

Role of IVIG is unproven but antibody plays an important role in immune response to EV. Pleconaril in enteroviral meningitis RCT, 38% to 50% improvement in symptoms in the drug-treated group with improvement noted as early as 24 hours after initiation of therapy – no longer available.

[Current Opinion in Pediatrics. 13(1):65-9, 2001]

Human Parechovirus has been described in Japan, Canada and now the Netherlands, causing neonatal sepsis or encephalitis in about 10% of cases where culture suggests enterovirus but PCR is negative. [Clin Infect Dis. 2006 Jan 15;42(2):204-10]