Parechovirus: An important emerging infection in young infants

Epidemics of human parechovirus (HPeV) causing disease in young children have occurred every 2 years in Australia since 2013. HPeV genotype 3 caused the epidemic from late 2017 to early 2018. Most HPeV infections cause no or mild symptoms including gastroenteritis or influenza-like illness. Characteristically, young infants present with fever, irritability and on occasions a diffuse rash (“red, hot and angry” babies). Severe disease can manifest as meningoencephalitis, seizures or sepsis-like presentations (including septic shock), or less common presentations including signs of surgical abdomen. Testing for HPeV by specific molecular tests is indicated in children younger than 6 months of age with characteristic presentations without another confirmed diagnosis including febrile illnesses with other suggestive features (eg, rash, seizures), sepsis syndromes (including shock), and suspected meningoencephalitis (which may be detected by magnetic resonance imaging only). There are no effective antiviral therapies. Treatment is primarily supportive, including management of complications. Some infants with severe HPeV infection may have adverse neurodevelopment. Follow-up by a paediatrician is recommended.