Sepsis-like Disease in Infants Due to Human Parechovirus Type 3 During an Outbreak in Australia

Abstract

BACKGROUND: Infections with human parechoviruses (HPeVs) are associated with a wide range of clinical presentations in children, ranging from mild or asymptomatic infections to severe sepsis-like presentations or meningoencephalitis. METHODS: We reviewed medical records of infants admitted to 5 hospitals in New South Wales, Australia, during an outbreak of HPeV-3 infection. Data were collected on clinical presentation, laboratory markers, and outcome of infants with HPeV infection confirmed by reverse transcription polymerase chain reaction. RESULTS: We identified 118 infected infants. Most presented with an acute sepsis-like syndrome with high fever, tachycardia, poor perfusion, and severe irritability. Other common features were erythrodermic rash, abdominal distension, edema, and hepatitis. The age range of infants was 4 days to 9.5 months; 75% were <2 months old, including all but 1 of the 30 infants (25%) admitted to intensive care units (ICUs), who as a group, were significantly younger than infants not admitted to ICUs. Only 4% of evaluable cerebrospinal fluid samples had pleocytosis, but HPeV was detected in 95%. Brain magnetic resonance imaging on a small number of children demonstrated white matter changes and diffusion restriction. Sequencing of the VP1 gene confirmed HPeV-3 in all samples tested. All children recovered without ongoing complications at last follow-up. CONCLUSIONS: We report the largest series of HPeV-3 infection in infants, and the first outbreak in Australia. Infants presented with a severe sepsis-like syndrome with a high rate of ICU admissions, but all recovered from the acute infection without complications. Long-term sequelae are unknown.