Fatal neonatal parechovirus encephalitis

Abstract

Two infants developed encephalitis in the late neonatal period due to human parechovirus type 3 (HPeV-3). This finally resulted in intractable seizures leading to death. Both presented with classical signs and symptoms. HPeV-3 was detected in nasopharyngeal and rectal swabs, cerebrospinal fluid, serum and postmortem samples (for one infant). Ultrasound and magnetic resonance imaging findings showed severe white matter injury in one infant, and limited hippocampal injury in the other. Parents consented to autopsy in the latter, showing diffuse gliotic oedema of cerebral white matter, bilateral bronchopneumonia, and inflammation in spleen. We emphasise that polymerase chain reaction (PCR) testing for parechovirus in neonates with severe sepsis-like syndrome and meningoencephalitis is mandatory.

Figure 1

Diffusion weighted magnetic resonance imaging on the third day after presentation in patient 1. Inset: coronal reconstructed diffusion trace image, red colour highlighting areas with restricted diffusion. Structures affected are frontal and temporal white matter, cerebellar cortex, posterior limb of the internal capsule and genu corporis callosi, and anterior and mediodorsal thalamic subnuclei with the anterior thalamic radiation in the anterior limb of the internal capsule.

Figure 2

Coronal ultrasound scans and diffusion weighted magnetic resonance imaging in patient 2 on the eighth day after presentation. Normal echoic aspect of white matter and thalamus, mild ventricular dilatation. Hypersignal on diffusion weighted imaging symmetrical in hippocampus and fornix (arrow), unilateral in right caudate head and in a limited area of right frontal white matter.