Human Parechovirus Type 3 Infection as a Cause of Apnea in Premature Infants
Human parechoviruses (HPeVs) are newly recognized viruses, which have been reported to be associated with gastroenteritis or respiratory symptoms in young children. Among them, HPeV type 3 (HPeV3) has been known as a pathogen causing sepsis-like syndrome, central nervous system infections, and sudden infant death syndrome in young infants. Although respiratory-syncytial virus (RSV) and pertussis are known to cause apnea in young infants, little information is available regarding a role of HPeV3 on apnea in young infants.
We experienced four infants with apneic episodes caused by HPeV3 infection diagnosed by PCR and later confirmed by the direct sequencing of the VP1 region of the virus. The clinical courses of the cases were retrospectively reviewed. The nucleotide sequences of VP1 region were analyzed phylogenetically.
All four cases were preterm infants (median gestational age (GA) 30.5 weeks) and required oxygen supplementation for apnea and oxygen desaturation. Case 1 and 2 were monozygotic twins, delivered at GA of 27 weeks and hospitalized in NICU due to prematuity. On day 81 and 83, respectively, they presented with fever, lethargy, tachycardia and apnea. HPeV3 was detected in their serum and stool samples. Their mother had rhinorrhea and diarrhea a few days prior to their onset of disease and her stool samples were positive for HPeV3. Case 3 and 4 were dizygotic twins, delivered at GA of 34 weeks. They presented with fever, poor sucking, rash on trunks, and apnea on day 60 and 63, respectively, and required hosipitalization for sepsis work-up. Case 3 required mechanical ventilation for 3 days due to acute respiratory failure. All four cases survived without any sequelae.
The viral sequencing analysis of VP1 region demonstrated that each isolate was identical by 95% with the original strain A308/99 found in Japan in 1999, suggesting that these infections were caused by the same circulating strain.
This is the first case series of premature infants presented with apneic episodes caused by HPeV3. Although RSV and pertussis are known to be the common causes for apnea in young infants, HPeV3 infection should be included in the differential diagnosis of apneic infants, especially in those with prematurity.
T. Oishi, None
M. Okazaki, None
A. Kobayashi, None
J. Onozuka, None
O. Numata, None
A. Saitoh, None