Molecular and epidemiological study of human parechovirus infections in Taiwan, 2007-2012

As routine diagnostic assays for human parechoviruses (HPeVs) have not been included in the enteroviruses surveillance network in Taiwan, HPeVs may be the actual pathogens of hundreds of untypeable enteroviruses-suspected isolates.

In this study, these untypeable isolates collected from 2007 through 2012 were examined by reverse transcription-polymerase chain reaction (RT-PCR)-based methods to survey the epidemiology of HPeVs in Taiwan.

Thirty-eight HPeV isolates were identified from 575 untypeable isolates, including 23 HPeV type1 (HPeV1), 13 HPeV3, and two HPeV6. Most of the patients were Taiwanese children under 5 years of age and their infections were generally prevalent in summer and autumn, with the highest peak occurring in September. The ratio of male to female patients was 1.56 and 2.25 for HPeV1 and HPeV3, respectively. Fever and respiratory symptoms were reported in significantly more patients infected with HPeV1. The results of phylogenetic analyses showed that HPeV isolates between 2007 and 2012 belonged to different lineages, indicating that endemic circulation of HPeV existed in Taiwan.

This study showed that HPeVs have been endemic in Taiwan for some years despite a low positive rate. The detection tests of HPeVs are needed to correct a diagnostic deficit in the surveillance system. The epidemiological and genetic information obtained from the present study would contribute to the understanding of the etiology and epidemiology of HPeVs.