Diversity of human parechoviruses in Bulgaria, 2011: Detection of rare genotypes 8 and 10

- We report the first study on detection and strain identification of human parechoviruses in Bulgaria.
- We tested 229 hospitalized children < 5 years old with neurological or gastrointestinal symptoms.
- Four human parechovirus types were identified.
- Among them, human parechovirus types 8 and 10 were detected for the first time in Europe.
- HPeV-8 was detected for the first time in a child with neurological complications.

Human parechovirus (HPeV) infections are commonly asymptomatic but are also found in association with symptoms of the gastrointestinal and respiratory tract, or central nervous system. In order to study their distribution and genetic diversity in Bulgaria, specimens from 229 children aged < 5 years old hospitalized due to neurological manifestations (n = 104) and acute gastroenteritis (n = 125) were analyzed. Stool samples were tested using reverse transcription followed by real-time polymerase chain reaction toward the 5′UTR region, and the HPeVs detected were identified by PCR directed to VP1 followed by sequencing. HPeV infection rates of 1.9% and 7.2% were found in children presented with neurological symptoms or with acute diarrhea, respectively. Four different HPeV genotypes, HPeV-3 (n = 2), HPeV-5 (n = 2), HPeV-8 (n = 1) and HPeV-10 (n = 1) were identified. All but two HPeVs were detected in acute diarrheal cases, while a single HPeV-3 strain and an HPeV-8 strain were detected in association with facial palsy and encephalitis, respectively. This is the first report of HPeV-8 and HPeV-10 in Europe.