Epidemiology and genetic characterization of human parainfluenza virus-1 infection in pediatric patients from Hangzhou China, 2021–2022

Human parainfluenza virus-1 (HPIV-1) is a notable pathogen instigating acute respiratory tract infections in children. The article is to elucidate the epidemiological and genetic characteristics of HPIV-1 circulating in Hangzhou during the period of 2021–2022.

A cohort of 2360 nasopharyngeal swabs were amassed and subsequently examined via RT-PCR, with HPIV-1 positive samples undergoing P gene sequencing.

The highest HPIV-1 infection rates were found in children aged between 3 and 6 years. A pronounced positive rate persisted through the latter half of 2021, with a notable decline observed in the initial half of 2022. All HPIV-1 strains could be clustered into 2 groups: Cluster 1, with strains similar to those found in Japan (LC764865, LC764864), and Cluster 2, with strains similar to the Beijing strain (MW575643).

In conclusion, our study contributes to the comprehensive data on the epidemiological and genetic characteristics of HPIV-1 in pediatric patients from Hangzhou, post the COVID-19 peak.