Epidemiology, genetic characteristics and association with meteorological factors of human metapneumovirus infection in children in southern China: a ten-year retrospective study

This study aimed to determine the epidemiological and genetic features of HMPV infection in children in southern China, and the effect of meteorological factors on infection.14,817 children (≤14 years) with ARIs from 2010 to 2019 were examined for HMPV and other respiratory viruses by real-time quantitative PCR. Full-length F gene of 54 positive samples were sequenced and subjected to phylogenetic analysis. The correlation between the HMPV-positive rate and meteorological factors was analyzed by linear regression analysis.HMPV was detected in 524 (3.5%) children, who were mostly younger than one year. The seasonal peak of HMPV prevalence mainly occurred in spring. RSV was the most common virus coinfected with HMPV (5.3%). Phylogenetic analysis revealed that the sequenced HMPV strains belonged to four sublineages, including A2b (1.9%), A2c (31.5%), B1 (50.0%) and B2 (16.7%). After adjusting for all meteorological factors, sunshine duration was inversely correlated with the HMPV-positive rate.HMPV is an important respiratory pathogen that causes ARIs in children in southern China, particularly in children ≤5 years old. The prevalence peak of HMPV in this area appeared in spring, and the predominant subtype was B1. Meteorological factors, especially long sunshine duration might decrease the HMPV prevalence.