Epidemiological and clinical characteristics of parainfluenza virus infection in hospitalized neonates in Southeast China

Background: Human parainfluenza virus (HPIV) is a clinically significant pathogen responsible for acute respiratory tract infections (ARTIs) in infants. This study aimed to elucidate the epidemiological characteristics, clinical manifestations, and severity risk factors in neonates with HPIV. Methods: This retrospective study included infants admitted to the neonatology departments of two tertiary hospitals in southeast China between January 2016 and December 2023, diagnosed with lower respiratory tract infections (LRTIs) or febrile illnesses. HPIV was detected via standardized molecular assays, including either Double Amplification Technique or Direct Immunofluorescent Antibody Assay. Results: Among 7,557 neonates who underwent throat swabs, 212 neonates were tested positive for HPIV, accounting for 2.7% of all LRTI cases in the study cohort. The detection rate of HPIVs increased with age. Neonates with HPIV infection demonstrated significantly higher prevalence rates of nasal congestion (79.7% vs 59.6%, P < 0.001) and poor feeding (17% vs 4.7%, P < 0.001) compared to those with respiratory syncytial virus (RSV) infection. Conversely, moist rales (57.1% Vs 80.1%, P < 0.001) and wheezing (6.6% Vs 17.8%, P < 0.001) were observed less frequently in the HPIV group. Moreover, preterm birth, poor feeding and cyanosis were identified as significant risk factors for neonatal intensive care unit (NICU) hospitalization in HPIV-infected neonates. Conclusions : HPIV represents an important etiological agent of LRTIs among hospitalized neonates in Southeast China, exhibiting distinct clinical characteristics that differentiate it from RSV infection. Notably, preterm infants are at highest risk for severe disease manifestations,requiring intensive monitoring.