Objective  To understand the infection status of human parainfluenza virus (HPIV) in children with acute respiratory tract infection symptoms in Jiangxi provincial Children's Hospital and provide theoretical support for the prevention and control of HPIV infection.

  Methods  Nasal/pharyngeal swabs, sputum and bronchoalveolar lavage fluid samples were collected from children with acute respiratory infection hospitalized in Jiangxi provincial Children's Hospital from April 2010 to August 2020. Nested PCR and real-time fluorescent PCR were used to detect HPIV 1–4 and other common respiratory viruses, and SPSS 25.0 was used for statistical analysis (χ² test and Fisher's exact test).

  Results  The overall positive rate of HPIV was 12.50% (492/3 936), the positive rates of HPIV-1, 2, 3 and 4 were 1.88%, 0.61%, 8.71% and 1.30%, respectively. There was no significant difference in infection rate between boys and girls (χ²=2.290, P>0.05). The positive rate of HPIV-3 was 9.21% (247/2 683) in boys and 7.66% (96/1 253) in girls. The HPIV-3 infection was predominant in both boys and girls. Children aged 0–36 months were most likely to be infected with HPIV. The positive rate of HIPV decreased significantly in 2020 compared with the average positive rate from 2010 to 2019 (P<0.05). The most common clinical manifestation of HPIV infection was cough, accounting for 89.84% (442/492). Pulmonary infection was the most common clinical diagnosis, accounting for 33.94% (167/492), followed by bronchopneumonia 22.36% (110/492). In 492 cases, 192 (39.02%) were also infected with other respiratory viruses, and human rhinovirus virus (HRV) was the most common virus, followed by human adenovirus (HAdV) and respiratory syncytial virus (RSV). HPIV-1 infection increased significantly in autumn every two years, spreading from autumn to winter. HPIV-2 spread alternately with HPIV-1, mainly in autumn. HPIV-3 infection was common in spring and summer (April-August), with significantly differences compared with other months (χ²=23.143, P<0.05). There was no obvious seasonality of HPIV-4 infection. There was significant differences in the positive rate of HPIV-1 and HPIV-3 between inpatients and outpatients (χ²=6.125,10.525, P<0.05). There was significant differences in the positive rate of HPIV-1 and HPIV-3 between the cases of upper and lower respiratory tract infection (χ²=4.107,8.990, P<0.05).

  Conclusion  HPIV was an important pathogen causing respiratory tract infection in children in Jiangxi, especially in infants under 36 months old. The prevention of HPIV infection in this special group can follow the prevention and control measures of respiratory tract infectious diseases.