Epidemiology of human parainfluenza virus infection in patients with acute respiratory tract infection in Beijing, 2015–2020

  Objective  To understand the epidemiological characteristics of human parainfluenza virus (HPIV) infection in patients with acute respiratory tract infections (ARIs) in Beijing, and provide support for the development of prevention and control strategies for respiratory infectious diseases.

  Methods  The throat swabs, sputum, bronchoalveolar lavage fluid, tracheal aspirates and other pathogenic samples were collected from the patients with ARIs in 35 sentinel hospitals in Beijing from 2015 to 2020. Multiple real-time PCR was used to detect HPIV-1, HPIV-2, HPIV-3, HPIV-4 and other common respiratory tract viruses. The results were analyzed with SPSS 20.0 and χ² test was used to compare the rates between groups.

  Results  During 2015–2020, the positive rate of HPIV was 3.90% (1622/41557). HPIV-3 was the mostly detected pathogen, accounting for 58.45%, followed by HPIV-1 (19.17%), HPIV-2 (12.70%) and HPIV-4 (10.79%). The positive rate of HPIV in 2020 (1.65%, 70/4 234) was significantly lower than that during 2015–2019 (4.52%, 1569/37 323). The HPIV infection arte showed a peak every other year. The infection peak of HPIV was from May to July. The incidence trend of HPIV-3 infection was the similar to other HPIVs. The positive rate of HPIV-1 during summer-autumn was higher than that in other seasons. There was no obvious seasonality of HPIV-2 infection. The positive rate of HPIV-4 in autumn was higher than that in other seasons. The positive rate of HPIV in men was lower than that in women. The positive rate in 0–5 years old group was highest (8.81%, 685/7 776), followed by 6–15 years old group (4.07%, 173/4 247), and ≥ 60 years old group (3.25%, 442/13 582). There was significant differences in the positive rate of HPIV-1 and HPIV-3 between upper and lower respiratory tract infection cases ( χ²=4.449, P=0.039; χ²=17.513, P<0.001).

  Conclusion  HPIV is a common respiratory pathogens in Beijing. The main affecting population of HPIV infection is children under 15 years old. In 2020, the prevention and control of COVID-19 significantly reduced the incidence of HPIV infection.