[Epidemiological characteristics of human respiratory syncytial virus infection in febrile respiratory syndrome cases in China from 2010 to 2020].

Objective: To analyze the epidemiological characteristics of human respiratory syncytial virus (HRSV) in cases of febrile respiratory syndrome in China from 2010 to 2020. Methods: Based on the sub-project of the National Science and Technology Major Project for Infectious Disease Prevention and Control "Infectious Disease Monitoring Technology Platform", active monitoring of febrile respiratory syndrome cases was conducted in sentinel hospitals in 31 provinces across China (excluding Hong Kong, Macau, and Chinese Taiwan) from January 2010 to December 2020, resulting in the inclusion of 191 441 cases. Clinical specimens of monitored cases were screened for HRSV nucleic acid, and the differences in HRSV detection rates among different age groups, regions, and time periods were analyzed using the χ² test/Fisher exact probability method. Results: Among the 191 441 cases of febrile respiratory syndrome in China from 2010 to 2020, the age group M (Q₁, Q₃) was 9 (2, 40) years old, with 83 773 cases (43.8%) in the <5 years old group. There were 113 660 males, with a male-to-female ratio of 1.5∶1.0. There were as many as 105 508 cases (55.2%) of scattered children and preschool children. About 70 565 cases (36.9%) lived in the northern region. There were 13 858 HRSV positive cases, with a total positive rate of 7.2%. The positive rate of HRSV detection in the northern population was 5.7% (4 004/70 565), which was lower than that in the southern population (8.2%, 9 854/120 876), and the difference was statistically significant (χ²=407.4, P<0.001). HRSV was detected in all age groups, with the highest positive rate of 23.9% in the <6 months age group. The month with the highest positive rate was December, and autumn and winter were the main epidemic seasons. Both northern and southern HRSV subtypes were mainly infected with type A, with a low proportion of mixed infections of type A and type B. Conclusion: HRSV is a common pathogen causing respiratory infections in children from 2010 to 2020. It can be detected throughout the year and shows the main peak of prevalence in autumn and winter. The HRSV strain is mainly classified as a type A infection.