Dynamics of parainfluenza virus among hospitalized children with acute respiratory tract infection under two-child policy and COVID-19 pandemic in Hubei Province, China, 2014-2022.

To analyze changes in the detection of parainfluenza virus (PIV) in children hospitalized with acute respiratory tract infection (ARTI) during 2014-2022 in Hubei Province, and explore the impact of the universal two-child policy and the public health measures against COVID-19 epidemic on the prevalence of PIV in China. The study was conducted at the Maternal and Child Health Hospital of Hubei Province. Children aged <18 years with ARTI admitted from January 2014 to June 2022 were enrolled. The infection of PIV was confirmed by the direct immunofluorescence method in nasopharyngeal specimens. Adjusted logistic regression models were used to analyze the influence of the universal two-child policy implementation and public health measurements against COVID-19 on PIV detection. Totally 75 128 inpatients meeting the criteria were enrolled in this study from January 2014 to June 2022 with an overall PIV positive rate of 5.5%. The epidemic seasons of PIV prevalence lagged substantially in 2020. A statistically significant higher positive rate of PIV was observed in 2017-2019 compared to that in 2014-2015 (6.12% vs 2.89%, risk ratio = 2.12, p < 0.001) after the implementation of the universal two-child policy in 2016. A steep decline occurred in PIV positive rate during the COVID-19 epidemic in 2020 (0.92% vs 6.92%, p < 0.001) and it rebounded during the regular epidemic prevention and control period in 2021-2022 (6.35%, p = 0.104). In Hubei Province, the implementation of the universal two-child policy might have led to an increase of PIV prevalence, and public health measures during the COVID-19 epidemic might have influenced the fluctuation in PIV detection since 2020.

Epidemiological change of influenza virus in hospitalized children with acute respiratory tract infection during 2014-2022 in Hubei Province, China.

PURPOSE: Influenza virus (IFV) causes acute respiratory tract infection (ARTI) and leads to high morbidity and mortality annually. This study explored the epidemiological change of IFV after the implementation of the universal two-child policy and evaluated the impact of coronavirus disease 2019 (COVID-19) pandemic on the detection of IFV. METHODS: Hospitalized children under 18 years with ARTI were recruited from Hubei Maternal and Child Healthcare Hospital of Hubei Province from January 2014 to June 2022. The positive rates of IFV were compared among different periods by the implementation of the universal two-child policy and public health measures against COVID-19 pandemic. RESULTS: Among 75,128 hospitalized children with ARTI, the positive rate of IFV was 1.98% (1486/75128, 95% CI 1.88-2.01). Children aged 6-17 years had the highest positive rate of IFV (166/5504, 3.02%, 95% CI 2.58-3.50). The positive rate of IFV dropped to the lowest in 2015, then increased constantly and peaked in 2019. After the universal two-child policy implementation, the positive rate of IFV among all the hospitalized children increased from 0.40% during 2014-2015 to 2.70% during 2017-2019 (RR 6.72, 95% CI 4.94-9.13, P < 0.001), particularly children under one year shown a violent increasing trend from 0.20 to 2.01% (RR 10.26, 95% CI 5.47-19.23, P < 0.001). During the initial outbreak of COVID-19, the positive rate of IFV decreased sharply compared to that before COVID-19 (0.35% vs. 3.37%, RR 0.10, 95% CI 0.04-0.28, P < 0.001), and then rebounded to 0.91%, lower than the level before COVID-19 (RR 0.26, 95% CI 0.20-0.36, P < 0.001). CONCLUSION: IFV epidemiological pattern has changed after the implementation of the universal two-child policy. More attention should be emphasized to comprehend the health benefits generated by COVID-19 restrictions on IFV transmission in future.

Epidemiological Characteristics of Respiratory Syncytial Virus Infection Among Hospitalized Children With Acute Respiratory Tract Infections From 2014 to 2022 in a Hospital in Hubei Province, China: Longitudinal Surveillance Study.

BACKGROUND: Longitudinal studies characterizing the epidemic trend of respiratory syncytial virus (RSV) in Hubei Province are scarce. OBJECTIVE: We aimed to depict the dynamics of the RSV epidemic among hospitalized children with acute respiratory tract infections (ARTIs) during 2014 to 2022 in the Maternal and Child Health Hospital of Hubei Province and investigate the influence of the 2-child policy and the COVID-19 pandemic on RSV prevalence. METHODS: The medical records and testing results of hospitalized children with ARTI from January 2014 to June 2022 were extracted. Nasopharyngeal samples were tested with direct immunofluorescence assay. Detection rates of RSV were categorized according to the diagnosis of patients: (1) overall, (2) upper respiratory tract infection (URTI), and (3) lower respiratory tract infection (LRTI). Poisson regression models were used to investigate the association between RSV detection rate and age, gender, or diagnosis. The detection rates of RSV before and after the implementation of the universal 2-child policy were compared using a Poisson regression model. Multiple comparisons of RSV detection rates were conducted among 3 stages of the COVID-19 pandemic using chi-square tests. Seasonal autoregressive integrated moving average was performed to predict RSV behaviors from February 2020 to June 2020 under the assumption of a non-COVID-19 scenario. RESULTS: Among 75,128 hospitalized children with ARTI, 11.1% (8336/75,128) were RSV-positive. Children aged <1 year had higher detection rates than older children (4204/26,498, 15.9% vs 74/5504, 1.3%; P<.001), and children with LRTI had higher detection rates than children with URTI (7733/53,145, 14.6% vs 603/21,983, 2.7%; P<.001). Among all the children, a clear seasonal pattern of the RSV epidemic was observed before 2021. Most of the highest detection rates were concentrated between December and February. The yearly detection rate of RSV remained at a relatively low level (about 8%) from 2014 to 2017, then increased to 12% and above from 2018. The highest monthly detection rate was in December 2018 (539/1493, 36.1%), and the highest yearly rate was in 2021 (1372/9328, 14.7%). There was a moderate increase in the RSV detection rate after the 2-child policy was implemented (before: 860/10,446, 8.2% vs after: 4920/43,916, 11.2%; P<.001). The largest increase, by 5.83%, occurred in children aged <1 year. The RSV epidemic level decreased sharply in the short term after the COVID-19 outbreak (detection rate before: 1600/17,010, 9.4% vs after: 32/1135, 2.8%; P<.001). The largest decrease, by 12.0%, occurred in children aged <1 year, but a rebounding epidemic occurred after 2020 (680/5744, 11.8%; P<.001). CONCLUSIONS: Children have been experiencing increased prevalence of RSV since 2018 based on surveillance from a hospital in Hubei Province with a large sample size. The 2-child policy might have increased the RSV prevalence, and the COVID-19 epidemic had a temporary inhibitory effect on RSV transmission. Vaccines against RSV are urgently needed.