Applying the Moving Epidemic Method to Establish the Influenza Epidemic Thresholds and Intensity Levels for Age-Specific Groups in Hubei Province, China

Incidence of community-acquired pneumonia among children under 5 years in Suzhou, China: a hospital-based cohort study

OBJECTIVES

To depict the seasonality and age variations of community-acquired pneumonia (CAP) incidence in the context of the COVID-19 impact.

DESIGN

Retrospective cohort study.

PARTICIPANTS

The observational cohort study was conducted at Soochow University Affiliated Children's Hospital from January 2017 to June 2021 and involved 132 797 children born in 2017 or 2018. They were followed and identified CAP episodes by screening on the Health Information Systems of outpatients and inpatients in the same hospital.

OUTCOME

The CAP episodes were defined when the diagnoses coded as J09-J18 or J20-J22. The incidence of CAP was estimated stratified by age, sex, birth year, health status group, season and month, and the rate ratio was calculated and adjusted by a quasi-Poisson regression model. Stratified analysis of incidence of CAP by birth month was conducted to understand the age and seasonal variation.

RESULTS

The overall incidence of CAP among children aged ≤5 years was 130.08 per 1000 person years. Children aged ≤24 months have a higher CAP incidence than those aged >24 months (176.84 vs 72.04 per 1000 person years, p<0.001). The CAP incidence increased from October, peaked at December and January and the highest CAP incidence was observed in winter (206.7 per 1000 person years, 95% CI 204.12 to 209.28). A substantial decline of CAP incidence was observed during the COVID-19 lockdown from February to August 2020, and began to rise again when the communities reopened.

CONCLUSIONS

The burden of CAP among children is considerable. The incidence of CAP among children ≤5 years varied by age and season and decreased during COVID-19 lockdown.

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.