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. 2025 May 9;25(1):1724.
doi: 10.1186/s12889-025-22884-0.

Epidemiological characteristics of respiratory tract infections during and after the pandemic of COVID-19 from 2021 - 2023 in Shenzhen, southern China

Qiaoruo Jin  1 , Sheng Yu  1 , Jiuxin Qu  2
Affiliations

Epidemiological characteristics of respiratory tract infections during and after the pandemic of COVID-19 from 2021 - 2023 in Shenzhen, southern China

Qiaoruo Jin et al. BMC Public Health. .

Abstract

Objective: It is now understood that the COVID-19 pandemic and its associated containment measures have affected the epidemiology of other respiratory viruses. This study aimed to investigate respiratory pathogen infections in Shenzhen during and after the COVID-19 pandemic.

Methods: A retrospective analysis was conducted on test data from 24,814 patients at Shenzhen Third People's Hospital between January 2021 and December 2023. The analysis focused on changes in detection rates, epidemiological characteristics, and clinical features of respiratory pathogens, including three viruses and eight bacteria.

Results: The overall positivity rate for respiratory viruses increased after the COVID-19 epidemic (P < 0.05), whereas no significant difference was detected in the overall positivity rate of most respiratory bacteria. Notably, the detection rates of influenza A and B increased after the COVID-19 epidemic, with influenza A showing the most significant increase from 4.5 to 10.8% (P < 0.05). Conversely, the detection rates of PAE and MRSA decreased significantly (P < 0.05), whereas those of HIN and SMA increased significantly (P < 0.05). The seasonal patterns of influenza A changed markedly, with a shift in peak occurrence and extended periods of high positivity. The age distribution of infections also shifted, with adults showing higher detection rates after the pandemic than school-aged children and elderly individuals did.

Conclusion: The removal of non-pharmaceutical interventions following the COVID-19 pandemic has significantly affected the epidemiological and seasonal patterns of certain respiratory pathogens in Shenzhen. These findings highlight the need for continuous surveillance of multiple respiratory pathogens and adaptive public health strategies in the post-pandemic era.

Keywords: COVID-19 pandemic; Epidemiology; Non-pharmaceutical interventions; Respiratory infections; Seasonal patterns.

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Conflict of interest statement

Declarations. Ethical approval: This retrospective study was approved by the Ethics Committee of Shenzhen Third People’s Hospital and was conducted in accordance with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. The requirement for informed consent was waived by the Institutional Review Board due to the retrospective nature of the study. Consent for publication: Not applicable. Competing interests: The authors declare no competing interests.

Figures

Fig. 1
Fig. 1
Positive cases and rates of respiratory pathogens during the COVID-19 pandemic (2021–2022) and after the COVID-19 pandemic (2023). Three respiratory viruses were included: influenza virus A and B (IVA, IVB) and respiratory syncytial virus (RSV). Eight bacteria were included: Acinetobacter baumannii (ABA), Haemophilus influenzae (HIN), Klebsiella pneumoniae (KP), Pseudomonas aeruginosa (PAE), Staphylococcus aureus (SAU), Stenotrophomonas maltophilia (SMA), Streptococcus pneumoniae (SP) and methicillin-resistant Staphylococcus aureus (MRSA)
Fig. 2
Fig. 2
Seasonal patterns of viruses during the COVID-19 pandemic (2021–2022) and after the COVID-19 pandemic (2023). Three respiratory viruses have been identified: influenza virus A (IVA), influenza virus B (IVB) and respiratory syncytial virus (RSV). From 2021 to 2022, Shenzhen implemented various epidemic prevention and control measures, including key population screening, key venue management, vaccination and quarantine measures. From 11 December 2022, it stopped epidemic checks for incoming and returning people, and indoor venues stopped requiring negative nucleic acid tests. On 8 January 2023, Class A prevention and control measures for COVID-19 were lifted
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References

    1. Zhu N, Zhang D, Wang W, et al. A novel coronavirus from patients with pneumonia in China, 2019. N Engl J Med. 2020;382(8):727–33. - DOI - PMC - PubMed
    1. World Health Organization (WHO). WHO Director-General’s Opening Remarks at the Media Briefing on COVID-19. Available online: https://www.who.int/dg/speeches/detail/who-director-general-s-opening-re... (accessed on 11 March 2020).
    1. Zanin M, Xiao C, Liang T, et al. The public health response to the COVID-19 outbreak in Mainland China: a narrative review. J Thorac Dis. 2020;12(8):4434–49. - DOI - PMC - PubMed
    1. Lai S, Ruktanonchai NW, Zhou L, et al. Effect of non-pharmaceutical interventions to contain COVID-19 in China. Nature. 2020;585(7825):410–3. - DOI - PMC - PubMed
    1. Tian H, Liu Y, Li Y, et al. An investigation of transmission control measures during the first 50 days of the COVID-19 epidemic in China. Science. 2020;368(6491):638–42. - DOI - PMC - PubMed

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