Etiology of community-acquired pneumonia among adults in the Chinese mainland: a systematic review and meta-analysis

Jin Xu¹, Yongyu Su², Ming Guang^3*

¹Henan Center for Hygienic Testing, Henan Provincial Center for Disease Control and Prevention, Zhengzhou, 450016, China.

²Value & Implementation, Global Medical & Scientific A Hairs MSD China, Shanghai 200030, China.

³Department of Immunization and Planning, Shanxi Provincial Center for Disease Control and Prevention, Taiyuan, 030001, China.

^{*Correspondence:Ming Guang; Email: 52025017@qq.com}

Abstract

Background: This meta-analysis aimed to determine the etiology, comorbidities, and clinical features of community-acquired pneumonia (CAP) among adults in mainland China.

Methods: A systematic literature search was conducted in PubMed, Embase, and Cochrane Library to identify relevant studies that reported the etiology, pathogen distribution, and clinical characteristics of CAP in Chinese adults (aged >18 years) from 2004 to December 2024. Overall evidence from the included studies was quantitatively synthesized, and pooled estimates were expressed as weighted values with corresponding 95% confidence intervals (CIs).

Results: Of 5770 studies, 49 studies were eligible for inclusion. Among these, 44 studies (89%) reported bacterial agents; 21 studies (43%) and 33 studies (67%) reported viral and fungal pathogens, respectively. Furthermore, atypical pathogens were reported in 30 studies (61.2%). The predominant bacterial agents among patients diagnosed with CAP were Methicillin-resistant Staphylococcus aureus (13%), and Streptococcus pneumoniae (9%). Similarly, among viral and fungal pathogens, influenza virus (18%) and Candida albicans (17%) were most frequently identified in patients with CAP. Moreover, Mycoplasma pneumoniae (9%) was identified as a predominant other pathogen in patients with CAP, whereas overall other pathogens accounted for 23% of CAP cases.

Conclusion: CAP has become a serious public health issue in the Chinese Mainland. This systematic review represents a comprehensive evaluation currently available on the factors leading to CAP within the Chinese adult population. Among various etiological agents, bacteria continue to predominate and are the leading cause of CAP in this population.

PROSPERO registration number: CRD42022323132.

Keywords:intensive care unit, acute skin failure, meta-analysis, systematic review, nursing