Epidemiological characteristics of bacterial lower respiratory tract infections in Jingzhou, Central China, 2020-2024.

BACKGROUND

Lower respiratory tract infections (LRTIs) represent a significant global public health issue and impose a substantial disease burden. However, regional epidemiological surveillance data on bacterial LRTIs in central China remain insufficient. This study aimed to systematically analyze the epidemiological characteristics of patients with bacterial LRTIs in Jingzhou, Hubei Province, China.

METHODS

This study included 5,442 hospitalized patients diagnosed with LRTIs between January 2020 and December 2024. Detection of respiratory pathogens was performed both using a chip-based loop-mediated isothermal amplification (LAMP) assay and the standard culture method (SCM). The LAMP assay kit simultaneously detects ten predefined bacterial respiratory pathogens, including Streptococcus pneumoniae (S. pneumoniae), Staphylococcus aureus (S. aureus), Klebsiella pneumoniae (K. pneumoniae), Pseudomonas aeruginosa (P. aeruginosa), Acinetobacter baumannii (A. baumannii), Stenotrophomonas maltophilia (S. maltophilia), Haemophilus influenzae (H. influenzae), Legionella pneumophila (L. pneumophila), Mycoplasma pneumoniae (M. pneumoniae), and Mycobacterium tuberculosis (M. tuberculosis).

RESULTS

Among 5,442 samples, the overall positive rate of LAMP was 31.86%, with single-pathogen infections accounting for 26.17%. H. influenzae (8.18%) and S. pneumoniae (7.75%) were the most commonly detected pathogens. Dual-pathogen co-infections predominated among polymicrobial infections, with S. pneumoniae and H. influenzae representing the most frequent pathogen combination. The LAMP assay demonstrated a higher overall positive rate than SCM, with moderate agreement observed between the two methods for most pathogens. The overall pathogen positive rate exhibited seasonal variation, peaking from April to June. S. pneumoniae showed a bimodal distribution, with higher positive rate in May-June and November-December annually. During the COVID-19 pandemic era, S. pneumoniae and H. influenzae were predominant, while the positive rates of M. pneumoniae and M. tuberculosis notably increased in the post-pandemic era. School-aged children exhibited the highest positive rate, with M. pneumoniae as the predominant pathogen. Pathogen composition was more diverse among adults and older adults.

CONCLUSION

These findings demonstrate significant age-related and temporal variations in the pathogen spectrum of bacterial LRTIs and provide epidemiological evidence to support empirical antibacterial decision-making and population-targeted prevention strategies. In addition, LAMP may serve as a practical molecular diagnostic tool for rapid bacterial pathogen detection, although its clinical utility in primary healthcare settings warrants further investigation.