Pathogen Spectrum and Epidemiological Characteristics Detected by Multiplex Loop-Mediated Isothermal Amplification in Elderly Patients in Guangzhou

Lower respiratory tract infections (LRTIs) contribute substantially to morbidity and mortality in the elderly. This study aimed to investigate the distribution and epidemiological features of 10 common respiratory pathogens detected by multiplex Loop-Mediated Isothermal Amplification (LAMP) in elderly patients in Guangzhou, China, from 2022 to 2024, to support precise clinical management, rational antimicrobial use, and regional infection control. A cross-sectional study was performed, enrolling 4,010 elderly patients who underwent respiratory pathogen testing by multiplex LAMP from April 2022 to March 2024 at Guangdong Provincial People's Hospital. Multiplex LAMP was used to detect 10 major pathogens. Epidemiological characteristics were analyzed across genders, ages, seasons, months, specimen types, and departments. At least one pathogen was detected in 1,474 (36.76%) patients. Single detection was dominant (72.18%, 1,064/1,474). The detection rates of Haemophilus influenzae, Klebsiella pneumoniae, Pseudomonas aeruginosa, Acinetobacter baumannii, Staphylococcus aureus, Stenotrophomonas maltophilia, Escherichia coli, Streptococcus pneumoniae, Mycobacterium tuberculosis complex, and Mycoplasma pneumoniae were 11.40%, 10.75%, 8.10%, 5.89%, 5.41%, 3.02%, 2.66%, 2.64%, 0.56%, and 0.33%, respectively. The detection rates of Kpn and Mtb were significantly higher in males (P < 0.05). Significant age-group differences were observed for Sau, Eco, Pae, Aba, and Sma (P < 0.001) and for Kpn (P = 0.028). Kpn and Pae showed significant seasonal variation (P < 0.05). Pae positivity peaked in April 2022 (36.54%). Significant differences across specimen types and departments were observed for several pathogens (P < 0.05). Haemophilus influenzae was the most prevalent pathogen detected by multiplex LAMP in this elderly cohort in Guangzhou. Single-pathogen detection was the predominant pattern. These findings provide a basis for empirical antimicrobial therapy and regional epidemiological surveillance in elderly patients undergoing respiratory pathogen testing.