OBJECTIVE To investigate the age-group differences and seasonal distribution patterns of epidemiological characteristics of hospital-associated infection in elderly inpatients in a three-A hospital.

METHODS Based on the Xinglin Real-time Monitoring System, a retrospective analysis was conducted on clinical data of 67 157 patients hospitalized in the Air Force Hospital of Eastern Theater Command from Jan. 2020 to Dec. 2024. Elderly patients were divided into three age groups: young-age group (60-69 years), middle-age group (70-79 years) and oldest-age (≥80 years). The epidemiological characteristics and seasonal distribution patterns of the three groups were analyzed.

RESULTS From 2020 to 2024, there were 1 524 cases of hospital-associated infection, with an incidence rate of 2.27%. The infection rate was higher in the oldest-age group (6.08%) than those in the young-age group (1.77%) and the middle-age group (2.52%) (P < 0.001). The top three departments with the highest incidence rates of hospital-associated infection were the geriatric department (10.97%), intensive care unit (9.65%) and respiratory department (4.96%). The lower respiratory tract was the main site of infection, and the infection rate was higher in winter than in other seasons. The pathogens were predominantly gram-negative bacteria (60.35%), with Pseudomonas aeruginosa being the most frequently detected.

CONCLUSIONS Advanced age, male gender and hospitalization in winter are key risk factors for hospital-associated infection. Seasonal prevention and control strategies should be implemented in departments with high incidence of respiratory infections, and monitoring of multidrug-resistant bacteria should be enhanced.