Seasonal characteristics of nosocomial infection in a psychiatric hospital in China with different nosocomial prevention and control backgrounds: a retrospective study

This study aimed to investigate the relationship between various prevention and control measures for nosocomial infections (NIs) in psychiatric hospitals and patients with mental disorders. This study aimed to determine the characteristics of NIs in psychiatric hospitals and provide a reference for infection prevention and control in this setting. Data from the NI monitoring system of a psychiatric hospital in southeastern China were analysed. Patients who were hospitalized for mental disorders from January 1, 2016, to November 30, 2019, were classified into the non-COVID-19 containment group (NC19C group, n = 898), while those who were hospitalized from January 25, 2020, to November 30, 2022, were classified into the COVID-19 containment group (C19C group, n = 840). The data were analysed using SPSS version 22.0, and independent sample t tests, chi-square tests, correlation analyses, and multivariate logistic regression analyses were performed. A significance level of P < 0.0024 was applied. The incidence rate of NIs was higher in autumn in the NC19C group, while no seasonal difference was detected in the C19C group (P < 0.0024). Further analysis revealed that in the C19C group, the risk of hospitalized patients with mental disorders developing hospital-acquired pneumonia in spring was 0.362 times that in winter (OR = 0.362, 95% CI = 0.200 ~ 0.656, P = 0.001), and in summer, the risk was 0.342 times that in winter (OR = 0.342, 95% CI = 0.185 ~ 0.633 P = 0.001). Patients aged 18-44 years had a 4.260 times higher risk of developing hospital-acquired upper respiratory tract infections than did those aged 60 years and older (OR = 4.260, 95% CI = 2.143 ~ 8.470; P = 0.000). The risk of acquiring urinary tract infections in the hospital was 0.324 times greater among patients aged 18-44 years than for patients aged 60 years and older (OR = 0.324, 95% CI = 0.171-0.613; P = 0.001). The NC19C group did not exhibit the aforementioned differences. During the NC19C period, differences were observed in the diagnosis of hospital-acquired infections and sex (all P = 0.000). Psychiatric hospitals exhibit distinct nosocomial infection characteristics under the context of various infection control measures. Against the backdrop of strengthened infection control, the nosocomial infection characteristics of psychiatric hospitals may be associated with the features of mental disorders.