Abstract: OBJECTIVE To explore the risk factors for nosocomial infections in patients of psychogeriatric department and analyze the distribution of pathogens so as to provide guidance for clinical control and prevention of the nosocomial infections.METHODS By means of retrospective survey, the clinical data of 5 026 patients who were treated in the psychogeriatric department from Jan 2015 to Dec 2015 were analyzed.The incidence of nosocomial infections, infection sites, types of underlying mental diseases, and result of bacterial culture were statistically analyzed.The factors such as genders, age, length of hospital stay, number of complication with somatic diseases, self-care ability of daily living, and drug-induced adverse reactions were observed, the risk factors for the nosocomial infections in the patients of psychogeriatric department were explored, and the prevention measures were put forward.RESULTS Of the 5 026 patients, 251 had the nosocomial infections, with the infection rate 4.99%, of whom 53.39% had respiratory tract infections.The Alzheimer's disease and schizophrenia were dominant among the underlying mental diseases, accounting for 35.06% and 31.47%, respectively.The incidence rate of nosocomial infections was 10.89% in the patients aged no less than 80 years old, 3.08% in the patients aged less than 80 years old; the infection rate was 7.50% in the patients with the length of hospital stay no less than 30 days, 1.48% in the patients with the length of hospital stay less than 30 days; the infection rate was 8.53% in the patients complicated with no less than 3 types of somatic diseases, 1.37% in the patients complicated with less than 3 types of somatic diseases; the infection rate was 8.78% in the patients who were completely unable to take care of themselves about daily life, 2.36% in the patients who were not completely unable to take care of themselves about daily life; the infection rate was 7.77% in the patients with drug-induced adverse reactions, 1.77% in the patients without the drug-induced adverse reactions, and there was significant difference (P＜0.05).Totally 213 strains of pathogens were isolated, of which 135 (63.38%) were gram-negative bacteria, 73 (34.27%) were gram-positive bacteria, and 5 (2.35%) were fungi; Klebsiella pneumoniae and Escherichia coli were dominant among the gram-negative bacteria, accounting for 24.88% and 14.55%, respectively; Staphylococcus aureus was the predominant species of the gram-positive bacteria, accounting for 10.33%; Candida tropicalis and Candida albicans were dominant among the fungi, accounting for 1.41% and 0.94%, respectively.CONCLUSIONThe risk factors for the nosocomial infections in the patients of psychogeriatric department include the advanced age, long length of hospital stay, complication with multiple somatic diseases, completely unable to take care of themselves, and drug-induced adverse reactions.The gram-negative bacteria are dominant among the pathogens.It is necessary to take targeted prevention measures so as to reduce the incidence of the nosocomial infections.