Background: The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) varies for different regions and countries. Data from Taiwan’s nosocomial infection surveillance system indicate that the density of MRSA infection for drug-resistant strains in the intensive care units (ICU) of medical centers and regional hospitals was once as high as 4.7‰-6.0‰. MRSA often has such complications as sepsis, endocarditis, pneumonia and skin and soft tissue infections, which prolong hospitalization days and increase medical costs and mortality. Active nasal screening can detect patients with early colonization so that the early contact isolation of patients can be implemented to prevent subsequent MRSA infection. Therefore, the purpose of this study is to investigate the MRSA nasal colonization rate and its related factors within 48 hours of emergency patients being admitted to surgical intensive care units.
Methods: Secondary data analysis was used. The database used was designed for cross-sectional studies. Data were collected from adult surgical intensive care units in a regional teaching hospital. MRSA nasal screening was performed by administering Active Surveillance Culture (ASC) to emergency patients within 48 hours of admission, and the MRSA strain was cultured after the specimen was obtained. The relevant factors related to MRSA nasal colonization of individual cases were collected by means of tracking medical records. The data obtained were verified by descriptive statistics, chi-square tests, multivariate logistic regression analysis, etc.
Results: The study showed that the MRSA nasal colonization rate was 10.5% within 48 hours of admission to intensive care units. Univariate analysis showed that the pre-hospital residence, Acute Physiology and Chronic Health Evaluation II (APACHE II), abnormal pH value in the arterial blood gas analysis, abnormal hematocrit ratio, excessively high count of white blood cells in the blood and other variables had significant correlations with MRSA nasal colonization. In multivariate analysis, only two variables, namely, abnormal pH value in the arterial blood gas analysis and abnormal hematocrit ratio were significantly correlated with MRSA nasal colonization.
Discussion and Conclusions: The results of this study show that for the patients in intensive care units, their pre-hospital residences, APACHE II scores, arterial blood gas analysis pH values, hematocrit ratios, and blood white blood cell counts are the risk factors for ASC MRSA nasal colonization. Medical staff should actively assess whether ICU patients are in a high risk group for MRSA nasal colonization, and perform early contact isolation measures for such patients so as to reduce infection caused by MRSA colonization.