Incidence of bacteremia and antimicrobial resistance, and associated factors among patients transferred from long-term care hospital.

Objective: To evaluate the prevalence of bacteremia and antimicrobial resistance, and associated factors among infectious patients transferred from long-term care hospitals (LTCHs).

Methods: Consecutive adult patients who were transferred for suspected infection from affiliated LTCH's to study hospital emergency department (ED) over a 12 month period from January to December 2016 were included retrospectively. Patients with positive blood cultures (excluding contaminants as clinically determined) were defined as primary measure and subjected to further analysis according to antimicrobial resistance pattern. The latter was categorized into 4 subgroups based on groups of antimicrobial choices for empiric choices of suspected bloodstream infections. R-Group 0: bacteria susceptible to penicillin and amoxicillin; R-Group 1: bacteria resistant to penicillin/amoxicillin, first, second, or third generation cephalosporins. R-Group 2: ESBL-producing bacteria or bacteria resistant methicillin, fourth generation cephalosporin, or fluoroquinolone. R-Group 3: highly resistant pathogens including vancomycin resistant enterococci, carbapenem or colistin resistant Gram negatives. Blood culture isolate could therefore be included in >1 group.

Results: Among 756 patients who were transferred from LTCHs, we excluded 278 patients who were not suspicious of infection and 65 patients who were not checked blood culture at ED. In total, 422 patients were enrolled. The incidence of bacteremia was 20.4% (n = 86). The most frequent pathogen was E. coli (n = 25) followed by S. aureus (n = 10), S. epidermidis (n = 8), and K. pneumonia (n = 6). The incidences of the R-Group 1, 2, and 3 groups were 16.8% (n = 71), 14.4% (n = 61), and 1.4% (n = 6), respectively. Of the Gram-positive pathogens (n = 44), the R-Group 1, 2, and 3 groups were 84.1% (n = 37), 75.0% (n = 33), and 9.1% (n = 4), respectively. Of the Gram-negative pathogens (n = 46), the R-Group 1, 2, and 3 groups were 82.6% (n = 38), 69.6% (n = 32), and 4.3% (n = 2), respectively. Among tested variables, initial serum procalcitonin level was significantly associated with the presence of bacteremia (AOR 1.03, 95% confidence interval 1.00-1.05), R-Group 1 (1.04, 1.01-1.07) and the R-Group 2 (1.04, 1.00-1.06).

Conclusions: The prevalence of bloodstream infections in patients admitted from LTCH was high (20.4%) with majority of these infections from resistant bacteria. Procalcitonin levels were significantly higher in bacteremic patients with an increasing trend towards bacteria in the antimicrobial resistant groups.