Bacteremia in previously hospitalized patients: prolonged effect from previous hospitalization and risk factors for antimicrobial-resistant bacterial infections.
OBJECTIVE
Patients who came from the community but were recently discharged from the hospital have a higher risk of contracting antimicrobial-resistant bacterial infections. Our objectives are to determine the time from previous hospital discharge that affects subsequent antimicrobial susceptibility pattern and risk factors for antimicrobial-resistant infection in bacteremia in recently discharged patients.


METHODS
Excluding patients of hospital-acquired, patients with regular health care-associated exposure, and patients whose previous hospitalization was not at our hospital, a total of 789 nonduplicated bacteremia episodes from community adult patients were enrolled in a 1-year study period. Antimicrobial-resistant bacteria, including multidrug-resistant gram-negative bacilli, methicillin-resistant Staphylococcus aureus, and vancomycin-resistant enterococci causing bacteremia, were logistically analyzed according to different posthospitalization periods (3 to 90 days, 91 to 180 days, 181 to 360 days, and no hospitalization in the past 360 days) to identify the independent effect from previous hospitalization on subsequent antimicrobial-resistant bacteremia.


RESULTS
Of the 789 bacteremia patients, the proportion of antimicrobial-resistant bacteremia is 14.6% (95% confidence interval [CI] 9.8% to 19.4%) for 3 to 90 days, 9.6% (95% CI 1.6% to 17.6%) for 91 to 180 days, and 6.4% (95% CI 0% to 13.4%) for 181 to 360 days since last hospitalization and 1.0% (95% CI 0.1% to 1.9%) for no hospitalization within the last 360 days. Risk of antimicrobial-resistant bacteremia decreased monthly after discharge by an odds ratio of 0.83 (95% CI 0.76 to 0.90) (P<.01). Previous carriage of antimicrobial-resistant bacteria in the past 360 days and previous stay at ICU in the past 180 days were independent risk factors for antimicrobial-resistant bacteremia in previously hospitalized patients.


CONCLUSIONS
Previous hospitalization affects the antimicrobial susceptibility of subsequent bacteremia up to 360 days after hospital discharge. Presence of risk factors for antimicrobial-resistant bacteremia in previously hospitalized patients may help emergency physicians in selecting empirical antimicrobial agents and prompting infection control precautions.
Chen
Shey-Ying
SY
Department of Emergency Medicine, National Taiwan University Hospital, College of Medicine, National Taiwan University, Taipei, Taiwan.
Wu
Grace Hui-Min
GH
Chang
Shan-Chwen
SC
Hsueh
Po-Ren
PR
Chiang
Wen-Chu
WC
Lee
Chien-Chang
CC
Ma
Matthew Huei-Ming
MH
Hung
Chien-Ching
CC
Chen
Yee-Chun
YC
Su
Chan-Ping
CP
Tsai
Kuang-Chau
KC
Chen
Tony Hsiu-Hsi
TH
Chen
Shyr-Chyr
SC
Chen
Wen-Jone
WJ
D000900:Anti-Bacterial Agents / Q000009:adverse effects* / Q000627:therapeutic use; D016470:Bacteremia / Q000188:drug therapy / Q000209:etiology* / Q000382:microbiology; D017714:Community-Acquired Infections / Q000188:drug therapy / Q000209:etiology / Q000382:microbiology; D015897:Comorbidity; D016001:Confidence Intervals; D024881:Drug Resistance, Bacterial; D005260:Female; D006760:Hospitalization; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D013624:Taiwan / Q000453:epidemiology; D013997:Time Factors
D000900:Anti-Bacterial Agents