Prediction models to identify hospitalized patients at risk of being colonized or infected with multidrug-resistant Acinetobacter baumannii calcoaceticus complex.
BACKGROUND
The multidrug-resistant (MDR) Acinetobacter baumannii calcoaceticus complex (Abc) has emerged as an important cause of nosocomial infections. The aims of the study were to evaluate risk factors for MDR-Abc in intensive care units (ICUs) as well as in medical and surgical wards, to define the likelihood ratios (LRs) of risk factors and to determine if risk factors differ depending on whether colonization or infections are considered.


METHODS
Two prospective matched case-control studies were performed. MDR-Abc was defined as a strain resistant to four or more classes of antibiotics. The two case groups included patients with MDR-Abc infections or colonization. Controls were selected among patients not harbouring Abc. Matching criteria were the number of days from admission to MDR-Abc isolation among cases and the duration of hospitalization among controls.


RESULTS
Overall, 514 patients were included in the study. One hundred and thirty-seven patients were infected and 120 colonized. A Charlson score >3 and previous methicillin-resistant Staphylococcus aureus isolation and beta-lactam use were independent risk factors for colonization and infection. Bedridden status and previous ICU admission were associated with colonization, while the presence of a central venous catheter and surgery were related to infection. The analysis of LRs showed an association between the presence of more than two risk factors and colonization or infection. The highest predicting value was observed for the presence of more than two risk factors and colonization in patients with no history of ICU admission.


CONCLUSIONS
This study provides novel information that can be used to identify interventions for different stages of the spread of MDR-Abc.
Tacconelli
Evelina
E
Department of Infectious Diseases, Università Cattolica Sacro Cuore, 00168 Rome, Italy. etacconelli@rm.unicatt.it
Cataldo
Maria Adriana
MA
De Pascale
Gennaro
G
Manno
Daniela
D
Spanu
Teresa
T
Cambieri
Andrea
A
Antonelli
Massimo
M
Sanguinetti
Maurizio
M
Fadda
Giovanni
G
Cauda
Roberto
R
D000151:Acinetobacter Infections / Q000453:epidemiology* / Q000382:microbiology; D040981:Acinetobacter baumannii / Q000187:drug effects*; D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D016022:Case-Control Studies; D002408:Catheters, Indwelling / Q000009:adverse effects; D003428:Cross Infection / Q000453:epidemiology* / Q000382:microbiology; D024901:Drug Resistance, Multiple, Bacterial; D005260:Female; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D016106:Methicillin Resistance; D008875:Middle Aged; D011183:Postoperative Complications; D011446:Prospective Studies; D012307:Risk Factors; D013203:Staphylococcal Infections / Q000150:complications / Q000382:microbiology; D047090:beta-Lactams / Q000627:therapeutic use
D000900:Anti-Bacterial Agents; D047090:beta-Lactams