Criteria for a strain to be considered multidrug-resistant - both of the following:
(1) resistance to trimethoprim-sulfamethoxazole (TMP-SMX)
(2) resistance to >=2 of the following: ciprofloxacin, ceftazidime, amikacin, ticarcillin-clavulanate
Control groups used to determine risk:
(1) comparable risk for S. maltophilia (C controls)
(2) infection with susceptible strains of S. maltophilia (S controls)
Reference time: isolation of multidrug-resistant strain in culture
Risk factors infection with a multidrug-resistant strain (odds ratios 3.2 to 6.0):
(1) therapy with carbapenem in previous 90 days (vs C controls)
(2) therapy with quinolone in previous 90 days (vs C controls)
(3) therapy with trimethoprim-sulfamethoxazole (TMP-SMX) in previous 90 days (vs S controls)
(4) ICU admission in previous 30 days (vs C controls)
(5) history of S. maltophilia infection during previous year (vs S controls)
Factors associated with reduced risk of infection with a multidrug-resistant strain:
(1) non-ICU hospitalization within previous 30 days (vs both C and S controls)
(2) therapy with cephalosporin in previous 90 days (vs S controls)
where:
• The patients were treated at M.D. Anderson Cancer Hospital. The prevalence of infection with Stenotrophomonas maltophilia may be different at other hospitals.
