title: Clinical response and outcome of infection with Salmonella enterica serotype Typhi with decreased susceptibility to fluoroquinolones: a United States foodnet multicenter retrospective cohort study.
abstract: Patients with typhoid fever due to Salmonella enterica serotype Typhi strains for which fluoroquinolones MICs are elevated yet that are classified as susceptible by the current interpretive criteria of the Clinical and Laboratory Standards Institute may not respond adequately to fluoroquinolone therapy. Patients from seven U.S. states with invasive Salmonella serotype Typhi infection between 1999 and 2002 were enrolled in a multicenter retrospective cohort study. Patients infected with Salmonella serotype Typhi isolates with ciprofloxacin MICs of 0.12 to 1 microg/ml (decreased ciprofloxacin susceptibility but not resistant to ciprofloxacin [DCS]) were compared with patients infected with isolates with ciprofloxacin MICs <0.12 microg/ml for fever clearance time and treatment failure. Of 71 patients, 30 (43%) were female and 24 (34%) were infected with Salmonella serotype Typhi with DCS; the median age was 14 years (range, 1 to 51 years). Twenty-one (88%) of 24 isolates with DCS were resistant to nalidixic acid. The median antimicrobial-related fever clearance times in the DCS and non-DCS groups were 92 h (range, 21 to 373 h) and 72 h (range, 19 to 264 h) (P = 0.010), respectively, and the fluoroquinolone-related fever clearance times in the DCS and non-DCS groups were 90 h (range, 9 to 373 h) and 64 h (range, 34 to 204 h) (P = 0.153), respectively. Four (17%) of 24 patients in the DCS group and 2 (4%) of 46 patients in the non-DCS group (relative risk, 2.5; 95% confidence interval, 1.2 to 5.1) experienced treatment failure. Associations persisted after adjustment for potential confounders. We demonstrate that patients infected with Salmonella serotype Typhi isolates with DCS show evidence of a longer time to fever clearance and more frequent treatment failure. Nalidixic acid screening does not detect all isolates with DCS.
authors.affiliation: Enteric Diseases Epidemiology Branch, National Center for Zoonotic, Vectorborne, and Enteric Diseases, MS A-38, Centers for Disease Control and Prevention, 1600 Clifton Road, Atlanta, GA 30333, USA. jcrump@cdc.gov
authors.forename: John A
authors.initials: JA
authors.lastname: Crump
authors.forename: Katrina
authors.initials: K
authors.lastname: Kretsinger
authors.forename: Kathryn
authors.initials: K
authors.lastname: Gay
authors.forename: R Michael
authors.initials: RM
authors.lastname: Hoekstra
authors.forename: Duc J
authors.initials: DJ
authors.lastname: Vugia
authors.forename: Sharon
authors.initials: S
authors.lastname: Hurd
authors.forename: Susan D
authors.initials: SD
authors.lastname: Segler
authors.forename: Melanie
authors.initials: M
authors.lastname: Megginson
authors.forename: L Jeffrey
authors.initials: LJ
authors.lastname: Luedeman
authors.forename: Beletshachew
authors.initials: B
authors.lastname: Shiferaw
authors.forename: Samir S
authors.initials: SS
authors.lastname: Hanna
authors.forename: Kevin W
authors.initials: KW
authors.lastname: Joyce
authors.forename: Eric D
authors.initials: ED
authors.lastname: Mintz
authors.forename: Frederick J
authors.initials: FJ
authors.lastname: Angulo
mesh_terms: D000293:Adolescent; D000328:Adult; D000900:Anti-Bacterial Agents / Q000494:pharmacology* / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D002939:Ciprofloxacin / Q000494:pharmacology / Q000627:therapeutic use; D015331:Cohort Studies; D024881:Drug Resistance, Bacterial; D005260:Female; D024841:Fluoroquinolones / Q000494:pharmacology* / Q000627:therapeutic use; D005517:Foodborne Diseases / Q000453:epidemiology; D006760:Hospitalization; D006801:Humans; D007223:Infant; D008297:Male; D008826:Microbial Sensitivity Tests / Q000592:standards; D008875:Middle Aged; D011159:Population Surveillance; D012189:Retrospective Studies; D012485:Salmonella typhi / Q000187:drug effects*; D016896:Treatment Outcome; D014435:Typhoid Fever / Q000188:drug therapy* / Q000382:microbiology; D014481:United States
chemical_list: D000900:Anti-Bacterial Agents; D024841:Fluoroquinolones; D002939:Ciprofloxacin