title: Sex, drugs, bugs, and age: rational selection of empirical therapy for outpatient urinary tract infection in an era of extensive antimicrobial resistance.
abstract: BACKGROUND
  Optimal empirical therapy of urinary tract infection requires accurate knowledge of local susceptibility patterns, which may vary with organism and patient characteristics.
  
  
  METHODS
  Among 9,798 consecutive, non-duplicate, community-source urine isolates from ambulatory patients > 13 years old, from clinical laboratory and an academic medical center in Curitiba, Brazil (May 1st to December 1st, 2009), susceptibility data for ampicillin, nitrofurantoin, trimethoprim-sulfamethoxazole, gentamicin, fluoroquinolones, and ceftriaxone/cefotaxime were compared with organism and patient gender and age.
  
  
  RESULTS
  The female-to-male ratio decreased with age, from 28.1 (among 20-29 year-olds) to 3.3 (among > 80 year-olds). Overall, susceptibility prevalence varied widely by drug class, from unacceptably low levels (53.5% and 61.1%: ampicillin and trimethoprimsulfamethoxazole) to acceptable but suboptimal levels (81.2% to 91.7%: fluoroquinolones, ceftriaxone, nitrofurantoin, and gentamicin). E. coli isolates exhibited higher susceptibility rates than other isolates, from 3-4% higher (fluoroquinolones, gentamicin) to > 30% (nitrofurantoin, ceftriaxone). Males exhibited lower susceptibility rates than females. Within each gender, susceptibility declined with increasing age. For females, only nitrofurantoin and gentamicin were suitable for empirical therapy (> 80% susceptibility) across all age cohorts; fluoroquinolones were suitable only through age 60, and ceftriaxone only through age 80. For males, only gentamicin yielded > 80% susceptibility in any age cohort.
  
  
  CONCLUSIONS
  Few suitable empirical treatment options for community-source urinary tract infection were identified for women aged over 60 years or males of any age. Empirical therapy recommendations must consider the patient's demographic characteristics. Site-specific, age and gender-stratified susceptibility surveillance involving all uropathogens is needed.
authors.affiliation: Division of Microbiology, Frischmann Aisengart/DASA Medicina Diagnóstica and VITA Curitiba Hospital, Curitiba, PR, Brazil.
authors.forename: Jaime L
authors.initials: JL
authors.lastname: Rocha
authors.forename: Felipe Francisco
authors.initials: FF
authors.lastname: Tuon
authors.forename: James R
authors.initials: JR
authors.lastname: Johnson
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001938:Brazil / Q000453:epidemiology; D017714:Community-Acquired Infections / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology; D024881:Drug Resistance, Bacterial / Q000187:drug effects*; D005260:Female; D006090:Gram-Negative Bacteria / Q000187:drug effects* / Q000302:isolation & purification; D006094:Gram-Positive Bacteria / Q000187:drug effects* / Q000302:isolation & purification; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D012737:Sex Factors; D014552:Urinary Tract Infections / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology*; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents