Risk factors for invasive infection with fluoroquinolone-resistant S. pneumoniae and failure of oral outpatient fluoroquinolone therapy

Abstract number: p1397

Green  K., McGeer  A., Low  D.E.


There is increasing concern about the emergence of fluoroquinolone (FQ) resistance in S. pneumoniae. We looked at FQ resistance rates and risk factors in patients with invasive pneumococcal disease (IPD) in Toronto, Canada.


From 01/00–12/04, TIBDN performed population-based surveillance for IPD in persons living in Toronto/Peel Region, Can. (pop 4M). IPD was defined as illness associated with isolation of SPN from a sterile site. Patients (pts) exposed to fluoroquinolones were classified as: treated with FQ for current infection before presenting with IPD (failure out-pt Rx) or received FQ for another infection in the previous 3 months (FQ prior 3 mos). Failures were defined as bacteremia while on or within 2 days of finishing oral FQ therapy.


1773/1879 (94%) case isolates were available for susceptibility testing; 28 (1.5%) hadciprofloxacin MIC >= 4 (CipR), 21(1.2%) had levofloxacin MIC >= 8 (LevR) and 5 (0.3%) had moxifloxacin MIC >= 4 (MoxR). 145 pts received FQ prior to presentation with IPD; 28 (1.5%) pts failed their out-patient FQ Rx for current infection while 117 (6.2%) had received a FQ for a different infection in the prior 3 months. Of the 21 LevR isolates identified, 6(28.4%) were in pts failing FQ Rx, 8 (38%) were in residents of nursing homes and 4 (19%) were nosocomial isolates. Of the 5 pts with MoxR isolates, 2 were failing Ciprofloxacin out-pt Rx, 2 had received a FQ for another infection in the prior 3 months and 1 isolate was from a nursing home resident with no FQ exposure. FQ resistance in these patient groups is shown in the Table below.


Patients who have been receiving a FQ for therapy and present to hospital with pneumonia or sepsis should be treated with a different class of antibiotics. FQ resistance in IPD in Toronto occurs almost exclusively in patients with recent direct exposure to fluoroquinolones, or recent exposure to a healthcare institution. In patients with none of these risk factors, all isolates were susceptible to moxifloxacin.

Session Details

Date: 01/08/2007
Time: 00:00-00:00
Session name: XXIst ISTH Congress
Location: Oxford, UK
Presentation type:
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