JAMA：头孢克肟治疗淋球菌感染临床失败率相对较高

　　加拿大学者的一项研究表明，头孢克肟治疗淋球菌感染的临床失败率相对较高，并且与最低抑菌浓度（MIC）升高具有相关性。论文发表于《美国医学会杂志》[JAMA2013;309(2):163]。

　　此项回顾性队列研究共纳入291例淋球菌培养阳性的患者，并依据当地指南推荐给予头孢克肟治疗。受试者接受常规治愈判断检测。通过分子分型和明确排除再暴露，以治愈判断访视时分离出与治疗前相同的淋球菌定义头孢克肟治疗失败。

　　结果显示，在133例返回接受治愈判断检测的患者中，13例为培养阳性；其中9例被确定为出现头孢克肟治疗失败，涉及尿道、口咽和直肠三个部位。在接受一次治愈判断检测的患者中，总体临床治疗失败率为6.77%。与头孢克肟MIC≥0.12 μg/mL相关的临床失败率为25.0%，与MIC<0.12 μg/mL相关的治疗失败率则为1.90%；二者相对危险度为13.13（P<0.001）。

Neisseria gonorrhoeae Treatment Failure and Susceptibility to Cefixime in Toronto, Canada

Importance  Although cephalosporins are the cornerstone of treatment of Neisseria gonorrhoeaeinfections, cefixime is the only oral antimicrobial option. Increased minimum inhibitory concentrations (MICs) to cefixime have been identified worldwide and have been associated with reports of clinical failure.

Objective  To assess the risk of clinical treatment failure of N gonorrhoeae infections associated with the use of cefixime.

Design, Setting, and Population  A retrospective cohort study of culture-positive N gonorrhoeae infections at a single sexual health clinic in Toronto, Canada, that routinely performs test of cure. The cohort comprised N gonorrhoeae culture-positive individuals identified between May 1, 2010, and April 30, 2011, treated with cefixime as recommended by Public Health Agency of Canada guidelines.

Main Outcome Measures  Cefixime treatment failure, defined as the repeat isolation of N gonorrhoeae at the test-of-cure visit identical to the pretreatment isolate by molecular typing and explicit denial of reexposure.

Results  There were 291 N gonorrhoeae culture-positive individuals identified. Of 133 who returned for test of cure, 13 were culture positive; 9 patients were determined to have experienced cefixime treatment failure, involving urethral (n = 4), pharyngeal (n = 2), and rectal (n = 3) sites. The overall rate of clinical treatment failure among those who had a test of cure was 6.77% (95% CI, 3.14%-12.45%; 9/133). The rate of clinical failure associated with a cefixime MIC of 0.12 μg/mL or greater was 25.0% (95% CI, 10.69%-44.87%; 7/28) compared with 1.90% (95% CI, 0.23%-6.71%; 2/105) of infections with cefixime MICs less than 0.12 μg/mL, with a relative risk of 13.13 (95% CI, 2.88-59.72; P < .001).

Conclusion and Relevance  The rate of clinical failure following treatment of N gonorrhoeaeinfections with cefixime was relatively high at a Toronto clinic and was associated with elevated MICs.