Duration of Persistence of Gonococcal DNA Detected by Ligase Chain Reaction in Men and Women following Recommended Therapy for Uncomplicated Gonorrhea

Abstract

Neisseria gonorrhoeae infection remains relatively common in the United States, representing a public health challenge. Ligase chain reaction (LCR) is both highly sensitive and specific for the detection of N. gonorrhoeae in urine and patient-obtained vaginal swab specimens. Because of the LCR test's exquisite sensitivity, it may potentially detect DNA from nonviable organisms following effective therapy, leading to false-positive test results and unnecessary additional treatment. The purpose of the present study was to determine the duration that gonococcal DNA is detectable by LCR following therapy for uncomplicated gonococcal infection. One hundred thirty men and women between the ages of 16 and 50 years presenting to a sexually transmitted disease clinic with urogenital gonorrhea were enrolled. After the standard history was taken and a genital examination was done, the patients were asked to submit either a urine specimen (men) or a urine specimen plus a self-obtained vaginal swab specimen (women) for N. gonorrhoeae testing by LCR at the initial visit and each day during the study period. At enrollment, patients were treated with single doses of ofloxacin, cefixime, or ceftriaxone. The median time to a negative urine LCR test result was 1 day for the men (mean, 1.6 ؎ 0.14 days) and 2 days for the women (mean, 1.7 ؎ 0.19 days). Among the women the clearance time was significantly longer for vaginal specimens (mean, 2.8 ؎ 0.30 days) than for urine specimens (mean, 1.7 ؎ 0.11 days). Irrespective of patient gender and specimen type, gonococcal DNA can be expected to be absent from urogenital specimens within 2 weeks following successful therapy.Gonorrhea is the second most common reportable infectious disease in the United States, and its control represents a continuing public health challenge. In 2000, over 350,000 cases of gonorrhea were reported, a 21% increase over the number of reported cases since 1997 and a sustained reversal of the downward trend in the prevalence of gonococcal infections reported in the United States from 1977 to 1997 (2). At the same time, over the past decade powerful new tools for the diagnosis of gonorrhea have become available. Among these are nucleic acid amplification tests which permit the use of specimens obtained by simplified specimen collection methods (i.e., voided urine specimens or, for women, patient-collected vaginal swab specimens) without any compromise in the sensitivity of detection (4,7,8,(11)(12)(13). Because nucleic acid amplification tests do not require living organisms for the detection of infection, concern has also been expressed about the potential for residual nucleic acids from nonviable organisms to persist in the genital tract, giving rise to false-positive test results if patients are retested too soon following successful therapy. Support for these concerns comes from studies demonstrating the persistence of Chlamydia trachomatis nucleic acids for periods as long as 2 to 3 weeks following therapy (1,5,14). No similar studies have been performed to de...

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