Chlamydia trachomatis Testing Sensitivity in Midstream Compared With First-Void Urine Specimens

Abstract

PURPOSE Traditionally fi rst-void urine specimens are used to test for Chlamydia trachomatis. In contrast, midstream urine specimens are traditionally recommended for microscopy and culture of presumptive bacterial urinary tract infections. The ability to test for both C trachomatis and urinary tract infection on a single midstream urine specimen would greatly aid clinical practice, as an urinary tract infection is an extremely common complaint in primary care. This study set out to determine how well positive C trachomatis results obtained on fi rst-void specimens would correlate with positive fi ndings in matched midstream specimens. METHODSOne hundred women with a fi rst-void urine specimen positive for C trachomatis also provided midstream specimens for comparison. All specimens had C trachomatis testing performed using a DNA detection method. RESULTSOf the 100 eligible participants with a fi rst-void specimen positive for C trachomatis, 96 (96%) also had a positive midstream specimen (95% exact confi dence limits, 90.1%, 98.9%).CONCLUSIONS These results suggest that by using newer nucleic acid amplifi cation techniques (NAATs), timing of specimen collection is not so important in testing for C trachomatis as previously thought. The sensitivity of NAAT testing on midstream urine specimens in women is suffi ciently equivalent to testing on fi rst-void specimens to consider in clinical practice and research settings where fi rst-void specimens have formerly been collected. 2012;10:50-53. doi:10.1370/afm.1323. Ann Fam Med INTRODUCTION C hlamydia trachomatis (C trachomatis)is the most common sexually transmitted bacterial infection.1 It may have few, if any, symptoms in women. The complications of infertility, pelvic infl ammatory disease, and ectopic pregnancy are serious, yet treatment is simple once infection is detected. Although there are a variety of methods for testing for C trachomatis, no single test is ideal. Currently, to test for the infection in women, nucleic acid amplifi cation tests (NAATs) are preferred, and either a vaginal swab or fi rst-void urine specimen is recommended for case fi nding, but neither has a 100% sensitivity. In the United States vaginal swabs are the preferred sample. 2-4Dysuria and increased urinary frequency associated with presumed urinary tract infection are extremely common reasons for seeking treatment in primary care.5 About 10% of women suffer from symptoms of a urinary tract infection in any year, 6 and seeking treatment provides a potential opportunity to detect both symptomatic and asymptomatic infection with C trachomatis. The sexually active woman is at risk of both urinary tract infection and C trachomatis infection. 51 UR INE T ES T ING F OR C T R ACHO M AT ISOne diffi culty in testing for C trachomatis in women seeking treatment for dysuria and frequency is that traditionally a fi rst-void urine specimen has been recommended, which is different from the midstream specimen used to diagnose a urinary tract infection. This distinction is made on the basi...

Risk factors for Chlamydia trachomatis infection in adolescents: results from a representative population-based survey in Germany, 2003–2006

“…The prevalence in our study might have been underestimated due to the long storage time between taking of specimens being taken and testing. In addition, if the collected urine was not first-void, there could be a reduction in sensitivity [3,26,27].…”

Women's preferences for testing and management of sexually transmitted infections among low-income New York City family planning clients

“…Recent evidence suggests use of midstream urine specimens for chlamydia testing results in only a small reduction in the sensitivity of Chlamydia tests. 12 However, these tests currently only have United States Food and Drug Administration clearance for use with first-catch urine. For women who require both tests, a self-collected vaginal swab for chlamydia testing combined with midstream urine for urinary tract infection testing may be more appropriate than using midstream urine specimens for both.…”

In This Issue: Challenges of Managing Multimorbidity

“…A clinical study by Mangin and colleagues 19 compares fi rst-void with midstream urine sampling and fi nds similar diagnostic rates for Chlamydia trachomatis testing. Based on this study's fi ndings, we can dispense with the inconvenient practice of collecting fi rst-void urine for Chlamydia testing.…”