Direct urine polymerase chain reaction for chlamydia and gonorrhoea: A simple means of bringing high-throughput rapid testing to remote settings?

Sexual Health (Impact Factor: 1.37). 05/2013; 10(4). DOI: 10.1071/SH12108
Source: PubMed


Background Rapid point-of-care tests (POCTs) for chlamydia (Chlamydia trachomatis) and gonorrhoea (Neisseria gonorrhoeae) have the potential to confer health benefits in certain populations even at moderate sensitivities; however, suitable POCTs for these organisms are currently lacking.

In this study, we investigated the use of direct urine polymerase chain reaction (PCR), with the view of implementing a simplified PCR strategy for high-throughput chlamydia and gonorrhoea screening in remote settings. Briefly, a simple dilution of the urine was performed before adding it directly to a real-time PCR reaction. The method was evaluated using 134 stored urine specimens that had been submitted for chlamydia and gonorrhoea testing and had been tested using a commercial C. trachomatis and N. gonorrhoeae PCR method. These included samples that were PCR-positive for chlamydia (n=87), gonorrhoea (n=16) or both (n=2). Direct urine testing was conducted using previously described in-house real-time PCR methods for C. trachomatis and N. gonorrhoeae as well as for recognised N.gonorrhoeae antimicrobial resistance mechanisms.

The overall sensitivities and specificities of the direct urine PCR were 78% and 100% for chlamydia, and 83% and 100% for gonorrhoea. N.gonorrhoeae penicillin and quinolone resistance mechanisms were characterised in 14 of the 18 N. gonorrhoeae-positive samples.

The results of this study show that the simplified PCR strategy may be a feasible approach for rapid screening and improving chlamydia and gonorrhoea treatment in remote settings.

22 Reads
  • [Show abstract] [Hide abstract]
    ABSTRACT: To compare a rapid, office-based test with standard cell culture for screening of women for Chlamydia trachomatis infections. An 8-month prospective crossover trial used alternating screening protocols in two Baltimore (Md) sexually transmitted disease clinics from January 2 through August 14, 1991. Consecutive women attending the two clinics who had no indication for administration of antichlamydial antibiotic therapy (eg, history of recent sexual contact with a partner with a sexually transmitted disease, mucopurulent cervicitis, pelvic inflammatory disease, known gonorrhea, or previously diagnosed Chlamydia infections). Chlamydia screening was offered according to one of two protocols. Use of the two screening protocols was alternated between clinics each month. In the "rapid test clinic," eligible women were screened with both a 30-minute enzyme immunoassay test and tissue culture. Patients screened with the rapid test were asked to remain in the clinic until their rapid assay results were available so that, if positive, the patients could be treated. In the "routine screening clinic," eligible women were screened for Chlamydia by cell culture. Women identified as being infected with Chlamydia by screening culture were later confidentially notified of their test results by health department disease intervention specialists and referred for therapy. Performance of screening tests for bringing infected patients to therapy; time intervals between initial clinic visits and therapy; and pelvic inflammatory disease occurring between initial visits and therapy. Chlamydia cultures were positive in 100 (6.6%) of 1526 women screened with the solid-phase immunoassay, 47 of which were detected and treated on the basis of rapid test results. In contrast, 93 (74%) of 126 women with positive screening cultures returned to the clinic and received therapy. The median interval between testing and therapy for women with positive screening cultures was 14 days, and three (3.2%) developed pelvic inflammatory disease in the interval between testing and return for therapy. Neither cell culture nor a rapid diagnostic test performed well for ensuring therapy of women with Chlamydia infections. The sensitivity of the rapid diagnostic test was low, and nearly one fourth of the women with positive screening cultures did not return for therapy. Evaluation of screening for Chlamydia should consider the utility of strategies for bringing patients to treatment, as well as the more usual measures of test performance, such as sensitivity, specificity, and predictive values.
    JAMA The Journal of the American Medical Association 10/1994; 272(11):867-70. DOI:10.1001/jama.272.11.867 · 35.29 Impact Factor
  • JAMA The Journal of the American Medical Association 08/1997; 278(2):117-8. DOI:10.1001/jama.278.2.117 · 35.29 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Screening tests for detection of Chlamydia trachomatis include those processed in laboratories and those designed to be processed at the point of care. The latter tests can yield results at the time of the initial patient visit, but most available lab-processed tests have greater sensitivity. In settings where a proportion of patients do not return for treatment after positive test results, the less sensitive rapid tests could lead to the treatment of more patients and be more cost-effective. To determine the situations, if any, in which a rapid test might be more cost-effective and treat more infections than lab-based tests. A decision analysis framework was used to compare one point-of-care test (the BioStar Chlamydia OIA) with two lab-based tests (cell culture and the polymerase chain reaction [PCR] assay). It was assumed that all women in the model would be screened. Variables included in the analysis were the prevalence, test sensitivity and specificity, the probability of developing pelvic inflammatory disease after treated and untreated chlamydial infections, and the likelihood that patients would wait for rapid test results or return to the facility for treatment. The rapid test treated more cases of infection than the PCR alone if the return rate was less than 65%. A two-test algorithm of the rapid test followed by a PCR test on those initially testing negative identified and treated the greatest number of chlamydial infections and was the most cost-effective at all prevalences above 9%, but this finding was sensitive to the cost estimate for pelvic inflammatory disease. In settings where patient return for treatment is a problem, point-of-care tests contribute significantly to the detection and treatment of chlamydial infections among women.
    Sex Transm Dis 05/1999; 26(4):232-40. DOI:10.1097/00007435-199904000-00010 · 2.84 Impact Factor
Show more