Attitudes to, and experience of, pooled sampling for sexually transmitted infection testing: a web-based survey of English sexual health services

Pooled 3-Anatomic-Site Testing for Chlamydia trachomatis and Neisseria gonorrhoeae: A Systematic Review and Meta-Analysis

BACKGROUND

Pooled testing for Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) may be a cost-saving solution to increase screening by simplifying testing procedures and reducing resource burdens. We conducted a systematic review and meta-analysis to examine the performance of pooled 3-anatomic-site testing (pharyngeal, rectal, and urogenital sites) for CT and NG in comparison with single-anatomic-site testing.

METHODS

We conducted a systematic literature search in PubMed, Embase, and Web of Science to identify original evaluation studies of the performance of pooled testing for CT and NG infections and identified 14 studies for inclusion. Each study was systematically evaluated for bias. We conducted bivariate fixed-effects and random-effects meta-analyses using a full Bayesian method of the positive percent agreement and negative percent agreement.

RESULTS

The combined positive percent agreement for CT was 93.11% (95% confidence interval [CI], 91.51%-94.55%), and the negative percent agreement was 99.44% (95% CI, 99.18%-99.65%). For NG, the combined positive percent agreement was 93.80% (95% CI, 90.26%-96.61%), and the negative percent agreement was 99.73% (95% CI, 99.30%-99.97%).

CONCLUSIONS

We found that pooled 3-anatomic-site tests performed similarly to single-anatomic-site tests for the detection of CT and NG. The pooled 3-anatomic-site tests have the added potential benefit of reduced cost and resource requirement, which could lead to improved testing access and screening uptake.

Diagnostic accuracy of pooling urine, anorectal, and oropharyngeal specimens for the detection of Chlamydia trachomatis and Neisseria gonorrhoeae: a systematic review and meta-analysis

BACKGROUND

Screening for Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) at genital and extragenital sites is needed for most key populations, but molecular diagnostic tests for CT/NG are costly. We aimed to determine the accuracy of pooled samples from multiple anatomic sites from one individual to detect CT/NG using the testing of a single sample from one anatomic site as the reference.

METHODS

In this systematic review and meta-analysis, we searched five databases for articles published from January 1, 2000, to February 4, 2021. Studies were included if they contained original data describing the diagnostic accuracy of pooled testing compared with single samples, resource use, benefits and harms of pooling, acceptability, and impact on health equity. We present the pooled sensitivities and specificities for CT and NG using a bivariate mixed-effects logistic regression model. The study protocol is registered in PROSPERO, an international database of prospectively registered systematic reviews (CRD42021240793). We used GRADE to evaluate the quality of evidence.

RESULTS

Our search yielded 7814 studies, with 17 eligible studies included in our review. Most studies were conducted in high-income countries (82.6%, 14/17) and focused on men who have sex with men (70.6%, 12/17). Fourteen studies provided 15 estimates for the meta-analysis for CT with data from 5891 individuals. The pooled sensitivity for multisite pooling for CT was 93.1% [95% confidence intervals (CI) 90.5-95.0], I²=43.3, and pooled specificity was 99.4% [99.0-99.6], I²=52.9. Thirteen studies provided 14 estimates for the meta-analysis for NG with data from 6565 individuals. The pooled sensitivity for multisite pooling for NG was 94.1% [95% CI 90.9-96.3], I²=68.4, and pooled specificity was 99.6% [99.1-99.8], I²=83.6. Studies report significant cost savings (by two thirds to a third).

CONCLUSION

Multisite pooled testing is a promising approach to improve testing coverage for CT/NG in resource-constrained settings with a small compromise in sensitivity but with a potential for significant cost savings.

Pooling Pharyngeal, Anorectal, and Urogenital Samples for Screening Asymptomatic Men Who Have Sex with Men for Chlamydia trachomatis and Neisseria gonorrhoeae

Screening for Chlamydia trachomatis and Neisseria gonorrhoeae at the pharyngeal, urogenital, and anorectal sites is recommended for men who have sex with men (MSM). Combining the three individual-site samples into a single pooled sample could result in significant cost savings, provided there is no significant sensitivity reduction. The aim of this study was to examine the sensitivity of pooled samples for detecting chlamydia and gonorrhea in asymptomatic MSM using a nucleic acid amplification test. Asymptomatic MSM who tested positive for chlamydia or gonorrhoea were invited to participate. Paired samples were obtained from participants prior to administration of treatment. To form the pooled sample, the anorectal swab was agitated in the urine specimen transport tube and then discarded. The pharyngeal swab and 2 ml of urine sample were then added to the tube. The difference in sensitivity between testing of pooled samples and individual-site testing was calculated against an expanded gold standard, where an individual is considered positive if either pooled-sample or individual-site testing returns a positive result. All samples were tested using the Aptima Combo 2 assay. A total of 162 MSM were enrolled in the study. Sensitivities of pooled-sample testing were 86% (94/109; 95% confidence interval [CI], 79 to 92%]) for chlamydia and 91% (73/80; 95% CI, 83 to 96%) for gonorrhea. The sensitivity reduction was significant for chlamydia (P = 0.02) but not for gonorrhea (P = 0.34). Pooling caused 22 infections (15 chlamydia and 7 gonorrhoea) to be missed, and the majority were single-site infections (19/22). Pooling urogenital and extragenital samples from asymptomatic MSM reduced the sensitivity of detection by approximately 10% for chlamydia but not for gonorrhea.