Point-of-care test for detection of urogenital chlamydia in women shows low sensitivity. A performance evaluation study in two clinics in Suriname

• Published in: PloS one Vol. 7; no. 2; p. e32122
• Main Authors: van der Helm, Jannie J, Sabajo, Leslie O A, Grunberg, Antoon W, Morré, Servaas A, Speksnijder, Arjen G C L, de Vries, Henry J C
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 29.02.2012; Public Library of Science (PLoS)
• Subjects: Acids; Adult; Bacteria; Biology; Cells (Biology); Chlamydia; Chlamydia infections; Chlamydia Infections - diagnosis; Chlamydia Infections - microbiology; Chlamydia trachomatis; Chlamydia trachomatis - genetics; Clinics; Computed tomography; Corporate sponsorship; Cost analysis; Diagnostic systems; Disease transmission; Female; Health aspects; Health risks; Health services; Humans; Infections; Infectious diseases; Laboratories; Medical tests; Medicine; Neisseria gonorrhoeae; Nucleic Acid Amplification Techniques - methods; Pay-per-view television; Performance evaluation; Point-of-Care Systems - standards; Predictive Value of Tests; Public health; Reagent Strips; Sensitivity; Sensitivity analysis; Sensitivity and Specificity; Sexually transmitted disease prevention; Sexually transmitted diseases; Sexually Transmitted Diseases - diagnosis; Sexually Transmitted Diseases - microbiology; STD; Suriname; Trends; Vaginal Smears; Womens health; Young Adult; Suriname; Netherlands
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0032122

In general, point-of-care (POC) tests for Chlamydia trachomatis (Ct) show disappointing test performance, especially disappointing sensitivity results. However, one study sponsored by the manufacturer (Diagnostics for the Real World) reported over 80% sensitivity with their Chlamydia Rapid Test (CRT). We evaluated the performance of this CRT in a non-manufacturer-sponsored trial. Between July 2009 and February 2010, we included samples from 912 women in both high- and low-risk clinics for sexually transmitted infections (STIs) in Paramaribo, Suriname. Sensitivity, specificity, positive- and negative predictive values (PPV and NPV) for CRT compared to NAAT (Aptima, Gen-Probe) were determined. Quantitative Ct load and human cell load were determined in all CRT and/or NAAT positive samples. CRT compared to NAAT showed a sensitivity and specificity of 41.2% (95% CI, 31.9%-50.9%) and 96.4% (95% CI, 95.0%-97.5%), respectively. PPV and NPV were 59.2% (95% CI, 47.5%-70.1%) and 92.9% (95% CI, 91.0%-94.5%), respectively. Quantitative Ct bacterial load was 73 times higher in NAAT-positive/CRT-positive samples compared to NAAT-positive/CRT-negative samples (p<0.001). Human cell load did not differ between true-positive and false-negative CRT results (p = 0.835). Sensitivity of CRT in samples with low Ct load was 12.5% (95% CI, 5.2%-24.2%) and in samples with high Ct load 73.5% (95% CI, 59.9%-84.4%). The sensitivity of CRT for detecting urogenital Ct in this non-manufacturer-sponsored study did not meet the expectations as described previously. The CRT missed samples with a low Ct load. Improved POC are needed as meaningful diagnostic to reduce the disease burden of Ct.