Point-of-care tests using enzyme detection to diagnoseChlamydia trachomatisinfection do not work. But when they fail in clinical trials, they reappear under different names

Infection by Chlamydia trachomatis (CT) is the most prevalent sexually transmitted infection (STI) world wide. The most frequently used diagnostic test for CT is a nucleic acid amplification test (NAAT), which is highly sensitive and specific. To further shorten time delay until diagnosis has been made, in order to prevent CT spread, the use of point-of-care (POC) tests may be the way forward. The diagnostic performance of three POC tests, Handilab-C, Biorapid CHLAMYDIA Ag test and QuickVue Chlamydia test, was evaluated and compared with NAAT. All women, above the age of 16 years, attending for a consultation at an STI clinic between September 2007 and April 2008, were asked to participate. Women were asked to complete a short questionnaire and to collect six self-taken vaginal swabs (SVS). SVS 2 was used for NAAT and SVS 3 to 5 were randomised for the different POC tests. SVS 1 and 6 were used for determining quantitative CT load to validate the use of successive SVS. All POC tests were performed without knowledge of NAAT results. NAAT was used as the 'gold standard'. 772 women were included. CT prevalence was 11% in our population. Sensitivities of the Biorapid CHLAMYDIA Ag test, QuickVue Chlamydia and Handilab-C test were 17%, 27% and 12%, respectively. The evaluated POC tests, owing to their very low sensitivities, are not ready for widespread use. These results underline the need for good-quality assurance of POC tests, especially in view of the increased availability of these tests on the internet.

To evaluate the performance of a Conformitée Européenne (CE)-marked home test for Chlamydia trachomatis (CT) that is available over the internet.

Chlamydia trachomatis is a common sexually transmitted infection in young women. Available point-of-care (POC) diagnostic tests perform poorly, but development of new devices can be costly and time consuming. We explored the feasibility (user friendliness) and test characteristics (sensitivity and specificity) of a new prototype device to detect Chlamydia in adolescent women by using small numbers of subjects and rapid communication with the manufacturer. We compared cervical POC test results to the gold standard (cervical nucleic acid amplification testing). We also assessed the accuracy of the POC test on self-collected vaginal swabs by comparing results to cervical nucleic acid amplification test and to the cervical POC test. We frequently reviewed user experience and test results with the manufacturer. The results showed the feasibility and accuracy of the device. Feasibility--initial device malfunctions were identified and corrected. This device would be easy to use in a nonclinical setting, as it is self-contained and the color change for some specimens was dramatic and immediate. Accuracy--initial prototypes demonstrated low sensitivities (38%) for vaginal and cervical swabs. After feedback, the company developed new prototypes with improved sensitivity (80%). However, the increased sensitivity was accompanied by a high percentage of indeterminate results and false positives that lowered specificity.