Alarmingly poor performance in Chlamydia trachomatis point-of-care testing
Abstract number: P1886
van Dommelen L., van Tiel F.H., Ouburg S., Brouwers E.E., Terporten P.H., Savelkoul P., Morré S.A., Bruggeman C.A., Hoebe C.J.
Objectives: Infection by Chlamydia trachomatis (CT) is the most prevalent sexually transmitted disease (STD) worldwide. 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 could be the way forward. Three POC tests, Handilab-C, Biorapid CHLAMYDIA Ag test and QuickVue Chlamydia test, were evaluated regarding diagnostic performance in comparison with NAAT.
Methods: All women, above the age of 16 years old, consulting at an STD clinic between September 2007 and April 2008, were asked to participate. Women were asked to complete a short questionnaire and to collect 6 self-taken vaginal swabs (SVS). SVS 2 was used for NAAT and SVS 3 to 5 were randomized for the different POC tests. SVS 1 and 6 were used for determining quantitative CT load to validate the use of successively SVS. All POC tests were performed without knowledge of NAAT results. NAAT was used as the 'gold standard' for sensitivity. During the consultation, demographic data were collected and, if indicated, samples were collected for other STD diagnostics. A questionnaire was handed out to add more specific questions concerning CT testing methods.
Results: 772 women were included. The median age of first sexual contact was 16 (range 636 years). The median lifetime number of sexual partners was 9 and almost half of these contacts were considered as unsafe sexual contact. During the last six months, the median number of newly acquired sexual partners was 3. 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.
Conclusions: Our results show poorer laboratory performance of the different POC tests than has previously been described and underline the need for good quality assurance of POC tests, especially in view of the Internet era. Although excellent guidelines on CT POC test evaluation exist, these guidelines are regularly ignored, and thus tighter regulations are urgently needed to prevent unrestrained marketing. In our opinion, the CT POC tests evaluated in our study are not ready for widespread use.
|Session name:||Abstracts 20th European Congress of Clinical Microbiology and Infectious Diseases|
|Location:||Vienna, Austria, 10 - 13 April 2010|
|Back to top|