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Point-of-care tests using enzyme detection to diagnose Chlamydia trachomatis infection do not work. But when they fail in clinical trials, they reappear under different names
  1. Julius Schachter
  1. Correspondence to Dr Julius Schachter, Department of Laboratory Medicine, University of California, San Francisco, CA 94110, USA; julius.schachter{at}ucsf.edu

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While scanning De Baetselier and colleagues’ article evaluating an enzymatic Chlamydia trachomatis (CT) point-of-care assay (POC), I was struck by a feeling of déjà vu.1 They found the BioChekSwab Rapid Test performed poorly, missing all nine infections detected by PCR. This reminded me of a paper by Moi in 2007 reporting the very poor performance of a POC for CT, HandiLab-C.2 Reading further, I realised this was not coincidence. The two assays seemed to use the same technology.

BioChekSwab Rapid Test seems to be an updated HandiLab-C test that was widely available about 10 years ago. Sold in at least 17 countries, it had a CE mark with approval for POC professional use and over-the-counter sale (meaning self-test).Web1 In 2006, workers at the National Chlamydia Screening Programme, concerned about use of the test in England (it was for sale in pharmacies and supermarkets), asked me to speak about chlamydia diagnostics at their annual meeting. My talk emphasised nucleic acid amplification tests (NAATs) for CT diagnosis and warned about using HandiLab-C because the technology was not new and there were no reproducible clinical data supporting its use despite the company’s claims.

Within a year, the Moi paper appeared stating that the HandiLab-C assay was not what it claimed. Subsequent trials confirmed that, finding sensitivity of only 12.5% and 19.4% in two clinics in the Philippines, and 12% in an STD clinic in the Netherlands.3 ,4

I was familiar with the HandiLab-C technology because in the 1980s Diversified Diagnostics Inc. (DDI) had a similar assay ‘MicroZyme the Easy Test’, claiming sensitivity of 96% and specificity of 97.9% for CT detection.Web2 It was described as the only totally biochemical test system; easy to perform; only 10 min to get a result. The procedure was collect …

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