澳大利亚昆士兰詹姆斯·库克大学的Dermot S. Hurly博士对2014年的两项针对沙眼衣原体测试的POCT(不包含BioChekSwab)进行回顾发现,存在同样的高假阴性和假阳性率。
在看完本份报告后,他总结道,“我看不到该项检测在任何情况下是有益的,它应该从市场中被移除。”
Point-of-Care Rapid Assay Lacks Sensitivity for Chlamydia Trachomatis
NEW YORK (Reuters Health) - The BioChekSwab rapid test for Chlamydia trachomatis showed a sensitivity of 0% in a study of 137 women in Rwanda.
"The assay received the CE label and is therefore sold as a reliable assay," Dr. Irith De Baetselier from Institute of Tropical Medicine in Antwerp, Belgium, told Reuters Health by email. "Unfortunately, we showed with this small study that the assay doesn't work at all in our setting."
The BioChekSwab uses an enzyme substrate that, when hydrolyzed by a C. trachomatis-specific peptide hydrolase, produces a fluorescence that can be read colorimetrically by adding a color-developing agent, Dr. De Baetselier and colleagues explain in Sexually Transmitted Infections, online October 16. The test is also marketed as SELFCheck Chlamydia by EnZtek Diagnostics Incorporated in Rio Vista, California.
The researchers assessed the sensitivity and specificity of this assay in the setting of the Ring Plus clinical trial in Rwanda, which included 137 nonpregnant women between 18 and 35 years old.
None of the nine samples positive for C. trachomatis by the gold-standard nucleic acid amplification testing (NAAT) was detected by the BioChekSwab Rapid Assay, yielding a sensitivity of 0%.
The rapid assay also generated four false-positive results, for a specificity of 96.9%, according to the report.
The rapid assay has a positive predictive value of 0% and a negative predictive value of 93.2%. Eight additional samples became positive after the assay cut-off reading time of 2 minutes, but none of these were positive by NAAT.
"If the assay would increase in sensitivity/specificity, the test would be surely useful in any setting, but in particular in low resource settings with no access to molecular testing," Dr. De Baetselier said. "Unfortunately, this isn't the case yet."
Dr. De Baetselier added, "Labels or certifications such as ISO-13485:2003 and the well-known CE label give a false representation of the quality of the assays. For people who are in need, want to get tested anonymously and search the internet, such a CE label gives a false feeling of reliability and quality. The WHO has a prequalification of diagnostics program for in vitro diagnostics for high-burden diseases such as HIV, which is very extensive, but as they mention they cannot assess all assays . . . However, I still believe that assays that are available over the internet should at least been reviewed independently."
Robert Herd, chief technology officer for EnZtek Diagnostics, told Reuters Health by email, "To date we have over 1,700 patients studied, and verified with PCR, from five additional sites. These studies were conducted by PhD and MD professionals, worldwide. We have no idea of the caliber of the testing personnel in Rwanda, although we understand they were not at the Doctor level, and had not conducted studies such as the BioChekSwab (BCS) study."
Herd also cited several pieces of correspondence between the authors and EnZtek that, he suggested, call into question the quality of the study.
Herd noted, "We have not sold the Point Of Care BCS for Chlamydia for almost two years. This is due to the prevalence of PCR testing throughout the world. Also, we have sold the chlamydia test into third world countries for over 20 years, and millions of tests in a bottle format. This is the first negative response we have received over that time."
"At this time," Herd concluded, "we are conducting a legal review of all correspondence, study information, data, credentials, and other issues regarding this contradictory issue."
Dr. Dermot S. Hurly from James Cook University in Queensland, Australia, reviewed two C. trachomatis point-of-care tests (not including BioChekSwab) in 2014 and found them similarly wanting due to high false-negative and false-positive rates.
After reading the current report, he concluded, "I cannot see any situation where this test would be useful. It should be removed from the market."