Sensitivity, specificity, inclusivity and exclusivity of the updated Aptima Combo 2 assay, which provides detection coverage of the new diagnostic-escape Chlamydia trachomatis variantsShow others and affiliations
2020 (English)In: BMC Infectious Diseases, E-ISSN 1471-2334, Vol. 20, no 1, article id 419Article in journal (Refereed) Published
Abstract [en]
Background: Four new variants of Chlamydia trachomatis (nvCTs), detected in several countries, cause false-negative or equivocal results using the Aptima Combo 2 assay (AC2; Hologic). We evaluated the clinical sensitivity and specificity, as well as the analytical inclusivity and exclusivity of the updated AC2 for the detection of CT and Neisseria gonorrhoeae (NG) on the automated Panther system (Hologic).
Methods: We examined 1004 clinical AC2 samples and 225 analytical samples spiked with phenotypically and/or genetically diverse NG and CT strains, and other potentially cross-reacting microbial species. The clinical AC2 samples included CT wild type (WT)-positive (n = 488), all four described AC2 diagnostic-escape nvCTs (n = 170), NG-positive (n = 214), and CT/NG-negative (n = 202) specimens.
Results: All nvCT-positive samples (100%) and 486 (99.6%) of the CT WT-positive samples were positive in the updated AC2. All NG-positive, CT/NG-negative, Trichomonas vaginalis (TV)-positive, bacterial vaginosis-positive, andCandida-positive AC2 specimens gave correct results. The clinical sensitivity and specificity of the updated AC2 for CT detection was 99.7 and 100%, respectively, and for NG detection was 100% for both. Examining spiked samples, the analytical inclusivity and exclusivity were 100%, i.e., in clinically relevant concentrations of spiked microbe.
Conclusions: The updated AC2, including two CT targets and one NG target, showed a high sensitivity, specificity, inclusivity and exclusivity for the detection of CT WT, nvCTs, and NG. The updated AC2 on the fully automated Panther system offers a simple, rapid, high-throughput, sensitive, and specific diagnosis of CT and NG, which can easily be combined with detection of Mycoplasma genitalium and TV.
Place, publisher, year, edition, pages
BioMed Central, 2020. Vol. 20, no 1, article id 419
Keywords [en]
Finnish new variant, Chlamydia trachomatis, Aptima combo 2, 23S rRNA, Validation, Surveillance
National Category
Infectious Medicine
Identifiers
URN: urn:nbn:se:oru:diva-84850DOI: 10.1186/s12879-020-05148-7ISI: 000542951400002PubMedID: 32546213Scopus ID: 2-s2.0-85086686721OAI: oai:DiVA.org:oru-84850DiVA, id: diva2:1458632
Note
Funding Agencies:
Örebro County Council Research Committee
Foundation for Medical Research at Örebro University Hospital, Örebro, Sweden
2020-08-172020-08-172024-01-17Bibliographically approved