ABSTRACT
This study demonstrates that the clinical sensitivity, specificity, and reproducibility of the novel cobas human papillomavirus (HPV) test on the cobas 6800 system for high-risk HPV types fulfills the criteria for use in population-based cervical screening. The criteria were formulated by an international consortium, using the cobas 4800 HPV test as a validated reference assay. The cobas HPV test detected over 98% of histologically confirmed cervical intraepithelial neoplasia grade 2+ (CIN2+) lesions in women age 30 years or older, with a specificity of 98.9% compared with the reference cobas 4800 test. Both the intra- and interlaboratory agreement for the cobas HPV test were 98%. The clinical performance of the cobas HPV test is comparable to those of longitudinally validated HPV assays and fulfills the criteria for its use in primary cervical screening.
Subject(s)
Early Detection of Cancer/methods , Molecular Diagnostic Techniques/methods , Papillomaviridae/classification , Papillomaviridae/isolation & purification , Papillomavirus Infections/diagnosis , Uterine Cervical Dysplasia/diagnosis , Uterine Cervical Neoplasms/diagnosis , Adult , Female , Humans , Longitudinal Studies , Middle Aged , Papillomaviridae/genetics , Papillomavirus Infections/virology , Reproducibility of Results , Sensitivity and SpecificityABSTRACT
Objectives: To examine the comparative stochasticity profile of six commercial SARS-CoV-2 nucleic acid amplification tests (NAATs) and how this may affect retesting paradigms. Methods: Commercial quality control (QC) material was serially diluted in viral transport media to create a panel covering 10-10,000 copies/ml. The panel was tested across six commercial NAATs. A subset of high cycle threshold results was retested on a rapid PCR assay to simulate retesting protocols commonly used to discriminate false positives. Results: Performance beyond the LOD differed among assays, with three types of stochasticity profiles observed. The ability of the rapid PCR assay to reproduce a true weak positive specimen was restricted to its own stochastic performance at the corresponding viral concentration. Conclusion: Stochastic performance of various NAATs overlap across low viral concentrations and affect retesting outcomes. Relying on retesting alone to discriminate false positives risk missing true positives even when a more sensitive assay is deployed for confirmatory testing.
ABSTRACT
In 2018, there were an estimated 570,000 new cases of cervical cancer globally, with most of them occurring in women who either had no access to cervical screening, or had not participated in screening in regions where programs are available. Where programs are in place, a major barrier for women across many cultures has been the requirement to undergo a speculum examination. With the emergence of HPV-based primary screening, the option of self-collection (where the woman takes the sample from the vagina herself) may overcome this barrier, given that such samples when tested using a PCR-based HPV assay have similar sensitivity for the detection of cervical pre-cancers as practitioner-collected cervical specimens. Other advantages of HPV-based screening using self-collection, beyond the increase in acceptability to women, include scalability, efficiency, and high negative predictive value, allowing for long intervals between negative tests. Self-collection will be a key strategy for the successful scale up of cervical screening programs globally in response to the WHO call for all countries to work towards the elimination of cervical cancer as a public health problem. This review will examine self-collection for HPV-based cervical screening including the collection devices, assays and possible routine laboratory processes considering how they can be utilized in cervical screening programs.