Description
Introduction:
In Kenya, cervical cancer is the leading cause of cancer deaths, causing up to 3,200 deaths in 2020. The World Health Organization has recommended human papilloma virus (HPV) DNA testing as the primary screening method for cervical cancer. The Ministry of Health, Kenya, is considering a near point of care test for HPV screening; GeneXpert is a potentially scalable screening platform. We present the accuracy of GeneXpert in detecting high-risk HPV, as part of the validation process by the National Oncology Reference Laboratory (NORL).
Methods:
We conducted a comparative study between the Aptima HPV assay (reference assay) and Cepheid Xpert HPV Assay (test assay). The study was conducted from March-August 2019, using cervical samples from women > 30 years old. We computed the sensitivity, specificity, positive and negative predictive values and kappa coefficient (<0: no agreement; 0-0.2: slight; 0.21-0.40: fair; 0.41-0.6: moderate; 0.61-0.8: substantial and 0.81-1: near perfect agreement). The confidence interval for each variable was calculated at 95% (95%CI) using a normal distribution.
Results:
Out of the 156 cervical samples analysed, 34 (21.8%) and 37(23.7%) tested positive for HPV (HPV16, 18-45 and others) by Gene expert HPV assay and Aptima assay respectively. Gene expert Qualitative assay Sensitivity was 91.9% (95%CI 78.1%- 98.3%). Xpert assay achieved a specificity of 100.0% (95%CI 96.9%-100.0%). Upon solving the assay discrepancies, there was 94% concordance of GeneXpert with the Aptima HPV assay. The PPV and NPV were 100.0% (95%CI 89.7%-100.0%) and 97.5% (95%CI 93.0%-99.5 %) respectively. The kappa value was 0.945 (95%CI 0.884 - 1.000)
Conclusion:
There was good agreement between both assays for HPV 16 and HPV 18-45 detection. Since GeneXpert offers simplicity of testing, flexibility with non-batching of individual samples, rapid turnaround time and a large footprint, it can support HPV testing scale-up in Kenya, to move towards cervical cancer elimination.
| Country | Kenya |
|---|---|
| Organization | Government of Kenya |
| Position | Head: NATIONAL ONCOLOGY REFERENCE LABORATORY |
| Received a Grant? | No |
