Diagnostic accuracy of self-collected vaginal samples for HPV DNA detection in women from South India

To assess the efficacy of self-collected vaginal samples compared with physician-collected cervical samples for the detection of HPVDNA.

A hospital-based cross-sectional study was carried out among patients with newly diagnosed cervical cancer attending the Gynecologic Oncology Division, Department of Obstetrics and Gynecology and Radiation Oncology Department at Government Medical College, Kozhikode, Kerala between March 2017 and April 2019. Consenting patients collected their vaginal samples, followed by cervical sample collection by the clinician. The paired samples were transported at 4-8 °C to the laboratory. Amplification of LCR/E6/E7 regions of the HPV genome was done by polymerase chain reaction (PCR). The agreement level between paired samples was assessed by the Kappa index.

Among the 114 cervical cancer patients enrolled in the present cross-sectional study, the prevalence of HPV DNA was 78.1% (95% confidence interval [CI] 69.2%-85%) in cervical samples and 77.2% in vaginal samples (95% CI 68.7%-83.9%). The overall agreement between the two sampling methods was 93.9% and the kappa value was 0.82 (P<0.001). The sensitivity of HPV detection using vaginal samples was 98.9% (95% CI 93.9%-99.8%) and the specificity was 100% (95% CI 86.7%-100%) with cervical sampling as the gold standard. By Kappa index, an almost perfect agreement for HPV DNA detection between self-collected and physician-collected samples was observed.

Self-collection of vaginal samples ensures equity of cervical cancer screening in low-income countries such as India.