Performance evaluation of Sanity 2.0 system in detecting high risk Human papillomavirus in Uganda

Abstract

Aim: We aimed to evaluate the performance of the Sanity 2.0 system as a point-of-care screening test for high-risk Human papillomavirus (hr-HPV) using Cobas 4800 as the gold standard. Background: Cervical cancer is a leading cause of cancer deaths among women worldwide. Almost all sexually active individuals are exposed with one or more hr-HPV genotypes and persistent infection can induce pre or cancerous lesions. Methods :This study involved n=500 archived Cobas 4800 HPV screened samples. They were subjected to Sanity 2.0 to compare their performance and hr-HPVs diagnostic accuracy. STATA and R software were used for analysis and visualization respectively. Results: The median age of participants was 41 years (IQR 40-42). Of the 495 samples analyzed using Sanity 2.0 test of which 100 were cases and 395 were non-cases on the Cobas 4800 test, 133 (26.9) were positive, 270 (54.6) were negative and 92 (18.6) were invalid. Sanity showed more discriminatory power in genotype identification, 43/133 (32.33%) compared to Cobas 4800, 11/100 (11%). Genotypes 16 (12.03%), 18 (9.02%), 35 (8.27%) and 56 (7.52%) were the most frequent. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPP) of Sanity 2.0 were 88.76% (88.58 – 88.98), 84.92% (84.79 – 85.05), 88.76% (88.58 – 88.98) and 84.92% (84.79 – 85.05) respectively. Conclusion: Sanity 2.0 assay showed high NPV in detecting hr-HPVs. Despite itslow PPV, Sanity runs 4 samples per run hence its deployment as a point-of-care-test would reduce turnaround-time associated with Cobas 4800 batch processing in resource-limited settings. The high hr-HPV genotype discriminatory power of Sanity 2.0 in this study would have implications on current and future vaccines initiatives.