Abstract C116: High-risk HPV screening and typing shows high co-infection rate and potential for low vaccine coverage in a low- and middle-income country

Abstract Introduction. Cervical cancer is almost always a result of infection with a high risk human papillomavirus (hrHPV) of which there are 14 different types. This type of cancer is prevalent in low- and middle-income countries (LMICs) where screening programs for pre- or invasive cervical cancer by Pap test or visual inspection with ascetic acid are limited in scope as is local expertise in evaluating Pap smears. Since 2006, a HPV vaccine protecting against hrHPV types 16 and 18 has been recommended by the WHO, and through the GAVI Alliance, is provided to some fractions of populations in more than 70 countries. A newer and more expensive vaccine protects again 9 types of HPV A broader spectrum 9-valent vaccine released in 2014 protects against HPV types 6, 11, 16, 18, 31, 33, 45, 52, and 58. Preventing cervical cancer by vaccination against HPV is considered to be a promising strategy. Materials and Methods. In three separate studies, we implemented molecular screening for hrHPV from cervical swab specimens, providing access to pre-cancer testing for women from several regions of Honduras, which is ranked the poorest country in the northern hemisphere. We screened 2,645 women from two rural regions and an urban region of Honduras. In the final study of 1725 Honduran factory workers, we substituted a large-capacity rice cooker for a standard laboratory hotplate to accelerate laboratory throughput for DNA extraction. A DNA-based multi-color melt curve analysis by PCR followed, and we were able to rapidly screen for all 14 hrHPV types. Results. Across all three studies, there was an average hrHPV positivity prevalence of 22%. The most common types of hrHPV found in each study were as follows: Study 1 hrHPV types 16, 31, 58, 59, and 68; Study 2 hrHPV types 16, 39, 52, 58, and 68; and Study 3 were hrHPV types 16, 35, 58, 63, and 64 were the most common. Among those infected with a hrHPV type, 18% had co-infections with multiple hrHPV types. Based on these results, the vast majority of infected women would not have been protected by the divalent HPV vaccine and a significant proportion of women would still not be protected by the multivalent vaccine, which does not cover the hrHPV types 35, 39, 52, 59, 63, 64, 88 found in these samples. Conclusions. Cervical cancer remains a prevalent and deadly disease in LMICs. Our studies examining the prevalence of hrHPV types in several different regions of Honduras identified high prevalence rates of viral types not targeted by commercially available vaccines. These findings suggest that vaccination programs alone should not be considered complete coverage against cervical cancer-causing high-risk HPV, and that further location-specific testing of cervical tissue for hrHPV typing is warranted. Citation Format: Aaron E Atkinson, Carlos Alberto Matute Mandujano, Suyapa Bejarano, Linda S Kennedy, Gregory J Tsongalis. High-risk HPV screening and typing shows high co-infection rate and potential for low vaccine coverage in a low- and middle-income country [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr C116.