Bhutan (2010) and Rwanda (2011) were the first countries in Asia and Africa to introduce national, primarily school-based, human papillomavirus (HPV) vaccination programmes. These target 12 year-old girls and initially included catch-up campaigns (13-18 year-olds in Bhutan and ninth school grade in Rwanda). In 2013, to obtain the earliest indicators of vaccine effectiveness, we performed two school-based HPV urine surveys; 973 female students (median age: 19 years, 5th-95th percentile: 18-22) were recruited in Bhutan and 912 (19 years,[17][18][19][20] in Rwanda. Participants self-collected a first-void urine sample using a validated protocol. HPV prevalence was obtained using two PCR assays that differ in sensitivity and type spectrum, namely GP51/GP61 and E7-MPG. 92% students in Bhutan and 43% in Rwanda reported to have been vaccinated (median vaccination age 5 16, 5th-95th: 14-18). HPV positivity in urine was significantly associated with sexual activity measures. In Rwanda, HPV6/11/16/18 prevalence was lower in vaccinated than in unvaccinated students (prevalence ratio, PR 5 0.12, 95% confidence interval, CI: 0.03-0.51 by GP51/GP61, and 0.45, CI: 0.23-0.90 by E7-MPG). For E7-MPG, cross-protection against 10 high-risk types phylogenetically related to HPV16 or 18 was of borderline significance (PR 5 0.68; 95% CI: 0.45-1.01). In Bhutan, HPV6/11/16/18 prevalence by GP51/GP61 was lower in vaccinated than in unvaccinated students but CIs were broad. In conclusion, our study supports the feasibility of urine surveys to monitor HPV vaccination and quantifies the effectiveness of the quadrivalent vaccine in women vaccinated after pre-adolescence. Future similar surveys should detect increases in vaccine effectiveness if vaccination of 12 year-olds continues.National, primarily school-based, HPV vaccination programmes were started in Bhutan in 2010 1 and in Rwanda in 2011. 2 HPV6/11/16/18 vaccine coverage was reported as >90% in the target groups of both countries. In Bhutan, this target was 12 year-old girls, with a one-round catch-up campaign in 2010 for 13-18 year-old girls. In Rwanda, the target was girls attending primary school grade 6 (aged 12 years) in 2011, with three-rounds of catch-up vaccination in 2011, 2012 and 2013 for secondary school grade 3 (aged 15 years). Efforts were also made to reach out-of-school girls in health centres in both countries. 1,2 These two early-introducing countries provide the first opportunity to evaluate the impact of HPV vaccination in low/medium income countries (LMIC), of which the most feasible and informative measure in the medium-term (5-15 years) is type-specific HPV infection in sentinel populations of adolescent girls and young women. To this end, the International Agency for Research on Cancer (IARC) has developed long-term monitoring studies with the ministries of health of the two countries, beginning with two cervical cell surveys in the country capitals (Thimphu and Kigali) to establish robust baseline estimates of HPV prevalence among unvaccinated sexually activ...
f GP5؉/6؉-based PCR followed by reverse line blot hybridization (GP5؉/6؉RLB) and multiplex type-specific PCR (E7-MPG) are two human papillomavirus (HPV) genotyping methodologies widely applied in epidemiological research. We investigated their relative analytical performance in 4,662 samples derived from five studies in Bhutan, Rwanda, and Mongolia coordinated by the International Agency for Research on Cancer (IARC). A total of 630 samples were positive by E7-MPG only (13.5%), 24 were positive by GP5؉/6؉RLB only (0.5%), and 1,014 were positive (21.8%) by both methods. Ratios of HPV type-specific positivity of the two tests (E7-MPG:GP5؉/6؉RLB ratio) were calculated among 1,668 samples that were HPV positive by one or both tests. E7-MPG:GP5؉/6؉RLB ratios were >1 for all types and highly reproducible across populations and sample types. E7-MPG:GP5؉/6؉RLB ratios were highest for HPV53 (7.5) and HPV68 (7.1). HPV16 (1.6) and HPV18 (1.7) had lower than average E7-MPG:GP5؉/6؉RLB ratios. Among E7-MPG positive infections, median mean fluorescence intensity (MFI; a semiquantitative measure of viral load) tended to be higher among samples positive for the same virus type by GP5؉/6؉RLB than for those negative for the same type by GP5؉/6؉RLB. Exceptions, however, included HPV53, -59, and -82, for which the chances of being undetected by GP5؉/6؉RLB appeared to be MFI independent. Furthermore, the probability of detecting an additional type by E7-MPG was higher when another type was already detected by GP5؉/6؉RLB, suggesting the existence of masking effects due to competition for GP5؉/6؉ PCR primers. In conclusion, this analysis is not an evaluation of clinical performance but may inform choices for HPV genotyping methods in epidemiological studies, when the relative merits and dangers of sensitivity versus specificity for individual types should be considered, as well as the potential to unmask nonvaccine types following HPV vaccination. Human papillomavirus (HPV) DNA detection and genotyping are central to molecular epidemiological studies of HPV natural history and carcinogenicity, as well as to evaluations of HPV vaccine efficacy and effectiveness. There are various PCR-based methods for HPV DNA detection and genotyping, of which one of the most commonly used in epidemiological studies is the GP5ϩ/6ϩ primer set targeting conserved sequences within the L1 gene, thus allowing detection of a broad range of mucosal HPV types in a single reaction. The HPV genotype can subsequently be identified by various methods, of which the most commonly used is hybridization with type-specific probes using a reverse line blot hybridization assay (henceforth referred to as GP5ϩ/6ϩRLB) (1). The GP5/6 primers were initially developed to maximize detection of HPV6, and were subsequently elongated at their 3= ends to generate the primers GP5ϩ and GP6ϩ to improve the detection of a broader range of HPV types (3). This methodology has been widely validated against clinical outcomes in large population-based screening programs and shows favorable c...
BackgroundA pilot screening campaign in Rwanda, based on careHPV-testing followed by visual inspection with acetic acid triage (careHPV+VIA triage), was evaluated against other WHO-recommended screening options, namely HPV screen-and-treat and VIA screen-and-treat.Methods764 women aged 30-69 underwent at visit 1: i) VIA, and cervical cell collection for ii) careHPV in Rwanda, and iii) liquid-based cytology and GP5+/6+ HR-HPV PCR in The Netherlands. All 177 women positive by VIA, careHPV and/or PCR were recalled, of whom 84% attended. At visit 2, VIA was again used to triage screen-positive women for treatment and to obtain biopsies from all women either from visible lesions or at 12 o’clock of the squamocolumnar junction. Cross-sectional screening indices were estimated primarily against histological high-grade squamous intraepithelial lesions or worse (hHSIL+), after imputation of missing histology data, based on 1-visit or 2-visit approaches.ResultsIn a 1-visit screen-and-treat approach, VIA had sensitivity and specificity of 41% and 96%, respectively, versus 71% and 88% for careHPV, and 88% and 86% for PCR. In a 2-visit approach (in which hHSIL+ imputed among women without visit 2 were considered untreated) careHPV sensitivity dropped to 59% due to loss of 13% of hHSIL+. For careHPV+VIA triage, sensitivity dropped further to 35%, as another 24% of hHSIL+ were triaged to no treatment.ConclusionsCareHPV was not as sensitive as gold-standard PCR, but detected considerably more hHSIL+ than VIA. However, due to careHPV-positive hHSIL+ women being lost to follow-up and/or triaged to no treatment, 2-visit careHPV+VIA triage did not perform better than VIA screen-and-treat.Electronic supplementary materialThe online version of this article (10.1186/s12905-018-0549-5) contains supplementary material, which is available to authorized users.
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