Prevalence of Human Papillomavirus and Estimation of Human Papillomavirus Vaccine Effectiveness in Thimphu, Bhutan, in 2011-2012 and 2018: A Cross-sectional Study

BACKGROUND: Bhutan implemented a national program for human papillomavirus (HPV) vaccination in 2010 involving girls aged 12 to 18 years and achieving nearly 90% coverage. OBJECTIVE: To estimate HPV vaccine effectiveness in a city in Bhutan. DESIGN: 2 cross-sectional surveys, 2011-2012 and 2018. SETTING: 2 hospitals in Thimphu, capital of Bhutan. PARTICIPANTS: Sexually active women aged 17 to 29 years: 1445 participants from the baseline survey and 1595 from the repeated survey. INTERVENTION: National HPV vaccination program. MEASUREMENTS: HPV was assessed in cervical cell samples by using general primer GP5+/GP6+-mediated polymerase chain reaction. Human papillomavirus types were stratified as vaccine types (HPV6/11/16/18) and nonvaccine types. Age- and sexual behavior-adjusted overall, total, and indirect (herd immunity) vaccine effectiveness (VE) was computed as (1 - HPV prevalence ratio) for HPV among all women and among unvaccinated women. RESULTS: Between the 2 surveys, the prevalence of HPV vaccine types decreased from 8.3% to 1.4%, whereas the prevalence of nonvaccine types increased from 25.8% to 31.4%. The overall and indirect adjusted VE against vaccine-targeted HPV types was 88% (95% CI, 80% to 92%) and 78% (CI, 61% to 88%), respectively. Among women younger than 27 years, who were targeted by the vaccination program, the overall and indirect adjusted VE was 93% (CI, 87% to 97%) and 88% (CI, 69% to 95%), respectively. No impact on nonvaccine HPV types was detectable. LIMITATION: Hospital-based recruitment; self-reported vaccination status. CONCLUSION: In Bhutan, the prevalence of vaccine-targeted HPV types has decreased sharply, providing the first evidence of the effectiveness of a high-coverage national HPV vaccination program in a lower-middle-income country. PRIMARY FUNDING SOURCE: Bill & Melinda Gates Foundation

Experiences of Becoming and Being Academic Women in Bhutan

No research has previously been carried out on women in Bhutan becoming and being academics. Although there is a strong legal environment for gender equality generally, in practice there are socio-cultural interpretations of Buddhist teachings that have negatively impacted upon women. We used interviews following Giddens' structuration theory where signification is given prominence. In this exploratory study, eight research assistants (RAs) interviewed two junior and two senior female academics each in English. Each RA transcribed the data which were analyzed with the assistance of NVivo. The major inspiration for the younger women to become academics was their teachers. Parents, family and partners were also seen as important support. Social structures and practices, supported by certain Buddhist interpretations, were dominant in affecting these academic women's role. Teaching load was apparently shared equally but research and service roles were strongly gendered. Discriminatory practices were identified including unequal access to learning opportunities (including overseas), in research and in access to power (information). Two thirds of the interviewed women had practical suggestions about how to improve gender equity though very few mentioned affirmative action strategies common in the West. The vast majority of the 30 women interviewed indicated that they were happy with their work as academics. Policy, practice and research implications are identified

Evaluation of cytology versus human papillomavirus-based cervical cancer screening algorithms in Bhutan

To evaluate the performance of existing versus alternative cervical cancer screening protocols in Bhutan, cervical exfoliated cells were collected for cytology and high-risk human papillomavirus (HR-HPV) testing among 1,048 women aged 30-69 years. Conventional smears were prepared and read locally. HR-HPV was tested by GP5+/6+ polymerase chain reaction, followed by genotyping and human DNA methylation analysis among HR-HPV-positives, in Europe. Test positivity was 7.5% for ASCUS or worse (ASCUS+) cytology and 14.0% for HR-HPV. All women with ASCUS+ and/or HR-HPV positivity (n=192) were recalled for colposcopy, among whom a total of 29 cases of histologically confirmed cervical intraepithelial neoplasia grade 2 or worse (CIN2+) were identified. An additional 7 CIN2+ cases were imputed among women without colposcopy. Corrected sensitivities for CIN2+ and CIN3+ were 61% and 74% for ASCUS+, 86% and 96% for HR-HPV, and 47% and 70% for ASCUS+ triage of HR-HPV. Specificity varied from 88% for HR-HPV up to 98% for ASCUS+ triage of HR-HPV, similarly for CIN2+ and CIN3+. Among HR-HPV-positive women with biopsies, methylation analysis offered similar discrimination of CIN2/3 and cervical cancer as ASCUS+, and better than HPV16/18 genotyping alone, but sample sizes were limited. In conclusion, the performance of cytology in Bhutan is in the mid-range of that reported in other screening settings. HR-HPV testing has the potential to improve detection of CIN2+, albeit with a higher referral rate for colposcopy. Cytological triage of HR-HPV-positives (performed in the absence of knowledge of HR-HPV status) reduced referral but missed more than one third of CIN2+

Human papillomavirus testing on self-collected samples to detect high-grade cervical lesions in rural Bhutan: The REACH-Bhutan study

BACKGROUND: "REACH-Bhutan" aimed to evaluate the feasibility and clinical performance of a community-based screening program for cervical cancer in rural Bhutan using self-collected samples for high-risk human papillomavirus (HR-HPV) testing. METHODS: In April/May 2016, 2590 women aged 30-60 years were screened across rural Bhutan by providing a self-collected sample for careHPV testing. All careHPV-positive women, plus a random sample of careHPV-negative women, were recalled for colposcopy and biopsy. Self-samples also underwent GP5+/6+ polymerase chain reaction (PCR)-based HR-HPV DNA detection and genotyping. Cross-sectional screening indices were estimated against histological high-grade squamous intraepithelial lesions or worse (hHSIL+), including imputation of hHSIL+ in women without colposcopy. RESULTS: HR-HPV positivity was 10.2% by careHPV and 14.8% by GP5+/6+ PCR. Twenty-two cases of hHSIL+ were histologically diagnosed, including one invasive cancer; an additional 7 hHSIL+ were imputed in women without colposcopy. HR-HPV testing by GP5+/6+ showed higher sensitivity for hHSIL+ (89.7%, 95% CI 72.6-97.8) than careHPV (75.9%, 95% CI 56.5-89.7). Negative predictive value was also slightly higher for GP5+/6+ (99.9%, 95% CI 99.6-100) than careHPV (99.7%, 95% CI 99.4-99.9). Specificity, however, was lower for GP5+/6+ (86.1%, 95% CI 84.6-87.4) than careHPV (90.6%, 95% CI 89.4-91.7), as was positive predictive value (6.9%, 95% CI 4.5-9.9 vs. 8.5%, 95% CI 5.4-12.6). Of 377 HR-HPV-positive women by GP5+/6+, 173 (45.9%) were careHPV-positive, including 54.7% HPV16-positive and 30.2% HPV18-positive women. CONCLUSIONS: The final REACH-Bhutan results show that screening for cervical cancer with self-collection of samples and HR-HPV testing, in addition to our previous report of achieving high participation, can also perform well to detect women with hHSIL+

Impact of Human Papillomavirus Vaccination, Rwanda and Bhutan

Rwanda and Bhutan, 2 low- and middle-income countries, implemented primarily school-based national human papillomavirus (HPV) vaccination in 2011 (Rwanda) and 2010 (Bhutan). We estimated vaccination effectiveness through urine-based HPV prevalence surveys in schools in 2013-2014 and 2017. In Rwanda, 912 participants from baseline surveys and 1,087 from repeat surveys were included, and in Bhutan, 973 participants from baseline surveys and 909 from repeat surveys were included. The overall effectiveness against vaccine-targeted HPV types (i.e., HPV-6/11/16/18) was 78% (95% CI 51%-90%) in Rwanda, and 88% (6%-99%) in Bhutan and against other α-9 types was 58% (21-78) in Rwanda and 63% (27-82) in Bhutan. No effect against other HPV types was detectable. Prevalence of vaccine-targeted HPV types decreased significantly, as well as that of other α-9 types, suggesting cross-protection. These findings provide direct evidence from low- and middle-income countries of the marked effectiveness of high-coverage school-based, national HPV vaccination programs

Comparison of Two Widely Used Human Papillomavirus Detection and Genotyping Methods, GP5+/6+-Based PCR Followed by Reverse Line Blot Hybridization and Multiplex Type-Specific E7-Based PCR

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