Dorothy A. Machalek

Older women testing positive forHPV16/18 on cervical screening and risk of high‐grade cervical abnormality

AbstractIn Australia's HPV‐based cervical screening program, we previously showed that risk of histological high‐grade abnormality at 1 year post screening decreased with age in women with oncogenic HPV. In this study, we followed 878 HPV16/18 positive women aged 55 years and over for up to 3 years post screening test, to determine the proportion with histological high‐grade abnormality (HGA, incorporating high‐grade squamous intraepithelial abnormality (HSIL), adenocarcinoma in situ (AIS), squamous cell carcinoma (SCC) and adenocarcinoma) and to correlate risk of HGA with liquid‐based cytology result and with prior screening history. HGA was detected in 7.8% at 1 year and 10.0% at 3 years, with no significant difference (P = .136), despite the number of women with follow‐up information significantly increasing from 82.9% to 91.0% (P < .0001). The proportion of HPV16/18 positive women with HGA at 3 years was highest in those with an HSIL cytology result (79.0%) and lowest in those with negative cytology (6.2%). Women with an adequate screening history had fewer HGA than such women with inadequate prior screening (6.6% vs 16.0%,P = .001) or with a history of an abnormality (6.6% vs 14.4%,P = .001). HPV16/18 infection in women over 55 years may have a different natural history from that in younger women, in whom HGA are more common after HPV16/18 detection. In HPV‐based cervical screening programs, management algorithms for screen‐detected abnormalities based on risk stratification should include factors such as age, screening history and index cytology result, so that women receive appropriate investigation and follow‐up.

Impact of one and two human papillomavirus (HPV) vaccine doses on community-level HPV prevalence in South African adolescent girls: study protocol and rationale for a pragmatic before–after design

Introduction Vaccines against human papillomavirus (HPV) are the key to controlling cervical cancer in low/middle-income countries (LMICs) where incidence is highest, but there have been limited data from these settings on programme impact on HPV prevalence, and none in a population with endemic HIV infection. Furthermore, for many LMICs, the currently recommended two-dose schedule is difficult to deliver at scale, so there is mounting interest in a single-dose schedule. Methods and analysis The H uman Papillomavirus O ne and Two-Dose P opulation E ffectiveness Study is a hybrid impact evaluation of the national South African HPV vaccination programme, which has targeted grade 4 girls aged at least 9 years in public schools with two doses of vaccine since 2014, and a single-dose vaccine ‘catch-up’ programme delivered in one district in 2019. Impacts of both schedules on the prevalence of type-specific HPV infection will be measured using repeat cross-sectional surveys in adolescent girls and young women aged 17–18 years recruited at primary healthcare clinics in the four provinces. A baseline survey in 2019 measured HPV prevalence in the cohort who were ineligible for vaccination because they were already above the target age or grade under either the national programme or the single-dose programme in the selected district. HPV prevalence surveys are repeated in 2021 in the selected district, and in 2023 in all four provinces. We will calculate prevalence ratios to compare the prevalence of HPV types 16 and 18 in the single-dose (2021) and two-dose (2023) cohorts, with the vaccine-ineligible (2019) cohort. Ethics and dissemination The project was approved by the University of the Witwatersrand Human Research Ethics Committee (HREC #181005), and the University of New South Wales HREC (#181-005). Findings will be disseminated through peer-reviewed journals, scientific meetings, reports and community forums.