Comparison of human papillomavirus-based cervical cancer screening strategies in Tanzania among women with and without HIV.

Cervical cancer is the most common female cancer in Eastern Africa, and the World Health Organization (WHO) recommends human papillomavirus (HPV)-based screening as a key element to eliminate the disease. In this cross-sectional study from Tanzania, we compared nine HPV-based cervical cancer screening strategies, including HPV testing at standard cut-off; HPV testing at increased viral load cut-offs; HPV testing with partial/extended genotyping, and HPV testing with visual inspection with acetic acid (VIA). We pooled data collected during 2008 to 2009 and 2015 to 2017 from 6851 women aged 25 to 65. Cervical cytology samples were HPV tested with Hybrid Capture 2, and HPV positive samples were genotyped with INNO-LiPA Extra II. Human immunodeficiency virus (HIV) testing and VIA were done according to local standards. We calculated sensitivity, specificity, positive and negative predictive value of screening strategies, with high-grade cytological lesions as reference, separately for women with and without HIV. HPV testing at standard cut-off (1.0 relative light units [RLU]) had highest sensitivity (HIV+: 97.8%; HIV-: 91.5%), but moderate specificity (HIV+: 68.1%; HIV-: 85.7%). Increasing the cut-off for HPV positivity to higher viral loads (5.0/10.0 RLU) increased specificity (HIV+: 74.2%-76.5%; HIV-: 89.5%-91.2%), with modest sensitivity reductions (HIV+: 91.3%-95.7%; HIV-: 83.5%-87.8%). Limiting test positivity to HPV types 16/18/31/33/35/45/52/58 improved specificity while maintaining high sensitivity (HIV+: 90.2%; HIV-: 81.1%). Triage with VIA and/or partial genotyping for HPV16/18 or HPV16/18/45 had low sensitivities (≤65%). In conclusion, HPV testing alone, or HPV testing with extended genotyping or increased viral load cut-offs, may improve cervical cancer screening in Sub-Saharan Africa.

Factors associated with a cervical high-grade lesion on cytology or a positive visual inspection with acetic acid among more than 3300 Tanzanian women.

OBJECTIVES: Cervical cancer screening by visual inspection with acetic acid (VIA) is a widely used alternative to cytology in developing countries. This study aimed to evaluate risk factors associated with a positive VIA test and with cervical high-grade lesions on cytology. METHODS: We conducted a large cross-sectional study among 3339 women from urban and rural Tanzania. Study participants were interviewed about socio-demographic, reproductive and lifestyle factors. Blood samples were tested for HIV, and a gynaecological examination was performed. Human papillomavirus (HPV) status was determined by Hybrid Capture 2, and HPV genotyping was done using the LiPA Extra test. We used multivariable logistic regression to estimate adjusted odds ratios (ORs) and confidence intervals (CIs). RESULTS: The strongest risk factors for VIA positivity were positivity to HIV (OR = 3.48; 95% CI: 2.34-5.17) or to high-risk HPV (HrHPV) (OR = 1.97; 95% CI: 1.37-2.85). HrHPV was by far the strongest predictor of high-grade cytology (OR = 110.1; 95% CI: 50.4-240.4), while there was no significant association with HIV in the multivariable analysis (OR = 1.27; 95% CI: 0.78-2.08). After adjustment for HrHPV, HIV and age, the risk of high-grade cytology also increased with increasing age, number of births and low body mass index (BMI), while high BMI decreased the risk of VIA positivity. CONCLUSIONS: Infection with HrHPV is a major risk factor for high-grade cytology, while VIA positivity is associated with HIV and to a lesser extent with HrHPV.