Evaluation of cervical visual inspection screening in Dar es Salaam, Tanzania

Objective: To evaluate the feasibility and performance of screening for cervical cancer using visual inspection with acetic acid (VIA) or with Lugol's iodine (VILI) in Dar es Salaam, Tanzania.

Methods: The accuracy of tests for detecting cervical intraepithelial neoplasia (CIN) was assessed in a cross-sectional study of 10378 women. All women who were screened underwent colposcopy, and biopsies were offered to those with abnormal colposcopy results.

Results: The positivity rates were 3.8% for VIA and 4.8% for VILI. The peak positivity rates for both visual tests were observed just after training or re-training and gradually declined thereafter. CIN 1 was diagnosed in 41 women, CIN 2-3 in 33 women, and invasive cancer in 200 women, showing high detection rates of invasive cancer. The sensitivity and specificity for the detection of CIN 2-3 lesions were 60.6% (95% confidence interval [CI], 42.1-77.1) and 98.2% (95% CI, 97.9-98.4), respectively, for VIA; and 93.9% (95% CI, 79.8-99.3) and 97.3% (95% CI, 97.0-97.6), respectively, for VILI. Two-thirds of the women detected with CIN 2-3 lesions were treated.

Conclusion: Both visual screening tests are useful and accurate, especially in low-income settings. Standardization of assessment of the visual inspection techniques, continual training and supervision, and quality control measures are important for successful visual screening programs.