Evaluation of a low-cost liquid-based Pap test in rural El Salvador: a split-sample study

J Low Genit Tract Dis. 2014 Apr;18(2):151-5. doi: 10.1097/LGT.0b013e31829aa052.


Objective: We sought to test the diagnostic efficacy of a low-cost, liquid-based cervical cytology that could be implemented in low-resource settings.

Materials and methods: A prospective, split-sample Pap study was performed in 595 women attending a cervical cancer screening clinic in rural El Salvador. Collected cervical samples were used to make a conventional Pap (cell sample directly to glass slide), whereas residual material was used to make the liquid-based sample using the ClearPrep method. Selected samples were tested from the residual sample of the liquid-based collection for the presence of high-risk Human papillomaviruses.

Results: Of 595 patients, 570 were interpreted with the same diagnosis between the 2 methods (95.8% agreement). There were comparable numbers of unsatisfactory cases; however, ClearPrep significantly increased detection of low-grade squamous intraepithelial lesions and decreased the diagnoses of atypical squamous cells of undetermined significance. ClearPrep identified an equivalent number of high-grade squamous intraepithelial lesion cases as the conventional Pap. High-risk human papillomavirus was identified in all cases of high-grade squamous intraepithelial lesion, adenocarcinoma in situ, and cancer as well as in 78% of low-grade squamous intraepithelial lesions out of the residual fluid of the ClearPrep vials.

Conclusions: The low-cost ClearPrep Pap test demonstrated equivalent detection of squamous intraepithelial lesions when compared with the conventional Pap smear and demonstrated the potential for ancillary molecular testing. The test seems a viable option for implementation in low-resource settings.

Publication types

  • Evaluation Study

MeSH terms

  • Adult
  • Carcinoma, Squamous Cell / diagnosis*
  • Cervical Intraepithelial Neoplasia / diagnosis*
  • Early Detection of Cancer / economics
  • Early Detection of Cancer / methods*
  • El Salvador
  • Female
  • Humans
  • Middle Aged
  • Papanicolaou Test / economics
  • Papanicolaou Test / methods*
  • Papillomaviridae / isolation & purification
  • Prospective Studies
  • Rural Population
  • Sensitivity and Specificity