[Comparison between various methods of pregnancy screening during a large-scale ivermectin treatment in Cameroon]

During a mass treatment with ivermectin which is contraindicated to pregnant women, authors made a screening for pregnancy by questioning 2,580 women from 15 to 45 years old. 1,409 of these women were also interrogated by a female physician assisted by a native matron to detect pregnant women. In 1,798 women, at least one immunological pregnancy test has been used in the field. A nine months follow-up was made to check answers. Women's knowledge led to a good appreciation of pregnancy as they correctly appreciated their pregnancy from the second month: specificity was good (98%) but sensitivity was moderate (71%). Conclusions made by gynecological team after detailed questionnaire were more sensitive (80%), but specificity decrease dramatically to 59%. Combinations of several items in the questionnaire showed no benefit. Sensitivity of the various immunological pregnancy tests tried was included in 70 to 90% and specificity was varying from 87 to 97%. Simple questioning of women was the most efficient method (efficiency value was 94% against 63% for interview and 92% for pregnancy tests). However, the use of this method induced the risk that about 29% of women have been treated although they were pregnant.