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Gregory Greene, Beatriz E Munoz, Harran Mkocha, Abdul Majeed, Sheila K West, Shannath L Merbs; Screening for Trichiasis Using a Novel System in Tanzania. Invest. Ophthalmol. Vis. Sci. 2014;55(13):5452.
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Simple surgical intervention advocated by the WHO’s SAFE strategy can alleviate trachomatous trichiasis (TT) and prevent subsequent blindness. However, a large surgical backlog of TT cases exists, with Tanzania alone requiring an estimated 15,000 surgeries per year to achieve the 2020 WHO goal of TT elimination. A significant proportion of cases has been found not to present to surgery and remains unconnected to the health system. To increase identification and referral of these individuals, we have developed a novel screening tool and training program for Community Treatment Assistants (CTAs) and tested this intervention during Mass Drug Administration (MDA) in Kongwa District, a trachoma hyper-endemic area of central Tanzania.
36 communities were randomized on a 1:1 basis to either intervention or usual training for TT recognition. CTAs in intervention villages received an additional afternoon of training and a TT identification card consisting of a scripted interview, TT examination instructions, and visual aids. CTAs screened MDA participants 15 years and older for TT and recorded all cases found during MDA over ten months on a referral list. Following MDA, a master grader conducted a follow-up survey to confirm positive screening results and to detect potentially missed cases. During follow-up, re-examinations were conducted for all individuals screened positive as well as samples of 100 individuals screened negative and 50 individuals that did not present for initial screening during MDA in each village.
5,256 individuals were screened during MDA. Based on the follow-up survey, CTAs assigned to additional training and use of the TT identification card correctly identified three times more TT cases than did CTAs assigned to usual training (49 compared to 9, p<0.05). CTAs assigned to intervention also screened positive 258 (11.7%) individuals who were determined not to have TT. The sensitivity for the intervention is 60%, and specificity is 90%, as compared to usual training with an estimated sensitivity of 21% and specificity of 99%.
Additional training and use of the TT identification card resulted in significantly higher numbers of TT cases recognized and referred as well as an improved sensitivity. However, these results indicate that referred cases may still require verification following initial screening with this tool.
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