[Conjunctival bacilloscopy in leprosy diagnosis and follow-up].

PURPOSE: To identify Mycobacterium leprae in ocular conjunctivae and evaluate conjunctival bacilloscopy as leprosy diagnosis and follow-up test.

METHODS: We used the superior tarsal conjunctiva scraping technique in 52 newly diagnosed leprosy patients between July and September 2004 at the "Oculistas Associados de Brasília", in Brasília, DF, Brazil, and compared the conjunctival bacilloscopy with skin bacilloscopy.

RESULTS: Both the conjunctival bacilloscopy index (CBI) and skin bacilloscopy index (SBI) showed correlation since Pearson's r and Cohen kappa measure of agreement were respectively 76.3% (p<0.01) and 0.615 (p<0.01). Pearson chi-square also evidenced the correlation (p<0.01). Comparison of CBI and SBI (17 cases of positive CBI out of 26 SBI) gives a sensitivity of 65.4% (CI95% - 0.519-0.690); 25 cases of positive CBI out of 26 cases of negative SBI give a specificity of 96.2% (CI95% - 0.826-0.998); positive predictive value of 94.4%; negative predictive value of 73.5%, and accuracy of 80.8%. Likelihood ratio was 17. Mean time to eliminate the bacilli from conjunctiva was 5 months (CI95% - 3.57-6.43).

CONCLUSION: We suggest the use of conjunctival bacilloscopy in addition with skin bacilloscopy to confirm leprosy diagnosis. Conjunctival bacilloscopy may also be useful for treatment follow-up in leprosy.