Hanseníase: Resumos Hanseniasis Abstracts Bacteriologia, Imunologia Bacteriology, Immunology

The fluorescent leprosy antibody absorption (FLA-ABS) test was improved by absorbing the serum with suspensions of BCG and M. vaccae. This test was positive in nearly 100% of patients with bacteriologically positive forms of leprosy and in approximately 80% of tuberculoid cases but negative in 18 patients with pulmonary tuberculosis, in 50 healthy noncontacts, and in 136 of 138 non-leprosy patients in general hospitals. The 2 positive sera of the last group showed a cross-reaction with M. smegmatis, but M. smegmatis were incapable of absorbing the positive reactions to M. leprae. Therefore, the serological sensitivity and the specificity of the FLA-ABS test proved to be satisfactory for detecting subclinical infections with M. leprae. The test was positive in 57 of 62 (91.9%) household contacts of leprosy patients. The mean antibody titers were higher in infants, in grandchildren and children of patients, and in contacts of lepromatous patients than in comparison groups. Among 39 of these household contacts who were tested with lepromin, 7 showed doubtful Mitsuda reactions but were positive in the FLA-ABS test. Such cases should be carefully observed since they are apparently infected with M. leprae but have not developed cell mediated immunity. Among 15,000 school children in a leprosy endemic area, 173 children were tested with FLA-ABS because they had a palpable auricular nerve or a suspicious skin eruption. A positive reaction was found in 109 (63%) of them. The percentage of positivity was slightly higher in the villages than in an urban area, corresponding to a higher leprosy incidence rate in the former. The FLA-ABS test results showed no cor-