Kinetic changes of antibody to M. leprae and its relation with clinical disease.
A sero-epidemiological survey on 1,833 healthy residents was carried out in 6 villages of a leprosy high-endemic area in Wenshan and Guangnan counties, Yunnan Province. The part of the residents with initially antibody-positive as well as the part of residents with initially antibody-negative have been followed up for 3 consecutive years by serology and clinical examination for studying kinetic changes of antibody to M. leprae and its relation with clinical disease. The results showed that the rates of subclinical infection of leprosy in a high-endemic area are different from village to village, and the risk of developing clinical disease does not associate with subclinical infection rate. It correlates with the number of cured accumulative leprosy cases and active cases within the village. The authors consider that in leprosy high-endemic villages, especially those cropped up new multi-bacillary leprosy cases frequently in recent years, it may be helpful to use serology to detect early leprosy cases.