Leprosy trends in northern Thailand: 1951-1990.

Data of new, previously untreated leprosy patients from 6 northern provinces of Thailand, diagnosed at McKean Rehabilitation Center, Chiang Mai and associated clinics between 1951 and 1990 were analysed. The following trends were found: 1) Decreasing numbers of new, previously untreated patients. 2) Increasing average age of patients at onset and presentation of disease. 3) Decreasing duration between onset and presentation. 4) Increasing percentage of patients presenting within the first year of symptoms. 5) Increasing percentage of paucibacillary cases. 6) Decreasing percentage of patients presenting with deformity. These trends are a reflection of those seen for the whole of Thailand and indicate that leprosy control is being effective. Patients are presenting at an earlier stage than before, with consequent reduction in disability and infectivity. Better usage of chemotherapy since 1976 has helped to reduce the transmission of bacilli from person to person, combined with effective health education activities which have dispelled some wrong ideas about leprosy and encouraged patients to seek help early in the course of the disease. Additional factors related to public health and living standards have also contributed.

Hepatitis B antigen and antibody in patients with leprosy: a study of three resettlement villages in Thailand.

It remains uncertain whether the cellular immune abnormalities of patients with lepromatous leprosy interfere with resolution of hepatitis B virus (HBV) infections. To investigate this question in an area coendemic for the two diseases, we determined the prevalence of hepatitis B surface antigen (HBsAg) and antibody (anti-HBs) in: 1) 204 leprosy patients living in three leprosy resettlement villages; 2) 198 contacts living in the same villages; and 3) 44 newly diagnosed leprosy patients in Thailand. Within the villages, the prevalence of HBsAg positivity was inversely related to age, tended to be more frequent in patients with tuberculoid than lepromatous leprosy, and was similar after age adjustment among persons with and without leprosy. The prevalence of HBV markers found in newly diagnosed patients was similar to that in the villagers. We conclude that extensive HBV transmission had occurred in the resettlement villages and that the natural history of HBV infection was similar in persons with, whether tuberculoid or lepromatous, and without leprosy.