THE OCCURRENCE OF REACTIONS AND IMPAIRMENTS IN LEPROSY - EXPERIENCE IN THE LEPROSY CONTROL PROGRAM OF 3 PROVINCES IN NORTHEASTERN THAILAND,1978-1995 - I - OVERVIEW OF THE STUDY

Aim: This paper is the first in a series of three reports on the occur rence of reactions and impairments in leprosy in Thailand. This first paper gives a general overview about the methodology of the study, som e epidemiological observations, delay in detection, multidrug therapy (MDT) completion rates and relapses. The other two papers report on: I T. Reactions and III. Neural and Other impairments. This study was car ried out from 1987 until 1995 in three neighboring provinces in northe astern Thailand. Study design: A population-based, prospective cohort study. Study population: All 640 newly diagnosed leprosy patients in t he three provinces, registered between October 1987 and September 1990 , were included [420 paucibacillary (PB) and 220 multibacillary (MB)]. This group was followed up (actively and passively) until the end of 1995. Methods: Patients were found by active and passive case finding. All new, untreated leprosy patients from the area were enrolled and s tarted on the World Health Organization (WHO) MDT (WHO/MDT) regimen. A vertical control service was run by specialized leprosy workers. Duri ng treatment the patients received their monthly doses at home. During surveillance the patients were followed up once a year by a special t eam. Patients were questioned about delay in detection. Treatment comp letion rates were calculated. The occurrence of reactions and neural a nd other impairments at the beginning of, during and after treatment w as ascertained. After treatment, the occurrence of late reactions and relapses was recorded. Results: A higher frequency of leprosy was foun d among the male patients, especially in the MB group. However, in the PB group a higher female/male ratio was found in the age group 55 yea rs and older. There was an increase in the detection rate from the you ngest age group to the age group 55 years and older, which showed the highest detection rate. Treatment completion rates were high, 95% in b oth in the PB and MB treatment groups. About 50% of the new cases repo rted a delay between onset and registration of 1 year or more. By 1995 , 93% of the original patient group was still available for follow up. By the end of 1995, 8 PB and 2 MB relapses were recorded.