THE OCCURRENCE OF REACTIONS AND IMPAIRMENTS IN LEPROSY - EXPERIENCE IN THE LEPROSY CONTROL PROGRAM OF 3 PROVINCES IN NORTHEASTERN THAILAND,1978-1995 - III - NEURAL AND OTHER IMPAIRMENTS

Aim: This the third paper in a series of three papers on the occurrenc e of reactions and impairments in leprosy in Thailand, and focuses on the prevalence and incidence of neural and other impairments in lepros y. Study design: A population-based, prospective cohort study. Study s ubjects: All 640 newly diagnosed and registered leprosy patients in th ree provinces of northeastern Thailand between October 1987 and Septem ber 1990 were included [420 paucibacillary (PB) and 220 multibacillary (MB)I. This group of patients was followed up until the end of 1995. Methods: Clinical data; data on the sensibility and motor function of eyes, hands and feet, and data on wounds and bone loss were obtained w here appropriate. The occurrence of neural and other impairments at fi rst examination, during treatment and during surveillance was ascertai ned. Results: The relationship between impairment prevalence (grades 2 of the combined PB and MB groups and grades 1 and 2 together of the c ombined PB and MB groups) and duration of disease (before diagnosis) w as found to be statistically significant. Increased delay in detection led to increased problems of impairments. Too many patients still dev elop new/additional impairments while on treatment and thereafter. The incidence rate of nerve function impairment (NFI) among patients with out impairments at first examination while on treatment was 1.7 [95% c onfidence interval (CI) 0.45-4.4] per 100 person-years at risk (PYAR) for the PB group and 12 (CI 8.4-17) per 100 PYAR for the MB group. Add itionally, 2% of the PB and 11% of the MB patients who already had imp airments at first examination developed new NFI while on treatment. Th e outcome, comparing the first examination with the last examination d uring/after surveillance changes in the voluntary muscle test (VMT), t he sensory test (ST), wound count and bone loss], indicated that of th e PB patients 3.7% improved, 3.7% got worse and 3.9% kept the same imp airment; of the MB patients 19% improved, 18% got worse and 2.9% kept the same impairment. During treatment most of the new/additional impai rments were due to new/increase in NFI; during surveillance slightly m ore than 50% were due to new/increase in NFI. Eighty-three percent of the MB patients without impairments at first examination who developed NFI during treatment improved (completely or partially) after receivi ng prednisolone. Only 62% of the MB patients with a grade 1 impairment at first examination and who developed a severe reaction or recent si lent neuropathy improved after receiving prednisolone. There is a need for an indicator to measure new/additional impairments while on treat ment and thereafter. It is proposed to measure changes in impairment b y measuring changes in VMT ST, wound count and bone loss.