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

Aim: This is the second paper in a series of three papers on the occur rence of reactions and impairments in leprosy in Thailand, and focuses on the prevalence and incidence of reactions, including silent neurop athy Study design: A population-based, prospective cohort study. Study population: All 640 newly diagnosed and registered leprosy patients i n three neighboring provinces in northeastern Thailand registered betw een October 1987 and September 1990 were included [420 paucibacillary (PB) and 220 multibacillary (MB)], This group was followed up (activel y and passively) until the end of 1995, Methods: Clinical data and dat a on the sensibility and motor function of the eyes, hands and feet we re obtained when appropriate, The occurrence of reactions, including s ilent neuropathy, at the beginning of, during and after treatment was ascertained. During surveillance mild late reactions were also recorde d.Results: Severe reversal reactions (RR) at the start of and during t reatment were seen in 2.6% [confidence interval (CI) 1.1-4.1] of the P B and 29% (CI 23-35) of the MB patients, In the PB group the majority (82%) of severe RR were found at the start of treatment. In the MB gro up 35% of the severe RR were found at the start of treatment and anoth er 59% during the first year of treatment. It is shown that there is a statistically highly significant increasing proportion of patients wi th severe RR starting from tuberculoid and going toward border-line le promatous, The incidence rate of severe RR during treatment was 1.4 (C I 0.46-4.5) per 100 person-years at risk (PYAR) for PB patients and 12 (CI 9.0-16) per 100 PYAR for MB patients, Late (mild and severe) RR w ere seen in 2.7% of the PB and 9% of the MB patients (35% of these rea ctions being considered severe), Late reactions were mainly seen in bo rderline tuberculoid (PB group) and in borderline lepromatous patients . Recent silent neuropathies were seen at first examination and during treatment in 1.4% of the PB and 4.1% of the MB patients, During surve illance only a few silent neuropathies were seen. If all severe RR, se vere erythema nodosum leprosum and silent neuropathies at the start of , during and after treatment were added together, then 53% of the bord erline lepromatous and 42% of the lepromatous patients had or develope d one or another serious complication in need of steroid treatment.