The epidemiology of reactions and nerve damage

The ALERT MDT Field Evaluation Study (AMFES) in Ethiopia, which was begun in 1988, involves the follow-up of 594 new patients for as long as 10 years after completion of treatment, including 6-monthly assessments of nerve function. In contrast to similar studies in India and Bangladesh, the Ethiopian cohort presented late, had a high rate of disability at diagnosis (55%), a high rate of multibacillary disease (51%) and a high rate of subsequent neuropathy (43%). Preliminary findings include the following. One-third of the patients never exhibited nerve damage. True acute neuropathy has a very good prognosis when treated with a standard course of steroids; full recovery was observed in 88% of nerves. Chronic and recurrent neuropathy have a worse prognosis; these problems need to be identified early and managed appropriately, employing either new steroid regimens or new drugs. The risk factors identified in this study include, for neuropathy, older age, delay of diagnosis, thickened nerves at diagnosis, and reversal reactions. Risk factors for chronic or recurrent neuropathy include classification, impairment at diagnosis, and reversal and ENL reactions. Those factors associated with a poor outcome include impairment at diagnosis, and chronic or recurrent neuropathy. Various problems faced in research in the area of leprosy reactions and neuropathy are discussed, as are the priorities for research in the future.