Ninety-seven cases of skin ulcers due to Mycobacterium ulcerans were seen at two mission hospitals in the Lower Congo between 1961 and 1968. There were more cases than expected among those 5.0 to 14.0 years old and fewer than expected in those 15 years old or older. No secular changes were noted during the 7-year study period. There was no association of the disease with nationality, nor was there significant familial clustering of cases. The geographic distribution of cases appeared to approximate the population distribution, and there was no temporal relation between geographically clustered cases. The anatomic distribution of skin ulcers differed from that found in Uganda in that there were more lesions on the arms. Comparison of the anatomic distribution of ulcers with the distribution of total skin area among the body parts showed an excess of lesions on the arms and a deficit on the head-neck-trunk. There was no association between climatic variables and the date of onset or presumed date of infection of all cases or of cases by age, sex, or by anatomic distribution of lesions.
Present address: Department of Pathology, Peter Bent Brigham Hospital, Boston, Massachusetts 02115.