Rheumatoid arthritis in a tribal Xhosa population in the Transkei, Southern Africa.

An epidemiological survey of rheumatoid arthritis (RA) was undertaken in a tribal Xhosa community in the Transkei of Southern Africa. 577 respondents aged 18 and over were examined clinically and of these, 549 were investigated radiologically and 482 serologically. The presence of RA was then assessed by means of a modification of the Rome criteria, as used in previous comparable surveys. The prevalence of 'definite' RA in the adults aged 18 and over in this population was 0-68% and of 'probable' RA, 1-6%. The combined 'definite' and 'probable' prevalence was 2-2%. The relatively low prevalence of RA in this population is consistent with the results of other surveys in unsophisticated African Negro populations in West Africa and South Africa, and contrasts with the higher prevalence encountered in an urbanized South African Negro community and in populations in Europe and the USA.