Prevalence of stroke - A door-to-door survey in rural Bolivia

Background and Purpose-We carried out a door-to-door survey in rural areas of the Cordillera Province, Santa Cruz Department, Bolivia. A cluster sample of 10 124 inhabitants was selected, and 9955 subjects were screened. The aim was to determine the prevalence of the most common neurological diseases (epilepsy, stroke, parkinsonism, and peripheral neuropathy) in this population. Methods-We used a modified. version of the World Health Organization screening instrument. On screening we found that: 1130 subjects tested positive, and 1027 underwent a complete neurological examination. According to the World Health Organization guidelines, we defined stroke as rapidly developing clinical signs of focal (or global) disturbance of cerebral functions, lasting more than 24 hours or leading to death, with no apparent cause other than that of vascular origin. We considered only first stroke and excluded a possible stroke. Results-We found 16 subjects (cases) who had experienced 1 complete stroke on prevalent day (November 1, 1994). The crude prevalence of stroke was 174/100 000 (322/100 000 age-adjusted to the world standard population) and 663/100 000 in subjects aged greater than or equal to 35 years. Prevalence was >2-fold higher in men than in women (247/100 000 and 99/100 000, respectively) and increased rapidly with age. Seven cases were hospitalized and received specific treatment. Conclusions-Our crude prevalence is lower compared with rates from developed countries, probably because of a high case fatality rate. Our findings are comparable with those reported from other surveys carried out in rural developing countries.