Prevalence of Parkinson's disease in a rural village of coastal Ecuador. A two-phase door-to-door survey.

Occupational exposure to toxic solvents increases the odds for having Parkinson's disease (PD). We performed a door-to-door survey to assess PD prevalence in Atahualpa, a rural village of coastal Ecuador where more than 50 % of men work as carpenters, being in contact with toxic solvents under poor safety settings. During Phase I, rural doctors screened all Atahualpa residents aged ≥40 years with a questionnaire directed to identify those with PD. In Phase II, neurologists evaluated individuals who screened as suspected cases of PD, as well as a random sample of negative individuals to assess possible false negative cases. As a result, the census yielded 642 Atahualpa residents aged ≥40 years. An affirmative response to the questionnaire was obtained in seven persons. Neurological examination confirmed the diagnosis of PD in two of them (both carpenters). Examination of 14 non-suspected individuals disclosed no further PD patients. Prevalence of PD in Atahualpa residents aged ≥40 years was 312 per 100,000 which increased to 671 per 100,000 when only people aged ≥60 years was considered. Job-specific prevalence was 1,470 per 100,000 in carpenters. In conclusions, PD prevalence in Atahualpa is similar to that reported from other regions. However, we noted an increase in PD prevalence when only carpenters were considered. Unsafe occupational exposure to toxic substances may counterbalance the apparently lower risk of PD in the non-industrialized world.