Chronic diarrhoeal illness in US Peace Corps volunteers.

Chronic diarrhoea of unknown aetiology is increasingly recognized as a problem in international travellers, and has been reported in US Peace Corps volunteers. In December 1987, we surveyed all Peace Corps medical officers to determine the magnitude of this problem and obtain preliminary data on potential risk factors. A rate of nine cases of chronic diarrhoea per 1000 volunteers per year was reported by medical officers representing 4607 volunteers in 43 countries. The highest rates were reported in Haiti, where one-third of the volunteers reportedly developed chronic diarrhoea during their two-year stay, as well as in Central and West Africa and Nepal. Volunteers were reported to drink unpasteurized milk routinely in eight (42%) of 19 countries with greater than or equal to one case of chronic diarrhoea during the previous two years, but in only two (11%) of 19 countries where none of the volunteers had chronic diarrhoea (odds ratio = 6.2, p = 0.06, Fisher exact test). Intensive prospective studies in areas of high incidence are needed to define this syndrome further.