RESUMEN
A study of diarrheal diseases associated with Cyclospora cayetanensis was conducted in Nepal and Lao PDR. A total of 2083 samples were included in this study. Samples in Nepal were collected from October 1999 to August 2002 whereas samples in Lao PDR were collected from February 2002 to June 2003. C. cayetanensis was detected by direct microscopy using ultraviolet and differential interference contrast microscopy. The overall positive rate in Nepal was 9.2% (128/ 1397). A higher positive rate was observed in children aged 10 years and under (11.1%) and was lowest in the age group of 51-60 years (3.1%). A significantly higher positive rate was observed in the summer (rainy season) (12.6%) with the lowest prevalence in the spring (dry season) (1.8%) (p < 0.05). The positive rate was closely associated with rainfall (ml/month). Interestingly, only one of the total 686 samples (0.1%) from Lao PDR was found to be positive for Cyclospora oocysts.