Previously, our earlier work demonstrated the use of structural equation modeling to evaluate the effectiveness of point-of-use biosand filters (BSF) to reduce the occurrence of diarrhea in rural Guatemala. While prior research in laboratory and field locations has documented the effectiveness of BSF to remove agents of diarrhea, experience in field sites suggests that multiple local factors greatly influence the occurrence of diarrhea. In addition to the BSF, this study evaluated household education level, socioeconomic status, water source and handling, and sanitation as factors impacting the occurrence of diarrhea for households in the village of Enseado do Aritapera in Para, Brazil. Of the 18 correlations examined, 16 were negatively correlated, and the strongest correlation was between the utilization of an ‘improved’ water source and the reduction of the occurrence of diarrhea within the household. While proper operation and maintenance of the BSF was found to have a negative correlation with the occurrence of diarrhea, it was not the most influential factor. This result supports the prior findings from our earlier work suggesting that more research is needed to evaluate which intervention should be prioritized for maximum return on investment with aid distribution.