Preliminary insights regarding water as a transmission vehicle for and in Tigray, Ethiopia.

This study was part of a larger One Health project with the aim of investigating the epidemiology of and infections among humans and animals in rural areas of Tigray, Ethiopia. Here we report on the contamination of different drinking water sources in four locations of this region with these oocysts and cysts; 19 samples were from unprotected surface water sources and 18 from protected water sources. A modified version of the standard ISO 15553 technique was used for analysis, and cysts were detected in 6 of the samples (16%) and in two (5%), with one of these samples containing both parasites. The number of cysts in positive samples ranged from 3 to 22 cysts per 10 L sample, and the number of oocysts in positive samples ranged from 1 to 3 oocysts per 10 L sample. Low numbers of parasites and absence of nuclei, as indicated by the absence of DAPI staining, precluded further molecular analyses. We found no association with contamination and whether the water source was protected or not, but there was an association with location, with one location more likely to have a contaminated sample than the others. These preliminary data suggest that this location should be in focus for further parts of this study.