Detection of and in soil and water samples in the Quindío River basin, Colombia.

Two zoonotic protozoan pathogens, and , are important causes of waterborne infections in the Quindío region in Colombia. No previous data exist on how contamination occurs at the source for drinking water consumed by the human population in this region. Our aim was to describe the frequency of and DNA in 11 sampling points during a five-month period in water and adjacent soil at the Quindío River basin (Andean region in the central western part of Colombia). The study employed nested PCR for , using the B1 gene as the amplification target, and single-round PCR for assemblage A and assemblage B, amplifying the gene, followed by DNA sequencing. In 50 soil samples, 28% (14/50) were positive for For , distribution was in equal parts for assemblage A (8%; 4/50) and assemblage B (8%, 4/50). Genotyping of sequences showed two soil samples with type I strain, another two samples of soil with type III strain, but most samples were of unidentified strains. In water samples, was detected in 9.1% (5/55), assemblage A in 34.5% (19/55), and assemblage B in 12.7% (7/55). DNA positivity was associated with lower soil temperature ( = 0.0239). Presence of and was evidenced in soil and water samples in the Quindío River basin, indicating soil as the potential source of contamination for the river that it is destined for human consumption. Monitoring these protozoa in drinking water is necessary to prevent public health risks in human populations.