Detection of Giardia duodenalis and Toxoplasma gondii in soil and water samples in the Quindío River basin, Colombia

• Published in: Food and waterborne parasitology Vol. 28; p. e00175
• Main Authors: Pinto-Duarte, Valeria Alejandra, Hérnandez-Arango, Natalia Marcela, Marin-Gallego, Benyi Juliana, Toloza-Beltrán, Paola Andrea, Lora-Suarez, Fabiana María, Gómez-Marín, Jorge Enrique
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Inc 01.09.2022; Elsevier
• Subjects: Colombia; Environmental monitoring; Giardia; Quindío; Soil; Toxoplasma; Water pollution; Waterborne diseases; Toxoplasma; Colombia; Waterborne diseases; Quindío; Soil; Giardia; Water pollution; Environmental monitoring
• ISSN: 2405-6766; 2405-6766
• DOI: 10.1016/j.fawpar.2022.e00175

Two zoonotic protozoan pathogens, Giardia duodenalis and Toxoplasma gondii, 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 G. duodenalis and T. gondii 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 T. gondii, using the B1 gene as the amplification target, and single-round PCR for G. duodenalis assemblage A and assemblage B, amplifying the gdh gene, followed by DNA sequencing. In 50 soil samples, 28% (14/50) were positive for T. gondii. For G. duodenalis, distribution was in equal parts for assemblage A (8%; 4/50) and assemblage B (8%, 4/50). Genotyping of T. gondii 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, T. gondii was detected in 9.1% (5/55), G. duodenalis assemblage A in 34.5% (19/55), and G. duodenalis assemblage B in 12.7% (7/55). T. gondii DNA positivity was associated with lower soil temperature (p = 0.0239). Presence of G. duodenalis and T. gondii 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. •55 water and 50 soil samples from Colombian Quindio river basin were studied.•Positive soil: 28% T. gondii, 8% G. intestinalis assemblages A and B.•Positive water: 9.1% T. gondii, 4.5% G. intestinalis assemblages A and B.•Soil and water are potential sources of contamination for river water that is destined for human consumption.