There is a dearth of knowledge regarding transmission of Cryptosporidium (C) and Giardia (G) species through water and water-related sources in Pakistan. To this end, we conducted a study to evaluate the prevalence of these parasites in different water bodies, soil, and mixed raw vegetables in Pakistan. Researchers collected 200 samples from each reservoir including municipal water, sewage water, canal water, raw vegetables, soil of public parks, and soil of grazing areas. Researchers amplified the 18S ribosomal RNA gene of parasites using newly designed genus-specific primers through polymerase chain reaction testing. The sequencing analysis revealed that the obtained sequences belonged to C parvum and G lamblia. Phylogenetic clustering and sequence analysis of C parvum showed that the C parvum Pak1 (OM540369) and C parvum Pak2 (OM540370) as well as C parvum Pak3 (OM510450) and C parvum Pak6 (OM510445) were closely similar to each other. In the case of G lamblia, all the sequences appeared in the same clade. The epidemiological data showed lower prevalence of C parvum (11.5%) in all reservoirs, compared with G lamblia (20.5%). Among different reservoirs, prevalence of Cryptosporidium and Giardia was observed in sewage water (C = 13%, G = 26.5%), municipal water (C = 10%, G = 35%), canal water (C = 9.5%, G = 18.5%), raw vegetables (C = 5.5%, G = 8%), soil of public parks (C = 13%, G = 14%), and soil of grazing areas (C = 18.5%, G = 21.5%). Among targeted risk factors, poor hygienic conditions significantly affected the prevalence of parasites in sewage water (C = 20%, G = 41.2%), municipal water (C = 14.7%, G = 48.8.5%), raw vegetables (C = 11.3%, G = 15.1%), and soil of public parks (C = 19.5%, G = 21.9%). Similarly, contamination with sewage waste significantly affected (P < .05) the prevalence of these parasites in municipal water (C = 13.6%, G = 41.1%), canal water (C = 13.3%, G = 25%), raw vegetables (C = 12.1%, G = 15.1%), and soil of public parks (C = 23.3%, G = 15%). Results of this study illustrated a high risk of parasitic zoonosis through water bodies, soil, and vegetables.
Keywords: Cryptosporidium parvum; Giardia lamblia; PCR; Surveillance; Water security.