Background

It has been speculated that the large populations of free-roaming dogs within Aboriginal communities of central Australia harbour zoonotic parasites, and contribute to high incidence of parasitic infections among local children.

Aims

To examine the prevalence of zoonotic gastrointestinal parasites infecting dogs and children, in three Aboriginal communities of Australia's Western Desert.

Methods

Faecal samples from dogs and children (<5 years) were screened for parasites by microscopy and cultured for Salmonella and Campylobacter. A nested-PCR technique was employed to genotype Giardia into human assemblages (A/B) and canine-specific assemblages (C/D). Dog owners were interviewed to identify risks for parasitic infection.

Results

Gastrointestinal parasites were detected in both dogs (61.9%, n=77) and children (63.6%, n=11). Giardia being the most prevalent (dogs 44.4%; children 45.5%). Hymenolepis spp. (9.1%) and Isospora belli (9.1%) were also detected in children. Other parasites recovered from dogs were: Sarcocystis spp. (9.5%), Dipylidium caninum (3.2%), Taenia spp. (4.8%) Isospora canis (1.6%), Salmonella (9.1%). Giardia assemblages A (36.4%) and B (9.1%) were identified in children; assemblages C (33.3%) and D (15.9%) were only identified in dogs. Two dogs were infected with human-type assemblages A and B.

Conclusion

Dogs and children were commonly infected with gastrointestinal parasites. Giardia and Hymenolepis infection in children was indicative of poor living conditions and inadequate hygiene. Dogs posed a zoonotic-risk due to inadequate faecal disposal; unrestricted roaming; consuming raw meat/offal; and access to sylvatic reservoirs. In such conditions, findings of genetically identical Giardia in dogs and children supports the role of dogs as a potential source of human infection.