Different but overlapping populations of Strongyloides stercoralis in dogs and humans-Dogs as a possible source for zoonotic strongyloidiasis

A Survey of Intestinal Parasites of Domestic Dogs in Central Queensland

Australia has a very high rate of dog ownership, which in some circumstances may lead to exposure to zoonotic parasitic diseases from those companion animals. Domestic dog faecal samples (n = 300) were collected from public spaces and private property in the greater Rockhampton (Central Queensland) region and tested for intestinal helminths and protozoa by direct microscopy, two flotation methods and a modified acid-fast stain for cryptosporidia. Intestinal parasites detected included hookworms (25%), Cystoisospora ohioensis complex (9%), Blastocystis hominis (3%), Giardia duodenalis (3%), Spirometra erinacei (1%) and Toxocara canis (1%), Sarcocystis spp. (2%), Cryptosporidium spp. (2%) and Cystoisospora canis (1%). One infection each with Trichuris vulpis, Dipylidium caninum and a protozoa belonging to the Entamoeba histolytica complex were identified. Sheather's sucrose centrifugal flotation was more sensitive than saturated salt passive flotation, but no single test detected all cases of parasitic infection identified. The test methodologies employed are poor at recovering larva of Strongyloides stercoralis, Aleurostrongylus abstrussis and eggs of cestodes such as Echinococcus granulosis, so the potential presence of these parasites in Central Queensland domestic dogs cannot be excluded by this survey alone.

Soil-Transmitted Helminths in Tropical Australia and Asia

Soil-transmitted helminths (STH) infect 2 billion people worldwide including significant numbers in South-East Asia (SEA). In Australia, STH are of less concern; however, indigenous communities are endemic for STH, including Strongyloides stercoralis, as well as for serious clinical infections due to other helminths such as Toxocara spp. The zoonotic hookworm Ancylostoma ceylanicum is also present in Australia and SEA, and may contribute to human infections particularly among pet owners. High human immigration rates to Australia from SEA, which is highly endemic for STH Strongyloides and Toxocara, has resulted in a high prevalence of these helminthic infections in immigrant communities, particularly since such individuals are not screened for worm infections upon entry. In this review, we consider the current state of STH infections in Australia and SEA.