Molecular surveillance detects the zoonotic nematode parasite Toxocara in soils from public spaces in a Minnesota community

Abstract

Toxocara canis and Toxocara cati are common nematode parasites of dogs and cats, and are capable of causing a variety of pathologies in humans. Human toxocariasis is a ubiquitous and likely under-diagnosed public health concern across the globe. Examination of soils in numerous public spaces worldwide readily detect Toxocara eggs and serological studies indicate a substantial exposure to this parasitic roundworm in human populations. This study sought to determine whether genetic evidence of pathogenic Toxocara species could be found in soils from local public spaces in a Minnesota community. Total genomic DNA was purified from soil samples obtained from public parks and PCR was performed using primers specific to either T. canis or T. cati. Genetic evidence for both species of Toxocara was found in soils surveyed. T. canis was identified in five of 12 public spaces surveyed and T. cati was present in two of the same 12 public spaces. Although the infectious potential of the Toxocara identified was not determined, the presence of this parasite in locations amenable to transmission to humans indicates the need for proper veterinary care of domestic dogs and cats as well as a greater emphasis on public health education and actions to prevent human infection.