Human toxocariasis and direct contact with dogs

Abstract

Toxocariasis in man is traditionally thought to be contracted through the ingestion of eggs from contaminated soil. The disease may manifest itself in different syndromes such as ocular larval migrans, visceral larval migrans and covert toxocariasis. This paper assesses the evidence for the soil contamination hypothesis and proposes that direct contact with dogs may provide a better explanation of the epidemiology of the disease. Hair was collected from 60 dogs from various places in Ireland and the UK and examined for the presence of Toxocara canis eggs. T. canis eggs were found in the hair of 25 per cent of the dogs; in total, 71 eggs were recovered, of which 4.2 per cent were embryonated and 23.9 per cent were embryonating. The maximum densities of the embryonating and embryonated eggs were 180 and 20 eggs per gram of hair, respectively, much higher than the densities reported for soil samples. It is suggested that dogs infected with T. canis may infect people by direct contact.

Frequency of human toxocariasis in a rural population from Cajamarca, Peru determined by DOT-ELISA test

“…CHIEFFI et al 8 and WOLFE et al 37 , reported a higher frequency of infection in individuals who were in contact with dogs. Ownership of dogs is very common in families living in the field, as they use the dogs to assist them with cattle, being considered very good work partners.…”

Human toxocariasis: a seroepidemiological survey in the Amazonian city of Yurimaguas, Peru

“…Ownership of pets such as dogs or cats and their presence at home is frequently associated with toxocariasis, as mentioned by many authors 5,22,24,28,[34][35][36][37] . However, this fact was not associated with the seropositivity in the studied population (p = 0.107).…”

Seroprevalence of Toxocara antibodies among patients suspected of ocular toxocariasis in Slovenia

“…By personal information of Western blot producer, their tests detect and confirm also infections caused by T. cati larvae, so it is suggested that some of our Toxocara positive patients could be infected by the eggs of T. cati. It was known that toxocariasis can be contracted through the ingestion of Toxocara eggs from contaminated soil or food but nowadays it is suggested that humans can be infected also by direct contact and than ingestion of emryonated Toxocara eggs in pet's hair (Wolfe and Wright, 2003).…”