Larval migration of Toxocara canis in piglets and transfer of larvae from infected porcine tissue to mice.

Visceral larva migrans (VLM), caused by Toxocara canis larvae in humans, animals and birds, is now well documented throughout the world. Seven piglets were infected orally with 5 x 104 embryonated eggs and the migration and distribution of T. canis larvae in the tissues were evaluated. After artificial gastric juice digestion, larval yields at necropsy from different organs and muscles on days 1, 3, 7, 15 and 30 post-infection (DPI) revealed 3.05, 0.97, 0.21, 0.13, 0.05, 0.14% recovery from liver, lungs, heart, kidneys, skeletal muscles and brain tissues respectively, with a total of 2486 (4.97%) recovery from all tissues together. The highest number of larvae 1527 (3.05%) was recovered from the liver throughout the period (1-30 DPI), indicating a special affinity of larvae for the liver. Subsequently five mice were each infected orally with 5 g of infected pig liver and, after necropsy on 10 DPI, 20 +/- 3.62, 17 +/- 5.10, 3 +/- 1.26, 12 +/- 3.92 and 30 +/- 5.69 larvae were recovered from liver, lungs, heart, brain and muscles, respectively. Thus, primarily, the migratory potential and adaptation of T. canis larvae in porcine tissue was examined and, subsequently, their establishment in the second paratenic host, the mouse, has been successful. No influence of host sex on the migratory potential of T. canis larvae was observed. The related pathology caused by migratory larvae and its zoonotic significance through the consumption of raw or undercooked pork has been emphasized.

Toxocaríase visceral / Visceral toxocariasis

Larva migrans visceral é uma infecção universal que ocorre mais frequentemente em crianças menores de 10 anos de idade, caracterizada por febre, hepatomegalia, doença pulmonar e eosinofilia. O agente é o ascaris intestinal de cães e gatos. O benefício das drogas anti-helmínticas não está definido. O tratamento com tiabendazol, albendazol ou mebendazol está indicado nas complicações da doença. A transmissão da infecção pode ser prevenida estimulando as crianças a lavarem suas mãos após brincarem em áreas onde há cães

[Toxocara canis (Nematoda) and toxocariasis of animals and humans]. / Toxocara canis (Nematoda) oraz toksokarozy zwierzat i czlowieka.

Some aspects of dog toxocarosis and syndrome of visceral larva migrans in human toxocarosis, particularly in children were presented. In detail the morphological characters and biology of Toxocara canis, its pathogenicity, ways of invasions as well as conditions favouring the spreading of parasites were discussed. Attention was paid to the efficacy of diagnosis of invasions, treatment and prophylaxis. The current toxocarosis threat was analysed and epidemiological prognosis was moved forward.

Zoonotic visceral and ocular larva migrans.

Infection of children with the larval stage of the dog roundworm Toxocara canis usually produces few, if any, clinical signs. In some children, however, the disease may be severe, with permanent ocular or neurologic sequelae. Because the prevalence of infection may exceed 10 per cent in some population subgroups, it is important to understand the modes of transmission and risk factors for infection. The clinical presentations of toxocariasis as well as recommendations for their prevention are described.

Toxocariasis.

Human infection with the larvae of the dog roundworm, Toxocara canis, occurs in Australia, especially in children, and though usually not serious, it can cause considerable damage if the larvae get into such organs as the eye.