[Toxocara canis as a cause of visceral larva migrans. Survival and development of eggs in the environment and potential ways of transmission to man: a review].

A review is given on the occurrence of Toxocariasis, the prevalence of T. canis among dogs and investigations on the prevalence of infective ova in soil- and sandsamples. The resistance of ascarid eggs and larvae against different environmental influences, including various sewage treatment-effects is discussed. The eggs are destroyed in 7 minutes when kept at 55 degrees C in a high humidity, slower when the humidity is lowered. When the temperature is -32 degrees C T. canis eggs are inactivated after 8 hours. Complete embryonation is reached in 4 days when the temperature is 30 degrees C. Potential ways of transmission to man are outlined (pica, vegetables, bathing etc.) and recommendations in order to prevent the disease are given such as deworming of dogs, methods to decimate occurrence of eggs in wastewater and sludge etc.