Toxocara canis is a parasitic nematode and has a cosmopolitan distribution. The definitive hosts are dogs, foxes, and less frequently other canids, and the life cycle is very complex in the hosts. The paratenic hosts, mammals and birds, acquire the infection by ingesting eggs excreted by infected canids. The larvae hatch in the small intestine, penetrate the mucosa, and after migration the larvae can be found in virtually all organs of the paratenic hosts. In humans the parasite causes visceral, ocular, and covert toxocarosis. The clinical signs and symptoms are a consequence of the extent and frequency of infection, larval migration, and the host response.
Toxocara excretory-secretory (ES) products are highly antigenic and useful in serodiagnosis, the antigen is produced by prolonged in vitro cultivation of the larvae. The antigen is composed of five major groups of molecules, which are heavily glycosylated proteins. The major host responses to these antigens include a marked eosinophilia and hypergammaglobulinemia.
Was this article helpful?