Toxocariasis
Background
Human toxocariasis is an infection with the larval stage of the dog roundworm, Toxocara canis, a parasitic worm. The extent of involvement in human disease of the cat roundworm, Toxocara cati, is unknown. The disease is caught by swallowing the microscopic Toxocara egg which is spread in infected dog or cat faeces.
Up to two per cent of the 'normal' population may be seropositive for Toxocara antibodies. The ocular form of the disease occurs mainly in children between the ages of six and twelve. It is rare in the UK. Visceral larval migrans usually self-resolves, but is treatable with anthelminthic drugs.