TOXOCARIASIS IN BRITAIN AS REVEALED BY SKIN SENSITIVITY TESTS

Infection of human beings with the dog nematode Toxocara canis can be diagnosed by an intradermal skin sensitivity test, T. canis being used as antigen. A survey using this test in patients with clinically suspected toxocariasis showed that 24 of 189 (12.7%) gave positive reactions, and 17 of these 24 had a history of close association with dogs or pica. Ninety per cent of the positive reactors had been referred because of persistent eosinophilia ; of 22 patients investigated for hepatomegaly 8 gave positive reactions and of these 6 were under the age of 10 years, suggesting that toxocaral infection may be an important cause of hepatomegaly in children in the United Kingdom. Seven positive reactors were found in the group of 44 patients investigated for dyspnoea or bronchospasm, and 4 positives in the 64 investigated for choroidoretinitis. The high incidence found in this survey suggests that toxocaral infection probably represents a serious hazard to health in the U.K. © 1968, British Medical Journal Publishing Group. All rights reserved.