Toxoplasmal and toxocaral infections: a clinical investigation into their relationship.

An investigation was carried out to determine whether a relationship existed between infections with Toxoplasma gondii and Toxocara canis. Antibodies were sought by the toxoplasma dye test and the toxocara skin sensitivity test. Sixty-seven patients were examined in the United Kingdom; 38 had positive toxoplasma dye tests, two of these being toxocara-positive; and 29 had negative dye tests, six of them being toxocara-positive. From the total of eight toxocarapositive patients antibodies to toxoplasma were detected in two, an incidence no greater than that expected for a normal population.Sera from 60 toxocara-positive African patients were examined; 20 possessed antibodies to Toxoplasma. Analysis according to age group or geographical location indicated that this incidence was no greater than that expected for patients without evidence of toxocaral infection.This study therefore showed no causal or clinically important relationship between toxoplasmal and toxocaral infections.