Clinical interpretation of eosinophilia and ELISA values [OD] in toxocarosis

The results of examination of 1264 patients in Poznań area, Poland by an ELISA test with E/S antigen were retrospectively analysed in order to evaluate the place the absorbance values (OD) may have in the clinical interpretation of toxocarosis. Mean OD values in the screened populations (except children living in a heavily contaminated area) were all below 1.500 and in the hospitalised symptomatic patients - all above 1.750. The level of eosinophilia correlated well with OD values. It is postulated that in population screenings the weakly positive OD values (0.600-1.190) are presented separately, as they usually have no clinical implications. The OD values 1.200-1.790 may occur in mild toxocarosis, whereas the values above 1.800 are common in clinically well expressed toxocarosis. Ocular toxocarosis usually have lower OD values. In conclusion OD values are good markers of clinical expression of toxocarosis and have to be considered together with eosinophilia, IgE antibodies response and observed symptoms and signs in a rational clinical evaluation of the Toxocara infection in human patients.