Preliminary observation on tuberculous allergy and cross reaction with atypical mycobacteria PPD (purified protein derivative) in babies immunized by BCG]

In order to know the cross reaction between BCG and Atypical Mycobacteria (AM) antigenicity, 1150 babies immunized by BCG, aged 12-24 week, undertook a bilateral arm control test with H-PPD. type 11 AM-PPD and BCG-PPD. The results showed that all the AM-PPD tested can bring about a delayed allergy in these babies. but the total positive rate (42.87%) and mean reactive diameter (3.87 mm) were the lowest and smallest among the above mentioned three types of PPD. The BCG-PPD derived allergy has highest positive rate and largest reactive diameter, but there is no statistical difference when compared to those of allergy caused by H-PPD.