Tuberculin testing for typical and atypical mycobacteria in tuberculous patients in upper Egypt

ABSTRACT

This study included one hundred and sixteen tuberculous patients [all proved to have active tuberculosis of different forms] as well as twenty non-tuberculous persons served as controls. Both groups were subjected to dual skin testing using typical mycobacterial antigen [PPD-T] as well as five different atypical mycobacterial antigens. There were no significant differences between responders to [PPD-T]in both groups. The response to atypical antigens was higher in tuberculous lymphadenitis [47%] than pulmonary tuberculosis [30%]. The greatest response was to M. fortuitum and M. avium, while the response to M. gordonae was minimal. Positive skin testing for atypical mycobacteria was recorded in a high percentage among diseased and healthy persons. Its presence means previous exposure to the organisms rather than disease. Atypical mycobacterial infection might have a role in resistant cases of tuberculosis to anti-mycobacterial drug therapy. Bacterial cultures and identification of the organisms are recommended in the tuberculous patients