Primary Drug-Resistant Tuberculosis

In an outbreak of tuberculosis, a strain of Mycobacterium tuberculosis isolated from the source case, before the administration of any chemotherapy, was highly resistant to isoniazid, streptomycin and para-aminosalicylic acid. All 23 members of the immediate household were found to be positive tuberculin reactors, and in six of them active tuberculous disease developed. Evidence of spread of this infection into the local community was indicated by a significant increase in the rate of tuberculin reactors among the non-household contacts of the source case. Physicians seem to be unaware that tuberculosis still exists in certain segments of our population. Careful and persistent follow-up observation of tuberculin reactors is extremely important and may avert disaster. The drug susceptibility pattern of the source case should be reported to the chest clinic or health agency checking the contact cases. Isoniazid-resistant strains may present a problem in chemoprophylaxis.