POLYMERASE CHAIN-REACTION OF NASAL SWABS FROM TUBERCULOSIS PATIENTS AND THEIR CONTACTS

Previous studies have found Mycobacterium leprae in nasal swabs from l eprosy patients, their contacts, and persons living in endemic areas. It might be expected that M. tuberculosis would be present on nasal mu cosa of pulmonary tuberculosis patients, but whether they can be detec ted in patients or contacts is unknown. We used the polymerase chain r eaction (PCR) technique on nasal swabs from tuberculosis patients, con tacts of tuberculosis patients, leprosy patients, and London controls to look for both M. tuberculosis and M. leprae. Swabs dipped in sputum specimens from smear-positive patients were used as positive controls , The PCRs were conducted in two independent laboratories. M. tubercul osis was detected in nasal swabs from 6/16 smear-positive tuberculosis patients and from 1/10 household contacts by one of the laboratories. All of the sputum swabs were positive for M. tuberculosis, and all of the London controls were negative, M, leprae were found in nasal swab s from 2/5 leprosy patients, but one laboratory also reported M. lepra e in swabs from 4/21 tuberculosis patients and from one sputum specime n. The results show that M. tuberculosis can be found in the noses of some tuberculosis patients, and suggest that the bacilli also may be d etected in some household contacts.