Tuberculosis (TB) is an extremely infectious airborne disease.  The right treatment needs the correct identification of the bacteria and the drug susceptibility result in order to provide an efficient cure to the patient.

In developed countries those processes are performed in every TB case while the poor countries still use the cheap conventional method of microscopic examination.  Bacterial culture, identification and drug susceptibility were not necessary in the past because:

  • Drug-resistant TB in the past was resistant to non standard drugs.  A combination of standard drugs could effectively destroy the germ at that time.

  • In the past, 95% of organisms in the specimen found under microscopic examination were TB bacteria.  Other species of mycobacterium that are usually found in water, soil and some animals like poultry, birds and fish were rarely detected.  So the majority of treatment were succeeded.

  • To get the drug susceptibility result in a short period (2-3 weeks), an expensive automatic method (Bactec) is needed.  The alternative cheaper method took 3-4 months to get results which is meaningless to help decide appropriate treatment.  Thus, several physician did not do bacterial culture.  Moreover; there are only 4 laboratories in Thailand that are able to culture TB bacteria which is not enough for country's requirement.

At present, the new phenomenon of TB and AIDS co-infection has made all concerned reviews whether culture is necessary or not.

With the tremendous support of the Drug-Resistant Tuberculosis Research Fund, bacterial culture and the drug susceptibility test are performed on these case with a positive microscopic examination.  The two main drugs used in the drug susceptibility test are Isoniazid and Rifampin.  This service is free of charge for all public and government hospitals in Thailand.  This helps physicians treat their patients in a correct, save and effective way and can break the transmission cycle in the community.


Copyright © 2010 Microbiology Department, Faculty of Medicine, Siriraj Hospital, Mahidol University. All rights reserved.