Introduction: In the Philippines, a diagnosis of pulmonary tuberculosis is very common especially in the presence of sputum findings positive for Acid Fast Bacilli (AFB). But it should be kept in mind that not all Mycobacterium are tuberculosis (TB). A previous study done at the University of Santo Tomas (UST) Hospital from 2003 to 2009 showed a 2.17% incidence of Mycobacterium other than tuberculosis (MOTT). However, due to its growing correlation with the Human Immunedeficiency Virus (HIV), updated incidence rates are warranted. Likewise, the importance of culture in the right diagnosis of diseases should always be emphasized.

Objectives: The study aimed to determine the incidence of MOTT in a tertiary hospital in Manila among patients suspected of having TB.

Materials and Methods: This is a retrospective study done at the UST Hospital, a quality-assured referral center for TB in Manila, with a TB Directly Observed Short Course (TB-DOTS) Clinic. Laboratory records of specimens submitted for culture and sensitivity studies for Mycobacterium tuberculosis (MTB) for which isolates of MOTT grew, using BACTECTM (Becton-Dickinson) method and Mycobacteria Growth Indicator Tube (MGITTM), from January 2003 to December 2014, were reviewed.

Results: A total of 6,886 specimens were submitted for MTB culture and sensitivity studies. Results showed 157 cases of MOTT with an incidence of 2.28%. Majority of the specimens with MOTT were from pulmonary sources (85%), most common of which was from sputum. Non pulmonary sources (15%) were mostly from urine, cerebro-spinal, and gastrointestinal tract. were isolated for MOTT. These find-ings are consistent with the previous local available data. Correct identification of this organism influence eventual decisions for treatment.

Conclusion: The incidence of positive culture for MOTT in our institution remains to be low. However, there is an increasing trend in the number of specimens which are turning out to be positive for MOTT. A future study on the correlation with the patients’ clinical profile is recommended.

Key words: mycobacterium, University of Santo Tomas Hospital, TB, mycobacterium tuberculosis

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