Objective: To characterize mycobacterium isolates from pulmomary tuberculosis suspected cases visiting National Tuberculosis Reference Laboratory at Ethiopian Health and Nutrition Research Institute, for diagnosis of pulmonary tuberculosis from January 4 to February 22, 2010 with total samples of 263. Methods: Sputum specimens were collected and processed; the deposits were cultured. For culturing Lowenstein Jensen medium (LJ) and Mycobacteria Growth Indicator Tube (BACTEC MGIT 960) were used. Capilia Neo was used for detecting NTM isolates from isolates of BACTEC MGIT 960. In Armauer Hansen Research Institute, Addis Ababa Ethiopia, Deletion typing PCR method for species identification (from confirmed Mycobacterium tuberculosis complex (MTBC) isolates by Capilia Neo) was done. Results: Out of 263 enrolled in the study, 124 and 117 of them were positive for mycobacterium growth by BACTEC MGIT 960 and LJ culture method, respectively. From BACTEC MGIT 960 positive media of 124 isolates, 117 were randomly taken to perform Capilia TB Neo test. From these 7 (6%) of them were found to be NTM and 110 (94%) were MTBC. From these 110 MTBC isolates, 81 of them were randomly taken and run by the deletion typing RD9 PCR method of molecular technique. Out of these 78 (96.3%) were found to be species of Mycobacterium tuberculosis and 3 (3.7%) were found to be not in the MTBC. Regarding the types of methods of culture media, Mycobacteria Growth Indicator Tube (BACTEC MGIT 960) method was found to have excellent agreement (with kappa value of 0.78) with the routine method of LJ. Conclusions: Pulmonary tuberculosis suspected cases visiting the National Tuberculosis Reference Laboratory at EHNRI that were confirmed to be pulmonary tuberculosis are caused by the species of Mycobacterium tuberculosis, hence treatment regimen including pyrazinamide can be applied to the patients as the first choice in the study area in Addis Ababa, Ethiopia. There is indication of the presence of NTM in patients visiting the tuberculosis reference laboratory and this is important because NTM is known to cause pulmonary disease similar with sign and symptom of pulmonary tuberculosis but different in treatment. BACTEC MGIT 960 has excellent agreement with LJ media but it has high tendency of having high contamination rate unless a better decontamination method is designed.

Objective: To assess the prevalence and risk factors of smear positive pulmonary tuberculosis among Gondar town prisoners, North West Ethiopia. Methods: A cross sectional study was conducted from February to July, 2008 in Gondar Prison. Prisoners with cough duration of more than two weeks were involved in the study by giving three sputum samples and filling the questionnaires prepared for risk factor assessment. Acid fast staining technique was employed to detect the presence of the Mycobacterium tuberculosis bacilli in the sputum samples. Data was analyzed using SPSS version13 computer software and presented in table. Chi-square test was used to assess associations and a P-value less than 0.05 was taken as significant. Results: A total of 384 prisoners, 349 male and 35 females, with a mean age of 33.3 years were involved in the study. The prevalence of smear positive pulmonary tuberculosis among those prisoners with cough duration of more than two weeks was 8.59%. Only the length of imprisonment had a significant association (χ ²= 18.82, P-value<0.0001) with the prevalence of tuberculosis. Conclusions: This study indicated that tuberculosis among prisoners with cough duration of more than two weeks in Gondar prison is very high. Therefore Periodic screening of the prisoners and screening of newly introduced prisoners should be practiced so as to minimize the burden of tuberculosis in prisoners.