Tehran University of Medical Sciences Journal of Medical Bacteriology 2251-8649 1 1-2 2015 10 12 23 30 EN Mehrdad Asghari Students Research Committee, Faculty of Paramedicine, Tabriz University of Medical Sciences, Tabriz, IR Iran. Siamak Heidarzadeh Department of Pathobiology, School of Public Health, Tehran University of Medical Sciences, Tehran, IR Iran. Ziba Vaise-Malekshahi Department of biology, Faculty of Science, Shahed University, Tehran, IR Iran. Maryam Hemmatzadeh Department of Laboratory Sciences, Faculty of Paramedicine, Tabriz University of Medical Sciences, Tabriz, IR Iran. Mohammad Javad Razzaghe-Karimi Department of Laboratory Sciences, Faculty of Paramedicine, Tabriz University of Medical Sciences, Tabriz, IR Iran. Hamideh Ashrafi Tuberculosis and Lung Disease Research Center, Tabriz University of Medical Sciences, Tabriz, IR Iran. Fatemeh Fallah Department of Microbiology, Shahid Beheshti University of Medical Sciences, Tehran, IR Iran. Raheleh Sadat Sajadi-Nia Shahid Beheshti University of Medical Sciences, Tehran, IR Iran. 2015 10 12 2015 10 12 Background:  Tuberculosis  is one of the most important causes of morbidity and mortality worldwide. Approximately 10-20% of tuberculosis is Extra- pulmonary tuberculosis (EPTB), which is much higher (50%) in patients suffering from immunity defects such as AIDS. EPTB diagnosis is difficult mostly because of various clinical manifestations  and aggressive  procedures needed for its diagnosis.  The main goal of this study was to determine  the prevalence  of  EPTB  in the  north  west  of  Iran  and  also  to investigate  the different clinical characteristics of the studied population, the various clinical manifestations and organ involvement of EPTB, as well. Methods:  This  study  was  carried  out  retrospectively  using  the  data  from Tabriz Tuberculosis  and Lung Disease  Research  Center from 2007 through 2011.   Questionnaires   were  designed   to  extract   relevant   information   to describe characteristics of EPTB affected population and also various clinical manifestations and organ involvement of the disease among the patients.  Results:  The  study  included  203  EPTB  cases  notified  from  2007  through2011 including, 91 (44.83%) males and 112 (55.17%) females. The mean age of the patients was 46.55 ± 18.3. The main extra pulmonary involvements of the  studied  population  were  lymphadenitis  (9.35%),  pleural  (7.39%)  and spinal  (5.42%)  among  males  and  lymphadenitis  (17.24%),  ocular  (7.88%), pleural (6.40%) and spinal (5.91%) among females, respectively. Conclusion:  Since EPTB diagnosis is a challenging and time sparing attempt even by the expert physicians, there is a need to perform further researches in order to identify the main clinical manifestations  and organ involvement  of EPTB in patients.   https://jmb.tums.ac.ir/index.php/jmb/article/view/7 https://jmb.tums.ac.ir/index.php/jmb/article/download/7/5