International Journal of Preventive Medicine (Int J Prev Med)2008-7802952018060319201920ENClinical Tuberculosis and Epidemiology Research Center, National Research Institute of Tuberculosis and Lung Diseases, Shahid Beheshti University of Medical Sciences, TehranMycobacteriology Research Center, National Research Institute of Tuberculosis and Lung Diseases, Shahid Beheshti University of Medical Sciences, TehranChronic Respiratory Diseases Research Center, National Research Institute of Tuberculosis and Lung Diseases, Shahid Beheshti University of Medical Sciences, TehranLung Transplantation Research Center, National Research Institute of Tuberculosis and Lung Diseases, Shahid Beheshti University of Medical Sciences, Tehran20180603<p><span class="fontstyle0"><strong>Background</strong>: </span><span class="fontstyle2">Close contact investigation is the essential key in tuberculosis (TB) case fnding and an effective strategy for TB control program within any society. </span></p><p><span class="fontstyle0"><strong>Methods</strong>: </span><span class="fontstyle2">In this prospective study, 1186 close family contacts of hospitalized TB patients (index) in a referral TB hospital in Tehran‑Iran<br />were passively studied. These people were studied to rollout TB infection and disease. Demographic characteristics, clinical and laboratory data of these individuals were reviewed and summarized for analysis.<br /></span></p><p><span class="fontstyle0"><strong>Results</strong>: </span><span class="fontstyle2">A total of 886 (74.4%) close‑family contacts completed their investigation. The index TB patients of these individuals were sputum smear negative for acid‑fast bacilli in 137 cases (11.6%) and the rest were<br />smear positive. A total of 610 (68.8%) close‑family contact ruled out for TB infection or disease (Group I). A total of 244 cases (27.5%) had latent TB infection (Group II) and active TB (Group III) was confrmed in 32 cases (3.6%). A signifcant difference was shown for female gender, signs and symptoms, family size, and positive radiological fnding between Group I and Group II. The study of index parameter including positive sputum smear/culture did not reveal any signifcant difference, but positive cavitary<br />lesion signifcantly more has seen in active TB group (</span><span class="fontstyle3">P </span><span class="fontstyle2">= 0.004). </span></p><p><span class="fontstyle0"><strong>Conclusions</strong>: </span><span class="fontstyle2">This study emphasizes on sign and symptoms and radiological fnding in TB contact investigation, where index parameters including positive smear/culture, does not implicate any priority. Although cavitary lesions in index patient have more accompanied by active TB, close contact study should include all of TB indexes. This investigation should include chest radiography for these individuals.<br /></span></p><p><span class="fontstyle0" style="color: #00652e;"><strong>Keywords</strong>: </span><span class="fontstyle3">Contact investigation, passive case fnding, tuberculosis</span> </p>http://ijpm.mui.ac.ir/index.php/ijpm/article/view/1920http://ijpm.mui.ac.ir/index.php/ijpm/article/download/1920/717717745