Associations between socio-environmental determinants and the risk of pulmonary tuberculosis in Guilan, Iran

Background: Certain social determinants may influence host susceptibility to tuberculosis (TB) infections, and increase the risk of developing the disease. Objectives: The present study aimed to evaluate the effects of several host and environmental factors on the risk of TB in northern Iranian households. Patients and Methods: This case control study was conducted for one year between 2010 and 2011 in the Guilan province in Iran. Eightyseven confirmed TB positive cases, based on convenience sampling, were included in this study. A patient positive for TB was confirmed by a positive sputum smear, chest X-ray, and clinical manifestations as diagnosed by a physician. The data were collected using observational methods, and were analyzed by SPSS software. Results: The average mean age of the TB cases was 51±22 years old, and 40.2 (35/87) of the TB cases were male and 59.8 (52/87) were female. The majority of TB cases were from rural areas (71.3, 62/87), while 28.7 (25/87) were from urban areas. Significant differences (P < 0.001) were observed between the geographical conditions and distribution of the disease. The room density of the individuals was significantly different (2.9±1.2 vs. 2.2±1.9, P<0.002) among the TB cases and control group, respectively. A statistical difference was observed between the groups in terms of the building materials (P < 0.05), while significantly inadequate UV irradiation was seen in the houses of the TB patients, compared to the control group (82.8 vs. 14.9,P<0.001). The hygiene of the houses seemed to be a significant risk factor (P