incidence of isolation of mycobacterium tuberculosis from blood samples in tuberculosis patients in imam khomeini hospital, tehran, iran

it is estimated that one third of the world's population is latently infected with tuberculosis (tb). the hiv epidemic fuels the tb epidemic by increasing the risk of reactivation of latent tb infection and by facilitating a more rapid progression of tb disease. although the incidence of tb is constant or decreasing in many regions of the world, rates remain high in developing countries as a consequence of the hiv epidemic. this study was conducted as a collaboration of the infectious diseases department of imam khomeini hospital with the microbiology department of tehran university of medical sciences. the hospital dataset of 94 patients admitted with tb during 2003-2005 was reviewed. we aimed to study factors correlating with positive blood culture including age, sex, immune deficiency status, hiv serology and sirs (systemic inflammatory response syndrome) status. in this study, we found that positive blood cultures are more frequent in patients less than 45 years old. positive blood cultures were also more frequent in hiv infected patients and there was a significant correlation between blood culture and sirs status. therefore, we recommend that we obtain blood cultures from these high-risk groups in order to increase early detection of tb.