Smoking effects on clinical manifestations and drug resistance patterns in pulmonary TB patients

Considering the rising trend of tuberculosis [TB] and cigarette smoking, an evaluation of the clinical manifestations and drug resistance patterns in TB patients with regard to smoking status seemed beneficial. Clinical manifestations and drug resistance patterns were studied in 872 new pulmonary TB patients classified as non-smokers, ever-smokers, and passive smokers during 3 years at the National Research Institute of Tuberculosis and Lung Disease. Both univariate and multivariate analyses were performed. Ever-smokers were mostly male [p<0.001], Iranian [p<0.001], and drug and alcohol users [p<0.001]. They were found to have a longer patient delay [15.9 versus 8.7 and 6.3 days, p=0.008], shorter diagnostic delay [106.8 versus 132.6 and 156 days, p=0.01], greater weight loss [p=0.01], and higher sputum expectoration [p<0.001]. Notably, the degree of smear positivity was associated with smoking [p<0.001] in both univariate and multivariate analyses. No statistical significance was found for the aforementioned factors among non-smokers and passive smokers. Some of the clinical manifestations of TB are significantly different with regard to the patients' smoking status.The degree of sputum smear positivity for acid fast bacilli was higher and patient delay was longer in ever-smoker patients

Performance of QuantiFERON-TB Gold test compared to tuberculin skin test in detecting talent tuberculosis infection in HUV-positive individuals in IRAN

There is limited data about the performance of QuantiFERON-TB Gold [QFT-G] test in detecting latent tuberculosis infection [LTBI] in our region. We intended to determine the performance of QFT-G compared to conventional tuberculin skin test [TST] in detecting LTBI in HIV-positive individuals in Iran. This study was conducted in a HIV clinic in Tehran, Iran in April 2007. A total of 50 consecutive HIV-positive patients, not currently affected with active tuberculosis [TB], were recruited; 43 [86%] were male. The mean age was 38 +/- 7.2 years [21-53]. All had history of Bacillus Calmetta Guerin [BCG] vaccination. A TST with purified protein derivative [PPD] and whole-blood interferon-gamma release assay [IGRA] in reaction, to ESAT-6 and CFP-10 antigens was performed and measured by enzyme-linked immune-sorbent assay [ELISA]. The agreement between TST and QFT=G results were analyzed using Kappa test. A total of 36 [72%] patients had negative TST. For QFT-G, 20 [40%] tested positive, 19 [38%] tested negative, and the results in 11 cases [22%] were indeterminate. A total of 14 [28%] patients had a CD4 count of < 200 .Of the 14, TST + group, 12 had QFT-G +, only one case TST +/QFT-G-, and QFT-G was indeterminate in one TST positive case. Of the 36 patients with negative TST test, 8 [22%] had positive GFT-G and 10 [28%] yielded indeterminate results. There was no association between a positive TST and receiving highly active anti-retroviral therapy [HAART] or CD4 counts was not significant [P=0.06]. Although TST results were not significantly different in patients with CD <200 vs. CD4>200 [P=0.095], association between QFT-G results and CD4 cutoff of 200 reached statistical significance [P= 0.027]. Agreement Kappa coefficient between TST and QFT-G was 0.54 [Kappa = 0.54, 95% CI = 38.4-69.6, P < 0.001]. Detecting LTBI in HIV-positive individuals showed moderate agreement between QFT-G and LTBI in our study. Interestingly, our findings revealed that nontuberculous mycobacteria and prior BCG vaccination have minimal influence on TST results in HIV patients in Iran

Risk factors associated with multidrug-resistant tuberculosis

Multi-drug resistant tuberculosis [MDR-TB], a form of TB resistant to isoniazid and rifampin, is considered as a major threat to TB control worldwide. Moreover, the infectivity of MDR-TB is similar to that of non-MDR TB. This study aims to find the risk factors associated with the development of MDR-TB among TB patients admitted to Masih Daneshvari Hospital, the national referral center for tuberculosis and lung diseases. The national referral institute for tuberculosis and lung diseases in Tehran [NRITLD] receives all the MDR-TB cases from all over the country. Based on this criterion alone, forty-eight pulmonary MDR-TB patients who were referred to this center between 2002 and 2005 were included in this study. For the purpose of comparison, 234 patients diagnosed with pulmonary TB were also selected randomly as the control group. The two groups were compared based on 102 demographic and clinical variables. These variables included age, sex, nationality, drug and opium use, method of referral, symptoms and etc. Immigration and refugee status as well as history of anti-TB medication were found to be the most significant among the risk factors associated with MDR-TB. Also, 95.8% of the MDR-TB cases reported a previous history of anti-TB medication. This number was 23.1% in the non-MDR group. MDR-TB was more prevalent among the Afghan patients; out of a total of 78 Afghan patients, 22 [46.8%] composed the MDR-TB category, whereas, 56 [23.9%] Afghan patients belonged to the non-TB category. All MDR-TB patients had positive smears whereas 13.2% of non-MDR-TB patients had negative smears. Dyspnea and weight loss were among other significant variables. History of close contact, diabetes, smoking, drug use, fever, and BCG scar in both MDR TB and non-MDR-TB groups were among the insignificant variables found in this study. The limited sample size and location of the study may have resulted in insignificant variables. However, based on the obtained data, patient's status as an immigrant or a refugee is an important risk factor for both MDR and non-MDR TB and is of particular concern in the growing trend of MDR-TB