Diagnostic Performance of Unstimulated IFN-γ (IRISA-TB) for Pleural Tuberculosis: A Prospective Study in South Africa and India.

Background: Tuberculous pleural effusion (TPE) is the most common form of extrapulmonary tuberculosis in many settings. The diagnostic performance of the frontline polymerase chain reaction–based GeneXpert MTB/RIF Ultra (Xpert Ultra) remains suboptimal (sensitivity of ∼30%), but data are limited. Improved diagnostic approaches are urgently needed to detect extrapulmonary tuberculosis (EPTB) in tuberculosis (TB)-endemic settings. Methods: This multicenter, prospective cohort study evaluated the diagnostic performance of a rapid (same-day) interferon gamma rapid immunosuspension assay (IRISA-TB) in patients with presumed TPE from South Africa and India. Participants underwent pleural biopsy, and testing with other available same-day diagnostic assays (adenosine deaminase [ADA], Xpert Ultra, and IRISA-TB) was concurrently undertaken. The reference standard for TB was microbiological and/or histopathological confirmation using pleural fluid and/or pleural biopsy samples. Results: A total of 217 participants with presumed TPE were recruited (106 from South Africa, 111 from India). The sensitivity of IRISA-TB (cut-point 20.5 pg/mL) was significantly better than that of Xpert Ultra (81.8% [70.4–90.2] vs 32.9% [22.1–45.1]; P < .001) and ADA at the 40 IU/mL cut-point used in India (81.8% [70.4–90.2] vs 53.8% [41.0–66.3]; P = .002). Compared with ADA at the 30 IU/mL cut-point used in South Africa, IRISA-TB had a higher specificity (96.6% [90.3–99.3] vs 87.1% [78.6–93.2]) and a higher positive predictive value (94.7% [85.5–97.3] vs 81.8% [72.4–88.5]). The negative predictive value (NPV; rule-out value) of IRISA-TB was significantly better than that of Xpert Ultra (87.5% [83.2–93.0] vs 64.9% [61.1–68.6]; P < .001) and ADA at the 40 IU/mL cut-point (87.5% [83.2–93.0] vs 74.1% [68.7–79.0]; P < .001). Conclusions: IRISA-TB demonstrated markedly better sensitivity and NPV than Xpert Ultra and excellent specificity for the diagnosis of TPE. These data have implications for clinical practice in TB-endemic settings

High Annual Risk of Tuberculosis Infection among Nursing Students in South India: A Cohort Study

Background: Nurses in developing countries are frequently exposed to infectious tuberculosis (TB) patients, and have a high prevalence of TB infection. To estimate the incidence of new TB infection, we recruited a cohort of young nursing trainees at the Christian Medical College in Southern India. Annual tuberculin skin testing (TST) was conducted to assess the annual risk of TB infection (ARTI) in this cohort. Methodology/Principal Findings: 436 nursing students completed baseline two-step TST testing in 2007 and 217 were TST-negative and therefore eligible for repeat testing in 2008. 181 subjects completed a detailed questionnaire on exposure to tuberculosis from workplace and social contacts. A physician verified the questionnaire and clinical log book and screened the subjects for symptoms of active TB. The majority of nursing students (96.7%) were females, almost 84% were under 22 years of age, and 80% had BCG scars. Among those students who underwent repeat testing in 2008, 14 had TST conversions using the ATS/CDC/IDSA conversion definition of 10 mm or greater increase over baseline. The ARTI was therefore estimated as 7.8% (95%CI: 4.3-12.8%). This was significantly higher than the national average ARTI of 1.5%. Sputum collection and caring for pulmonary TB patients were both high risk activities that were associated with TST conversions in this young nursing cohort. Conclusions: Our study showed a high ARTI among young nursing trainees, substantially higher than that seen in the general Indian population. Indian healthcare providers and the Indian Revised National TB Control Programme will need to implement internationally recommended TB infection control interventions to protect its health care workforce

Are the days of closed pleural biopsy over? No

Closed pleural biopsy used to be a popular method of evaluation of pleural effusion. With the advent of thoracoscopy, this valuable method is being neglected. Studies have shown that closed pleural biopsy especially done with image guidance has high yield and low complication rate as compared to thoracoscopy. Given the ease of the procedure and the less cost involved, imaged guided closed pleural biopsy should be considered as the initial diagnostic step in undiagnosed pleural biopsy especially in developing countries with high prevalence of tuberculosis

Bronchoscopic view of post-tuberculosis lung cavity: A case report

An elderly male, a former smoker, was evaluated at the pulmonary medicine clinic for recurrent episodes of streaky hemoptysis for the last 3 years. He had a history of being successfully treated for microbiologically confirmed pulmonary tuberculosis in the past. He presented in this consultation with two episodes of large volume hemoptysis, and the laboratory results suggested an ongoing active infection. Sputum smear was negative for an infectious etiology. Contrast-enhanced CT of the thorax revealed a lung cavity in the right upper lobe. He underwent flexible bronchoscopy with bronchoalveolar lavage which revealed Klebsiella pneumoniae infection. Small-diameter bronchoscope was used to navigate into the affected lung segment which revealed a cave-like appearance. This was an interesting finding and physicians should be familiar with such bronchoscopic findings and techniques in the management of their patients, particularly in tuberculosis endemic areas

Young patient with generalized lymphangiomatosis: Differentiating the differential

We present the case of a 19-year-old man who was extensively evaluated in multiple centres for long-standing cough, dyspnea, and hemoptysis without a definitive diagnosis. His chest radiograph at presentation showed mediastinal widening, bilateral pleural effusions, and Kerley B lines. Computed tomography of the thorax showed a confluent, fluid-density mediastinal lesion enveloping the mediastinal viscera without any mass effect. There were bilateral pleural effusions, prominent peribronchovascular interstitial thickening, interlobular septal thickening and lobular areas of ground glass density with relative sparing of apices. There were a few dilated retroperitoneal lymphatics and well-defined lytic lesions in the bones. In this case report, we aim to systematically discuss the relevant differentials and arrive at a diagnosis. We also briefly discuss the treatment options and prognosis along with our patient's course in the hospital and final outcome