***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
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    ***EXAMPLES*** 
    Input: Objective : To evaluate commonly available screening tests for pulmonary tuberculosis ( TB ) , using sputum bacteriology as a gold st and ard , in HIV-infected persons attending an urban voluntary counseling and testing clinic in Addis Ababa , Ethiopia . Design : Prospect i ve enrollment of HIV-infected persons , all of whom underwent TB screening , regardless of symptoms , with : ( 1 ) symptom screening and physical examination , ( 2 ) 3 sputum specimens for smear microscopy , and ( 3 ) chest radiograph .  One sputum was also sent for concentrated smear microscopy and mycobacterial culture . Chest radiographs were review ed by 2 independent radiologists . A confirmed TB diagnosis was defined as 1 positive sputum smear and /or 1 positive sputum culture . Results : We enrolled 438 HIV-infected persons : 265 ( 61 % ) females , median age 34 years ( range : 18 - 65 ) , median CD4 cell count 181 cells per cubic millimeter ( range : 2 - 1185 ) . Overall , 32 ( 7 % ) persons were diagnosed with TB , of whom 5 ( 16 % ) were asymptomatic but culture-confirmed TB cases . Screening for cough > 2 weeks would have detected only 12 ( 38 % ) confirmed TB cases ; screening for cough or fever , of any duration , would have detected 24 ( 75 % ) cases , with specificity of 64 % . Negative predictive value of screening for these 2 symptoms was 97 % . Simulation of the current Ethiopian national guidelines had a sensitivity of 63 % and specificity of 83 % for diagnosing TB disease among study patients . Conclusions : Traditional symptom screening is insufficient for detecting TB disease among HIV-infected persons but may serve to exclude TB disease . More sensitive , rapid , and low-cost diagnostic tests are needed to meet the dem and of re source -limited setting BACKGROUND The Xpert MTB/RIF ( Cepheid ) non-laboratory-based molecular assay has potential to improve the diagnosis of tuberculosis ( TB ) , especially in HIV-infected population s , through increased sensitivity , reduced turnaround time ( 2 h ) , and immediate identification of rifampicin ( RIF ) resistance . In a prospect i ve clinical validation study we compared the performance of Xpert MTB/RIF , MTBDRplus ( Hain Lifescience ) , LightCycler Mycobacterium Detection ( LCTB ) ( Roche ) , with acid fast bacilli ( AFB ) smear microscopy and liquid culture on a single sputum specimen . METHODS AND FINDINGS Consecutive adults with suspected TB attending a primary health care clinic in Johannesburg , South Africa , were prospect ively enrolled and evaluated for TB according to the guidelines of the National TB Control Programme , including assessment for smear-negative TB by chest X-ray , clinical evaluation , and HIV testing . A single sputum sample underwent routine decontamination , AFB smear microscopy , liquid culture , and phenotypic drug susceptibility testing . Residual sample was batched for molecular testing . For the 311 participants , the HIV prevalence was 70 % ( n = 215 ) , with 120 ( 38.5 % ) culture-positive TB cases . Compared to liquid culture , the sensitivities of all the test method ologies , determined with a limited and potentially underpowered sample size ( n = 177 ) , were 59 % ( 47%-71 % ) for smear microscopy , 76 % ( 64%-85 % ) for MTBDRplus , 76 % ( 64%-85 % ) for LCTB , and 86 % ( 76%-93 % ) for Xpert MTB/RIF , with specificities all > 97 % . Among HIV+ individuals , the sensitivity of the Xpert MTB/RIF test was 84 % ( 69%-93 % ) , while the other molecular tests had sensitivities reduced by 6 % . TB detection among smear-negative , culture-positive sample s was 28 % ( 5/18 ) for MTBDRplus , 22 % ( 4/18 ) for LCTB , and 61 % ( 11/18 ) for Xpert MTB/RIF . A few ( n = 5 ) RIF-resistant cases were detected using the phenotypic drug susceptibility testing methodology . Xpert MTB/RIF detected four of these five cases ( fifth case not tested ) and two additional phenotypically sensitive cases . CONCLUSIONS The Xpert MTB/RIF test has superior performance for rapid diagnosis of Mycobacterium tuberculosis over existing AFB smear microscopy and other molecular method ologies in an HIV- and TB-endemic region . Its place in the clinical diagnostic algorithm in national health programs needs exploration . Please see later in the article for the Editors ' Summary OBJECTIVE To assess the diagnostic value of provider-initiated symptom screening for tuberculosis ( TB ) and how HIV status affects it . METHODS We performed a secondary analysis of r and omly selected participants in a community-based TB-HIV prevalence survey in Harare , Zimbabwe . All completed a five-symptom question naire and underwent sputum TB culture and HIV testing . We calculated the sensitivity , specificity , and positive and negative predictive values of various symptoms and used regression analysis to investigate the relationship between symptoms and TB disease . FINDINGS We found one or more symptoms of TB in 21.2 % of 1858 HIV-positive ( HIV+ ) and 9.9 % of 7121 HIV-negative ( HIV- ) participants ( P < 0.001 ) . TB was subsequently diagnosed in 48 HIV+ and 31 HIV- participants . TB was asymptomatic in 18 culture-positive individuals , 8 of whom ( 4 in each HIV status group ) had positive sputum smears . Cough of any duration , weight loss and , for HIV+ participants only , drenching night sweats were independent predictors of TB . In HIV+ participants , cough of > or = 2 weeks ' duration , any symptom and a positive sputum culture had sensitivities of 48 % , 81 % and 65 % , respectively ; in HIV- participants , the sensitivities were 45 % , 71 % and 74 % , respectively . Symptoms had a similar sensitivity and specificity in HIV+ and HIV- participants , but in HIV+ participants they had a higher positive and a lower negative predictive value . CONCLUSION Even smear-positive TB may be missed by provider-initiated symptom screening , especially in HIV+ individuals . Symptom screening is useful for ruling out TB , but better TB diagnostics are urgently needed for re source -poor setting Background Delayed diagnosis of tuberculosis ( TB ) and drug-resistant TB are major challenges of TB control in Thail and . This study assessed the practicality of the Xpert MTB/RIF assay in a real-life setting with high prevalence of human immunodeficiency virus ( HIV ) infection and pulmonary tuberculosis ( PTB ) . Methods This prospect i ve study was conducted at 3 large tertiary care hospitals . Patients who had suspected PTB were enrolled into the study . Expectorated sputum sample s were sent for staining , mycobacterial culture , and Xpert MTB/RIF . Results Four hundred ninety-four patients were enrolled . From 355 cases with final diagnosis of PTB , 263 ( 71.8 % ) had definite diagnosis and 92 cases had probable diagnosis . Among TB culture-positive cases , Xpert MTB/RIF had 100 % and 81 % sensitivity in sputum smear-positive and smear-negative groups , respectively . The specificity was 95.7 % . The sensitivity and positive predictive value of Xpert MTB/RIF  in culture-negative but clinical ly diagnosed PTB was 37.8 % and 83.8 % , respectively . Centrifugation was required in 59 % cases with scanty sputum . Five cases were false-positive by Xpert MTB/RIF in patients with nontuberculous mycobacteria , old PTB scar , and immune reconstitution syndrome .  Discordant rifampicin susceptibility results of Xpert MTB/RIF and mycobacteria growth indicator tube ( MGIT ) were confirmed by using rpoB gene sequencing , which raised the sensitivity of Xpert MTB/RIF in detecting rifampicin resistance to 93.8 % . Conclusions Xpert MTB/RIF is an effective tool in diagnosing PTB but will be more cost-effective for sputum-negative patients and in setting s with high prevalence of rifampicin resistance . Early diagnosis of TB results in early treatment and implementation of strategies to limit spreading of TB . Sputum centrifugation may increase the yield of Xpert MTB/RIF BACKGROUND In South Africa , sputum smear microscopy has been replaced with Xpert MTB/RIF as the initial diagnostic test for tuberculosis . In a pragmatic parallel cluster-r and omised trial , we evaluated the effect on patient and programme outcomes . METHODS We r and omly allocated 20 laboratories ( clusters ) in medium-burden districts of South Africa to either an Xpert ( immediate Xpert ) or microscopy ( Xpert deferred ) group ( 1:1 ) , stratified by province . At two primary care clinics per laboratory , a systematic sample of adults giving sputum for tuberculosis investigation was assessed for eligibility . The primary outcome was mortality at 6 months from enrolment . Masking of participants ' group allocation was not possible because of the pragmatic trial design . The trial is registered with the IS RCT N registry ( IS RCT N68905568 ) and the South African Clinical Trial Register ( DOH-27 - 1011 - 3849 ) . FINDINGS Between June and November , 2012 , 4972 people were screened , and 4656 ( 93·6 % ) enrolled ( median age 36 years ; 2891 [ 62 % ] female ; 2212 [ 62 % ] reported being HIV-positive ) . There was no difference between the Xpert and microscopy groups with respect to mortality at 6 months ( 91/2324 [ 3·9 % ] vs 116/2332 [ 5·0 % ] , respectively ; adjusted risk ratio [ aRR ] 1·10 , 95 % CI 0·75 - 1·62 ] ) . INTERPRETATION Xpert did not reduce mortality at 6 months compared with sputum microscopy . Improving outcomes in drug-sensitive tuberculosis programmes might require not only better diagnostic tests but also better linkage to care . FUNDING Bill & Melinda Gates Foundation BACKGROUND In sub-Saharan Africa , the burden of human immunodeficiency virus (HIV)-associated tuberculosis is high . We conducted a trial with a 2-by-2 factorial design to assess the benefits of early antiretroviral therapy ( ART ) , 6-month isoniazid preventive therapy ( IPT ) , or both among HIV-infected adults with high CD4 + cell counts in Ivory Coast . METHODS We included participants who had HIV type 1 infection and a CD4 + count of less than 800 cells per cubic millimeter and who met no criteria for starting ART according to World Health Organization ( WHO ) guidelines . Participants were r and omly assigned to one of four treatment groups : deferred ART ( ART initiation according to WHO criteria ) , deferred ART plus IPT , early ART ( immediate ART initiation ) , or early ART plus IPT . The primary end point was a composite of diseases included in the case definition of the acquired immunodeficiency syndrome ( AIDS ) , non-AIDS-defining cancer , non-AIDS-defining invasive bacterial disease , or death from any cause at 30 months . We used Cox proportional models to compare outcomes between the deferred-ART and early-ART strategies and between the IPT and no-IPT strategies . RESULTS A total of 2056 patients ( 41 % with a baseline CD4 + count of ≥500 cells per cubic millimeter ) were followed for 4757 patient-years . A total of 204 primary end-point events were observed ( 3.8 events per 100 person-years ; 95 % confidence interval [ CI ] , 3.3 to 4.4 ) , including 68 in patients with a baseline CD4 + count of at least 500 cells per cubic millimeter ( 3.2 events per 100 person-years ; 95 % CI , 2.4 to 4.0 ) . Tuberculosis and invasive bacterial diseases accounted for 42 % and 27 % of primary end-point events , respectively . The risk of death or severe HIV-related illness was lower with early ART than with deferred ART ( adjusted hazard ratio , 0.56 ; 95 % CI , 0.41 to 0.76 ; adjusted hazard ratio among patients with a baseline CD4 + count of ≥500 cells per cubic millimeter , 0.56 ; 95 % CI , 0.33 to 0.94 ) and lower with IPT than with no IPT ( adjusted hazard ratio , 0.65 ; 95 % CI , 0.48 to 0.88 ; adjusted hazard ratio among patients with a baseline CD4 + count of ≥500 cells per cub 
    Output:
    
Adults with TB symptoms have extremely high prevalence of HIV infection , even when identified through community surveys .
TB prevalence and mortality increased substantially at primary care and inpatient level respectively .