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Background The lateral flow urine lipoarabinomannan (LF‐LAM) assay Alere Determine™ TB LAM Ag is recommended by the World Health Organization (WHO) to help detect active tuberculosis in HIV‐positive people with severe HIV disease. This review update asks the question, "does new evidence justify the use of LF‐LAM in a broader group of people?”, and is part of the WHO process for updating guidance on the use of LF‐LAM. Objectives To assess the accuracy of LF‐LAM for the diagnosis of active tuberculosis among HIV‐positive adults with signs and symptoms of tuberculosis (symptomatic participants) and among HIV‐positive adults irrespective of signs and symptoms of tuberculosis (unselected participants not assessed for tuberculosis signs and symptoms). The proposed role for LF‐LAM is as an add on to clinical judgement and with other tests to assist in diagnosing tuberculosis. Search methods We searched the Cochrane Infectious Diseases Group Specialized Register; MEDLINE, Embase, Science Citation Index, Web of Science, Latin American Caribbean Health Sciences Literature, Scopus, the WHO International Clinical Trials Registry Platform, the International Standard Randomized Controlled Trial Number Registry, and ProQuest, without language restriction to 11 May 2018. Selection criteria Randomized trials, cross‐sectional, and observational cohort studies that evaluated LF‐LAM for active tuberculosis (pulmonary and extrapulmonary) in HIV‐positive adults. We included studies that used the manufacturer's recommended threshold for test positivity, either the updated reference card with four bands (grade 1 of 4) or the corresponding prior reference card grade with five bands (grade 2 of 5). The reference standard was culture or nucleic acid amplification test from any body site (microbiological). We considered a higher quality reference standard to be one in which two or more specimen types were evaluated for tuberculosis diagnosis and a lower quality reference standard to be one in which only one specimen type was evaluated. Data collection and analysis Two review authors independently extracted data using a standardized form and REDCap electronic data capture tools. We appraised the quality of studies using the Quality Assessment of Diagnostic Accuracy Studies‐2 (QUADAS‐2) tool and performed meta‐analyses to estimate pooled sensitivity and specificity using a bivariate random‐effects model and a Bayesian approach. We analyzed studies enrolling strictly symptomatic participants separately from those enrolling unselected participants. We investigated pre‐defined sources of heterogeneity including the influence of CD4 count and clinical setting on the accuracy estimates. We assessed the certainty of the evidence using the GRADE approach. Main results We included 15 unique studies (nine new studies and six studies from the original review that met the inclusion criteria): eight studies among symptomatic adults and seven studies among unselected adults. All studies were conducted in low‐ or middle‐income countries. Risk of bias was high in the patient selection and reference standard domains, mainly because studies excluded participants unable to produce sputum and used a lower quality reference standard. Participants with tuberculosis symptoms LF‐LAM pooled sensitivity (95% credible interval (CrI) ) was 42% (31% to 55%) (moderate‐certainty evidence) and pooled specificity was 91% (85% to 95%) (very low‐certainty evidence), (8 studies, 3449 participants, 37% with tuberculosis). For a population of 1000 people where 300 have microbiologically‐confirmed tuberculosis, the utilization of LF‐LAM would result in: 189 to be LF‐LAM positive: of these, 63 (33%) would not have tuberculosis (false‐positives); and 811 to be LF‐LAM negative: of these, 174 (21%) would have tuberculosis (false‐negatives). By clinical setting, pooled sensitivity was 52% (40% to 64%) among inpatients versus 29% (17% to 47%) among outpatients; and pooled specificity was 87% (78% to 93%) among inpatients versus 96% (91% to 99%) among outpatients. Stratified by CD4 cell count, pooled sensitivity increased, and specificity decreased with lower CD4 cell count. Unselected participants not assessed for signs and symptoms of tuberculosis LF‐LAM pooled sensitivity was 35% (22% to 50%), (moderate‐certainty evidence) and pooled specificity was 95% (89% to 96%), (low‐certainty evidence), (7 studies, 3365 participants, 13% with tuberculosis). For a population of 1000 people where 100 have microbiologically‐confirmed tuberculosis, the utilization of LF‐LAM would result in: 80 to be LF‐LAM positive: of these, 45 (56%) would not have tuberculosis (false‐positives); and 920 to be LF‐LAM negative: of these, 65 (7%) would have tuberculosis (false‐negatives). By clinical setting, pooled sensitivity was 62% (41% to 83%) among inpatients versus 31% (18% to 47%) among outpatients; pooled specificity was 84% (48% to 96%) among inpatients versus 95% (87% to 99%) among outpatients. Stratified by CD4 cell count, pooled sensitivity increased, and specificity decreased with lower CD4 cell count. Authors' conclusions We found that LF‐LAM has a sensitivity of 42% to diagnose tuberculosis in HIV‐positive individuals with tuberculosis symptoms and 35% in HIV‐positive individuals not assessed for tuberculosis symptoms, consistent with findings reported previously. Regardless of how people are enrolled, sensitivity is higher in inpatients and those with lower CD4 cell, but a concomitant lower specificity. As a simple point‐of‐care test that does not depend upon sputum evaluation, LF‐LAM may assist with the diagnosis of tuberculosis, particularly when a sputum specimen cannot be produced., Lateral flow urine lipoarabinomannan assay for detecting active tuberculosis in people living with HIV Why is improving the diagnosis of tuberculosis important? Tuberculosis causes more deaths in people living with HIV than any other disease. The lateral flow urine lipoarabinomannan assay (LF‐LAM, Alere Determine™ TB LAM Ag assay) is a World Health Organization‐recommended rapid test to assist in detection of active tuberculosis in HIV‐positive people with severe HIV disease. Rapid and early tuberculosis diagnosis may allow for prompt treatment and alleviate severe illness and death. An incorrect tuberculosis diagnosis may result in anxiety and unnecessary treatment. What is the aim of this review? To find out how accurate LF‐LAM is for diagnosing tuberculosis in HIV‐positive people with tuberculosis symptoms (symptomatic participants) and those not assessed for tuberculosis symptoms (unselected participants). This is an update of the 2016 Cochrane Review. What was studied in this review? LF‐LAM is a commercially available point‐of‐care test that detects lipoarabinomannan (LAM), a component of the bacterial cell walls, present in some people with active tuberculosis. The test is simple and shows results in 25 minutes. LF‐LAM results were measured against culture or molecular tests (benchmark). What are the main results of this review? Fifteen studies: eight studies evaluated LF‐LAM for tuberculosis among symptomatic participants and seven studies among unselected participants. All studies were conducted in low‐ or middle‐income countries. Tuberculosis diagnosis among symptomatic participants: LF‐LAM registered positive in 42% (sensitivity) of people who actually had tuberculosis and did not register positive in 91% of people who were actually negative (specificity). Tuberculosis diagnosis among unselected participants: LF‐LAM sensitivity was 35% and specificity 95%. How confident are we in the review’s results? Several studies excluded participants who could not produce sputum and most studies relied on a lower quality benchmark. Few studies and participants were included in some analyses and only one study was conducted outside of sub‐Saharan Africa. Results should be interpreted with caution. What do the results mean? Among symptomatic participants, in theory, for a population of 1000 people where 300 have microbiologically‐confirmed tuberculosis, the utilization of LF‐LAM would result in: 189 to be LF‐LAM positive: of these, 63 (33%) would not have tuberculosis (false‐positives); and 811 to be LF‐LAM negative: of these, 174 (21%) would have tuberculosis (false‐negatives). Among unselected participants, in theory, for a population of 1000 people where 100 have microbiologically‐confirmed tuberculosis, the utilization of LF‐LAM would result in: 80 to be LF‐LAM positive: of these, 45 (56%) would not have tuberculosis (false‐positives); and 920 to be LF‐LAM negative: of these, 65 (7%) would have tuberculosis (false‐negatives). Who do the review’s results apply to? HIV‐positive people with tuberculosis symptoms and those not assessed for tuberculosis symptoms. What are the implications of this review? LF‐LAM has sensitivity around 40% to detect tuberculosis. As the test does not require sputum collection, LF‐LAM may be the only way to diagnose tuberculosis when sputum cannot be produced. How up‐to‐date is this review? To 11 May 2018.

Background Xpert MTB/RIF (Xpert MTB/RIF) and Xpert MTB/RIF Ultra (Xpert Ultra), the newest version, are the only World Health Organization (WHO)‐recommended rapid tests that simultaneously detect tuberculosis and rifampicin resistance in persons with signs and symptoms of tuberculosis, at lower health system levels. A previous Cochrane Review found Xpert MTB/RIF sensitive and specific for tuberculosis (Steingart 2014). Since the previous review, new studies have been published. We performed a review update for an upcoming WHO policy review. Objectives To determine diagnostic accuracy of Xpert MTB/RIF and Xpert Ultra for tuberculosis in adults with presumptive pulmonary tuberculosis (PTB) and for rifampicin resistance in adults with presumptive rifampicin‐resistant tuberculosis. Search methods We searched the Cochrane Infectious Diseases Group Specialized Register, MEDLINE, Embase, Science Citation Index, Web of Science, Latin American Caribbean Health Sciences Literature, Scopus, the WHO International Clinical Trials Registry Platform, the International Standard Randomized Controlled Trial Number Registry, and ProQuest, to 11 October 2018, without language restriction. Selection criteria Randomized trials, cross‐sectional, and cohort studies using respiratory specimens that evaluated Xpert MTB/RIF, Xpert Ultra, or both against the reference standard, culture for tuberculosis and culture‐based drug susceptibility testing or MTBDRplus for rifampicin resistance. Data collection and analysis Four review authors independently extracted data using a standardized form. When possible, we also extracted data by smear and HIV status. We assessed study quality using QUADAS‐2 and performed meta‐analyses to estimate pooled sensitivity and specificity separately for tuberculosis and rifampicin resistance. We investigated potential sources of heterogeneity. Most analyses used a bivariate random‐effects model. For tuberculosis detection, we first estimated accuracy using all included studies and then only the subset of studies where participants were unselected, i.e. not selected based on prior microscopy testing. Main results We identified in total 95 studies (77 new studies since the previous review): 86 studies (42,091 participants) evaluated Xpert MTB/RIF for tuberculosis and 57 studies (8287 participants) for rifampicin resistance. One study compared Xpert MTB/RIF and Xpert Ultra on the same participant specimen. Tuberculosis detection Of the total 86 studies, 45 took place in high tuberculosis burden and 50 in high TB/HIV burden countries. Most studies had low risk of bias. Xpert MTB/RIF pooled sensitivity and specificity (95% credible Interval (CrI)) were 85% (82% to 88%) and 98% (97% to 98%), (70 studies, 37,237 unselected participants; high‐certainty evidence). We found similar accuracy when we included all studies. For a population of 1000 people where 100 have tuberculosis on culture, 103 would be Xpert MTB/RIF‐positive and 18 (17%) would not have tuberculosis (false‐positives); 897 would be Xpert MTB/RIF‐negative and 15 (2%) would have tuberculosis (false‐negatives). Xpert Ultra sensitivity (95% confidence interval (CI)) was 88% (85% to 91%) versus Xpert MTB/RIF 83% (79% to 86%); Xpert Ultra specificity was 96% (94% to 97%) versus Xpert MTB/RIF 98% (97% to 99%), (1 study, 1439 participants; moderate‐certainty evidence). Xpert MTB/RIF pooled sensitivity was 98% (97% to 98%) in smear‐positive and 67% (62% to 72%) in smear‐negative, culture‐positive participants, (45 studies). Xpert MTB/RIF pooled sensitivity was 88% (83% to 92%) in HIV‐negative and 81% (75% to 86%) in HIV‐positive participants; specificities were similar 98% (97% to 99%), (14 studies). Rifampicin resistance detection Xpert MTB/RIF pooled sensitivity and specificity (95% Crl) were 96% (94% to 97%) and 98% (98% to 99%), (48 studies, 8020 participants; high‐certainty evidence). For a population of 1000 people where 100 have rifampicin‐resistant tuberculosis, 114 would be positive for rifampicin‐resistant tuberculosis and 18 (16%) would not have rifampicin resistance (false‐positives); 886 would be would be negative for rifampicin‐resistant tuberculosis and four (0.4%) would have rifampicin resistance (false‐negatives). Xpert Ultra sensitivity (95% CI) was 95% (90% to 98%) versus Xpert MTB/RIF 95% (91% to 98%); Xpert Ultra specificity was 98% (97% to 99%) versus Xpert MTB/RIF 98% (96% to 99%), (1 study, 551 participants; moderate‐certainty evidence). Authors' conclusions We found Xpert MTB/RIF to be sensitive and specific for diagnosing PTB and rifampicin resistance, consistent with findings reported previously. Xpert MTB/RIF was more sensitive for tuberculosis in smear‐positive than smear‐negative participants and HIV‐negative than HIV‐positive participants. Compared with Xpert MTB/RIF, Xpert Ultra had higher sensitivity and lower specificity for tuberculosis and similar sensitivity and specificity for rifampicin resistance (1 study). Xpert MTB/RIF and Xpert Ultra provide accurate results and can allow rapid initiation of treatment for multidrug‐resistant tuberculosis., Xpert MTB/RIF and Xpert Ultra for diagnosing pulmonary tuberculosis and rifampicin resistance in adults Why is improving the diagnosis of pulmonary tuberculosis important? Tuberculosis causes more deaths globally than any other infectious disease. When detected early and effectively treated, tuberculosis is largely curable, but in 2017, around 1.6 million people died of tuberculosis. Xpert MTB/RIF and Xpert Ultra, the newest version, are World Health Organization‐recommended tests that simultaneously detect tuberculosis and rifampicin resistance in persons with tuberculosis symptoms. Rifampicin is an important anti‐tuberculosis drug. Not recognizing tuberculosis early may result in delayed diagnosis and treatment, severe illness, and death. An incorrect tuberculosis diagnosis may result in anxiety and unnecessary treatment. What is the aim of this review? To determine how accurate Xpert MTB/RIF and Xpert Ultra are for diagnosing pulmonary tuberculosis (PTB) and rifampicin resistance in adults. This is an update of the 2014 Cochrane Review. What was studied in this review? Xpert MTB/RIF and Xpert Ultra, with results measured against culture (benchmark). What are the main results in this review? 95 studies: 86 studies (42,091 participants) evaluated Xpert MTB/RIF for tuberculosis; 57 studies (8287 participants) for rifampicin resistance. One study compared Xpert Ultra and Xpert MTB/RIF. For PTB, Xpert MTB/RIF was sensitive (85%), registering positive in people who actually had tuberculosis, and specific (98%), i.e. it did not register positive in people who were actually negative. Xpert Ultra had higher sensitivity than Xpert MTB/RIF (88% versus 83%) in one study. For rifampicin resistance, Xpert MTB/RIF was highly sensitive (96%) and specific (98%). Xpert Ultra gave similar results. Xpert MTB/RIF was better for diagnosing tuberculosis in HIV‐negative than in HIV‐positive people. How confident are we in the results of this review? Confident. We included many studies and used the best reference standards. Who do the results of this review apply to? People with presumed PTB or rifampicin resistance. What are the implications of this review? In theory, among 1000 people where 100 have tuberculosis on culture, 103 would be Xpert MTB/RIF‐positive and 18 (17%) would not have tuberculosis (false‐positives); 897 would be Xpert MTB/RIF‐negative and 15 (2%) would have tuberculosis (false‐negatives). Among 1000 people where 100 have rifampicin resistance, 114 would be positive for rifampicin resistance and 18 (16%) would not have rifampicin resistance (false‐positives); 886 would be negative for rifampicin resistance and four (0.4%) would have rifampicin resistance (false‐negatives). How up‐to‐date is this review? To 11 October 2018.

Background Linezolid was recently re‐classified as a Group A drug by the World Health Organization (WHO) for treatment of multi‐drug resistant tuberculosis (MDR‐TB) and extensively drug‐resistant tuberculosis (XDR‐TB), suggesting that it should be included in the regimen for all patients unless contraindicated. Linezolid use carries a considerable risk of toxicity, with the optimal dose and duration remaining unclear. Current guidelines are mainly based on evidence from observational non‐comparative studies. Objectives To assess the efficacy of linezolid when used as part of a second‐line regimen for treating people with MDR and XDR pulmonary tuberculosis, and to assess the prevalence and severity of adverse events associated with linezolid use in this patient group. Search methods We searched the following databases: the Cochrane Infectious Diseases Specialized Register; CENTRAL; MEDLINE; Embase; and LILACS up to 13 July 2018. We also checked article reference lists and contacted researchers in the field. Selection criteria We included studies in which some participants received linezolid, and others did not. We included randomized controlled trials (RCTs) of linezolid for MDR and XDR pulmonary tuberculosis to evaluate efficacy outcomes. We added non‐randomized cohort studies to evaluate adverse events. Primary outcomes were all‐cause and tuberculosis‐associated death, treatment failure, and cure. Secondary outcomes were treatment interrupted, treatment completed, and time to sputum culture conversion. We recorded frequency of all and serious adverse events, adverse events leading to drug discontinuation or dose reduction, and adverse events attributed to linezolid, particularly neuropathy, anaemia, and thrombocytopenia. Data collection and analysis Two review authors (BS and DC) independently assessed the search results for eligibility and extracted data from included studies. All review authors assessed risk of bias using the Cochrane ‘Risk of bias' tool for RCTs and the ROBINS‐I tool for non‐randomized studies. We contacted study authors for clarification and additional data when necessary. We were unable to perform a meta‐analysis as one of the RCTs adopted a study design where participants in the study group received linezolid immediately and participants in the control group received linezolid after two months, and therefore there were no comparable data from this trial. We deemed meta‐analysis of non‐randomized study data inappropriate. Main results We identified three RCTs for inclusion. One of these studies had serious problems with allocation of the study drug and placebo, so we could not analyse data for intervention effect from it. The remaining two RCTs recruited 104 participants. One randomized 65 participants to receive linezolid or not, in addition to a background regimen; the other randomized 39 participants to addition of linezolid to a background regimen immediately, or after a delay of two months. We included 14 non‐randomized cohort studies (two prospective, 12 retrospective), with a total of 1678 participants. Settings varied in terms of income and tuberculosis burden. One RCT and 7 out of 14 non‐randomized studies commenced recruitment in or after 2009. All RCT participants and 38.7% of non‐randomized participants were reported to have XDR‐TB. Dosing and duration of linezolid in studies were variable and reported inconsistently. Daily doses ranged from 300 mg to 1200 mg; some studies had planned dose reduction for all participants after a set time, others had incompletely reported dose reductions for some participants, and most did not report numbers of participants receiving each dose. Mean or median duration of linezolid therapy was longer than 90 days in eight of the 14 non‐randomized cohorts that reported this information. Duration of participant follow‐up varied between RCTs. Only five out of 14 non‐randomized studies reported follow‐up duration. Both RCTs were at low risk of reporting bias and unclear risk of selection bias. One RCT was at high risk of performance and detection bias, and low risk for attrition bias, for all outcomes. The other RCT was at low risk of detection and attrition bias for the primary outcome, with unclear risk of detection and attrition bias for non‐primary outcomes, and unclear risk of performance bias for all outcomes. Overall risk of bias for the non‐randomized studies was critical for three studies, and serious for the remaining 11. One RCT reported higher cure (risk ratio (RR) 2.36, 95% confidence interval (CI) 1.13 to 4.90, very low‐certainty evidence), lower failure (RR 0.26, 95% CI 0.10 to 0.70, very low‐certainty evidence), and higher sputum culture conversion at 24 months (RR 2.10, 95% CI 1.30 to 3.40, very low‐certainty evidence), amongst the linezolid‐treated group than controls, with no differences in other primary and secondary outcomes. This study also found more anaemia (17/33 versus 2/32), nausea and vomiting, and neuropathy (14/33 versus 1/32) events amongst linezolid‐receiving participants. Linezolid was discontinued early and permanently in two of 33 (6.1%) participants who received it. The other RCT reported higher sputum culture conversion four months after randomization (RR 2.26, 95% CI 1.19 to 4.28), amongst the group who received linezolid immediately compared to the group who had linezolid initiation delayed by two months. Linezolid was discontinued early and permanently in seven of 39 (17.9%) participants who received it. Linezolid discontinuation occurred in 22.6% (141/624; 11 studies), of participants in the non‐randomized studies. Total, serious, and linezolid‐attributed adverse events could not be summarized quantitatively or comparatively, due to incompleteness of data on duration of follow‐up and numbers of participants experiencing events. Authors' conclusions We found some evidence of efficacy of linezolid for drug‐resistant pulmonary tuberculosis from RCTs in participants with XDR‐TB but adverse events and discontinuation of linezolid were common. Overall, there is a lack of comparative data on efficacy and safety. Serious risk of bias and heterogeneity in conducting and reporting non‐randomized studies makes the existing, mostly retrospective, data difficult to interpret. Further prospective cohort studies or RCTs in high tuberculosis burden low‐income and lower‐middle‐income countries would be useful to inform policymakers and clinicians of the efficacy and safety of linezolid as a component of drug‐resistant TB treatment regimens., Linezolid for managing people with drug‐resistant tuberculosis What is drug‐resistant tuberculosis, and how might linezolid work? Tuberculosis is caused by infection with Mycobacterium tuberculosis bacteria. When there are symptoms or signs of illness, this is called active tuberculosis. An estimated one‐third of the world's population are infected with tuberculosis, and around 1.4 million people died from active tuberculosis in 2015. Bacteria that cause tuberculosis can develop resistance to the drugs most commonly used to treat tuberculosis, also called first‐line antibiotics. This is an increasing problem that makes treatment more difficult, because second‐line tuberculosis treatment drugs are less powerful against the bacteria, and more likely to cause harmful effects. Standard treatment for drug‐resistant tuberculosis requires patients to take multiple antibiotics for nearly two years. Linezolid is a second‐line drug that laboratory studies have found to be good at killing bacteria that cause tuberculosis, but that can also cause frequent, serious harmful effects. The review question Recent international guidelines recommend trying to include linezolid in the treatment of all patients with multi‐drug resistant tuberculosis, but there is concern about whether enough good evidence exists to tell us how well it works, what dose is best, and how safe it is for people who take it. Study characteristics We searched for evidence up to 13 July 2018. We analysed data from two trials, one of which randomly allocated 65 people with drug‐resistant tuberculosis to either a linezolid‐containing or linezolid‐free drug combination, and another that randomly allocated 39 participants to receive linezolid as part of their treatment from the start or have it added after a delay of two months. We also included 14 studies, including 1678 people, in which some participants received linezolid but others did not, but this was not determined at random. What are the main results of the review? One trial showed a higher likelihood of cure and lower risk of treatment failure in participants receiving linezolid compared to those who did not. The second trial showed that participants who received linezolid immediately had a higher chance of tuberculosis being cleared from their sputum four months after the start of the study than those who added linezolid after a two‐month delay. When they examined safety, the first trial found a higher risk of developing low red blood cell counts, nausea and vomiting, and nerve damage in people receiving linezolid. From 11 of the non‐randomized studies that reported this, 22.6% of people had to stop linezolid due to adverse effects (side effects), though further comparisons of harmful effects were not possible due to incomplete reporting in the non‐randomized studies. Overall, although there is some evidence of benefit, we have very low certainty in its accuracy. More high‐quality studies are required before we can be certain how effective and safe linezolid is for drug‐resistant tuberculosis. How up‐to‐date is this review? This review is current up to 13 July 2018.