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Rifampin-resistant tuberculosis (RR-TB) is a key contributor to global antimicrobial resistance; >400,000 persons had RR-TB in 2020, nearly 40% of whom probably died as a result (1). More than 57% [...]

Rationale: C-reactive protein (CRP) has demonstrated utility as a point-of-care triage test for tuberculosis (TB) in clinical settings, particularly among people with human immunodeficiency virus (HIV), but its performance for general-population TB screening is not well characterized. Objective: To assess the accuracy of CRP for detecting pulmonary TB disease among individuals undergoing community-based screening or presenting for evaluation of TB symptoms in Kampala, Uganda. Methods: We pooled data from two case–control studies conducted between May 2018 and December 2022 among adolescents and adults (⩾15 yr) in Kampala, Uganda. We conducted community-based screening for TB, regardless of symptoms. We enrolled people with Xpert MTB/RIF Ultra–positive (including trace) sputum results and a sample of people with Ultra-negative results. We also enrolled symptomatic patients diagnosed with TB and controls with negative TB evaluations from ambulatory care settings. Participants underwent further evaluation, including sputum culture, CRP, and HIV testing. We assessed the accuracy of CRP alone or with symptom screening against a bacteriologic reference standard. Our primary analysis evaluated the sensitivity and specificity of CRP at a cutoff of 5 mg/L. Diagnostic performance was summarized by calculating the area under the receiver operating curve (AUC). Results: In the community setting (n = 544), CRP ⩾ 5 mg/L had a sensitivity of 55.3% (95% confidence interval, 47.0–63.4%) and specificity of 84.7% (79.7–88.8%) for confirmed TB; AUC was 0.75 (0.70–0.79). Screening for CRP ⩾ 5 mg/L or positive symptoms increased sensitivity to 92.0% (86.4–95.8%) at the expense of specificity (57.1% [50.8–63.2%]). In the ambulatory care setting (n = 944), sensitivity of CRP ⩾ 5 mg/L was 86.7% (81.8–90.7%), specificity was 68.6% (64.8–72.2%), and AUC (0.84 [0.81–0.87]) did not differ significantly by HIV status. CRP ⩾ 5 mg/L was >90% sensitive among individuals with a medium or high semiquantitative Xpert result in both settings. Conclusions: Although CRP did not meet World Health Organization (WHO) TB screening benchmarks in the community, it demonstrated high specificity, and sensitivity was high among individuals with high sputum bacillary burden who are likely to be most infectious. In ambulatory care, estimated sensitivity and specificity were each within 4 percentage points of WHO benchmarks, with no meaningful difference in performance by HIV status. [ABSTRACT FROM AUTHOR]

Background In settings with large case detection gaps, active case-finding (ACF) may play a critical role in the uberculosis (TB) response. However, ACF is resource intensive, and its effectiveness depends on whether people detected with TB through ACF might otherwise spontaneously resolve or be diagnosed through routine care. We analysed the potential effectiveness of ACF for TB relative to the counterfactual scenario of routine care alone. Methods We constructed a Markov simulation model of TB natural history, diagnosis, symptoms, ACF and treatment, using a hypothetical reference setting using data from South East Asian countries. We calibrated the model to empirical data using Bayesian methods, and simulated potential 5-year outcomes with an 'aspirational' ACF intervention (reflecting maximum possible effectiveness) compared with the standard-of-care outcomes. Results Under the standard of care, 51% (95% credible interval, CrI: 31%, 75%) of people with prevalent TB at baseline were estimated to be diagnosed and linked to care over 5 years. With aspirational ACF, this increased to 88% (95% CrI: 84%, 94%). Most of this difference represented people who were diagnosed and treated through ACF but experienced spontaneous resolution under standard-of-care. Aspirational ACF was projected to reduce the average duration of TB disease by 12 months (95% CrI: 6%, 18%) and TB-associated disability-adjusted life-years by 71% (95% CrI: 67%, 76%). Conclusion These data illustrate the importance of considering outcomes in a counterfactual standard of care scenario, as well as trade-offs between overdiagnosis and averted morbidity through earlier diagnosis—not just for TB, but for any disease in which population-based screening is recommended. [ABSTRACT FROM AUTHOR]

Background "Trace" results on Xpert MTB/RIF Ultra ("Ultra"; Cepheid) —a molecular diagnostic test for tuberculosis (TB)—are often interpreted as an indication for TB treatment, but may also represent detection of nonviable bacilli or analytical error. In community-screening settings where individual TB risk is low, there is limited guidance on how to interpret Ultra-trace results. Methods We conducted systematic Ultra TB screening of adults and adolescents (≥15 years) in Kampala, Uganda, through door-to-door and event-based sputum collection. We enrolled individuals with trace-positive sputum for detailed clinical, radiographic, and microbiological (including 2 sputum cultures, repeat Ultra, and for people with HIV, urine lipoarabinomannan) evaluation, and compared those findings with similar evaluations in controls with Ultra-negative and Ultra-positive (non-trace) sputum. Results Of 21 957 people screened with Ultra, 211 (1.0%) tested positive, including 96 (46% of positives) with trace results. Of 92 people enrolled with trace-positive sputum; 12% (11/92) were HIV-positive and 14% (13/92) had prior TB. The prevalence of TB among participants with trace-positive sputum results was 14% (13/92) by culture, 24% (22/92) using broader microbiological criteria, and 26% (24/92) after accounting for clinical diagnosis. The prevalence of cough and of abnormal chest computed tomography (CT) findings were 32% and 26%, respectively, if Ultra-negative; 34% and 54% if trace-positive/non–microbiologically confirmed; 72% and 95% if trace-positive/microbiologically confirmed; and 71% and 93% if Ultra-positive (more than trace). Conclusions Most individuals with trace-positive sputum in Ugandan communities did not have microbiologically confirmed TB but had more symptoms and chest CT abnormalities than people with Ultra-negative sputum. [ABSTRACT FROM AUTHOR]

Background Several clinical trials of tuberculosis preventive treatment (TPT) for household contacts of patients with multidrug- or rifampin-resistant tuberculosis (MDR/RR-TB) are nearing completion. The potential benefits of delivering TPT to MDR/RR-TB contacts extend beyond the outcomes that clinical trials can measure. Methods We developed an agent-based, household-structured TB and MDR/RR-TB transmission model, calibrated to an illustrative setting in India. We simulated contact investigation in households of patients with MDR/RR-TB, comparing an MDR/RR-TPT regimen (assuming 6-month duration, 70% efficacy) and associated active case finding against alternatives of contact investigation without TPT or no household intervention. We simulated the TB and MDR/RR-TB incidence averted relative to placebo over 2 years, as measurable by a typical trial, as well as the incidence averted over a longer time horizon, in the broader population, and relative to no contact investigation. Results Observing TPT and placebo recipients for 2 years as in a typical trial, MDR/RR-TPT was measured to prevent 72% (interquartile range, 45%–100%) of incident MDR/RR-TB among recipients; the median number needed to treat (NNT) to prevent 1 MDR/RR-TB case was 73, compared to placebo. This NNT decreased to 54 with 13–18 years of observation, to 27 when downstream transmission effects were also considered, and to 12 when the effects of active TB screening were included by comparing to a no-household-contact-intervention scenario. Conclusions If forthcoming trial results demonstrate efficacy, the long-term population impact of TPT for MDR/RR-TB—including the large effect of increased active TB detection among MDR/RR-TB contacts—could be much greater than suggested by trial outcomes alone. [ABSTRACT FROM AUTHOR]

Introduction In high-burden settings, low-complexity screening tests for tuberculosis (TB) could expand the reach of community-based case-finding efforts. The potential costs and cost-effectiveness of approaches incorporating these tests are poorly understood. Methods We developed a microsimulation model assessing 3 approaches to community-based case-finding in hypothetical populations (India-, South Africa-, The Philippines-, Uganda-, and Vietnam-like settings) with TB prevalence 4 times that of national estimates: (1) screening with a point-of-care C-reactive protein (CRP) test, (2) screening with a more sensitive "Hypothetical Screening test" (95% sensitive for Xpert Ultra-positive TB, 70% specificity; equipment/labor costs similar to Xpert Ultra, but using a $2 cartridge) followed by sputum Xpert Ultra if positive, or (3) testing all individuals with sputum Xpert Ultra. Costs are expressed in 2023 US dollars and include treatment costs. Results Universal Xpert Ultra was estimated to cost a mean $4.0 million (95% uncertainty range: $3.5 to $4.6 million) and avert 3200 (2600 to 3900) TB-related disability-adjusted life years (DALYs) per 100 000 people screened ($670 [The Philippines] to $2000 [Vietnam] per DALY averted). CRP was projected to cost $550 (The Philippines) to $1500 (Vietnam) per DALY averted but with 44% fewer DALYs averted. The Hypothetical Screening test showed minimal benefit compared to universal Xpert Ultra, but if specificity were improved to 95% and per-test cost to $4.5 (all-inclusive), this strategy could cost $390 (The Philippines) to $940 (Vietnam) per DALY averted. Conclusions Screening tests can meaningfully improve the cost-effectiveness of community-based case-finding for TB but only if they are sensitive, specific, and inexpensive. [ABSTRACT FROM AUTHOR]

Ultralight dark matter (ULDM) is an interesting alternative to the cold dark matter (CDM) paradigm. Due to the extremely low mass of the constituent particle (∼10−22 eV), ULDM can exhibit quantum effects up to kiloparsec scales. In particular, runaway collapse in the centres of ULDM haloes is prevented by quantum pressure, providing a possible resolution to the 'core-cusp problem' of CDM. However, the the detailed relationship between the ULDM core mass and that of the overall halo is poorly understood. We simulate the collapse of both spherical and aspherical isolated ULDM overdensities using AxioNyx , finding that the central cores of collapsed haloes undergo sustained oscillatory behaviour, which affects both their peak density and overall morphology. The asphericity of the post-collapse core fluctuates both quantitatively and qualitatively, with oblate initial overdensities generating cores, which fluctuate between prolate and oblate configurations, and more complicated dynamics arising in triaxial scenarios. Furthermore, the peak central densities are higher in spherical configurations. Consequently, astrophysically realistic haloes may exhibit substantial departures from theoretical core–halo profiles and we would expect a significant variance of the properties of haloes with the same mass. [ABSTRACT FROM AUTHOR]

Background In highly resource-limited settings, many clinics lack same-day microbiological testing for active tuberculosis (TB). In these contexts, risk of pretreatment loss to follow-up is high, and a simple, easy-to-use clinical risk score could be useful. Methods and findings We analyzed data from adults tested for TB with Xpert MTB/RIF across 28 primary health clinics in rural South Africa (between July 2016 and January 2018). We used least absolute shrinkage and selection operator regression to identify characteristics associated with Xpert-confirmed TB and converted coefficients into a simple score. We assessed discrimination using receiver operating characteristic (ROC) curves, calibration using Cox linear logistic regression, and clinical utility using decision curves. We validated the score externally in a population of adults tested for TB across 4 primary health clinics in urban Uganda (between May 2018 and December 2019). Model development was repeated de novo with the Ugandan population to compare clinical scores. The South African and Ugandan cohorts included 701 and 106 individuals who tested positive for TB, respectively, and 686 and 281 randomly selected individuals who tested negative. Compared to the Ugandan cohort, the South African cohort was older (41% versus 19% aged 45 years or older), had similar breakdown of biological sex (48% versus 50% female), and had higher HIV prevalence (45% versus 34%). The final prediction model, scored from 0 to 10, included 6 characteristics: age, sex, HIV (2 points), diabetes, number of classical TB symptoms (cough, fever, weight loss, and night sweats; 1 point each), and >14-day symptom duration. Discrimination was moderate in the derivation (c-statistic = 0.82, 95% CI = 0.81 to 0.82) and validation (c-statistic = 0.75, 95% CI = 0.69 to 0.80) populations. A patient with 10% pretest probability of TB would have a posttest probability of 4% with a score of 3/10 versus 43% with a score of 7/10. The de novo Ugandan model contained similar characteristics and performed equally well. Our study may be subject to spectrum bias as we only included a random sample of people without TB from each cohort. This score is only meant to guide management while awaiting microbiological results, not intended as a community-based triage test (i.e., to identify individuals who should receive further testing). Conclusions In this study, we observed that a simple clinical risk score reasonably distinguished individuals with and without TB among those submitting sputum for diagnosis. Subject to prospective validation, this score might be useful in settings with constrained diagnostic resources where concern for pretreatment loss to follow-up is high., Author(s): Yeonsoo Baik 1,*, Hannah M. Rickman 1, Colleen F. Hanrahan 1, Lesego Mmolawa 2, Peter J. Kitonsa 3, Tsundzukana Sewelana 2, Annet Nalutaaya 3, Emily A. Kendall 3,4, Limakatso [...]

The importance of finding people with undiagnosed tuberculosis (TB) hinges on their future disease trajectories. Assays for systematic screening should be optimized to find those whose TB will contribute most to future transmission or morbidity. In this study, we constructed a mathematical model that tracks the future trajectories of individuals with TB at a cross-sectional timepoint ("baseline"), classifying them by bacterial burden (smear positive/negative) and symptom status (symptomatic/subclinical). We used Bayesian methods to calibrate this model to targets derived from historical survival data and notification, mortality, and prevalence data from five countries. We combined resulting disease trajectories with evidence on infectiousness to estimate each baseline TB state's contribution to future transmission. For a person with smear-negative subclinical TB at baseline, the expected future duration of disease was short (mean 4.8 [95% uncertainty interval 3.3 to 8.4] mo); nearly all disease courses ended in spontaneous resolution, not treatment. In contrast, people with baseline smear-positive subclinical TB had longer undiagnosed disease durations (15.9 [11.1 to 23.5] mo); nearly all eventually developed symptoms and ended in treatment or death. Despite accounting for only 11 to 19% of prevalent disease, smear-positive subclinical TB accounted for 35 to 51% of future transmission--a greater contribution than symptomatic or smear-negative TB. Subclinical TB with a high bacterial burden accounts for a disproportionate share of future transmission. Priority should be given to developing inexpensive, easy-to-use assays for screening both symptomatic and asymptomatic individuals at scale--akin to rapid antigen tests for other diseases--even if these assays lack the sensitivity to detect paucibacillary disease. [ABSTRACT FROM AUTHOR]

Background The Xpert MTB/RIF (Xpert) assay offers rapid and accurate diagnosis of tuberculosis (TB) but still suffers from imperfect sensitivity. The newer Xpert MTB/RIF Ultra cartridge has shown improved sensitivity in recent field trials, but at the expense of reduced specificity. The clinical implications of switching from the existing Xpert cartridge to the Xpert Ultra cartridge in different populations remain uncertain. Methods and findings We developed a Markov microsimulation model of hypothetical cohorts of 100,000 individuals undergoing diagnostic sputum evaluation with Xpert for suspected pulmonary TB, in each of 3 emblematic settings: an HIV clinic in South Africa, a public TB center in India, and an adult primary care setting in China. In each setting, we used existing data to project likely diagnostic results, treatment decisions, and ultimate clinical outcomes, assuming use of the standard Xpert versus Xpert Ultra cartridge. Our primary outcomes were the projected number of additional unnecessary treatments generated, the projected number of TB deaths averted, and the projected number of unnecessary treatments generated per TB death averted, if standard Xpert were switched to Xpert Ultra. We also simulated alternative approaches to interpreting positive results of the Ultra cartridge's semi-quantitative trace call. Extensive sensitivity and uncertainty analyses were performed to evaluate the drivers and generalizability of projected results. In the Indian TB center setting, replacing the standard Xpert cartridge with the Xpert Ultra cartridge was projected to avert 0.5 TB deaths (95% uncertainty range [UR]: 0, 1.3) and generate 18 unnecessary treatments (95% UR: 10, 29) per 1,000 individuals evaluated-resulting in a median ratio of 38 incremental unnecessary treatments added by Ultra per incremental death averted by Ultra compared to outcomes using standard Xpert (95% UR: 12, indefinite upper bound). In the South African HIV care setting-where TB mortality rates are higher and Ultra's improved sensitivity has greater absolute benefit-this ratio improved to 7 unnecessary treatments per TB death averted (95% UR: 2, 43). By contrast, in the Chinese primary care setting, this ratio was much less favorable, at 372 unnecessary treatments per TB death averted (95% UR: 75, indefinite upper bound), although the projected number of unnecessary treatments using Xpert Ultra was lower (with a possibility of no increased overtreatment) when using specificity data only from lower-burden settings. Alternative interpretations of the trace call had little effect on these ratios. Limitations include uncertainty in key parameters (including the clinical implications of false-negative results), the exclusion of transmission effects, and restriction of this analysis to adult pulmonary TB. Conclusions Switching from the standard Xpert cartridge to the Xpert Ultra cartridge for diagnosis of adult pulmonary TB may have different consequences in different clinical settings. In settings with high TB and HIV prevalence, Xpert Ultra is likely to offer considerable mortality benefit, whereas in lower-prevalence settings, Xpert Ultra will likely result in considerable overtreatment unless the possibility of higher specificity of Ultra in lower-prevalence settings in confirmed. The ideal use of the Ultra cartridge may therefore involve a more nuanced, setting-specific approach to implementation, with priority given to populations in which the anticipated prevalence of TB (and HIV) is the highest., Author(s): Emily A. Kendall 1,*, Samuel G. Schumacher 2, Claudia M. Denkinger 2, David W. Dowdy 3 Introduction Introduced in 2010, Xpert MTB/RIF (Xpert)-a molecular assay for the detection of [...]

The genetic relatedness of Vibrio cholerae O1/O139 isolates obtained from 100 patients and 146 of their household contacts in Dhaka, Bangladesh, between 2002 and 2005 was assessed by multilocus variable-number tandem-repeat analysis. Isolate genotypes were analyzed at five loci containing tandem repeats. Across the population, as well as within households, isolates with identical genotypes were clustered in time. Isolates from individuals within the same household were more likely to have similar or identical genotypes than were isolates from different households, but even within a household, isolates from different individuals often had different genotypes. When household contacts were sampled regularly for 3 weeks after the illness of the household index patient, isolates with genotypes related to the index patient appeared in contacts, on average, ~3 clays after the index patient, while isolates with unrelated genotypes appeared in contacts ~6 days after. Limited data revealed that multiple isolates from the same individual collected within days of each other or even from a single stool sample may have identical, similar, or unrelated genotypes as well. Our results demonstrate that genetically related V. cholerae strains cluster in local outbreaks but also suggest that multiple distinct strains of V. cholerae O1 may circulate simultaneously within a household. doi: 10.1128/JB.00698-10

Background Novel drug regimens are needed for tuberculosis (TB) treatment. New regimens aim to improve on characteristics such as duration, efficacy, and safety profile, but no single regimen is likely to be ideal in all respects. By linking these regimen characteristics to a novel regimen's ability to reduce TB incidence and mortality, we sought to prioritize regimen characteristics from a population-level perspective. Methods and Findings We developed a dynamic transmission model of multi-strain TB epidemics in hypothetical populations reflective of the epidemiological situations in India (primary analysis), South Africa, the Philippines, and Brazil. We modeled the introduction of various novel rifampicin-susceptible (RS) or rifampicin-resistant (RR) TB regimens that differed on six characteristics, identified in consultation with a team of global experts: (1) efficacy, (2) duration, (3) ease of adherence, (4) medical contraindications, (5) barrier to resistance, and (6) baseline prevalence of resistance to the novel regimen. We compared scale-up of these regimens to a baseline reflective of continued standard of care. For our primary analysis situated in India, our model generated baseline TB incidence and mortality of 157 (95% uncertainty range [UR]: 113-187) and 16 (95% UR: 9-23) per 100,000 per year at the time of novel regimen introduction and RR TB incidence and mortality of 6 (95% UR: 4-10) and 0.6 (95% UR: 0.3-1.1) per 100,000 per year. An optimal RS TB regimen was projected to reduce 10-y TB incidence and mortality in the India-like scenario by 12% (95% UR: 6%-20%) and 11% (95% UR: 6%-20%), respectively, compared to current-care projections. An optimal RR TB regimen reduced RR TB incidence by an estimated 32% (95% UR: 18%-46%) and RR TB mortality by 30% (95% UR: 18%-44%). Efficacy was the greatest determinant of impact; compared to a novel regimen meeting all minimal targets only, increasing RS TB treatment efficacy from 94% to 99% reduced TB mortality by 6% (95% UR: 1%-13%, half the impact of a fully optimized regimen), and increasing the efficacy against RR TB from 76% to 94% lowered RR TB mortality by 13% (95% UR: 6%-23%). Reducing treatment duration or improving ease of adherence had smaller but still substantial impact: shortening RS TB treatment duration from 6 to 2 mo lowered TB mortality by 3% (95% UR: 1%-6%), and shortening RR TB treatment from 20 to 6 mo reduced RR TB mortality by 8% (95% UR: 4%-13%), while reducing nonadherence to the corresponding regimens by 50% reduced TB and RR TB mortality by 2% (95% UR: 1%-4%) and 6% (95% UR: 3%-10%), respectively. Limitations include sparse data on key model parameters and necessary simplifications to model structure and outcomes. Conclusions In designing clinical trials of novel TB regimens, investigators should consider that even small changes in treatment efficacy may have considerable impact on TB-related incidence and mortality. Other regimen improvements may still have important benefits for resource allocation and outcomes such as patient quality of life., Author(s): Emily A. Kendall 1,*, Sourya Shrestha 2, Ted Cohen 3, Eric Nuermberger 1, Kelly E. Dooley 1,4, Lice Gonzalez-Angulo 5, Gavin J. Churchyard 6, Payam Nahid 7, Michael L. [...]

Background: SARS-CoV-2 antigen-detection rapid diagnostic tests can diagnose COVID-19 rapidly and at low cost, but lower sensitivity compared with reverse-transcriptase polymerase chain reaction (PCR) has limited clinical adoption.Methods: We compared antigen testing, PCR testing, and clinical judgment alone for diagnosing symptomatic COVID-19 in an outpatient setting (10% COVID-19 prevalence among the patients tested, 3-day PCR turnaround) and a hospital setting (40% prevalence, 24-hour PCR turnaround). We simulated transmission from cases and contacts, and relationships between time, viral burden, transmission, and case detection. We compared diagnostic approaches using a measure of net benefit that incorporated both clinical and public health benefits and harms of intervention.Results: In the outpatient setting, we estimated that using antigen testing instead of PCR to test 200 individuals could be equivalent to preventing all symptomatic transmission from one person with COVID-19 (one "transmission-equivalent"). In a hospital, net benefit analysis favored PCR, and testing 25 patients with PCR instead of antigen testing achieved one transmission-equivalent of benefit. In both settings, antigen testing was preferable to PCR if PCR turnaround time exceeded 2 days. Both tests provided greater net benefit than management based on clinical judgment alone, unless intervention carried minimal harm and was provided equally regardless of diagnostic approach.Conclusions: For diagnosis of symptomatic COVID-19, we estimated that speed of diagnosis with antigen testing is likely to outweigh its lower accuracy compared to PCR wherever PCR turnaround time is 2 days or longer. This advantage may be even greater if antigen tests are also less expensive. [ABSTRACT FROM AUTHOR]

Abstract Background Frequent reporting of cases of hysterical conversion reaction (HCR) among hospitalized female medical patients in Bangladesh’s public hospital system led us to explore the prevalence of “HCR” diagnoses within hospitals and the manner in which physicians identify, manage, and perceive patients whom they diagnose with HCR. Methods We reviewed admission records from women’s general medicine wards in two public hospitals to determine how often and at what point during hospitalization patients received diagnoses of HCR. We also interviewed 13 physicians about their practices and perceptions related to HCR. Results Of 2520 women admitted to the selected wards in 2008, 6% received diagnoses of HCR. HCR patients had wide-ranging symptoms including respiratory distress, headaches, chest pain, convulsions, and abdominal complaints. Most doctors diagnosed HCR in patients who had any medically-unexplained physical symptom. According to physician reports, women admitted to medical wards for HCR received brief diagnostic evaluations and initial treatment with short-acting tranquilizers or placebo agents. Some were referred to outpatient psychiatric treatment. Physicians reported that repeated admissions for HCR were common. Physicians noted various social factors associated with HCR, and they described failures of the current system to meet psychosocial needs of HCR patients. Conclusions In these hospital settings, physicians assign HCR diagnoses frequently and based on vague criteria. We recommend providing education to increase general physicians’ awareness, skill, and comfort level when encountering somatization and other common psychiatric issues. Given limited diagnostic capacity for all patients, we raise concern that when HCR is used as a "wastebasket" diagnosis for unexplained symptoms, patients with treatable medical conditions may go unrecognized. We also advocate introducing non-physician hospital personnel to address psychosocial needs of HCR patients, assist with triage in a system where both medical inpatient beds and psychiatric services are scarce commodities, and help ensure appropriate follow up.

Background New, sensitive diagnostic tests facilitate identification and investigation of milder forms of tuberculosis (TB) disease. We used community-based TB testing with the Xpert MTB/RIF Ultra assay ("Ultra") to characterize individuals with previously undiagnosed TB and compare them to those from the same community who were diagnosed with TB through routine care. Methods We offered community-based sputum Ultra testing to adult residents of a well-defined area (population 34 000 adults) in Kampala, Uganda, via door-to-door screening and venue-based testing, then used detailed interview and laboratory testing to characterize TB-positive individuals. We compared these individuals to residents diagnosed with pulmonary TB at local health facilities and a representative sample of residents without TB (controls). Results Of 12 032 residents with interpretable Ultra results, 113 (940 [95% confidence interval {CI}, 780–1130] per 100 000) tested positive, including 71 (63%) positive at the lowest (trace) level. A spectrum of TB disease was observed in terms of chronic cough (93% among health facility–diagnosed cases, 77% among residents with positive community-based Ultra results at levels above trace, 33% among trace-positive community participants, and 18% among TB-negative controls), TB symptom prevalence (99%, 87%, 60%, and 38%, respectively), and C-reactive protein (75th percentile: 101 mg/L, 28 mg/L, 6 mg/L, and 4 mg/L, respectively). Community-diagnosed cases were less likely than health facility–diagnosed cases to have human immunodeficiency virus coinfection or previous TB. The specificity of Ultra was 99.4% (95% CI, 99.2%–99.5%) relative to a single spot sputum culture. Conclusions People with undiagnosed prevalent TB in the community have different characteristics than those diagnosed with pulmonary TB in health facilities. Newer diagnostic tests may identify a group of people with early or very mild disease. [ABSTRACT FROM AUTHOR]

Background: International and internal migration are recognized risk factors for tuberculosis (TB). Geographic mobility, including travel for work, education, or personal reasons, may also play a role in TB transmission, but this relationship is poorly defined. We aimed to define geographic mobility among participants in facility- and community-based TB case finding in Kampala, Uganda, and to assess associations between mobility, access to care, and TB disease. Methods: We included consecutive individuals age ≥15 years diagnosed with TB disease through either routine health facility practices or community-based case finding (consisting of door-to-door testing, venue-based screening, and contact investigation). Each case was matched with one (for community-based enrollment) or two (health facility enrollment) TB-negative controls. We conducted a latent class analysis (LCA) of eight self-reported characteristics to identify and define mobility; we selected the best-fit model using Bayesian Information Criterion. We assessed associations between mobility and TB case status using multivariable conditional logistic regression. Results: We enrolled 267 cases and 432 controls. Cases were more likely than controls to have been born in Kampala (p<0.001); there was no difference between cases and controls for remaining mobility characteristics. We selected a two-class LCA model; the "mobile" class was perfectly correlated with a single variable: travel (>3 km) from residence ≥2 times per month. Mobility was associated with a 28% reduction in odds of being a TB case (adjusted matched odds ratio 0.72 [95% confidence interval 0.49, 1.06]). Conclusion: Frequency of out-of-neighborhood travel is an easily measured variable that correlates closely with predicted mobility class membership. Mobility was associated with decreased risk of TB disease; this may be in part due to the higher socioeconomic status of mobile individuals in this population. However, more research is needed to improve assessment of mobility and understand how mobility affects disease risk and transmission. [ABSTRACT FROM AUTHOR]

The article examines that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is increasingly recognized that individuals without recognizable symptoms play an important role in the transmission of infectious pathogens. Topics include reports that World Health Organization has adopted ambitious targets to end the TB epidemic, including several percentage reduction in incidence from 2015 to 2035.

Background: When evaluating symptomatic patients for tuberculosis (TB) without access to same-day diagnostic test results, clinicians often make empiric decisions about starting treatment. The number of TB symptoms and/or underweight status could help identify patients at highest risk for a positive result. We sought to evaluate the usefulness of BMI assessment and a count of characteristic TB symptoms for identifying patients at highest risk for TB. Methods: We enrolled adult patients receiving pulmonary TB diagnoses and a representative sample with negative TB evaluations at four outpatient health facilities in Kampala, Uganda. We asked patients about symptoms of chronic cough, night sweats, chest pain, fever, hemoptysis, or weight loss; measured height and weight; and collected sputum for mycobacterial culture. We evaluated the diagnostic accuracy (for culture-positive TB) of two simple scoring systems: (a) number of TB symptoms, and (b) number of TB symptoms plus one or more additional points for underweight status (body mass index [BMI] ≤ 18.5 kg/m2). Results: We included 121 patients with culture-positive TB and 370 patients with negative culture results (44 of whom had been recommended for TB treatment by evaluating clinicians). Of the six symptoms assessed, the median number of symptoms that patients reported was two (interquartile range [IQR]: 1, 3). The median BMI was 20.9 kg/m2 (IQR: 18.6, 24.0), and 118 (24%) patients were underweight. Counting the number of symptoms provided an area under the Receiver Operating Characteristic curve (c-statistic) of 0.77 (95% confidence interval, CI: 0.72, 0.81) for identifying culture-positive TB; adding two points for underweight status increased the c-statistic to 0.81 (95%CI: 0.76, 0.85). A cutoff of ≥3 symptoms had sensitivity and specificity of 65% and 74%, whereas a score of ≥4 on the combined score (≥2 symptoms if underweight, ≥4 symptoms if not underweight) gave higher sensitivity and specificity of 69% and 81% respectively. A sensitivity analysis defining TB by Xpert MTB/RIF status produced similar results. Conclusion: A count of patients' TB symptoms may be useful in clinical decision-making about TB diagnosis. Consideration of underweight status adds additional diagnostic value. [ABSTRACT FROM AUTHOR]

Background To appropriately treat tuberculosis (TB) with regimens that combine novel and older drugs, evidence-based, context-specific strategies for drug-susceptibility testing (DST) will be required. Methods We created a Markov state-transition model of 100 000 adults with TB receiving a novel, fluoroquinolone (FQ)–containing regimen. We estimated clinical outcomes and resource utilization with no FQ-DST, universal FQ-DST, or FQ-DST only for patients with rifampin-resistant TB ("targeted FQ-DST"). We considered scenarios of stronger (South Africa) and weaker (Southeast Asia) correlation of fluoroquinolone resistance with rifampin resistance, with sensitivity analysis for other setting and regimen characteristics. Results Relative to no FQ-DST, targeted FQ-DST increased cure of FQ-resistant TB by 7.5% (interquartile range [IQR], 6.7%–9.2%) in South Africa and 1.7% (IQR, 0.7%–2.5%) in Southeast Asia. However, rare FQ resistance among the more prevalent rifampin-susceptible TB accounted for 50% of FQ-resistant TB in South Africa and 83% in Southeast Asia. As a result, universal FQ-DST further increased cure of FQ-resistant TB by 3.4% (IQR, 2.3%–5.4%) in South Africa and 5.8% (IQR, 5.1%–6.3%) in Southeast Asia. With targeted FQ-DST, 1 additional patient was cured per 50 (IQR, 42–70) tests in South Africa and 44 (IQR, 37–51) in Southeast Asia. When expanding from targeted to universal FQ-DST, 1 additional cure required 3500 (IQR, 2300–5500) tests in South Africa and 410 (IQR, 370–450) in Southeast Asia. Conclusions FQ-DST improved patient outcomes and was particularly important for high-risk patient groups and less robust regimens. A universal strategy was favored in generalized epidemics of fluoroquinolone resistance. [ABSTRACT FROM AUTHOR]

At the onset of an interaction between two initially independent systems, each system tends to experience an increase in its n-Rényi entropies, such as its von Neumann entropy (n = 1) and its mixedness (n = 2). We here ask which properties of a system determine how quickly its Rényi entropies increase and, therefore, how sensitive the system is to becoming entangled. We find that the rate at which the n-Rényi entropy increases in an interaction is determined by a quantity which we term the n-fragility of the system. The 2-fragility is closely related to the notion of 2-norm coherence, in that it too quantifies the extent to which a density matrix is 'off-diagonal' with respect to the eigenbasis of a reference operator. Nevertheless, the 2-fragility is not a coherence monotone in the resource theoretic sense since it depends also on the eigenvalues of the reference operator. It is this additional sensitivity to the eigenvalues of the reference operator, here the interaction Hamiltonian, which enables the 2-fragility to quantify the rate of entropy production in interactions. We give an example using the light–matter interaction and we anticipate applications to the study of the rates at which two systems exchange classical and quantum information when starting to interact. [ABSTRACT FROM AUTHOR]

The article explores contact tracing, besides being a useful public health tool for both finding super spreaders and treating the exposed, is often central to learning about the dynamics of disease transmission. In their article in this issue of Clinical Infectious Diseases, Martinez and colleagues demonstrate this utility, by using contact investigation data to evaluate the association between tuberculosis (TB) and human immunodeficiency virus (HIV) from the perspective of TB transmission.