Who Transmits Tuberculosis to Whom: A Cross-Sectional Analysis of a Cohort Study in Lima, Peru.

Rationale: The persistent burden of tuberculosis (TB) disease emphasizes the need to identify individuals with TB for treatment and those at a high risk of incident TB for prevention. Targeting interventions toward those at high risk of developing and transmitting TB is a public health priority. Objectives: We aimed to identify characteristics of individuals involved in TB transmission in a community setting, which may guide the prioritization of targeted interventions. Methods: We collected clinical and sociodemographic data from a cohort of patients with TB in Lima, Peru. We used whole-genome sequencing data to assess the genetic distance between all possible pairs of patients; we considered pairs to be the result of a direct transmission event if they differed by three or fewer SNPs, and we assumed that the first diagnosed patient in a pair was the transmitter and the second was the recipient. We used logistic regression to examine the association between host factors and the likelihood of direct TB transmission. Measurements and Main Results: Analyzing data from 2,518 index patients with TB, we identified 1,447 direct transmission pairs. Regardless of recipient attributes, individuals less than 34 years old, males, and those with a history of incarceration had a higher likelihood of being transmitters in direct transmission pairs. Direct transmission was more likely when both patients were drinkers or smokers. Conclusions: This study identifies men, young adults, former prisoners, alcohol consumers, and smokers as priority groups for targeted interventions. Innovative strategies are needed to extend TB screening to social groups such as young adults and prisoners with limited access to routine preventive care.

Spatial scale of tuberculosis transmission in Lima, Peru.

Spatially targeted interventions may be effective alternatives to individual or population-based prevention strategies against tuberculosis (TB). However, their efficacy may depend on the mechanisms that lead to geographically constrained hotspots. Local TB incidence may reflect high levels of local transmission; conversely, they may point to frequent travel of community members to high-risk areas. We used whole-genome sequencing to explore patterns of TB incidence and transmission in Lima, Peru. Between 2009 and 2012, we recruited incident pulmonary TB patients and their household contacts, whom we followed for the occurrence of TB disease. We used whole-genome sequences of 2,712 Mycobacterial tuberculosis isolates from 2,440 patients to estimate pariwise genomic distances and compared these to the spatial distance between patients' residences. Genomic distances increased rapidly as spatial distances increased and remained high beyond 2 km of separation. Next, we divided the study catchment area into 1 × 1 km grid-cell surface units and used household spatial coordinates to locate each TB patient to a specific cell. We estimated cell-specific transmission by calculating the proportion of patients in each cell with a pairwise genomic distance of 10 or fewer single-nucleotide polymorphisms. We found that cell-specific TB incidence and local transmission varied widely but that cell-specific TB incidence did not correlate closely with our estimates of local transmission (Cohen's k = 0.27). These findings indicate that an understanding of the spatial heterogeneity in the relative proportion of TB due to local transmission may help guide the implementation of spatially targeted interventions.

Safety and effectiveness of three novel all-oral shortened regimens for rifampicin- or multidrug-resistant tuberculosis in Kazakhstan.

BACKGROUND: In 2019, WHO called for operational research on all-oral shortened regimens for multidrug- and rifampicin-resistant tuberculosis (MDR/RR-TB). We report safety and effectiveness of three nine-month all-oral regimens containing bedaquiline (Bdq), linezolid (Lzd), and levofloxacin (Lfx) and reinforced with cycloserine (Cs) and clofazimine (Cfz), delamanid (Dlm) and pyrazinamide (Z), or Dlm and Cfz. METHODS: We conducted a prospective cohort study of patients initiating treatment for pulmonary MDR/RR-TB under operational research conditions at public health facilities in Kazakhstan. Participants were screened monthly for adverse events. Participants with baseline resistance were excluded from the study and treated with a longer regimen. We analyzed clinically relevant adverse events of special interest in all participants and sputum culture conversion and end-of-treatment outcomes among individuals who were not excluded. RESULTS: Of 510 participants, 41% were women, median age was 37 years (interquartile range: 28-49), 18% had a body mass index <18·5 kg/m2, and 51% had cavitary disease. Three hundred and ninety-nine (78%) initiated Bdq-Lzd-Lfx-Cs-Cfz, 83 (16%) started Bdq-Lzd-Lfx-Dlm-Z, and 28 (5%) initiated Bdq-Lzd-Lfx-Dlm-Cfz. Fifty-eight individuals (11%) were excluded from the study, most commonly due to identification of baseline drug resistance (n = 52; 90%). Among the remaining 452 participants, treatment success frequencies were 92% (95% confidence interval [CI]: 89 to 95), 89% (95%CI: 80 to 94), and 100% (95%CI: 86 to 100) for regimens with Cs/Cfz, Dlm/Z, and Dlm/Cfz respectively. Clinically-relevant adverse events of special interest were uncommon. CONCLUSION: All regimens demonstrated excellent safety and effectiveness, expanding the potential treatment options for patients, providers, and programs.

Effectiveness of Bedaquiline Use beyond Six Months in Patients with Multidrug-Resistant Tuberculosis.

Rationale: Current recommendations for the treatment of rifampicin- and multidrug-resistant tuberculosis include bedaquiline (BDQ) used for 6 months or longer. Evidence is needed to inform the optimal duration of BDQ. Objectives: We emulated a target trial to estimate the effect of three BDQ duration treatment strategies (6, 7-11, and ⩾12 mo) on the probability of successful treatment among patients receiving a longer individualized regimen for multidrug-resistant tuberculosis. Methods: To estimate the probability of successful treatment, we implemented a three-step approach comprising cloning, censoring, and inverse probability weighting. Measurements and Main Results: The 1,468 eligible individuals received a median of 4 (interquartile range, 4-5) likely effective drugs. In 87.1% and 77.7% of participants, this included linezolid and clofazimine, respectively. The adjusted probability of successful treatment was 0.85 (95% confidence interval [CI], 0.81-0.88) for 6 months of BDQ, 0.77 (95% CI, 0.73-0.81) for 7-11 months, and 0.86 (95% CI, 0.83-0.88) for ⩾12 months. Compared with 6 months of BDQ, the ratio of treatment success was 0.91 (95% CI, 0.85-0.96) for 7-11 months and 1.01 (95% CI, 0.96-1.06) for ⩾12 months. Naive analyses that did not account for bias revealed a higher probability of successful treatment with ⩾12 months (ratio, 1.09 [95% CI, 1.05-1.14]). Conclusions: BDQ use beyond 6 months did not increase the probability of successful treatment among patients receiving longer regimens that commonly included new and repurposed drugs. When not properly accounted for, immortal person-time bias can influence estimates of the effects of treatment duration. Future analyses should explore the effect of treatment duration of BDQ and other drugs in subgroups with advanced disease and/or receiving less potent regimens.

Tuberculosis clinical presentation and treatment outcomes in pregnancy: a prospective cohort study.

BACKGROUND: There is limited research to guide TB treatment specifically in pregnant women and few studies have described the presentation of TB in pregnant women. We aimed to understand TB presentation and treatment outcomes in pregnant women in a low HIV burden setting. We describe a cohort of women of childbearing age treated for TB disease in Lima, Peru, and compare clinical presentation and treatment outcomes among pregnant and non-pregnant women between 2009 and 2012, including 36 pregnant women. METHODS: This is a prospective cohort study. Subjects were recruited from across 106 public health centers in Lima, Peru. Baseline demographic, medical history, and drug-susceptibility test results were collected. We used descriptive statistics to describe demographic and clinical characteristics of the women using Pearson chi-squared, Fisher's exact tests, or Kruskal-Wallis. RESULTS: Among 4500 individuals with pulmonary TB disease, 1334 women were included in analysis with 36 (2.69%) pregnant women. Pregnant women had similar demographics, past medical histories, and clinical presentation to non-pregnant women, except being more likely to be married (p = 0.01) and have cardiac disease (p = 0.04) and less likely to have weight loss (p = 0.05). Twenty (71.4%) pregnant women had pan-susceptible TB compared with 616 (63.1%) non-pregnant women; four (14.3%) pregnant women had mono-resistant TB compared with 154 (15.8%) non-pregnant women; and four (14.3%) pregnant women had multi-drug-resistant TB compared with 140 (14.3%) of non-pregnant women (p = 0.53). Twenty-eight (96.6%) pregnant women had a successful outcome (cure, completed treatment, treatment ended early by clinical team) while one (3.4%) had an unsuccessful outcome (treatment failed) and 1074 (97.3%) non-pregnant women had a successful outcome while 30 (2.7%) had an unsuccessful outcome (p = 0.56). CONCLUSION: In this cohort with low HIV co-infection, we found high TB treatment success rates in both pregnant and non-pregnant women, irrespective of drug-susceptibility profiles. If treated appropriately, pregnant women with TB disease can have successful outcomes.

Community-based outreach associated with increased health utilization among Navajo individuals living with diabetes: a matched cohort study.

BACKGROUND: Navajo community members face high rates of diabetes mellitus and other chronic diseases. The Navajo Community Health Representative Outreach Program collaborated with healthcare providers and academic partners to implement structured and coordinated outreach to patients living with diabetes. The intervention, called Community Outreach and Patient Empowerment or COPE, provides home-based health coaching and community-clinic linkages to promote self-management and engagement in healthcare services among patients living with diabetes. The purpose of this study was to evaluate how outreach by Navajo Community Health Representatives ("COPE Program") affected utilization of health care services among patients living with diabetes. METHODS: De-identified data from 2010 to 2014 were abstracted from electronic health records at participating health facilities. In this observational cohort study, 173 cases were matched to 2880 controls. Healthcare utilization was measured as the number of times per quarter services were accessed by the patient. Changes in utilization over 4 years were modeled using a difference-in-differences approach, comparing the trajectory of COPE patients' utilization before versus after enrollment with that of the control group. The model was estimated using generalized linear mixed models for count outcomes, controlling for clustering at the patient level and the service unit level. RESULTS: COPE enrollees showed a 2.5% per patient per quarter (pppq) greater increase in total utilization (p = 0.001) of healthcare services than non-COPE enrollees; a 3.2% greater increase in primary care visits (p = 0.024); a 6.3% greater increase in utilization of counseling and behavioral health services (p = 0.013); and a 9.0% greater increase in pharmacy visits (p <  0.001). We found no statistically significant differences in utilization trends of inpatient, emergency room, specialty outpatient, dental, laboratory, radiology, or community encounter services among COPE participants versus control. CONCLUSIONS: A structured intervention consisting of Community Health Representative outreach and coordination with clinic-based providers was associated with a modest increase in health care utilization, including primary care and counseling services, among Navajo patients living with diabetes. Community health workers may provide an important linkage to enable patients to access and engage in clinic-based health care. TRIAL REGISTRATION: NCT03326206, registered 10/31/2017, retrospectively registered.

B vitamins attenuate the epigenetic effects of ambient fine particles in a pilot human intervention trial.

Acute exposure to fine particle (PM2.5) induces DNA methylation changes implicated in inflammation and oxidative stress. We conducted a crossover trial to determine whether B-vitamin supplementation averts such changes. Ten healthy adults blindly received a 2-h, controlled-exposure experiment to sham under placebo, PM2.5 (250 µg/m3) under placebo, and PM2.5 (250 µg/m3) under B-vitamin supplementation (2.5 mg/d folic acid, 50 mg/d vitamin B6, and 1 mg/d vitamin B12), respectively. We profiled epigenome-wide methylation before and after each experiment using the Infinium HumanMethylation450 BeadChip in peripheral CD4+ T-helper cells. PM2.5 induced methylation changes in genes involved in mitochondrial oxidative energy metabolism. B-vitamin supplementation prevented these changes. Likewise, PM2.5 depleted 11.1% [95% confidence interval (CI), 0.4%, 21.7%; P = 0.04] of mitochondrial DNA content compared with sham, and B-vitamin supplementation attenuated the PM2.5 effect by 102% (Pinteraction = 0.01). Our study indicates that individual-level prevention may be used to complement regulations and control potential mechanistic pathways underlying the adverse PM2.5 effects, with possible significant public health benefit in areas with frequent PM2.5 peaks.

Community Outreach for Navajo People Living with Diabetes: Who Benefits Most?

INTRODUCTION: The Community Outreach and Patient Empowerment (COPE) intervention provides integrated outreach through community health representatives (CHRs) to people living with diabetes in Navajo Nation. The aim of this study was to identify groups for whom the intervention had the greatest effect on glycated hemoglobin A1c (HbA1c). METHODS: We analyzed de-identified data extracted from routine health records dated from December 1, 2010, through August 31, 2014, to compare net change in HbA1c among COPE patients and non-COPE patients. We used linear mixed models to assess whether the intervention was modified by age, sex, preferred language, having a primary care provider, baseline HbA1c, or having a mental health condition. RESULTS: Age, having a primary care provider, and baseline HbA1c significantly modified HbA1c levels. Among patients aged 64 or younger, COPE participation was associated with a net decrease in HbA1c of 0.77%; among patients aged 65 or older, the net decrease was 0.49% (P = .03). COPE participation was associated with a steeper decrease in HbA1c among patients without a primary care physician (net decrease, 0.99%) than among patients with a primary care provider (net decrease, 0.57%) (P = .03). COPE patients with a baseline HbA1c >9% had a net decrease of 0.70%, while those with a baseline HbA1c ≤9% had a net decrease of 0.34% (P = .01). We found no significant differences based on sex, preferred language, or having a mental health condition. CONCLUSION: Findings suggest that the COPE intervention was robust and equitable, benefiting all groups living with diabetes in Navajo Nation, but conferring the greatest benefit on the most vulnerable.

Meta-analysis of epigenome-wide association studies of cognitive abilities.

Cognitive functions are important correlates of health outcomes across the life-course. Individual differences in cognitive functions are partly heritable. Epigenetic modifications, such as DNA methylation, are susceptible to both genetic and environmental factors and may provide insights into individual differences in cognitive functions. Epigenome-wide meta-analyses for blood-based DNA methylation levels at ~420,000 CpG sites were performed for seven measures of cognitive functioning using data from 11 cohorts. CpGs that passed a Bonferroni correction, adjusting for the number of CpGs and cognitive tests, were assessed for: longitudinal change; being under genetic control (methylation QTLs); and associations with brain health (structural MRI), brain methylation and Alzheimer's disease pathology. Across the seven measures of cognitive functioning (meta-analysis n range: 2557-6809), there were epigenome-wide significant (P < 1.7 × 10-8) associations for global cognitive function (cg21450381, P = 1.6 × 10-8), and phonemic verbal fluency (cg12507869, P = 2.5 × 10-9). The CpGs are located in an intergenic region on chromosome 12 and the INPP5A gene on chromosome 10, respectively. Both probes have moderate correlations (~0.4) with brain methylation in Brodmann area 20 (ventral temporal cortex). Neither probe showed evidence of longitudinal change in late-life or associations with white matter brain MRI measures in one cohort with these data. A methylation QTL analysis suggested that rs113565688 was a cis methylation QTL for cg12507869 (P = 5 × 10-5 and 4 × 10-13 in two lookup cohorts). We demonstrate a link between blood-based DNA methylation and measures of phonemic verbal fluency and global cognitive ability. Further research is warranted to understand the mechanisms linking genomic regulatory changes with cognitive function to health and disease.

Integrating community health representatives with health care systems: clinical outcomes among individuals with diabetes in Navajo Nation.

BACKGROUND: We studied the impact of Community Outreach and Patient Empowerment (COPE) intervention to support Community Health Representatives (CHR) on the clinical outcomes of patients living with diabetes in the Navajo Nation extending into the States of Arizona, Utah, and New Mexico. The COPE intervention integrated CHRs into healthcare teams by providing a structured approach to referrals and home visits. METHODS: We abstracted routine clinical data from the Indian Health Service's information system on individuals with diabetes mellitus seen at participating clinical sites from 2010 to 2014. We matched 173 COPE participants to 2880 patients with similar demographic and clinical characteristics who had not participated in COPE. We compared the changes in clinical outcomes between the two groups using linear mixed models. RESULTS: Over the four years of the study, COPE patients had greater improvements in glycosylated hemoglobin (- 0.56%) than non-COPE participants (+ 0.07%) for a difference in differences of 0.63% (95% confidence interval (CI): 0.50, 0.76). Low-density lipoprotein fell more steeply in the COPE group (- 10.58 mg/dl) compared to the non-COPE group (- 3.18 mg/dl) for a difference in differences of 7.40 mg/dl (95%CI: 2.00, 12.80). Systolic blood pressure increased slightly more among COPE (2.06 mmHg) than non-COPE patients (0.61 mmHg). We noted no significant change for body mass index in either group. CONCLUSION: Structured outreach by Community Health Representatives as part of an integrated care team was associated with improved glycemic and lipid levels in the target Navajo population. TRIAL REGISTRATION: Trial registration: NCT03326206. Registered 31 October 2017 - Retrospectively registered, https://clinicaltrials.gov/ct2/show/study/NCT03326206.

Traffic-Related Air Pollution, Blood Pressure, and Adaptive Response of Mitochondrial Abundance.

BACKGROUND: Exposure to black carbon (BC), a tracer of vehicular-traffic pollution, is associated with increased blood pressure (BP). Identifying biological factors that attenuate BC effects on BP can inform prevention. We evaluated the role of mitochondrial abundance, an adaptive mechanism compensating for cellular-redox imbalance, in the BC-BP relationship. METHODS AND RESULTS: At ≥ 1 visits among 675 older men from the Normative Aging Study (observations=1252), we assessed daily BP and ambient BC levels from a stationary monitor. To determine blood mitochondrial abundance, we used whole blood to analyze mitochondrial-to-nuclear DNA ratio (mtDNA/nDNA) using quantitative polymerase chain reaction. Every standard deviation increase in the 28-day BC moving average was associated with 1.97 mm Hg (95% confidence interval [CI], 1.23-2.72; P<0.0001) and 3.46 mm Hg (95% CI, 2.06-4.87; P<0.0001) higher diastolic and systolic BP, respectively. Positive BC-BP associations existed throughout all time windows. BC moving averages (5-day to 28-day) were associated with increased mtDNA/nDNA; every standard deviation increase in 28-day BC moving average was associated with 0.12 standard deviation (95% CI, 0.03-0.20; P=0.007) higher mtDNA/nDNA. High mtDNA/nDNA significantly attenuated the BC-systolic BP association throughout all time windows. The estimated effect of 28-day BC moving average on systolic BP was 1.95-fold larger for individuals at the lowest mtDNA/nDNA quartile midpoint (4.68 mm Hg; 95% CI, 3.03-6.33; P<0.0001), in comparison with the top quartile midpoint (2.40 mm Hg; 95% CI, 0.81-3.99; P=0.003). CONCLUSIONS: In older adults, short-term to moderate-term ambient BC levels were associated with increased BP and blood mitochondrial abundance. Our findings indicate that increased blood mitochondrial abundance is a compensatory response and attenuates the cardiac effects of BC.

Associations of Annual Ambient Fine Particulate Matter Mass and Components with Mitochondrial DNA Abundance.

BACKGROUND: Fine particulate matter (PM2.5) represents a mixture of components with potentially different toxicities. However, little is known about the relative effects of PM2.5 mass and PM2.5 components on mitochondrial DNA (mtDNA) abundance, which may lie on the pathway of PM2.5-associated disease. METHODS: We studied 646 elderly male participants in the Normative Aging Study from Greater Boston to investigate associations of long-term exposure to PM2.5 mass and PM2.5 components with mtDNA abundance. We estimated concentrations of pollutants for the 365-day preceding examination at each participant's address using spatial- and temporal-resolved chemical transport models. We measured blood mtDNA abundance using RT-PCR. We applied a shrinkage and selection method (adaptive LASSO) to identify components most predictive of mtDNA abundance, and fit multipollutant linear mixed-effects models with subject-specific intercept to estimate the relative effects of individual PM component. RESULTS: MtDNA abundance was negatively associated with PM2.5 mass in the previous year and-after adjusting for PM2.5 mass-several PM2.5 components, including organic carbon, sulfate (marginally), and nitrate. In multipollutant models including as independent variables PM2.5 mass and PM2.5 components selected by LASSO, nitrate was associated with mtDNA abundance. An SD increase in annual PM2.5-associated nitrate was associated with a 0.12 SD (95% confidence intervals [CI] = -0.18, -0.07) decrease in mtDNA abundance. Analyses restricted to PM2.5 annual concentration below the current 1-year U.S. Environmental Protection Agency standard produced similar results. CONCLUSIONS: Long-term exposures to PM2.5-associated nitrate were related to decreased mtDNA abundance independent of PM2.5 mass. Mass alone may not fully capture the potential of PM2.5 to oxidize the mitochondrial genome.See video abstract at, http://links.lww.com/EDE/B274.

Effectiveness of a bedaquiline, linezolid, clofazimine "core" for multidrug-resistant tuberculosis.

Rationale: Treatment outcomes may be compromised among patients with multidrug- or rifampicin-resistant tuberculosis with additional fluoroquinolone resistance. Evidence is needed to inform optimal treatment for these patients. Objectives: We compared the effectiveness of longer individualized regimens comprised of bedaquiline for 5 to 8 months, linezolid, and clofazimine to those reinforced with at least 1 third-tier drug and/or longer duration of bedaquiline. Methods: We emulated a target trial to compare the effectiveness of initiating and remaining on the core regimen to one of five regimens reinforced with (1) bedaquiline for ≥9 months, (2) bedaquiline for ≥9 months and delamanid, (3) imipenem, (4) a second-line injectable, or (5) delamanid and imipenem. We included patients in whom a fluoroquinolone was unlikely to be effective based on drug susceptibility testing and/or prior exposure. Our analysis consisted of cloning, censoring, and inverse-probability weighting to estimate the probability of successful treatment. Measurements and Main Results: Adjusted probabilities of successful treatment were high across regimens, ranging from 0.75 (95%CI:0.61, 0.89) to 0.84 (95%CI:0.76, 0.91). We found no substantial evidence that any of the reinforced regimens improved effectiveness of the core regimen, with ratios of treatment success ranging from 1.01 for regimens reinforced with bedaquiline ≥9 months (95%CI:0.79, 1.28) and bedaquiline ≥9 months plus delamanid (95%CI:0.81, 1.31) to 1.11 for regimens reinforced by a second-line injectable (95%CI:0.92, 1.39) and delamanid and imipenem (95%CI:0.90, 1.41). Conclusions: High treatment success underscores the effectiveness of regimens comprised of bedaquiline, linezolid, and clofazimine, highlighting the need for expanded access to these drugs.

Acute kidney injury (AKI) in patients with Covid-19 infection is associated with ventilatory management with elevated positive end-expiratory pressure (PEEP).

BACKGROUND: Acute kidney injury (AKI) in Covid-19 patients admitted to the intensive care unit (ICU) is common, and its severity may be associated with unfavorable outcomes. Severe Covid-19 fulfills the diagnostic criteria for acute respiratory distress syndrome (ARDS); however, it is unclear whether there is any relationship between ventilatory management and AKI development in Covid-19 ICU patients. PURPOSE: To describe the clinical course and outcomes of Covid-19 ICU patients, focusing on ventilatory management and factors associated with AKI development. METHODS: Single-center, retrospective observational study, which assessed AKI incidence in Covid-19 ICU patients divided by positive end expiratory pressure (PEEP) tertiles, with median levels of 9.6 (low), 12.0 (medium), and 14.7 cmH2O (high-PEEP). RESULTS: Overall mortality was 51.5%. AKI (KDIGO stage 2 or 3) occurred in 38% of 101 patients. Among the AKI patients, 19 (53%) required continuous renal replacement therapy (CRRT). In AKI patients, mortality was significantly higher versus non-AKI (81% vs. 33%, p < 0.0001). The incidence of AKI in low-, medium-, or high-PEEP patients were 16%, 38%, and 59%, respectively (p = 0.002). In a multivariate analysis, high-PEEP patients showed a higher risk of developing AKI than low-PEEP patients (OR = 4.96 [1.1-21.9] 95% CI p < 0.05). ICU mortality rate was higher in high-PEEP patients, compared to medium-PEEP or low-PEEP patients (69% vs. 44% and 42%, respectively; p = 0.057). CONCLUSION: The use of high PEEP in Covid-19 ICU patients is associated with a fivefold higher risk of AKI, leading to higher mortality. The cause and effect relationship needs further analysis.

Diagnostic accuracy of molecular detection of Mycobacterium tuberculosis in pediatric stool samples: A systematic review and meta-analysis.

BACKGROUND: Stool is a promising specimen option to diagnose pediatric tuberculosis (TB), but studies have reported a wide range of test sensitivities. We conducted a meta-analysis to assess the accuracy of Xpert MTB/RIF or 'in-house' molecular tests on stool samples against culture or Xpert MTB/RIF on respiratory samples or clinically-diagnosed unconfirmed TB and aimed to identify factors that contribute to the heterogeneity of reported sensitivity. METHODS: We searched EMBASE and Pubmed databases and conference abstract books for studies reporting molecular stool testing against a clinical or microbiological reference standard among children. RESULTS: We identified 16 studies that included 2,481 children in stool test analyses. Pooled specificity was 98% [95%CI: 96-99], pooled sensitivity was 57% [95%CI: 40-72] against culture and 3% [95%CI: 2-6] among children with clinically-diagnosed, unconfirmed TB. There was much heterogeneity. Sensitivity was higher among children with a smear-positive sputum test. Rifampin resistance in stool was reported in two studies and detected in 5/14 children (36%). CONCLUSION: Our results suggest molecular stool tests have potential as diagnostic rule-in tests, but it is challenging to optimize sensitivity due to between-study variation in methodology and test procedures. Therefore, we recommend future research with rigorous study design and standardized results reporting.

Altered cord blood mitochondrial DNA content and pregnancy lead exposure in the PROGRESS cohort.

INTRODUCTION: Lead (Pb) crosses the placenta and can cause oxidative stress, reduced fetal growth and neurological problems. The principal source of oxidative stress in human cells is mitochondria. Therefore, disruption of normal mitochondrial function during pregnancy may represent a primary mechanism behind the adverse effects of lead. We sought to assess the association of Pb exposure during pregnancy with mitochondrial DNA (mtDNA) content, a sensitive marker of mitochondrial function, in cord blood. MATERIALS AND METHODS: This study comprised mother-infant pairs from the Programming Research in Obesity, Growth, Environment and Social Stressors (PROGRESS) study, a prospective birth-cohort that enrolled 1050 pregnant women from Mexico City who were receiving prenatal care between December 2007 and July 2011. Quantitative PCR was used to calculate relative MtDNA content (mitochondrial-to-nuclear DNA ratio (mtDNA/nDNA)) in cord blood. Lead concentrations in both maternal blood (2nd and 3rd trimester and at delivery day) and in cord blood were measured by ICP-MS. Multivariable regression models adjusting for multiple confounders were fitted with 410 mother-infant pairs for whom complete data for mtDNA content, lead levels, and covariates were available. RESULTS: Maternal blood Pb measured in the second (mean 3.79 µg/dL, SD 2.63; ß = 0.059, 95% CI 0.008, 0.111) and third trimester (mean 3.90 µg/dL; SD 2.84; ß = 0.054, 95% CI 0.002, 0.107) during pregnancy and PB in cord blood (mean 3.50 µg/dL, SD 2.59; ß = 0.050, 95% CI 0.004; 0.096) were associated with increased cord blood mtDNA content (mean 1.46, SD 0.44). In two-way interaction analyses, cord blood Pb marginally interacted with gestational age leading to an increase in mtDNA content for pre-term births (Benjamini-Hochberg False Discovery Rate correction; BH-FDR = 0.08). CONCLUSION: This study shows that lead exposure in pregnancy alters mtDNA content in cord blood; therefore, alteration of mtDNA content might be a mechanism underlying the toxicity of lead.

Epigenome-wide cross-tissue predictive modeling and comparison of cord blood and placental methylation in a birth cohort.

AIM: We compared predictive modeling approaches to estimate placental methylation using cord blood methylation. MATERIALS & METHODS: We performed locus-specific methylation prediction using both linear regression and support vector machine models with 174 matched pairs of 450k arrays. RESULTS: At most CpG sites, both approaches gave poor predictions in spite of a misleading improvement in array-wide correlation. CpG islands and gene promoters, but not enhancers, were the genomic contexts where the correlation between measured and predicted placental methylation levels achieved higher values. We provide a list of 714 sites where both models achieved an R2 ≥0.75. CONCLUSION: The present study indicates the need for caution in interpreting cross-tissue predictions. Few methylation sites can be predicted between cord blood and placenta.

B-vitamin Supplementation Mitigates Effects of Fine Particles on Cardiac Autonomic Dysfunction and Inflammation: A Pilot Human Intervention Trial.

Ambient fine particle (PM2.5) pollution triggers acute cardiovascular events. Individual-level preventions are proposed to complement regulation in reducing the global burden of PM2.5-induced cardiovascular diseases. We determine whether B vitamin supplementation mitigates PM2.5 effects on cardiac autonomic dysfunction and inflammation in a single-blind placebo-controlled crossover pilot trial. Ten healthy adults received two-hour controlled-exposure-experiment to sham under placebo, PM2.5 (250 µg/m3) under placebo, and PM2.5 (250 µg/m3) under B-vitamin supplementation (2.5 mg/d folic acid, 50 mg/d vitamin B6, and 1 mg/d vitamin B12), respectively. At pre-, post-, 24 h-post-exposure, we measured resting heart rate (HR) and heart rate variability (HRV) with electrocardiogram, and white blood cell (WBC) counts with hematology analyzer. Compared to sham, PM2.5 exposure increased HR (3.8 bpm, 95% CI: 0.3, 7.4; P = 0.04), total WBC count (11.5%, 95% CI: 0.3%, 24.0%; P = 0.04), lymphocyte count (12.9%, 95% CI: 4.4%, 22.1%; P = 0.005), and reduced low-frequency power (57.5%, 95% CI: 2.5%, 81.5%; P = 0.04). B-vitamin supplementation attenuated PM2.5 effect on HR by 150% (P = 0.003), low-frequency power by 90% (P = 0.01), total WBC count by 139% (P = 0.006), and lymphocyte count by 106% (P = 0.02). In healthy adults, two-hour PM2.5 exposure substantially increases HR, reduces HRV, and increases WBC. These effects are reduced by B vitamin supplementation.

Effects of Air Pollution and Blood Mitochondrial DNA Methylation on Markers of Heart Rate Variability.

BACKGROUND: The mitochondrion is the primary target of oxidative stress in response to exogenous environments. Mitochondrial DNA (mtDNA) is independent from nuclear DNA and uses separate epigenetic machinery to regulate mtDNA methylation. The mtDNA damage induced by oxidative stress can cause mitochondrial dysfunction and is implicated in human diseases; however, mtDNA methylation has been largely overlooked in environmental studies relating to human disease. The purpose of this study was to examine the association between exposure to fine metal-rich particulates (particulate matter <2.5 µm in diameter [PM2.5]) from welding in a boilermaker union and blood mtDNA methylation in relation to heart rate variability. METHODS AND RESULTS: Forty-eight healthy men were recruited on multiple sampling cycles at the Boilermaker Union Local 29, located in Quincy, Massachusetts. We measured personal PM2.5 in the background ambient environment. We measured blood mtDNA methylation in the mtDNA promoter (D-loop) and genes essential for ATP synthesis (MT-TF and MT-RNR1) by bisulfite pyrosequencing. All analyses were adjusted for demographics, type of job, season, welding-work day, and mtDNA methylation experimental batch effect. The participants' PM2.5 exposure was significantly higher after a welding-work day (mean 0.38 mg/m(3)) than the background personal level (mean 0.15 mg/m(3), P<0.001). Blood mtDNA methylation in the D-loop promoter was associated with PM2.5 levels (ß=-0.99%, SE=0.41, P=0.02). MT-TF and MT-RNR1 methylation was not associated with PM2.5 exposure (ß=0.10%, SE=0.45, P=0.82). Interaction of PM2.5 exposure levels and D-loop promoter methylation was significantly associated with markers of heart rate variability. CONCLUSIONS: Blood mtDNA methylation levels were negatively associated with PM2.5 exposure and modified the adverse relationships between PM2.5 exposure and heart rate variability outcomes.