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BackgroundTens of millions of children are exposed to Mycobacterium tuberculosis globally every year; however, there are no contemporary estimates of the risk of developing tuberculosis in exposed children. The effectiveness of contact investigations and preventive therapy remains poorly understood.MethodsIn this systematic review and meta-analysis, we investigated the development of tuberculosis in children closely exposed to a tuberculosis case and followed for incident disease. We restricted our search to cohort studies published between Jan 1, 1998, and April 6, 2018, in MEDLINE, Web of Science, BIOSIS, and Embase electronic databases. Individual-participant data and a pre-specified list of variables were requested from authors of all eligible studies. These included characteristics of the exposed child, the index case, and environmental characteristics. To be eligible for inclusion in the final analysis, a dataset needed to include: (1) individuals below 19 years of age; (2) follow-up for tuberculosis for a minimum of 6 months; (3) individuals with household or close exposure to an individual with tuberculosis; (4) information on the age and sex of the child; and (5) start and end follow-up dates. Studies assessing incident tuberculosis but without dates or time of follow-up were excluded. Our analysis had two primary aims: (1) estimating the risk of developing tuberculosis by time-period of follow-up, demographics (age, region), and clinical attributes (HIV, tuberculosis infection status, previous tuberculosis); and (2) estimating the effectiveness of preventive therapy and BCG vaccination on the risk of developing tuberculosis. We estimated the odds of prevalent tuberculosis with mixed-effects logistic models and estimated adjusted hazard ratios (HRs) for incident tuberculosis with mixed-effects Poisson regression models. The effectiveness of preventive therapy against incident tuberculosis was estimated through propensity score matching. The study protocol is registered with PROSPERO (CRD42018087022).FindingsIn total, study groups from 46 cohort studies in 34 countries-29 (63%) prospective studies and 17 (37%) retrospective-agreed to share their data and were included in the final analysis. 137 647 tuberculosis-exposed children were evaluated at baseline and 130 512 children were followed for 429 538 person-years, during which 1299 prevalent and 999 incident tuberculosis cases were diagnosed. Children not receiving preventive therapy with a positive result for tuberculosis infection had significantly higher 2-year cumulative tuberculosis incidence than children with a negative result for tuberculosis infection, and this incidence was greatest among children below 5 years of age (19·0% [95% CI 8·4-37·4]). The effectiveness of preventive therapy was 63% (adjusted HR 0·37 [95% CI 0·30-0·47]) among all exposed children, and 91% (adjusted HR 0·09 [0·05-0·15]) among those with a positive result for tuberculosis infection. Among all children

Background: The Directly Observed Treatment-Short Course (DOTS) Programme was implemented by WHO and includes a combination of four anti-tuberculosis (TB) drugs (isoniazid, pyrazinamide, ethambutol and rifampicin) for a period of six months to eradicate the TB infection completely. Diabetes mellitus (DM) is recognized as one of a strong contributor of TB according to World Health Organization (WHO). The presence of diabetes mellitus type 2 (DM type 2) makes TB treatment complicated. Thus, the objective of the current meta-analysis was to identify and quantify the impact of type 2DM on treatment outcomes of TB patients treated under the DOTS Programme. Methods: This meta-analysis was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Through a systematic review of relevant literature, we focused on studies investigating treatment outcomes including extended treatment duration and recurrence for individuals with both TB and DM undergoing DOTS therapy. The extracted information included study designs, sample sizes, patient characteristics and reported treatment results. Results: In 44 studies from different parts of the world, the pooled HR for the impact of DM on extended treatment duration and reoccurrence were HR 0.72, 95% CI 0.56-0.83, p < .01 and HR 0.93, 95% CI 0.70-1.04, p = .08, respectively. The pooled HR for impact of DM on composite TB treatment outcomes was calculated as 0.76 (95% CI 0.60-0.87), p < .01 with an effect size of 41.18. The heterogeneity observed among the included studies was moderate (I² = 55.79%). Conclusions: A negative impact of DM was found on recurrence and extended treatment duration in TB patients treated with DOTS therapy. DM type 2 is responsible for the TB treatment prolongation and TB recurrence rates. By implementing effective management strategies and advancing research, the challenges can be mitigated, arising due to the complex interaction between DM and TB. [ABSTRACT FROM AUTHOR]

BackgroundHelicobacter pylori, a lifelong and typically asymptomatic infection of the stomach, profoundly alters gastric immune responses, and may benefit the host in protection against other pathogens. We explored the hypothesis that H. pylori contributes to the control of infection with Mycobacterium tuberculosis.Methodology/principal findingsWe first examined M. tuberculosis-specific IFN-gamma and H. pylori antibody responses in 339 healthy Northern Californians undergoing routine tuberculin skin testing. Of 97 subjects (29%) meeting criteria for latent tuberculosis (TB) infection (LTBI), 45 (46%) were H. pylori seropositive. Subjects with LTBI who were H. pylori-seropositive had 1.5-fold higher TB antigen-induced IFN-gamma responses (p = 0.04, ANOVA), and a more Th-1 like cytokine profile in peripheral blood mononuclear cells, compared to those who were H. pylori seronegative. To explore an association between H. pylori infection and clinical outcome of TB exposure, we evaluated H. pylori seroprevalence in baseline samples from two high risk TB case-contact cohorts, and from cynomolgus macaques experimentally challenged with M. tuberculosis. Compared to 513 household contacts who did not progress to active disease during a median 24 months follow-up, 120 prevalent TB cases were significantly less likely to be H. pylori infected (AOR: 0.55, 95% CI 0.0.36-0.83, p = 0.005), though seroprevalence was not significantly different from non-progressors in 37 incident TB cases (AOR: 1.35 [95% CI 0.63-2.9] p = 0.44). Cynomolgus macaques with natural H. pylori infection were significantly less likely to progress to TB 6 to 8 months after M. tuberculosis challenge (RR: 0.31 [95% CI 0.12-0.80], p = 0.04).Conclusions/significanceH. pylori infection may induce bystander effects that modify the risk of active TB in humans and non-human primates. That immunity to TB may be enhanced by exposure to other microbial agents may have important implications for vaccine development and disease control.

Background and Aims: COVID‐19 vaccinations have reduced morbidity and mortality from the disease. Antibodies against severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2) have been associated with immune protection. Seroprevalence studies revealed high immunoglobulin G (IgG) antibody levels to SARS‐CoV‐2 in the Pakistani population before vaccinations. We investigated the effect of BBIBP‐CorV vaccination on circulating IgG antibodies and interferon (IFN)‐γ from T cells measured in a cohort of healthy individuals, with respect to age, gender, and history of COVID‐19. Methods: The study was conducted between April and October 2021. BBIBP‐CorV vaccinated participants were followed up to 24 weeks. Antibodies to SARS‐CoV‐2 Spike protein and its receptor‐binding domain (RBD) were measured. IFNγ secreted by whole blood stimulation of Spike protein and extended genome antigens was determined. Results: Study participants with a history of prior COVID‐19 displayed a higher magnitude of IgG antibodies to Spike and RBD. IgG seropositivity was greater in those with prior COVID‐19, aged 50 years or younger and in females. At 24 weeks after vaccination, 37.4% of participants showed IFN‐γ responses to SARS‐CoV‐2 antigens. T cell IFN‐γ release was higher in those with prior COVID‐19 and those aged 50 years or less. Highest IFN‐γ release was observed to extended genome antigens in individuals both with and without prior COVID‐19. Conclusion: We found that IgG seropositivity to both Spike and RBD was affected by prior COVID‐19, age and gender. Importantly, seropositive responses persisted up to 24 weeks after vaccination. Persistence of vaccine induced IgG antibodies may be linked to the high seroprevalence observed earlier in unvaccinated individuals. Increased T cell reactivity to Spike and extended genome antigens reflects cellular activation induced by BBIBP‐CorV. COVID‐19 vaccination may have longer lasting immune responses in populations with a higher seroprevalence. These data inform on vaccination booster policies for high‐risk groups. Key points: Baseline seropositivity high in population in those without prior COVID‐19—no antibody waning after vaccination may be due to cross‐reactivity or continued transmission ‐inactivated vaccination induced T cell response to antigens other than Spike providing additional immunogenicity ‐COVID‐19 vaccination may have longer lasting immune responses in populations with a higher seroprevalence—these data inform on vaccination booster policies [ABSTRACT FROM AUTHOR]

Background Few studies have evaluated the association between preexisting vitamin D deficiency and incident tuberculosis (TB). We assessed the impact of baseline vitamins D levels on TB disease risk. Methods and findings We assessed the association between baseline vitamin D and incident TB in a prospective cohort of 6,751 HIV-negative household contacts of TB patients enrolled between September 1, 2009, and August 29, 2012, in Lima, Peru. We screened for TB disease at 2, 6, and 12 months after enrollment. We defined cases as household contacts who developed TB disease at least 15 days after enrollment of the index patient. For each case, we randomly selected four controls from among contacts who did not develop TB disease, matching on gender and year of age. We also conducted a one-stage individual-participant data (IPD) meta-analysis searching PubMed and Embase to identify prospective studies of vitamin D and TB disease until June 8, 2019. We included studies that assessed vitamin D before TB diagnosis. In the primary analysis, we defined vitamin D deficiency as 25-(OH)D 75nmol/L. We estimated the association between baseline vitamin D status and incident TB using conditional logistic regression in the Lima cohort and generalized linear mixed models in the meta-analysis. We further defined severe vitamin D deficiency as 25-(OH)D < 25 nmol/L and performed stratified analyses by HIV status in the IPD meta-analysis. In the Lima cohort, we analyzed 180 cases and 709 matched controls. The adjusted odds ratio (aOR) for TB risk among participants with baseline vitamin D deficiency compared to sufficient vitamin D was 1.63 (95% CI 0.75-3.52; p = 0.22). We included seven published studies in the meta-analysis and analyzed 3,544 participants. In the pooled analysis, the aOR was 1.48 (95% CI 1.04-2.10; p = 0.03). The aOR for severe vitamin D deficiency was 2.05 (95% CI 0.87-4.87; p trend for decreasing 25-(OH)D levels from sufficient vitamin D to severe deficiency = 0.02). Among 1,576 HIV-positive patients, vitamin D deficiency conferred a 2-fold (aOR 2.18, 95% CI 1.22-3.90; p = 0.01) increased risk of TB, and the aOR for severe vitamin D deficiency compared to sufficient vitamin D was 4.28 (95% CI 0.85-21.45; p = 0.08). Our Lima cohort study is limited by the short duration of follow-up, and the IPD meta-analysis is limited by the number of possible confounding covariates available across all studies. Conclusion Our findings suggest vitamin D predicts TB disease risk in a dose-dependent manner and that the risk of TB disease is highest among HIV-positive individuals with severe vitamin D deficiency. Randomized control trials are needed to evaluate the possible role of vitamin D supplementation on reducing TB disease risk., Author(s): Omowunmi Aibana 1, Chuan-Chin Huang 2, Said Aboud 3, Alberto Arnedo-Pena 4, Mercedes C. Becerra 2, Juan Bautista Bellido-Blasco 4, Ramesh Bhosale 5, Roger Calderon 6, Silvia Chiang 7, [...]

Background: Short-acting β2-agonists (SABA), the most potent and rapid-acting relievers are commonly used to provide quick relief of asthma symptoms. However, there is an increasing concern regarding the misuse of SABA medicines. Objective: This qualitative systematic review aims to determine, evaluate, and summarize the perceptions, attitudes, and behaviors towards the use of SABA from the patients' perspectives. Methods: The databases searched included PubMed, Scopus, PsycINFO, CINAHL, and Cochrane database. Original research articles reporting the perceptions, attitudes, or behaviors of asthma patients towards the use of SABA, which was available as full text, published in the English language between the year 2000 and February 2023 were included in the review. Commentaries, letters to editor, review articles, and conference proceedings were excluded. Results: A total of five articles were included. Six overarching themes were obtained: (1) perceptions on health status; (2) perceptions and attitudes towards the impact of asthma; (3) perceptions towards asthma control; (4) perceptions towards asthma knowledge; (5) risk perceptions; (6) perceptions, attitudes, and behaviors towards the use of SABA. Conclusion: Despite the fact that SABA could rapidly alleviate asthma symptoms, SABA over-users were less likely to describe their health status and asthma control as 'excellent'. Most SABA over-users did not know that frequent SABA usage would worsen their asthma control, and they exhibited psychological linkage towards the use of SABA. Collaborative efforts between policymakers, healthcare professionals and patients are warranted to reconstruct SABA prescribing practice and usage. [ABSTRACT FROM AUTHOR]