RESUMO
A subset of individuals exposed to Mycobacterium tuberculosis (Mtb) that we refer to as 'resisters' (RSTR) show evidence of IFN-γ- T cell responses to Mtb-specific antigens despite serially negative results on clinical testing. Here we found that Mtb-specific T cells in RSTR were clonally expanded, confirming the priming of adaptive immune responses following Mtb exposure. RSTR CD4+ T cells showed enrichment of TH17 and regulatory T cell-like functional programs compared to Mtb-specific T cells from individuals with latent Mtb infection. Using public datasets, we showed that these TH17 cell-like functional programs were associated with lack of progression to active tuberculosis among South African adolescents with latent Mtb infection and with bacterial control in nonhuman primates. Our findings suggested that RSTR may successfully control Mtb following exposure and immune priming and established a set of T cell biomarkers to facilitate further study of this clinical phenotype.
Assuntos
Linfócitos T CD4-Positivos , Mycobacterium tuberculosis , Tuberculose , Mycobacterium tuberculosis/imunologia , Humanos , Animais , Adolescente , Tuberculose/imunologia , Tuberculose/microbiologia , Linfócitos T CD4-Positivos/imunologia , Células Th17/imunologia , Feminino , Macaca mulatta , Masculino , Fenótipo , Interferon gama/metabolismo , Interferon gama/imunologia , Antígenos de Bactérias/imunologia , Tuberculose Latente/imunologia , Tuberculose Latente/microbiologia , África do Sul , Adulto Jovem , Linfócitos T Reguladores/imunologia , AdultoRESUMO
BACKGROUND: Tuberculosis (TB) remains a major public health problem globally, even compared to COVID-19. Genome-wide studies have failed to discover genes that explain a large proportion of genetic risk for adult pulmonary TB, and even fewer have examined genetic factors underlying TB severity, an intermediate trait impacting disease experience, quality of life, and risk of mortality. No prior severity analyses used a genome-wide approach. METHODS AND FINDINGS: As part of our ongoing household contact study in Kampala, Uganda, we conducted a genome-wide association study (GWAS) of TB severity measured by TBScore, in two independent cohorts of culture-confirmed adult TB cases (n = 149 and n = 179). We identified 3 SNPs (P<1.0 x 10-7) including one on chromosome 5, rs1848553, that was GWAS significant (meta-analysis p = 2.97x10-8). All three SNPs are in introns of RGS7BP and have effect sizes corresponding to clinically meaningful reductions in disease severity. RGS7BP is highly expressed in blood vessels and plays a role in infectious disease pathogenesis. Other genes with suggestive associations defined gene sets involved in platelet homeostasis and transport of organic anions. To explore functional implications of the TB severity-associated variants, we conducted eQTL analyses using expression data from Mtb-stimulated monocyte-derived macrophages. A single variant (rs2976562) associated with monocyte SLA expression (p = 0.03) and subsequent analyses indicated that SLA downregulation following MTB stimulation associated with increased TB severity. Src Like Adaptor (SLAP-1), encoded by SLA, is highly expressed in immune cells and negatively regulates T cell receptor signaling, providing a potential mechanistic link to TB severity. CONCLUSIONS: These analyses reveal new insights into the genetics of TB severity with regulation of platelet homeostasis and vascular biology being central to consequences for active TB patients. This analysis also reveals genes that regulate inflammation can lead to differences in severity. Our findings provide an important step in improving TB patient outcomes.
Assuntos
Tuberculose , Adulto , Humanos , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Inflamação/genética , Polimorfismo de Nucleotídeo Único , Qualidade de Vida , Tuberculose/genética , Uganda , Locos de Características QuantitativasRESUMO
MOTIVATION: The identification of differentially expressed genes (DEGs) from transcriptomic datasets is a major avenue of research across diverse disciplines. However, current bioinformatic tools do not support covariance matrices in DEG modeling. Here, we introduce kimma (Kinship In Mixed Model Analysis), an open-source R package for flexible linear mixed effects modeling including covariates, weights, random effects, covariance matrices, and fit metrics. RESULTS: In simulated datasets, kimma detects DEGs with similar specificity, sensitivity, and computational time as limma unpaired and dream paired models. Unlike other software, kimma supports covariance matrices as well as fit metrics like Akaike information criterion (AIC). Utilizing genetic kinship covariance, kimma revealed that kinship impacts model fit and DEG detection in a related cohort. Thus, kimma equals or outcompetes current DEG pipelines in sensitivity, computational time, and model complexity. AVAILABILITY AND IMPLEMENTATION: Kimma is freely available on GitHub https://github.com/BIGslu/kimma with an instructional vignette at https://bigslu.github.io/kimma_vignette/kimma_vignette.html.
Assuntos
Perfilação da Expressão Gênica , Software , Humanos , RNA-Seq , Análise de Sequência de RNA , Modelos LinearesRESUMO
Resistance to M. tuberculosis, often referred to as "RSTR" in the literature, is being increasingly studied because of its potential relevance as a clinical outcome in vaccine studies. This review starts by addressing the importance of epidemiological characterization of this phenotype, and ongoing challenges in that characterization. Then, this review summarizes the extant genetic and genomic studies of this phenotype, including heritability studies, candidate gene studies, and genome-wide association studies, as well as whole transcriptome studies. Findings from recent studies that used longitudinal characterization of the RSTR phenotype are compared to those using a cross-sectional definition, and the challenges of using tuberculin skin test and interferon-gamma release assay are discussed. Finally, future directions are proposed. Since this is a rapidly evolving area of public health significance, this review will help frame future research questions and study designs.
Assuntos
Mycobacterium tuberculosis , Tuberculose , Humanos , Epidemiologia Molecular , Estudo de Associação Genômica Ampla , Estudos Transversais , Tuberculose/epidemiologia , Tuberculose/genética , Mycobacterium tuberculosis/genética , Teste TuberculínicoRESUMO
Tuberculosis and sarcoidosis are inflammatory diseases characterized by granulomas that may occur in any organ but are often found in the lung. The panoply of classical human leukocyte antigen (HLA) alleles associated with occurrence and/or severity of both diseases varies considerably across studies. This heterogeneity of results, due to variation in factors like ancestry and disease subphenotype, as well as the use of simple modeling strategies to elucidate likely complex relationships, has made conclusions about underlying commonalities difficult. Here we perform HLA association analyses in individuals of African ancestry, using a greater resolution to include subphenotypes of disease and employing more comprehensive analytical techniques. Using a novel application of nearest-neighbor feature selection to score allelic importance, we investigated HLA allele association with Mycobacterium tuberculosis exposure outcomes in the first analysis of both latent Mycobacterium tuberculosis infection and active disease compared with those who, despite long-term exposure to active index cases, have neither positive diagnostic tests nor display clinical symptoms. We also compared persistent to resolved sarcoidosis. This led to the identification of novel HLA associations and evidence of main effects and interaction effects. We found strikingly similar main effects and interaction effects at HLA-DRB1, -DQB1, and -DPB1 in those resistant to tuberculosis (either latent or active) and persistent sarcoidosis.
Assuntos
Mycobacterium tuberculosis , Sarcoidose , Tuberculose , Alelos , Frequência do Gene , Predisposição Genética para Doença , Cadeias HLA-DRB1/genética , Humanos , Mycobacterium tuberculosis/genética , Sarcoidose/genética , Tuberculose/genéticaRESUMO
Data sharing is a valuable aspect of science and required by most funding bodies and journals. However, the national regulatory guidelines of many African nations do not explicitly allow for broad genetic data sharing. Given these restrictions, there is a need to reconsider these policies and propose creative solutions.
Assuntos
Pesquisa em Genética/legislação & jurisprudência , Genômica/normas , Disseminação de Informação/legislação & jurisprudência , África , Genômica/legislação & jurisprudência , Humanos , Disseminação de Informação/métodosRESUMO
Genetic studies of both the human host and Mycobacterium tuberculosis (MTB) demonstrate independent association with tuberculosis (TB) risk. However, neither explains a large portion of disease risk or severity. Based on studies in other infectious diseases and animal models of TB, we hypothesized that the genomes of the two interact to modulate risk of developing active TB or increasing the severity of disease, when present. We examined this hypothesis in our TB household contact study in Kampala, Uganda, in which there were 3 MTB lineages of which L4-Ugandan (L4.6) is the most recent. TB severity, measured using the Bandim TBscore, was modeled as a function of host SNP genotype, MTB lineage, and their interaction, within two independent cohorts of TB cases, N = 113 and 121. No association was found between lineage and severity, but association between multiple polymorphisms in IL12B and TBscore was replicated in two independent cohorts (most significant rs3212227, combined p = 0.0006), supporting previous associations of IL12B with TB susceptibility. We also observed significant interaction between a single nucleotide polymorphism (SNP) in SLC11A1 and the L4-Ugandan lineage in both cohorts (rs17235409, meta p = 0.0002). Interestingly, the presence of the L4-Uganda lineage in the presence of the ancestral human allele associated with more severe disease. These findings demonstrate that IL12B is associated with severity of TB in addition to susceptibility, and that the association between TB severity and human genetics can be due to an interaction between genes in the two species, consistent with host-pathogen coevolution in TB.
Assuntos
Coevolução Biológica , Mycobacterium tuberculosis/genética , Polimorfismo de Nucleotídeo Único , Tuberculose/genética , Adolescente , Adulto , Idoso , Proteínas de Transporte de Cátions/genética , Evolução Molecular , Feminino , Genoma Bacteriano , Interações Hospedeiro-Patógeno , Humanos , Subunidade p40 da Interleucina-12/genética , Masculino , Pessoa de Meia-Idade , Mycobacterium tuberculosis/patogenicidade , Tuberculose/microbiologia , Tuberculose/patologiaRESUMO
BACKGROUND: Tuberculosis (TB) is the most deadly infectious disease globally and is highly prevalent in the developing world. For individuals infected with both Mycobacterium tuberculosis (Mtb) and human immunodeficiency virus (HIV), the risk of active TB is 10% or more annually. Previously, we identified in a genome-wide association study (GWAS) a region on chromosome 5 associated with resistance to TB, which included epigenetic marks that could influence gene regulation. We hypothesized that HIV-infected individuals exposed to Mtb who remain disease free carry epigenetic changes that strongly protect them from active TB. METHODS: We conducted a methylome-wide study in HIV-infected, TB-exposed cohorts from Uganda and Tanzania and integrated data from our GWAS. RESULTS: We identified 3 regions of interest that included markers that were differentially methylated between TB cases and controls with latent TB infection: chromosome 1 (RNF220, Pâ =â 4â ×â 10-5), chromosome 2 (between COPS8 and COL6A3, Pâ =â 2.7â ×â 10-5), and chromosome 5 (CEP72, Pâ =â 1.3â ×â 10-5). These methylation results co-localized with associated single-nucleotide polymorphisms (SNPs), methylation QTLs, and methylationâ ×â SNP interaction effects. These markers were in regions with regulatory markers for cells involved in TB immunity and/or lung. CONCLUSIONS: Epigenetic regulation is a potential biologic factor underlying resistance to TB in immunocompromised individuals that can act in conjunction with genetic variants.
Assuntos
Resistência à Doença/genética , Epigênese Genética , Epigenoma , Infecções por HIV , Tuberculose , Biomarcadores , Estudo de Associação Genômica Ampla , HIV , Infecções por HIV/complicações , Infecções por HIV/genética , Humanos , Tanzânia , Tuberculose/genética , UgandaRESUMO
BACKGROUND: Childhood apraxia of speech (CAS) is a neurodevelopmental disorder with heterogeneous communication and other comorbid manifestations. While previous studies have characterized speech deficits associated with CAS, few studies have examined variability in reading and language and/or other developmental comorbidities. We sought to identify comorbid subgroups within CAS that could be clinically relevant as well as genetically distinctive. METHODS: In a group of 31 children with CAS and 8 controls, we performed hierarchical cluster analysis utilizing measures of articulation, vocabulary, and reading. We also conducted a chart review of the children with CAS to examine other clinical characteristics in these children and their association with subgroup membership. RESULTS: We identified 3 comorbid subgroups within CAS of varying severity. The high severity subgroup was characterized by poor reading and vocabulary, and the moderate severity subgroup by poor reading and non-word repetition but average vocabulary, compared to the mild severity subgroup. Subgroups were indistinguishable with respect to speech sound production, the hallmark of CAS, all demonstrating poor articulation. Children in the most severe subgroup were more likely to have early problems feeding (p = 0.036). CONCLUSIONS: Children with CAS may potentially be classified into comorbidity groups based on performance on vocabulary and reading measures, providing additional insight into the heterogeneity within CAS with implications for educational interventions.
Assuntos
Apraxias , Transtornos do Desenvolvimento da Linguagem , Apraxias/diagnóstico , Apraxias/epidemiologia , Criança , Humanos , Fonética , Fala , Distúrbios da Fala/epidemiologiaRESUMO
One in three people has been infected with Mycobacterium tuberculosis (MTB), and the risk for MTB infection in HIV-infected individuals is even higher. We hypothesized that HIV-positive individuals living in tuberculosis-endemic regions who do not get infected by Mycobacterium tuberculosis are genetically resistant. Using an "experiment of nature" design that proved successful in our previous work, we performed a genome-wide association study of tuberculin skin test positivity using 469 HIV-positive patients from prospective study cohorts of tuberculosis from Tanzania and Uganda to identify genetic loci associated with MTB infection in the context of HIV-infection. Among these individuals, 244 tested were tuberculin skin test (TST) positive either at enrollment or during the >8 year follow up, while 225 were not. We identified a genome-wide significant association between a dominant model of rs877356 and binary TST status in the combined cohort (Odds ratio = 0.2671, p = 1.22x10-8). Association was replicated with similar significance when examining TST induration as a continuous trait. The variant lies in the 5q31.1 region, 57kb downstream from IL9. Two-locus analyses of association of variants near rs877356 showed a haplotype comprised of rs877356 and an IL9 missense variant, rs2069885, had the most significant association (p = 1.59x10-12). We also replicated previously linked loci on chromosomes 2, 5, and 11. IL9 is a cytokine produced by mast cells and TH2 cells during inflammatory responses, providing a possible link between airway inflammation and protection from MTB infection. Our results indicate that studying uninfected, HIV-positive participants with extensive exposure increases the power to detect associations in complex infectious disease.
Assuntos
Cromossomos Humanos Par 5/genética , Estudo de Associação Genômica Ampla , Infecções por HIV/genética , Tuberculose/genética , Adulto , Doenças Endêmicas , Feminino , HIV/genética , HIV/patogenicidade , Infecções por HIV/complicações , Infecções por HIV/microbiologia , Infecções por HIV/virologia , Haplótipos/genética , Humanos , Masculino , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/patogenicidade , Testes Cutâneos , Tanzânia , Teste Tuberculínico , Tuberculose/complicações , Tuberculose/microbiologia , Tuberculose/virologia , UgandaRESUMO
Tuberculosis (TB) is a major public health burden worldwide, and more effective treatment is sorely needed. Consequently, uncovering causes of resistance to Mycobacterium tuberculosis (Mtb) infection is of special importance for vaccine design. Resistance to Mtb infection can be defined by a persistently negative tuberculin skin test (PTST-) despite living in close and sustained exposure to an active TB case. While susceptibility to Mtb is, in part, genetically determined, relatively little work has been done to uncover genetic factors underlying resistance to Mtb infection. We examined a region on chromosome 2q previously implicated in our genomewide linkage scan by a targeted, high-density association scan for genetic variants enhancing PTST- in two independent Ugandan TB household cohorts (n = 747 and 471). We found association with SNPs in neighboring genes ZEB2 and GTDC1 (peak meta p = 1.9 × 10-5) supported by both samples. Bioinformatic analysis suggests these variants may affect PTST- by regulating the histone deacetylase (HDAC) pathway, supporting previous results from transcriptomic analyses. An apparent protective effect of PTST- against body-mass wasting suggests a link between resistance to Mtb infection and healthy body composition. Our results provide insight into how humans may escape latent Mtb infection despite heavy exposure.
Assuntos
Cromossomos Humanos Par 2/genética , Glicosiltransferases/genética , Tuberculose/genética , Homeobox 2 de Ligação a E-box com Dedos de Zinco/genética , Adolescente , Índice de Massa Corporal , Criança , Resistência à Doença , Feminino , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Infecções por HIV/complicações , Histona Desacetilase 1/metabolismo , Humanos , Masculino , Polimorfismo de Nucleotídeo Único , Transdução de Sinais , Teste Tuberculínico , Tuberculose/complicações , Tuberculose/prevenção & controle , Uganda , Adulto JovemRESUMO
BACKGROUND: Resistance to latent Mycobacterium tuberculosis (M.tb) infection, identified by persistently negative tuberculin skin tests (TST) and interferon-gamma release assays (IGRA), after close contact with pulmonary tuberculosis (TB) patients has not been extensively characterized. Stability of this "resistance" beyond 2 years from exposure is unknown. METHODS: 407 of 657 eligible human immunodeficiency virus (HIV)-negative adults from a TB household contact study with persistently negative TST (PTST-) or with stable latent M.tb infection (LTBI) were retraced 9.5 years (standard deviation = 3.2) later. Asymptomatic retraced contacts underwent 3 IGRAs and follow-up TST, and their M.tb infection status classified as definite/possible/probable. RESULTS: Among PTST- with a definite classification, 82.7% were concordantly TST-/ quantiferon-TB Gold- (QFT-), and 16.3% converted to TST+/QFT+ LTBI. Among original LTBI contacts, 83.6% remained LTBI, and 3.9% reverted their TST and were QFT-. Although TST and QFT concordance was high (κ = 0.78), 1.0% of PTST and 12.5% of original LTBI contacts could not be classified due to discordant TST and QFT results. Epidemiological variables did not differ between retraced PTST- and LTBI contacts. CONCLUSION: Resistance to LTBI, defined by repeatedly negative TST and IGRA, in adults who have had close contact with pulmonary TB patients living in TB-endemic areas, is a stable outcome of M.tb exposure. Repeated longitudinal measurements with 2 different immune assays and extended follow-up provide enhanced discriminatory power to identify this resister phenotype and avoid misclassification. Resisters may use immune mechanisms to control aerosolized M.tb that differ from those used by persons who develop "classic" LTBI.
Assuntos
Resistência à Doença , Características da Família , Tuberculose Latente/diagnóstico , Tuberculose Pulmonar/transmissão , Adolescente , Adulto , Citocinas/sangue , Doenças Endêmicas , Feminino , Humanos , Testes de Liberação de Interferon-gama , Masculino , Mycobacterium tuberculosis , Teste Tuberculínico , Uganda , Adulto JovemRESUMO
Immunosuppression resulting from HIV infection increases the risk of progression to active tuberculosis (TB) both in individuals newly exposed to Mycobacterium tuberculosis (MTB) and in those with latent infections. We hypothesized that HIV-positive individuals who do not develop TB, despite living in areas where it is hyperendemic, provide a model of natural resistance. We performed a genome-wide association study of TB resistance by using 581 HIV-positive Ugandans and Tanzanians enrolled in prospective cohort studies of TB; 267 of these individuals developed active TB, and 314 did not. A common variant, rs4921437 at 5q33.3, was significantly associated with TB (odds ratio = 0.37, p = 2.11 × 10(-8)). This variant lies within a genomic region that includes IL12B and is embedded in an H3K27Ac histone mark. The locus also displays consistent patterns of linkage disequilibrium across African populations and has signals of strong selection in populations from equatorial Africa. Along with prior studies demonstrating that therapy with IL-12 (the cytokine encoded in part by IL12B, associated with longer survival following MTB infection in mice deficient in CD4 T cells), our results suggest that this pathway might be an excellent target for the development of new modalities for treating TB, especially for HIV-positive individuals. Our results also indicate that studying extreme disease resistance in the face of extensive exposure can increase the power to detect associations in complex infectious disease.
Assuntos
Loci Gênicos , Predisposição Genética para Doença , Subunidade p40 da Interleucina-12/genética , Tuberculose/genética , Adolescente , Feminino , Frequência do Gene , Estudo de Associação Genômica Ampla , Infecções por HIV/microbiologia , Humanos , Subunidade p40 da Interleucina-12/metabolismo , Desequilíbrio de Ligação , Modelos Logísticos , Masculino , Mycobacterium tuberculosis , Estudos Prospectivos , Fatores de Risco , Tanzânia , Tuberculose/diagnóstico , UgandaRESUMO
In the original published version of Table 2 the number of respondents who said "No" to the question "Does your consent form distinguish between targeted and incidental findings?" was indicated as "4." It should have read "44." This has now been corrected in both the PDF and HTML versions of the Article.
RESUMO
PURPOSE: While there has been a recent increase in scholarship around developing policies for the return of results from genetic sequencing, it is not clear whether these approaches are appropriate for genetic epidemiology studies. Because genetic epidemiological research increasingly utilizes genome sequencing methods, particularly in large data sets where researchers did not directly ascertain the subjects, it is important to understand researchers' perspectives on the return of results. METHODS: We conducted an online survey of members of the International Genetic Epidemiology Society to document the diversity of experiences and impressions regarding return of results. The survey contained both closed and open-ended questions. RESULTS: Among our respondents who enroll their own research participants, only 21% return secondary findings. Most respondents do not search their sequence data for clinically actionable findings not associated with their disease of interest. Many feel that genetic epidemiologists have a unique perspective on the return of results and that research studies should not follow the same procedures as clinical sequencing studies. CONCLUSION: Precision medicine initiatives that rely on both clinical and "big data" genomic research should account for variation in researcher perspectives and study design limitations when developing policies and standard practices regarding the return of results.
Assuntos
Pesquisa em Genética , Achados Incidentais , Epidemiologia Molecular/tendências , Pesquisadores , Revelação , Humanos , Análise de Sequência de DNA , Inquéritos e QuestionáriosRESUMO
Tuberculosis (TB), caused by Mycobacterium tuberculosis (Mtb), remains a major public health problem. Household contact studies identify children and adults along the spectrum from Mtb exposure to disease. In the Kawempe Community Health Study (conducted in Kampala, Uganda), 872 culture-confirmed pulmonary TB cases and their 2,585 contacts were enrolled during 2002-2012 and followed for up to 2 years each. Risk factors identified by time-to-event analysis for secondary TB differed among children, women, and men. Younger age (P = 0.0061), human immunodeficiency virus (HIV) (P = 0.0002), thinness (P = 0.01), absent bacille Calmette-Guérin vaccination (P = 0.002), and epidemiologic risk score (P < 0.0001) were risks for children. For women, risks were HIV (P < 0.0001), thinness (World Health Organization criteria; P < 0.0001), and epidemiologic risk score (P = 0.003). For men, HIV (P = 0.0007) and low body mass index (P = 0.008) resulted in faster progression to TB. Tuberculin skin testing (TST) identified contacts with Mtb infection and those with persistently negative TST. Risks for faster time to Mtb infection were identified, and included age (P = 0.0007), baseline TST induration (P < 0.0001), and epidemiologic risk score (P < 0.0001) only in children. Those with persistently negative TST comprised 10% of contacts but had no unique epidemiologic characteristics among adults. The burden of Mtb infection and disease is high in TB households, and risk factors for progression from exposure to infection and disease differ among children, women, and men.
Assuntos
Mycobacterium tuberculosis , Teste Tuberculínico/estatística & dados numéricos , Tuberculose Pulmonar/epidemiologia , Adolescente , Adulto , Criança , Pré-Escolar , Resistência à Doença , Suscetibilidade a Doenças/microbiologia , Características da Família , Feminino , HIV , Infecções por HIV/microbiologia , Humanos , Tuberculose Latente/epidemiologia , Tuberculose Latente/microbiologia , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Tuberculose Pulmonar/microbiologia , Uganda/epidemiologia , Adulto JovemRESUMO
BACKGROUND: Appraisal delay is the time a patient takes to consider a symptom as not only noticeable, but a sign of illness. The study's objective was to determine the association between appraisal delay in seeking tuberculosis (TB) treatment and geographic distance measured by network travel (driving and pedestrian) time (in minutes) and distance (Euclidean and self-reported) (in kilometers) and to identify other risk factors from selected covariates and how they modify the core association between delay and distance. METHODS: This was part of a longitudinal cohort study known as the Kawempe Community Health Study based in Kampala, Uganda. The study enrolled households from April 2002 to July 2012. Multivariable interval regression with multiplicative heteroscedasticity was used to assess the impact of time and distance on delay. The delay interval outcome was defined using a comprehensive set of 28 possible self-reported symptoms. The main independent variables were network travel time (in minutes) and Euclidean distance (in kilometers). Other covariates were organized according to the Andersen utilization conceptual framework. RESULTS: A total of 838 patients with both distance and delay data were included in the network analysis. Bivariate analyses did not reveal a significant association of any distance metric with the delay outcome. However, adjusting for patient characteristics and cavitary disease status, the multivariable model indicated that each minute of driving time to the clinic significantly (p = 0.02) and positively predicted 0.25 days' delay. At the median distance value of 47 min, this represented an additional delay of about 12 (95% CI: [3, 21]) days to the mean of 40 days (95% CI: [25, 56]). Increasing Euclidean distance significantly predicted (p = 0.02) reduced variance in the delay outcome, thereby increasing precision of the mean delay estimate. At the median Euclidean distance of 2.8 km, the variance in the delay was reduced by more than 25%. CONCLUSION: Of the four geographic distance measures, network travel driving time was a better and more robust predictor of mean delay in this setting. Including network travel driving time with other risk factors may be important in identifying populations especially vulnerable to delay.
Assuntos
Acessibilidade aos Serviços de Saúde , Aceitação pelo Paciente de Cuidados de Saúde/estatística & dados numéricos , Tempo para o Tratamento/estatística & dados numéricos , Viagem/estatística & dados numéricos , Tuberculose/terapia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Feminino , Geografia , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Fatores de Tempo , Uganda , Adulto JovemRESUMO
This study examined the spelling skills in middle childhood and adolescence in individuals with histories of early childhood speech sound disorders (SSD) with and without language impairment (LI). Youth without such histories were also included (No SSD/LI group). The heritability of spelling skills at each age level was estimated. Children with SSD were classified as SSD-only, SSD with LI but without childhood apraxia of speech (SSD + LI/ No CAS), and CAS and LI (CAS + LI). The SSD-only group did not differ in spelling from the No SSD/LI group, suggesting that SSD-only did not increase risk for poor spelling. The SSD + LI/No CAS and CAS + LI groups had poorer spelling skills than the SSD-only and No SSD/LI groups. Spelling was associated with phonological awareness in the middle childhood and adolescent samples and with rapid automatized naming in the adolescent sample. Heritability of spelling skills was stronger in adolescence than in middle childhood. Differences in the correlates of spelling and in heritability at the two ages suggest developmental changes in the factors contributing to spelling.