33 research outputs found
The epidemiology of dengue outbreaks in 2016 and 2017 in Ouagadougou, Burkina Faso.
BACKGROUND: Dengue is prevalent in as many as 128 countries with more than 100 million clinical episodes reported annually and four billion people estimated to be at risk. While dengue fever is systematically diagnosed in large parts of Asia and South America, the disease burden in Africa is less well investigated. This report describes two consecutive dengue outbreaks in Ouagadougou, Burkina Faso in 2016 and 2017. METHODS: Blood samples of febrile patients received at Schiphra laboratory in Ouagadougou, Burkina Faso, were screened for dengue infection using SD Bioline Dengue Duo rapid diagnostic test kits (Standard Diagnostics, Suwon, Republic of Korea). RESULTS: A total of 1,397 and 1,882 cases were reported by a single laboratory in 2016 and 2017, respectively. Most cases were at least 15 years of age and the results corroborated reports from WHO indicating the circulation of three dengue virus serotypes in Burkina Faso. CONCLUSION: This study complements data from other, simultaneously conducted surveillance efforts, and indicates that the dengue disease burden might be underestimated in sub-Saharan African nations. Dengue surveillance should be enhanced in African settings to determine the burden more accurately, and accelerated efforts towards a dengue vaccine should be put in place
Control of CD1d-restricted antigen presentation and inflammation by sphingomyelin.
Invariant natural killer T (iNKT) cells recognize activating self and microbial lipids presented by CD1d. CD1d can also bind non-activating lipids, such as sphingomyelin. We hypothesized that these serve as endogenous regulators and investigated humans and mice deficient in acid sphingomyelinase (ASM), an enzyme that degrades sphingomyelin. We show that ASM absence in mice leads to diminished CD1d-restricted antigen presentation and iNKT cell selection in the thymus, resulting in decreased iNKT cell levels and resistance to iNKT cell-mediated inflammatory conditions. Defective antigen presentation and decreased iNKT cells are also observed in ASM-deficient humans with Niemann-Pick disease, and ASM activity in healthy humans correlates with iNKT cell phenotype. Pharmacological ASM administration facilitates antigen presentation and restores the levels of iNKT cells in ASM-deficient mice. Together, these results demonstrate that control of non-agonistic CD1d-associated lipids is critical for iNKT cell development and function in vivo and represents a tight link between cellular sphingolipid metabolism and immunity
Early-Onset Neonatal Sepsis 2015 to 2017, the Rise of Escherichia coli, and the Need for Novel Prevention Strategies
Importance: Early-onset sepsis (EOS) remains a potentially fatal newborn condition. Ongoing surveillance is critical to optimize prevention and treatment strategies.
Objective: To describe the current incidence, microbiology, morbidity, and mortality of EOS among a cohort of term and preterm infants.
Design, setting, and participants: This prospective surveillance study included a cohort of infants born at a gestational age (GA) of at least 22 weeks and birth weight of greater than 400 g from 18 centers of the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network from April 1, 2015, to March 31, 2017. Data were analyzed from June 14, 2019, to January 28, 2020.
Main outcomes and measures: Early-onset sepsis defined by isolation of pathogenic species from blood or cerebrospinal fluid culture within 72 hours of birth and antibiotic treatment for at least 5 days or until death.
Results: A total of 235 EOS cases (127 male [54.0%]) were identified among 217 480 newborns (1.08 [95% CI, 0.95-1.23] cases per 1000 live births). Incidence varied significantly by GA and was highest among infants with a GA of 22 to 28 weeks (18.47 [95% CI, 14.57-23.38] cases per 1000). No significant differences in EOS incidence were observed by sex, race, or ethnicity. The most frequent pathogens were Escherichia coli (86 [36.6%]) and group B streptococcus (GBS; 71 [30.2%]). E coli disease primarily occurred among preterm infants (68 of 131 [51.9%]); GBS disease primarily occurred among term infants (54 of 104 [51.9%]), with 24 of 45 GBS cases (53.3%) seen in infants born to mothers with negative GBS screening test results. Intrapartum antibiotics were administered to 162 mothers (68.9%; 110 of 131 [84.0%] preterm and 52 of 104 [50.0%] term), most commonly for suspected chorioamnionitis. Neonatal empirical antibiotic treatment most frequently included ampicillin and gentamicin. All GBS isolates were tested, but only 18 of 81 (22.2%) E coli isolates tested were susceptible to ampicillin; 6 of 77 E coli isolates (7.8%) were resistant to both ampicillin and gentamicin. Nearly all newborns with EOS (220 of 235 [93.6%]) displayed signs of illness within 72 hours of birth. Death occurred in 38 of 131 infected infants with GA of less than 37 weeks (29.0%); no term infants died. Compared with earlier surveillance (2006-2009), the rate of E coli infection increased among very low-birth-weight (401-1500 g) infants (8.68 [95% CI, 6.50-11.60] vs 5.07 [95% CI, 3.93-6.53] per 1000 live births; P = .008).
Conclusions and relevance: In this study, EOS incidence and associated mortality disproportionately occurred in preterm infants. Contemporary cases have demonstrated the limitations of current GBS prevention strategies. The increase in E coli infections among very low-birth-weight infants warrants continued study. Ampicillin and gentamicin remained effective antibiotics in most cases, but ongoing surveillance should monitor antibiotic susceptibilities of EOS pathogens
Dissecting the Shared Genetic Architecture of Suicide Attempt, Psychiatric Disorders, and Known Risk Factors
Background Suicide is a leading cause of death worldwide, and nonfatal suicide attempts, which occur far more frequently, are a major source of disability and social and economic burden. Both have substantial genetic etiology, which is partially shared and partially distinct from that of related psychiatric disorders. Methods We conducted a genome-wide association study (GWAS) of 29,782 suicide attempt (SA) cases and 519,961 controls in the International Suicide Genetics Consortium (ISGC). The GWAS of SA was conditioned on psychiatric disorders using GWAS summary statistics via multitrait-based conditional and joint analysis, to remove genetic effects on SA mediated by psychiatric disorders. We investigated the shared and divergent genetic architectures of SA, psychiatric disorders, and other known risk factors. Results Two loci reached genome-wide significance for SA: the major histocompatibility complex and an intergenic locus on chromosome 7, the latter of which remained associated with SA after conditioning on psychiatric disorders and replicated in an independent cohort from the Million Veteran Program. This locus has been implicated in risk-taking behavior, smoking, and insomnia. SA showed strong genetic correlation with psychiatric disorders, particularly major depression, and also with smoking, pain, risk-taking behavior, sleep disturbances, lower educational attainment, reproductive traits, lower socioeconomic status, and poorer general health. After conditioning on psychiatric disorders, the genetic correlations between SA and psychiatric disorders decreased, whereas those with nonpsychiatric traits remained largely unchanged. Conclusions Our results identify a risk locus that contributes more strongly to SA than other phenotypes and suggest a shared underlying biology between SA and known risk factors that is not mediated by psychiatric disorders.Peer reviewe
Finishing the euchromatic sequence of the human genome
The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead
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Neonatal Fc Receptor Expression in Dendritic Cells Mediates Protective Immunity against Colorectal Cancer
Cancers arising in mucosal tissues account for a disproportionately large fraction of malignancies. Immunoglobulin G (IgG) and the neonatal Fc receptor for IgG (FcRn) have an important function in the mucosal immune system that we have now shown extends to the induction of CD8(+) T cell-mediated antitumor immunity. We demonstrate that FcRn within dendritic cells (DCs) was critical for homeostatic activation of mucosal CD8(+) T cells that drove protection against the development of colorectal cancers and lung metastases. FcRn-mediated tumor protection was driven by DCs activation of endogenous tumor-reactive CD8(+) T cells via the cross-presentation of IgG complexed antigens (IgG IC), as well as the induction of cytotoxicity-promoting cytokine secretion, particularly interleukin-12, both of which were independently triggered by the FcRn-IgG IC interaction in murine and human DCs. FcRn thus has a primary role within mucosal tissues in activating local immune responses that are critical for priming efficient anti-tumor immunosurveillance
Neonatal Fc receptor expression in dendritic cells mediates protective immunity against colorectal cancer
Cancers arising in mucosal tissues account for a disproportionately large fraction of malignancies. Immunoglobulin G (IgG) and the neonatal Fc receptor for IgG (FcRn) have an important function in the mucosal immune system that we have now shown extends to the induction of CD8(+) T cell-mediated antitumor immunity. We demonstrate that FcRn within dendritic cells (DCs) was critical for homeostatic activation of mucosal CD8(+) T cells that drove protection against the development of colorectal cancers and lung metastases. FcRn-mediated tumor protection was driven by DCs activation of endogenous tumor-reactive CD8(+) T cells via the cross-presentation of IgG complexed antigens (IgG IC), as well as the induction of cytotoxicity-promoting cytokine secretion, particularly interleukin-12, both of which were independently triggered by the FcRn-IgG IC interaction in murine and human DCs. FcRn thus has a primary role within mucosal tissues in activating local immune responses that are critical for priming efficient anti-tumor immunosurveillance
Recommended from our members
Neonatal Fc Receptor Expression in Dendritic Cells Mediates Protective Immunity against Colorectal Cancer
Cancers arising in mucosal tissues account for a disproportionately large fraction of malignancies. Immunoglobulin G (IgG) and the neonatal Fc receptor for IgG (FcRn) have an important function in the mucosal immune system that we have now shown extends to the induction of CD8+ T cell-mediated antitumor immunity. We demonstrate that FcRn within dendritic cells (DCs) was critical for homeostatic activation of mucosal CD8+ T cells that drove protection against the development of colorectal cancers and lung metastases. FcRn-mediated tumor protection was driven by DCs activation of endogenous tumor-reactive CD8+ T cells via the cross-presentation of IgG complexed antigens (IgG IC), as well as the induction of cytotoxicity-promoting cytokine secretion, particularly interleukin-12, both of which were independently triggered by the FcRn–IgG IC interaction in murine and human DCs. FcRn thus has a primary role within mucosal tissues in activating local immune responses that are critical for priming efficient anti-tumor immunosurveillance