RESUMO
Spotted fever group (SFG) rickettsiae are human pathogens that infect cells in the vasculature. They disseminate through host tissues by a process of cell-to-cell spread that involves protrusion formation, engulfment, and vacuolar escape. Other bacterial pathogens rely on actin-based motility to provide a physical force for spread. Here, we show that SFG species Rickettsia parkeri typically lack actin tails during spread and instead manipulate host intercellular tension and mechanotransduction to promote spread. Using transposon mutagenesis, we identified surface cell antigen 4 (Sca4) as a secreted effector of spread that specifically promotes protrusion engulfment. Sca4 interacts with the cell-adhesion protein vinculin and blocks association with vinculin's binding partner, α-catenin. Using traction and monolayer stress microscopy, we show that Sca4 reduces vinculin-dependent mechanotransduction at cell-cell junctions. Our results suggest that Sca4 relieves intercellular tension to promote protrusion engulfment, which represents a distinctive strategy for manipulating cytoskeletal force generation to enable spread.
Assuntos
Antígenos de Bactérias/metabolismo , Proteínas de Bactérias/metabolismo , Interações Hospedeiro-Patógeno , Mecanotransdução Celular , Infecções por Rickettsia/metabolismo , Infecções por Rickettsia/microbiologia , Rickettsia/patogenicidade , Vinculina/metabolismo , Actinas/metabolismo , Sequência de Aminoácidos , Antígenos de Bactérias/genética , Proteínas de Bactérias/genética , Caderinas/metabolismo , Adesão Celular , Linhagem Celular Tumoral , Elementos de DNA Transponíveis/genética , Febre/metabolismo , Febre/microbiologia , Humanos , Mutagênese Insercional , Mutação , Rickettsia/metabolismo , alfa Catenina/metabolismoRESUMO
The transcriptional programs that guide lymphocyte differentiation depend on the precise expression and timing of transcription factors (TFs). The TF BACH2 is essential for T and B lymphocytes and is associated with an archetypal super-enhancer (SE). Single-nucleotide variants in the BACH2 locus are associated with several autoimmune diseases, but BACH2 mutations that cause Mendelian monogenic primary immunodeficiency have not previously been identified. Here we describe a syndrome of BACH2-related immunodeficiency and autoimmunity (BRIDA) that results from BACH2 haploinsufficiency. Affected subjects had lymphocyte-maturation defects that caused immunoglobulin deficiency and intestinal inflammation. The mutations disrupted protein stability by interfering with homodimerization or by causing aggregation. We observed analogous lymphocyte defects in Bach2-heterozygous mice. More generally, we observed that genes that cause monogenic haploinsufficient diseases were substantially enriched for TFs and SE architecture. These findings reveal a previously unrecognized feature of SE architecture in Mendelian diseases of immunity: heterozygous mutations in SE-regulated genes identified by whole-exome/genome sequencing may have greater significance than previously recognized.
Assuntos
Doenças Autoimunes/genética , Fatores de Transcrição de Zíper de Leucina Básica/genética , Síndromes de Imunodeficiência/genética , Corticosteroides/uso terapêutico , Adulto , Doenças Autoimunes/complicações , Colite/complicações , Colite/genética , Colite/patologia , Feminino , Febre/complicações , Febre/tratamento farmacológico , Febre/genética , Haploinsuficiência , Heterozigoto , Humanos , Síndromes de Imunodeficiência/complicações , Linfopenia/complicações , Linfopenia/genética , Masculino , Pessoa de Meia-Idade , Mutação , Pancitopenia/complicações , Pancitopenia/tratamento farmacológico , Pancitopenia/genética , Linhagem , Polimorfismo de Nucleotídeo Único , Recidiva , Infecções Respiratórias/complicações , Infecções Respiratórias/diagnóstico por imagem , Infecções Respiratórias/genética , Esplenomegalia/complicações , Esplenomegalia/genética , Síndrome , Tomografia Computadorizada por Raios X , Adulto JovemRESUMO
Fever, an evolutionarily conserved physiological response to infection, is also commonly associated with many autoimmune diseases, but its role in T cell differentiation and autoimmunity remains largely unclear. T helper 17 (Th17) cells are critical in host defense and autoinflammatory diseases, with distinct phenotypes and pathogenicity. Here, we show that febrile temperature selectively regulated Th17 cell differentiation in vitro in enhancing interleukin-17 (IL-17), IL-17F, and IL-22 expression. Th17 cells generated under febrile temperature (38.5°C-39.5°C), compared with those under 37°C, showed enhanced pathogenic gene expression with increased pro-inflammatory activities in vivo. Mechanistically, febrile temperature promoted SUMOylation of SMAD4 transcription factor to facilitate its nuclear localization; SMAD4 deficiency selectively abrogated the effects of febrile temperature on Th17 cell differentiation both in vitro and ameliorated an autoimmune disease model. Our results thus demonstrate a critical role of fever in shaping adaptive immune responses with implications in autoimmune diseases.
Assuntos
Temperatura Corporal/imunologia , Febre/imunologia , Células Th17/imunologia , Imunidade Adaptativa , Animais , Diferenciação Celular/imunologia , Núcleo Celular/metabolismo , Citocinas/metabolismo , Encefalomielite Autoimune Experimental/genética , Encefalomielite Autoimune Experimental/imunologia , Febre/genética , Regulação da Expressão Gênica , Resposta ao Choque Térmico/imunologia , Camundongos , Proteína Smad4/deficiência , Proteína Smad4/metabolismo , Sumoilação , Células Th17/metabolismoRESUMO
Fever is an evolutionarily conserved response that confers survival benefits during infection. However, the underlying mechanism remains obscure. Here, we report that fever promoted T lymphocyte trafficking through heat shock protein 90 (Hsp90)-induced α4 integrin activation and signaling in T cells. By inducing selective binding of Hsp90 to α4 integrins, but not ß2 integrins, fever increased α4-integrin-mediated T cell adhesion and transmigration. Mechanistically, Hsp90 bound to the α4 tail and activated α4 integrins via inside-out signaling. Moreover, the N and C termini of one Hsp90 molecule simultaneously bound to two α4 tails, leading to dimerization and clustering of α4 integrins on the cell membrane and subsequent activation of the FAK-RhoA pathway. Abolishment of Hsp90-α4 interaction inhibited fever-induced T cell trafficking to draining lymph nodes and impaired the clearance of bacterial infection. Our findings identify the Hsp90-α4-integrin axis as a thermal sensory pathway that promotes T lymphocyte trafficking and enhances immune surveillance during infection.
Assuntos
Febre/imunologia , Proteínas de Choque Térmico HSP90/metabolismo , Integrina alfa4/metabolismo , Infecções por Salmonella/imunologia , Salmonella typhimurium/imunologia , Linfócitos T/imunologia , Animais , Carga Bacteriana , Adesão Celular , Movimento Celular , Dimerização , Quinase 1 de Adesão Focal/metabolismo , Vigilância Imunológica , Integrina alfa4/genética , Ativação Linfocitária , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Ligação Proteica , Transdução de Sinais , Proteína rhoA de Ligação ao GTP/metabolismoRESUMO
During infection, animals exhibit adaptive changes in physiology and behaviour aimed at increasing survival. Although many causes of infection exist, they trigger similar stereotyped symptoms such as fever, warmth-seeking, loss of appetite and fatigue1,2. Yet exactly how the nervous system alters body temperature and triggers sickness behaviours to coordinate responses to infection remains unknown. Here we identify a previously uncharacterized population of neurons in the ventral medial preoptic area (VMPO) of the hypothalamus that are activated after sickness induced by lipopolysaccharide (LPS) or polyinosinic:polycytidylic acid. These neurons are crucial for generating a fever response and other sickness symptoms such as warmth-seeking and loss of appetite. Single-nucleus RNA-sequencing and multiplexed error-robust fluorescence in situ hybridization uncovered the identity and distribution of LPS-activated VMPO (VMPOLPS) neurons and non-neuronal cells. Gene expression and electrophysiological measurements implicate a paracrine mechanism in which the release of immune signals by non-neuronal cells during infection activates nearby VMPOLPS neurons. Finally, we show that VMPOLPS neurons exert a broad influence on the activity of brain areas associated with behavioural and homeostatic functions and are synaptically and functionally connected to circuit nodes controlling body temperature and appetite. Together, these results uncover VMPOLPS neurons as a control hub that integrates immune signals to orchestrate multiple sickness symptoms in response to infection.
Assuntos
Apetite , Febre , Infecções , Neurônios , Área Pré-Óptica , Animais , Apetite/efeitos dos fármacos , Depressores do Apetite/farmacologia , Febre/induzido quimicamente , Febre/fisiopatologia , Hibridização in Situ Fluorescente , Infecções/induzido quimicamente , Infecções/fisiopatologia , Lipopolissacarídeos , Neurônios/efeitos dos fármacos , Comunicação Parácrina , Poli I-C , Área Pré-Óptica/citologia , Área Pré-Óptica/efeitos dos fármacos , Área Pré-Óptica/fisiologiaRESUMO
BACKGROUND: Guidelines recommend active fever prevention for 72 hours after cardiac arrest. Data from randomized clinical trials of this intervention have been lacking. METHODS: We randomly assigned comatose patients who had been resuscitated after an out-of-hospital cardiac arrest of presumed cardiac cause to device-based temperature control targeting 36°C for 24 hours followed by targeting of 37°C for either 12 or 48 hours (for total intervention times of 36 and 72 hours, respectively) or until the patient regained consciousness. The primary outcome was a composite of death from any cause or hospital discharge with a Cerebral Performance Category of 3 or 4 (range, 1 to 5, with higher scores indicating more severe disability; a category of 3 or 4 indicates severe cerebral disability or coma) within 90 days after randomization. Secondary outcomes included death from any cause and the Montreal Cognitive Assessment score (range, 0 to 30, with higher scores indicating better cognitive ability) at 3 months. RESULTS: A total of 393 patients were randomly assigned to temperature control for 36 hours, and 396 patients were assigned to temperature control for 72 hours. At 90 days after randomization, a primary end-point event had occurred in 127 of 393 patients (32.3%) in the 36-hour group and in 133 of 396 patients (33.6%) in the 72-hour group (hazard ratio, 0.99; 95% confidence interval, 0.77 to 1.26; P = 0.70) and mortality was 29.5% in the 36-hour group and 30.3% in the 72-hour group. At 3 months, the median Montreal Cognitive Assessment score was 26 (interquartile range, 24 to 29) and 27 (interquartile range, 24 to 28), respectively. There was no significant between-group difference in the incidence of adverse events. CONCLUSIONS: Active device-based fever prevention for 36 or 72 hours after cardiac arrest did not result in significantly different percentages of patients dying or having severe disability or coma. (Funded by the Novo Nordisk Foundation; BOX ClinicalTrials.gov number, NCT03141099.).
Assuntos
Temperatura Corporal , Reanimação Cardiopulmonar , Coma , Febre , Hipotermia Induzida , Parada Cardíaca Extra-Hospitalar , Humanos , Coma/etiologia , Febre/etiologia , Febre/prevenção & controle , Hipotermia Induzida/efeitos adversos , Hipotermia Induzida/instrumentação , Hipotermia Induzida/métodos , Parada Cardíaca Extra-Hospitalar/complicações , Parada Cardíaca Extra-Hospitalar/terapia , Resultado do Tratamento , Estado de ConsciênciaRESUMO
Climate change has profound effects on infectious disease dynamics, yet the impacts of increased short-term temperature fluctuations on disease spread remain poorly understood. We empirically tested the theoretical prediction that short-term thermal fluctuations suppress endemic infection prevalence at the pathogen's thermal optimum. This prediction follows from a mechanistic disease transmission model analyzed using stochastic simulations of the model parameterized with thermal performance curves (TPCs) from metabolic scaling theory and using nonlinear averaging, which predicts ecological outcomes consistent with Jensen's inequality (i.e., reduced performance around concave-down portions of a thermal response curve). Experimental observations of replicated epidemics of the microparasite Ordospora colligata in Daphnia magna populations indicate that temperature variability had the opposite effect of our theoretical predictions and instead increase endemic infection prevalence. This positive effect of temperature variability is qualitatively consistent with a published hypothesis that parasites may acclimate more rapidly to fluctuating temperatures than their hosts; however, incorporating hypothetical effects of delayed host acclimation into the mechanistic transmission model did not fully account for the observed pattern. The experimental data indicate that shifts in the distribution of infection burden underlie the positive effect of temperature fluctuations on endemic prevalence. The increase in disease risk associated with climate fluctuations may therefore result from disease processes interacting across scales, particularly within-host dynamics, that are not captured by combining standard transmission models with metabolic scaling theory.
Assuntos
Doenças Transmissíveis , Parasitos , Doenças Parasitárias , Animais , Daphnia , Temperatura , FebreRESUMO
An outbreak of coronavirus disease 2019 (COVID-19), which is caused by a novel coronavirus (named SARS-CoV-2) and has a case fatality rate of approximately 2%, started in Wuhan (China) in December 20191,2. Following an unprecedented global spread3, the World Health Organization declared COVID-19 a pandemic on 11 March 2020. Although data on COVID-19 in humans are emerging at a steady pace, some aspects of the pathogenesis of SARS-CoV-2 can be studied in detail only in animal models, in which repeated sampling and tissue collection is possible. Here we show that SARS-CoV-2 causes a respiratory disease in rhesus macaques that lasts between 8 and 16 days. Pulmonary infiltrates, which are a hallmark of COVID-19 in humans, were visible in lung radiographs. We detected high viral loads in swabs from the nose and throat of all of the macaques, as well as in bronchoalveolar lavages; in one macaque, we observed prolonged rectal shedding. Together, the rhesus macaque recapitulates the moderate disease that has been observed in the majority of human cases of COVID-19. The establishment of the rhesus macaque as a model of COVID-19 will increase our understanding of the pathogenesis of this disease, and aid in the development and testing of medical countermeasures.
Assuntos
Betacoronavirus/patogenicidade , Infecções por Coronavirus/patologia , Infecções por Coronavirus/fisiopatologia , Modelos Animais de Doenças , Pulmão/diagnóstico por imagem , Pneumonia Viral/patologia , Pneumonia Viral/fisiopatologia , Transtornos Respiratórios/patologia , Transtornos Respiratórios/virologia , Animais , Líquidos Corporais/virologia , Lavagem Broncoalveolar , COVID-19 , Infecções por Coronavirus/complicações , Infecções por Coronavirus/virologia , Tosse/complicações , Feminino , Febre/complicações , Pulmão/patologia , Pulmão/fisiopatologia , Pulmão/virologia , Macaca mulatta , Masculino , Pandemias , Pneumonia Viral/complicações , Pneumonia Viral/virologia , Radiografia , Transtornos Respiratórios/complicações , Transtornos Respiratórios/fisiopatologia , SARS-CoV-2 , Fatores de Tempo , Carga ViralRESUMO
BACKGROUND: Before April 2022, monkeypox virus infection in humans was seldom reported outside African regions where it is endemic. Currently, cases are occurring worldwide. Transmission, risk factors, clinical presentation, and outcomes of infection are poorly defined. METHODS: We formed an international collaborative group of clinicians who contributed to an international case series to describe the presentation, clinical course, and outcomes of polymerase-chain-reaction-confirmed monkeypox virus infections. RESULTS: We report 528 infections diagnosed between April 27 and June 24, 2022, at 43 sites in 16 countries. Overall, 98% of the persons with infection were gay or bisexual men, 75% were White, and 41% had human immunodeficiency virus infection; the median age was 38 years. Transmission was suspected to have occurred through sexual activity in 95% of the persons with infection. In this case series, 95% of the persons presented with a rash (with 64% having ≤10 lesions), 73% had anogenital lesions, and 41% had mucosal lesions (with 54 having a single genital lesion). Common systemic features preceding the rash included fever (62%), lethargy (41%), myalgia (31%), and headache (27%); lymphadenopathy was also common (reported in 56%). Concomitant sexually transmitted infections were reported in 109 of 377 persons (29%) who were tested. Among the 23 persons with a clear exposure history, the median incubation period was 7 days (range, 3 to 20). Monkeypox virus DNA was detected in 29 of the 32 persons in whom seminal fluid was analyzed. Antiviral treatment was given to 5% of the persons overall, and 70 (13%) were hospitalized; the reasons for hospitalization were pain management, mostly for severe anorectal pain (21 persons); soft-tissue superinfection (18); pharyngitis limiting oral intake (5); eye lesions (2); acute kidney injury (2); myocarditis (2); and infection-control purposes (13). No deaths were reported. CONCLUSIONS: In this case series, monkeypox manifested with a variety of dermatologic and systemic clinical findings. The simultaneous identification of cases outside areas where monkeypox has traditionally been endemic highlights the need for rapid identification and diagnosis of cases to contain further community spread.
Assuntos
Saúde Global , Mpox , Adulto , Exantema/etiologia , Feminino , Febre/etiologia , Saúde Global/estatística & dados numéricos , Humanos , Masculino , Mpox/epidemiologia , Mpox/terapia , Monkeypox virusRESUMO
Fever is common among individuals seeking healthcare after traveling to tropical regions. Despite the association with potentially severe disease, the etiology is often not determined. Plasma protein patterns can be informative to understand the host response to infection and can potentially indicate the pathogen causing the disease. In this study, we measured 49 proteins in the plasma of 124 patients with fever after travel to tropical or subtropical regions. The patients had confirmed diagnoses of either malaria, dengue fever, influenza, bacterial respiratory tract infection, or bacterial gastroenteritis, representing the most common etiologies. We used multivariate and machine learning methods to identify combinations of proteins that contributed to distinguishing infected patients from healthy controls, and each other. Malaria displayed the most unique protein signature, indicating a strong immunoregulatory response with high levels of IL10, sTNFRI and II, and sCD25 but low levels of sCD40L. In contrast, bacterial gastroenteritis had high levels of sCD40L, APRIL, and IFN-γ, while dengue was the only infection with elevated IFN-α2. These results suggest that characterization of the inflammatory profile of individuals with fever can help to identify disease-specific host responses, which in turn can be used to guide future research on diagnostic strategies and therapeutic interventions.
Assuntos
Infecções Bacterianas , Dengue , Gastroenterite , Malária , Infecções Respiratórias , Humanos , Dengue/diagnóstico , Infecções Respiratórias/complicações , Gastroenterite/complicações , Viagem , Febre/complicaçõesRESUMO
On 23 July 2022, the World Health Organization declared the global mpox outbreak as a public health emergency of international significance. The mpox virus (MPXV) that caused the outbreak was classified as clade IIb, which belongs to the West African clade. However, the relationship between MPXV clades and symptoms, as well as the severity of mpox outcomes, is not fully understood. Thus, we aimed to investigate the global mpox prevalence and the differences in clinical manifestations and outcomes among patients with mpox between pre-outbreak (2003-2021) and the current mpox outbreak. In this systematic review and meta-analysis, PubMed/MEDLINE, Web of Science, Embase, Cumulative Index to Nursing and Allied Health Literature, and Google Scholar were searched using the keyword "monkeypox" and "mpox" up to 13 October 2022. A random effects model was used to obtain the pooled prevalence and 95% confidence intervals. This study included 27 articles, and 5698 patients with mpox with 19 distinctive features from 19 countries across five continents were assessed. Patients with mpox during the 2022 mpox outbreak showed mild clinical manifestations and outcomes compared with those before the 2022 mpox outbreak: mild rash (relative ratio [RR]: 5.09, 95% confidence interval [CI]: 1.52-17.08), fever (0.68, 0.49-0.94), pruritus (0.25, 0.19-0.32), myalgia (0.50, 0.31-0.81), headache (0.56, 0.35-0.88), skin ulcer (0.32, 0.17-0.59), abdominal symptom (0.29, 0.20-0.42), pharyngitis (0.32, 0.18-0.58), nausea or vomiting (0.15, 0.02-0.93), conjunctivitis (0.11, 0.03-0.38), concomitant infection with HIV (1.70, 0.95-3 0.04), and death (0.02, 0.001-0.31). MPXV clade IIb exhibited higher infectivity but may cause mild disease symptoms and low mortality rate. It is important to consider MPXV infection in patients with mpox-related features and/or a history of sexual transmission to prevent the spread of the disease and recognise the current pandemic threat.
Assuntos
Exantema , Soropositividade para HIV , HIV-1 , Mpox , Humanos , Surtos de Doenças , Saúde Pública , FebreRESUMO
Fever is known to be elicited by prostaglandin E2 acting on the brain, but its origin has remained disputed. We show in mice that selective deletion of prostaglandin synthesis in brain endothelial cells, but not in neural cells or myeloid cells, abolished fever induced by intravenous administration of lipopolysaccharide and that selective rescue of prostaglandin synthesis in brain endothelial cells reinstated fever. These data demonstrate that prostaglandin production in brain endothelial cells is both necessary and sufficient for eliciting fever.
Assuntos
Dinoprostona , Células Endoteliais , Febre , Animais , Camundongos , Encéfalo/citologia , Encéfalo/metabolismo , Dinoprostona/metabolismo , Células Endoteliais/metabolismo , Febre/induzido quimicamente , LipopolissacarídeosRESUMO
SignificanceMetagenomic pathogen sequencing offers an unbiased approach to characterizing febrile illness. In resource-scarce settings with high biodiversity, it is critical to identify disease-causing pathogens in order to understand burden and to prioritize efforts for control. Here, metagenomic next-generation sequencing (mNGS) characterization of the pathogen landscape in Cambodia revealed diverse vector-borne and zoonotic pathogens irrespective of age and gender as risk factors. Identification of key pathogens led to changes in national program surveillance. This study is a "real world" example of the use of mNGS surveillance of febrile individuals, executed in-country, to identify outbreaks of vector-borne, zoonotic, and other emerging pathogens in a resource-scarce setting.
Assuntos
Suscetibilidade a Doenças , Recursos em Saúde , Metagenoma , Metagenômica/métodos , Vigilância em Saúde Pública , Sudeste Asiático/epidemiologia , Camboja/epidemiologia , Feminino , Febre/epidemiologia , Febre/etiologia , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Masculino , Estudos SoroepidemiológicosRESUMO
Passive whole-body hyperthermia increases limb blood flow and cardiac output ( Q Ì $\dot Q$ ), but the interplay between peripheral and central thermo-haemodynamic mechanisms remains unclear. Here we tested the hypothesis that local hyperthermia-induced alterations in peripheral blood flow and blood kinetic energy modulate flow to the heart and Q Ì $\dot Q$ . Body temperatures, regional (leg, arm, head) and systemic haemodynamics, and left ventricular (LV) volumes and functions were assessed in eight healthy males during: (1) 3 h control (normothermic condition); (2) 3 h of single-leg heating; (3) 3 h of two-leg heating; and (4) 2.5 h of whole-body heating. Leg, forearm, and extracranial blood flow increased in close association with local rises in temperature while brain perfusion remained unchanged. Increases in blood velocity with small to no changes in the conduit artery diameter underpinned the augmented limb and extracranial perfusion. In all heating conditions, Q Ì $\dot Q$ increased in association with proportional elevations in systemic vascular conductance, related to enhanced blood flow, blood velocity, vascular conductance and kinetic energy in the limbs and head (all R2 ≥ 0.803; P < 0.001), but not in the brain. LV systolic (end-systolic elastance and twist) and diastolic functional profiles (untwisting rate), pulmonary ventilation and systemic aerobic metabolism were only altered in whole-body heating. These findings substantiate the idea that local hyperthermia-induced selective alterations in peripheral blood flow modulate the magnitude of flow to the heart and Q Ì $\dot Q$ through changes in blood velocity and kinetic energy. Localised heat-activated events in the peripheral circulation therefore affect the human heart's output. KEY POINTS: Local and whole-body hyperthermia increases limb and systemic perfusion, but the underlying peripheral and central heat-sensitive mechanisms are not fully established. Here we investigated the regional (leg, arm and head) and systemic haemodynamics (cardiac output: Q Ì $\dot Q$ ) during passive single-leg, two-leg and whole-body hyperthermia to determine the contribution of peripheral and central thermosensitive factors in the control of human circulation. Single-leg, two-leg, and whole-body hyperthermia induced graded increases in leg blood flow and Q Ì $\dot Q$ . Brain blood flow, however, remained unchanged in all conditions. Ventilation, extracranial blood flow and cardiac systolic and diastolic functions only increased during whole-body hyperthermia. The augmented Q Ì $\dot Q$ with hyperthermia was tightly related to increased limb and head blood velocity, flow and kinetic energy. The findings indicate that local thermosensitive mechanisms modulate regional blood velocity, flow and kinetic energy, thereby controlling the magnitude of flow to the heart and thus the coupling of peripheral and central circulation during hyperthermia.
Assuntos
Débito Cardíaco , Hipertermia , Humanos , Masculino , Adulto , Hipertermia/fisiopatologia , Débito Cardíaco/fisiologia , Velocidade do Fluxo Sanguíneo/fisiologia , Fluxo Sanguíneo Regional/fisiologia , Febre/fisiopatologia , Adulto Jovem , Temperatura Alta , HemodinâmicaRESUMO
BACKGROUND: Optimization of antimicrobial stewardship is key to tackling antimicrobial resistance, which is exacerbated by overprescription of antibiotics in pediatric emergency departments (EDs). We described patterns of empiric antibiotic use in European EDs and characterized appropriateness and consistency of prescribing. METHODS: Between August 2016 and December 2019, febrile children attending EDs in 9 European countries with suspected infection were recruited into the PERFORM (Personalised Risk Assessment in Febrile Illness to Optimise Real-Life Management) study. Empiric systemic antibiotic use was determined in view of assigned final "bacterial" or "viral" phenotype. Antibiotics were classified according to the World Health Organization (WHO) AWaRe classification. RESULTS: Of 2130 febrile episodes (excluding children with nonbacterial/nonviral phenotypes), 1549 (72.7%) were assigned a bacterial and 581 (27.3%) a viral phenotype. A total of 1318 of 1549 episodes (85.1%) with a bacterial and 269 of 581 (46.3%) with a viral phenotype received empiric systemic antibiotics (in the first 2 days of admission). Of those, the majority (87.8% in the bacterial and 87.0% in the viral group) received parenteral antibiotics. The top 3 antibiotics prescribed were third-generation cephalosporins, penicillins, and penicillin/ß-lactamase inhibitor combinations. Of those treated with empiric systemic antibiotics in the viral group, 216 of 269 (80.3%) received ≥1 antibiotic in the "Watch" category. CONCLUSIONS: Differentiating bacterial from viral etiology in febrile illness on initial ED presentation remains challenging, resulting in a substantial overprescription of antibiotics. A significant proportion of patients with a viral phenotype received systemic antibiotics, predominantly classified as WHO Watch. Rapid and accurate point-of-care tests in the ED differentiating between bacterial and viral etiology could significantly improve antimicrobial stewardship.
Assuntos
Antibacterianos , Gestão de Antimicrobianos , Criança , Humanos , Antibacterianos/uso terapêutico , Gestão de Antimicrobianos/métodos , Prescrições de Medicamentos , Europa (Continente) , Serviço Hospitalar de Emergência , Febre/diagnóstico , Febre/tratamento farmacológico , Penicilinas/uso terapêuticoRESUMO
BACKGROUND: The incidence of pneumonic tularemia is very low; therefore, it is not feasible to conduct clinical efficacy testing of tularemia medical countermeasures (MCMs) in humans. The US Food and Drug Administration's Animal Model Qualification Program under the Drug Development Tools Program is a regulatory pathway for animal models used in MCM efficacy testing and approval under the Animal Rule. The National Institute of Allergy and Infectious Diseases and Biomedical Advanced Research and Development Authority worked together to qualify the cynomolgus macaque model of pneumonic tularemia. METHODS: Using the model parameters and end points defined in the qualified model, efficacy of the antibiotics doxycycline and ciprofloxacin was evaluated in separate studies. Antibiotic administration, aimed to model approved human dosing, was initiated at time points of 24 hours or 48 hours after onset of fever as an indicator of disease. RESULTS: Upon aerosol exposure (target dose of 1000 colony-forming units) to Francisella tularensis SchuS4, 80% of vehicle-treated macaques succumbed or were euthanized. Ciprofloxacin treatment led to 10 of 10 animals surviving irrespective of treatment time. Doxycycline administered at 48 hours post-fever led to 10 of 10 animals surviving, while 9/10 animals survived in the group treated with doxycycline 24 hours after fever. Selected surviving animals in both the placebo and doxycycline 48-hour group showed residual live bacteria in peripheral tissues, while there were no bacteria in tissues from ciprofloxacin-treated macaques. CONCLUSIONS: Both doxycycline and ciprofloxacin were efficacious in treatment of pneumonic tularemia, although clearance of bacteria may be different between the 2 drugs.
Assuntos
Francisella tularensis , Tularemia , Animais , Humanos , Tularemia/tratamento farmacológico , Tularemia/microbiologia , Ciprofloxacina/uso terapêutico , Doxiciclina/uso terapêutico , Modelos Animais de Doenças , Antibacterianos/uso terapêutico , Febre/tratamento farmacológico , MacacaRESUMO
We detected Mayaro virus (MAYV) in 3.4% (28/822) of febrile patients tested during 2018-2021 from Roraima State, Brazil. We also isolated MAYV strains and confirmed that these cases were caused by genotype D. Improved surveillance is needed to better determine the burden of MAYV in the Amazon Region.
Assuntos
Epidemiologia Molecular , Humanos , Brasil/epidemiologia , Febre/virologia , Febre/epidemiologia , Masculino , Filogenia , Adulto , Alphavirus/genética , Alphavirus/classificação , Feminino , Genótipo , Criança , Pessoa de Meia-Idade , Adolescente , Pré-Escolar , História do Século XXI , Adulto Jovem , Idoso , Infecções por Arenaviridae/epidemiologia , Infecções por Arenaviridae/virologia , Infecções por Alphavirus/epidemiologia , Infecções por Alphavirus/virologia , LactenteRESUMO
Bacterial zoonoses are established causes of severe febrile illness in East Africa. Within a fever etiology study, we applied a high-throughput 16S rRNA metagenomic assay validated for detecting bacterial zoonotic pathogens. We enrolled febrile patients admitted to 2 referral hospitals in Moshi, Tanzania, during September 2007-April 2009. Among 788 participants, median age was 20 (interquartile range 2-38) years. We performed PCR amplification of V1-V2 variable region 16S rRNA on cell pellet DNA, then metagenomic deep-sequencing and pathogenic taxonomic identification. We detected bacterial zoonotic pathogens in 10 (1.3%) samples: 3 with Rickettsia typhi, 1 R. conorii, 2 Bartonella quintana, 2 pathogenic Leptospira spp., and 1 Coxiella burnetii. One other sample had reads matching a Neoerhlichia spp. previously identified in a patient from South Africa. Our findings indicate that targeted 16S metagenomics can identify bacterial zoonotic pathogens causing severe febrile illness in humans, including potential novel agents.
Assuntos
Febre , Metagenômica , RNA Ribossômico 16S , Humanos , Tanzânia/epidemiologia , Adulto , Pré-Escolar , Adolescente , Metagenômica/métodos , Febre/microbiologia , Masculino , Feminino , Animais , Criança , RNA Ribossômico 16S/genética , Adulto Jovem , Bactérias/genética , Bactérias/classificação , Bactérias/isolamento & purificação , Zoonoses Bacterianas/microbiologia , Zoonoses Bacterianas/epidemiologia , Infecções Bacterianas/microbiologia , Infecções Bacterianas/epidemiologia , Infecções Bacterianas/diagnóstico , Zoonoses/microbiologia , Zoonoses/epidemiologiaRESUMO
Multisystem inflammatory syndrome in children (MIS-C) is a severe, hyperinflammatory disease that occurs after exposure to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The underlying immune pathology of MIS-C is incompletely understood, with limited data comparing MIS-C to clinically similar paediatric febrile diseases at presentation. SARS-CoV-2-specific T cell responses have not been compared in these groups to assess whether there is a T cell profile unique to MIS-C. In this study, we measured inflammatory cytokine concentration and SARS-CoV-2-specific humoral immunity and T cell responses in children with fever and suspected MIS-C at presentation (n = 83) where MIS-C was ultimately confirmed (n = 58) or another diagnosis was made (n = 25) and healthy children (n = 91). Children with confirmed MIS-C exhibited distinctly elevated serum IL-10, IL-6, and CRP at presentation. No differences were detected in SARS-CoV-2 spike IgG serum concentration, neutralisation capacity, antibody dependant cellular phagocytosis, antibody dependant cellular cytotoxicity or SARS-CoV-2-specific T cell frequency between the groups. Healthy SARS-CoV-2 seropositive children had a higher proportion of polyfunctional SARS-CoV-2-specific CD4+ T cells compared to children with MIS-C and those with other inflammatory or infectious diagnoses, who both presented a largely monofunctional SARS-CoV-2-specific CD4+ T cell profile. Treatment with steroids and/or intravenous immunoglobulins resulted in rapid reduction of inflammatory cytokines but did not affect the SARS-CoV-2-specific IgG or CD4+ T cell responses in MIS-C. In these data, MIS-C had a unique cytokine profile but not a unique SARS-CoV-2 specific humoral or T cell cytokine response.
Assuntos
COVID-19 , Doenças do Tecido Conjuntivo , Síndrome de Resposta Inflamatória Sistêmica , Humanos , Criança , SARS-CoV-2 , Citocinas , Imunoglobulina G , Febre , Anticorpos AntiviraisRESUMO
OBJECTIVE: COVID-19 immunization was implemented with emergency-use authorization. We had concerns/lack of information on mRNA vaccine side effects in different inborn errors of immunity (IEI) types. METHODS: We enrolled 141 patients (IEIP) and 151 healthy controls(HC) who received SARS-CoV-2 vaccine/s(Sinovac and/or Pfizer-BioNTech(mRNA vaccine), one to five doses), questioned them for side-effects, evaluated in three groups according to the vaccine/s they received; only Sinovac, only Pfizer-BioNTech, and both vaccines. RESULTS: Arm pain, generalized weakness, myalgia, and fever were common side effects in IEI-P and HC groups. Generalized weakness/fatigue, fever, and palpitation were significantly frequent in IEI-P who experienced COVID-19 compared to those who did not (p = 0.021, p = 0.047, and p = 0.024, respectively). Severe symptoms after vaccination, new-onset splenomegaly and pancytopenia, urticaria, herpes simplex virus (HSV), and varicella zoster virus (VZV) reactivation were seen in four IEI-P (2.8%). CONCLUSION: IEI-P mRNA vaccination is relatively safe compared to the conventional vaccine. Individuals who experience uncommon side effects should undergo immunological screening.