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1.
Cell ; 166(1): 5-8, 2016 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-27368093

RESUMEN

Recent infectious disease epidemics illustrate how health systems failures anywhere can create disease vulnerabilities everywhere. We must therefore prioritize investments in health care infrastructure in outbreak-prone regions of the world. We describe how "rooted" research collaborations can establish capacity for pathogen surveillance and facilitate rapid outbreak responses.


Asunto(s)
Investigación Biomédica , Brotes de Enfermedades , Fiebres Hemorrágicas Virales/epidemiología , África Occidental/epidemiología , Monitoreo Epidemiológico , Fiebre Hemorrágica Ebola/epidemiología , Fiebre Hemorrágica Ebola/fisiopatología , Fiebre Hemorrágica Ebola/virología , Fiebres Hemorrágicas Virales/fisiopatología , Fiebres Hemorrágicas Virales/virología , Cooperación Internacional , Virología/educación
2.
Immunity ; 54(4): 815-828.e5, 2021 04 13.
Artículo en Inglés | MEDLINE | ID: mdl-33852832

RESUMEN

Protective Ebola virus (EBOV) antibodies have neutralizing activity and induction of antibody constant domain (Fc)-mediated innate immune effector functions. Efforts to enhance Fc effector functionality often focus on maximizing antibody-dependent cellular cytotoxicity, yet distinct combinations of functions could be critical for antibody-mediated protection. As neutralizing antibodies have been cloned from EBOV disease survivors, we sought to identify survivor Fc effector profiles to help guide Fc optimization strategies. Survivors developed a range of functional antibody responses, and we therefore applied a rapid, high-throughput Fc engineering platform to define the most protective profiles. We generated a library of Fc variants with identical antigen-binding fragments (Fabs) from an EBOV neutralizing antibody. Fc variants with antibody-mediated complement deposition and moderate natural killer (NK) cell activity demonstrated complete protective activity in a stringent in vivo mouse model. Our findings highlight the importance of specific effector functions in antibody-mediated protection, and the experimental platform presents a generalizable resource for identifying correlates of immunity to guide therapeutic antibody design.


Asunto(s)
Ebolavirus/inmunología , Fiebre Hemorrágica Ebola/inmunología , Fragmentos Fab de Inmunoglobulinas/inmunología , Fragmentos Fc de Inmunoglobulinas/inmunología , Animales , Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/inmunología , Formación de Anticuerpos/inmunología , Citotoxicidad Celular Dependiente de Anticuerpos/inmunología , Femenino , Células HEK293 , Fiebre Hemorrágica Ebola/virología , Humanos , Inmunoglobulina G/inmunología , Ratones Endogámicos BALB C , Receptores Fc/inmunología
3.
J Infect Dis ; 2024 May 27.
Artículo en Inglés | MEDLINE | ID: mdl-38801652

RESUMEN

Ebola virus (EBOV) infection results in Ebola virus disease (EVD), an often severe disease with a nonspecific presentation. Since its recognition, periodic outbreaks of EVD continue to occur in sub-Saharan Africa. The 2013-2016 West African EVD outbreak was the largest recorded, resulting in a substantial cohort of EVD survivors with persistent health complaints and variable immune responses. In this study, we characterize humoral immune responses in EVD survivors and their contacts in Eastern Sierra Leone. We found high levels of EBOV IgG in EVD survivors and lower yet substantial antibody levels in household contacts, suggesting subclinical transmission. Neutralizing antibody function was prevalent but variable in EVD survivors, raising questions about the durability of immune responses from natural infection with EBOV. Additionally, we found that certain discrete symptoms-ophthalmologic and auditory-are associated with EBOV IgG seropositivity, while an array of symptoms are associated with the presence of neutralizing antibody.

4.
Curr Top Microbiol Immunol ; 440: 165-192, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37106159

RESUMEN

Lassa fever is caused by Lassa virus (LASV), an Old World Mammarenavirus that is carried by Mastomys natalensis and other rodents. It is endemic in Sierra Leone, Nigeria, and other countries in West Africa. The clinical presentation of LASV infection is heterogenous varying from an inapparent or mild illness to a fatal hemorrhagic fever. Exposure to LASV is usually through contact with rodent excreta. After an incubation period of 1-3 weeks, initial symptoms such as fever, headache, and fatigue develop that may progress to sore throat, retrosternal chest pain, conjunctival injection, vomiting, diarrhea, and abdominal pain. Severe illness, including hypotension, shock, and multiorgan failure, develops in a minority of patients. Patient demographics and case fatality rates are distinctly different in Sierra Leone and Nigeria. Laboratory diagnosis relies on the detection of LASV antigens or genomic RNA. LASV-specific immunoglobulin G and M assays can also contribute to clinical management. The mainstay of treatment for Lassa fever is supportive care. The nucleoside analog ribavirin is commonly used to treat acute Lassa fever but is considered useful only if treatment is begun early in the disease course. Drugs in development, including a monoclonal antibody cocktail, have the potential to impact the management of Lassa fever.


Asunto(s)
Fiebre de Lassa , Humanos , Fiebre de Lassa/diagnóstico , Fiebre de Lassa/tratamiento farmacológico , Fiebre de Lassa/epidemiología , Virus Lassa/genética , África Occidental , Sierra Leona/epidemiología , Anticuerpos Antivirales
5.
BMC Infect Dis ; 23(1): 626, 2023 Sep 25.
Artículo en Inglés | MEDLINE | ID: mdl-37749485

RESUMEN

BACKGROUND: Lower respiratory tract infections are the leading cause of mortality in young children globally. In many resource-limited settings clinicians rely on guidelines such as IMCI or ETAT + that promote empiric antibiotic utilization for management of acute respiratory illness (ARI). Numerous evaluations of both guidelines have shown an overall positive response however, several challenges have also been reported, including the potential for over-prescribing of unnecessary antibiotics. The aims of this study were to describe the antibiotic prescribing practices for children less than 24 months of age with symptoms of ARI, that were admitted to Kenema Government Hospital (KGH) in the Eastern Province of Sierra Leone, and to identify the number of children empirically prescribed antibiotics who were admitted to hospital with ARI, as well as their clinical signs, symptoms, and outcomes. METHODS: We conducted a prospective study of children < 24 months of age admitted to the KGH pediatric ward with respiratory symptoms between October 1, 2020 and May 31, 2022. Study nurses collected data on demographic information, medical and medication history, and information on clinical course while hospitalized. RESULTS: A total of 777 children were enrolled. Prior to arrival at the hospital, 224 children (28.8%) reported taking an antibiotic for this illness without improvement. Only 15 (1.9%) children received a chest radiograph to aid in diagnosis and 100% of patients were placed on antibiotics during their hospital stay. CONCLUSIONS: Despite the lives saved, reliance on clinical decision-support tools such as IMCI and ETAT + for pediatric ARI, is resulting in the likely over-prescribing of antibiotics. Greater uptake of implementation research is needed to develop strategies and tools designed to optimize antibiotic use for ARI in LMIC settings. Additionally, much greater priority needs to be given to ensuring clinicians have the basic tools for clinical diagnosis, as well as greater investments in essential laboratory and radiographic diagnostics that help LMIC clinicians move beyond the sole reliance on algorithm based clinical decision making.


Asunto(s)
Algoritmos , Antibacterianos , Humanos , Niño , Preescolar , Sierra Leona , Estudios Prospectivos , Antibacterianos/uso terapéutico , Hospitales Públicos , Toma de Decisiones
6.
Nature ; 544(7650): 309-315, 2017 04 20.
Artículo en Inglés | MEDLINE | ID: mdl-28405027

RESUMEN

The 2013-2016 West African epidemic caused by the Ebola virus was of unprecedented magnitude, duration and impact. Here we reconstruct the dispersal, proliferation and decline of Ebola virus throughout the region by analysing 1,610 Ebola virus genomes, which represent over 5% of the known cases. We test the association of geography, climate and demography with viral movement among administrative regions, inferring a classic 'gravity' model, with intense dispersal between larger and closer populations. Despite attenuation of international dispersal after border closures, cross-border transmission had already sown the seeds for an international epidemic, rendering these measures ineffective at curbing the epidemic. We address why the epidemic did not spread into neighbouring countries, showing that these countries were susceptible to substantial outbreaks but at lower risk of introductions. Finally, we reveal that this large epidemic was a heterogeneous and spatially dissociated collection of transmission clusters of varying size, duration and connectivity. These insights will help to inform interventions in future epidemics.


Asunto(s)
Ebolavirus/genética , Ebolavirus/fisiología , Genoma Viral/genética , Fiebre Hemorrágica Ebola/transmisión , Fiebre Hemorrágica Ebola/virología , Clima , Brotes de Enfermedades/estadística & datos numéricos , Ebolavirus/aislamiento & purificación , Geografía , Fiebre Hemorrágica Ebola/epidemiología , Humanos , Internacionalidad , Modelos Lineales , Epidemiología Molecular , Filogenia , Viaje/legislación & jurisprudencia , Viaje/estadística & datos numéricos
7.
Sensors (Basel) ; 23(13)2023 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-37447847

RESUMEN

Atomic clocks are highly precise timing devices used in numerous Positioning, Navigation, and Timing (PNT) applications on the ground and in outer space. In recent years, however, more precise timing solutions based on optical technology have been introduced as current technology capabilities advance. State-of-the-art optical clocks-predicted to be the next level of their predecessor atomic clocks-have achieved ultimate uncertainty of 1 × 10-18 and beyond, which exceeds the best atomic clock's performance by two orders of magnitude. Hence, the successful development of optical clocks has drawn significant attention in academia and industry to exploit many more opportunities. This paper first provides an overview of the emerging optical clock technology, its current development, and characteristics, followed by a clock stability analysis of some of the successfully developed optical clocks against current Global Navigation Satellite System (GNSS) satellite clocks to discuss the optical clock potentiality in GNSS positioning. The overlapping Allan Deviation (ADEV) method is applied to estimate the satellite clock stability from International GNSS Service (IGS) clock products, whereas the optical clock details are sourced from the existing literature. The findings are (a) the optical clocks are more stable than that of atomic clocks onboard GNSS satellites, though they may require further technological maturity to meet spacecraft payload requirements, and (b) in GNSS positioning, optical clocks could potentially offer less than a 1 mm range error (clock-related) in 30 s and at least 10 times better timing performance after 900 s in contrast to the Galileo satellite atomic clocks-which is determined in this study as the most stable GNSS atomic clock type used in satellite positioning.


Asunto(s)
Industrias , Nave Espacial , Tecnología , Incertidumbre
8.
PLoS Pathog ; 16(3): e1008352, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-32142546

RESUMEN

Lassa virus infects hundreds of thousands of people each year across rural West Africa, resulting in a high number of cases of Lassa fever (LF), a febrile disease associated with high morbidity and significant mortality. The lack of approved treatments or interventions underscores the need for an effective vaccine. At least four viral lineages circulate in defined regions throughout West Africa with substantial interlineage nucleotide and amino acid diversity. An effective vaccine should be designed to elicit Lassa virus specific humoral and cell mediated immunity across all lineages. Most current vaccine candidates use only lineage IV antigens encoded by Lassa viruses circulating around Sierra Leone, Liberia, and Guinea but not Nigeria where lineages I-III are found. As previous infection is known to protect against disease from subsequent exposure, we sought to determine whether LF survivors from Nigeria and Sierra Leone harbor memory T cells that respond to lineage IV antigens. Our results indicate a high degree of cross-reactivity of CD8+ T cells from Nigerian LF survivors to lineage IV antigens. In addition, we identified regions within the Lassa virus glycoprotein complex and nucleoprotein that contributed to these responses while T cell epitopes were not widely conserved across our study group. These data are important for current efforts to design effective and efficient vaccine candidates that can elicit protective immunity across all Lassa virus lineages.


Asunto(s)
Antígenos Virales/inmunología , Linfocitos T CD8-positivos/inmunología , Epítopos de Linfocito T/inmunología , Virus Lassa/inmunología , África Occidental , Reacciones Cruzadas , Femenino , Humanos , Masculino , Especificidad de la Especie
9.
BMC Infect Dis ; 22(1): 624, 2022 Jul 18.
Artículo en Inglés | MEDLINE | ID: mdl-35850699

RESUMEN

BACKGROUND: Globally, hearing loss is the second leading cause of disability, affecting approximately 18.7% of the world's population. However, the burden of hearing loss is unequally distributed, with the majority of affected individuals located in Asia or Sub-Saharan Africa. Following the 2014 West African Ebola Outbreak, disease survivors began to describe hearing loss as part of the constellation of symptoms known as Post-Ebola Syndrome. The goal of this study was to more fully characterize hearing loss among Ebola Virus Disease (EVD) survivors. METHODOLOGY AND PRINCIPAL FINDINGS: EVD survivors and their household contacts were recruited (n = 1,12) from Eastern Sierra Leone. Each individual completed a symptom questionnaire, physical exam, and a two-step audiometry process measuring both air and bone conduction thresholds. In comparison to contacts, EVD survivors were more likely to have complaints or abnormal findings affecting every organ system. A significantly greater percentage of EVD survivors were found to have hearing loss in comparison to contacts (23% vs. 9%, p < 0.001). Additionally, survivors were more likely to have bilateral hearing loss of a mixed etiology. Logistic regression revealed that the presence of any symptoms of middle or inner ear (p < 0.001), eye (p = 0.005), psychiatric (p = 0.019), and nervous system (p = 0.037) increased the odds of developing hearing loss. CONCLUSIONS AND SIGNIFICANCE: This study is the first to use an objective and standardized measurement to report hearing loss among EVD survivors in a clinically meaningful manner. In this study it was found that greater than 1/5th of EVD survivors develop hearing loss. The association between hearing impairment and symptoms affecting the eye and nervous system may indicate a similar mechanism of pathogenesis, which should be investigated further. Due to the quality of life and socioeconomic detriments associated with untreated hearing loss, a greater emphasis must be placed on understanding and mitigating hearing loss following survival to aid in economic recovery following infectious disease epidemics.


Asunto(s)
Pérdida Auditiva , Fiebre Hemorrágica Ebola , Sobrevivientes , Brotes de Enfermedades , Pérdida Auditiva/epidemiología , Fiebre Hemorrágica Ebola/complicaciones , Fiebre Hemorrágica Ebola/epidemiología , Humanos , Prevalencia , Sierra Leona/epidemiología , Sobrevivientes/estadística & datos numéricos
10.
Aust N Z J Psychiatry ; 56(6): 594-602, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35172624

RESUMEN

We review five key areas of contemporary psychodynamic practice and research to highlight the contributions psychodynamic concepts can make to clinical psychiatry. These areas are as follows: (1) Contributions to understanding the development of subjectivity. (2) The psychodynamic understanding of the effects of early childhood trauma and their consequences in adult life. (3) The vital importance of the psychodynamic notion of the 'holding environment' based on an understanding of the dynamics of the development of subjectivity and trauma which, if applied, might improve the quality of psychiatric care in the public mental health system and enhance both the clinical competence and morale of clinicians in the system. (4) The emerging scientific disciplines of Neuropsychoanalysis and Affective Neuroscience, which illustrate the importance of seriously studying the mind as well as the brain. (5) A brief summary of some research into the clinical effectiveness and efficacy of psychoanalysis and its related psychodynamic therapies.


Asunto(s)
Neurociencias , Psiquiatría , Psicoanálisis , Adulto , Preescolar , Donaciones , Humanos , Psicoterapia
11.
Clin Infect Dis ; 73(6): 1046-1054, 2021 09 15.
Artículo en Inglés | MEDLINE | ID: mdl-33822010

RESUMEN

BACKGROUND: Following the 2013-2016 West African Ebola outbreak, distinct, persistent health complaints were recognized in Ebola virus disease (EVD) survivors. Here we provide an in-depth characterization of post-Ebola syndrome >2.5 years after resolution of disease. Additionally, we report subphenotypes of post-Ebola syndrome with overlapping symptom clusters in survivors from Eastern Sierra Leone. METHODS: Participants in Eastern Sierra Leone were identified by the Sierra Leone Association of Ebola survivors. Survivors and their contacts were administered a questionnaire assessing self-reported symptoms and a physical examination. Comparisons between survivors and contacts were conducted using conditional logistic regression. Symptom groupings were identified using hierarchical clustering approaches. Simplified presentation of incredibly complex evaluations (SPICE), correlation analysis, logistic regression, and principal component analysis (PCA) were performed to explore the relationships between symptom clusters. RESULTS: Three hundred seventy-five EVD survivors and 1040 contacts were enrolled into the study. At enrollment, EVD survivors reported significantly more symptoms than their contacts in all categories (P < .001). Symptom clusters representing distinct organ systems were identified. Correlation and logistic regression analysis identified relationships between symptom clusters, including stronger relationships between clusters including musculoskeletal symptoms (r = 0.63, P < .001; and P < .001 for correlation and logistic regression, respectively). SPICE and PCA further highlighted subphenotypes with or without musculoskeletal symptoms. CONCLUSIONS: This study presents an in-depth characterization of post-Ebola syndrome in Sierra Leonean survivors >2.5 years after disease. The interrelationship between symptom clusters indicates that post-Ebola syndrome is a heterogeneous disease. The distinct musculoskeletal and non-musculoskeletal phenotypes identified likely require targeted therapies to optimize long-term treatment for EVD survivors.


Asunto(s)
Ebolavirus , Fiebre Hemorrágica Ebola , Estudios de Cohortes , Brotes de Enfermedades , Fiebre Hemorrágica Ebola/complicaciones , Fiebre Hemorrágica Ebola/epidemiología , Humanos , Sierra Leona/epidemiología , Síndrome
12.
J Virol ; 94(12)2020 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-32269122

RESUMEN

Early and robust T cell responses have been associated with survival from Lassa fever (LF), but the Lassa virus-specific memory responses have not been well characterized. Regions within the virus surface glycoprotein (GPC) and nucleoprotein (NP) are the main targets of the Lassa virus-specific T cell responses, but, to date, only a few T cell epitopes within these proteins have been identified. We identified GPC and NP regions containing T cell epitopes and HLA haplotypes from LF survivors and used predictive HLA-binding algorithms to identify putative epitopes, which were then experimentally tested using autologous survivor samples. We identified 12 CD8-positive (CD8+) T cell epitopes, including epitopes common to both Nigerian and Sierra Leonean survivors. These data should be useful for the identification of dominant Lassa virus-specific T cell responses in Lassa fever survivors and vaccinated individuals as well as for designing vaccines that elicit cell-mediated immunity.IMPORTANCE The high morbidity and mortality associated with clinical cases of Lassa fever, together with the lack of licensed vaccines and limited and partially effective interventions, make Lassa virus (LASV) an important health concern in its regions of endemicity in West Africa. Previous infection with LASV protects from disease after subsequent exposure, providing a framework for designing vaccines to elicit similar protective immunity. Multiple major lineages of LASV circulate in West Africa, and therefore, ideal vaccine candidates should elicit immunity to all lineages. We therefore sought to identify common T cell epitopes between Lassa fever survivors from Sierra Leone and Nigeria, where distinct lineages circulate. We identified three such epitopes derived from highly conserved regions within LASV proteins. In this process, we also identified nine other T cell epitopes. These data should help in the design of an effective pan-LASV vaccine.


Asunto(s)
Linfocitos T CD8-positivos/inmunología , Epítopos de Linfocito T/química , Fiebre de Lassa/inmunología , Virus Lassa/inmunología , Nucleoproteínas/inmunología , Proteínas del Envoltorio Viral/inmunología , Adolescente , Secuencia de Aminoácidos , Animales , Anticuerpos Antivirales/biosíntesis , Antígenos Virales/química , Antígenos Virales/genética , Antígenos Virales/inmunología , Linfocitos T CD8-positivos/virología , Niño , Epítopos de Linfocito T/genética , Epítopos de Linfocito T/inmunología , Femenino , Genes Reporteros , Proteínas Fluorescentes Verdes/genética , Proteínas Fluorescentes Verdes/inmunología , Antígenos HLA-DQ/genética , Antígenos HLA-DQ/inmunología , Haplotipos , Interacciones Huésped-Patógeno/genética , Interacciones Huésped-Patógeno/inmunología , Humanos , Sueros Inmunes/análisis , Memoria Inmunológica , Fiebre de Lassa/genética , Fiebre de Lassa/patología , Virus Lassa/patogenicidad , Masculino , Nigeria , Nucleoproteínas/genética , Sierra Leona , Sobrevivientes , Proteínas del Envoltorio Viral/genética , Adulto Joven
13.
Proc Natl Acad Sci U S A ; 115(32): E7578-E7586, 2018 08 07.
Artículo en Inglés | MEDLINE | ID: mdl-30038008

RESUMEN

The recent Ebola epidemic exemplified the importance of understanding and controlling emerging infections. Despite the importance of T cells in clearing virus during acute infection, little is known about Ebola-specific CD8+ T cell responses. We investigated immune responses of individuals infected with Ebola virus (EBOV) during the 2013-2016 West Africa epidemic in Sierra Leone, where the majority of the >28,000 EBOV disease (EVD) cases occurred. We examined T cell memory responses to seven of the eight Ebola proteins (GP, sGP, NP, VP24, VP30, VP35, and VP40) and associated HLA expression in survivors. Of the 30 subjects included in our analysis, CD8+ T cells from 26 survivors responded to at least one EBOV antigen. A minority, 10 of 26 responders (38%), made CD8+ T cell responses to the viral GP or sGP. In contrast, 25 of the 26 responders (96%) made response to viral NP, 77% to VP24 (20 of 26), 69% to VP40 (18 of 26), 42% (11 of 26) to VP35, with no response to VP30. Individuals making CD8+ T cells to EBOV VP24, VP35, and VP40 also made CD8+ T cells to NP, but rarely to GP. We identified 34 CD8+ T cell epitopes for Ebola. Our data indicate the immunodominance of the EBOV NP-specific T cell response and suggest that its inclusion in a vaccine along with the EBOV GP would best mimic survivor responses and help boost cell-mediated immunity during vaccination.


Asunto(s)
Anticuerpos Antivirales/inmunología , Linfocitos T CD8-positivos/inmunología , Ebolavirus/inmunología , Epidemias , Antígenos HLA/inmunología , Fiebre Hemorrágica Ebola/inmunología , Adolescente , Adulto , Anticuerpos Antivirales/sangre , Antígenos Virales/inmunología , Epítopos de Linfocito T/inmunología , Femenino , Antígenos HLA/sangre , Fiebre Hemorrágica Ebola/sangre , Fiebre Hemorrágica Ebola/epidemiología , Fiebre Hemorrágica Ebola/prevención & control , Humanos , Masculino , Nucleoproteínas/inmunología , Sierra Leona , Sobrevivientes , Vacunación/métodos , Proteínas Virales/inmunología , Adulto Joven
14.
J Infect Dis ; 221(1): 156-161, 2020 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-31301137

RESUMEN

Monoclonal antibodies can mediate protection against Ebola virus (EBOV) infection through direct neutralization as well as through the recruitment of innate immune effector functions. However, the antibody functional response following survival of acute EBOV disease has not been well characterized. In this study, serum antibodies from Ebola virus disease (EVD) survivors from Sierra Leone were profiled to capture variation in overall subclass/isotype abundance, neutralizing activity, and innate immune effector functions. Antibodies from EVD survivors exhibited robust innate immune effector functions, mediated primarily by IgG1 and IgA1. In conclusion, development of functional antibodies follows survival of acute EVD.


Asunto(s)
Anticuerpos Neutralizantes/sangre , Anticuerpos Antivirales/sangre , Fiebre Hemorrágica Ebola/inmunología , Inmunidad Innata , Inmunoglobulina G/sangre , Antígenos Virales/inmunología , Humanos , Inmunoglobulina A/sangre , Fagocitosis , Sierra Leona , Sobrevivientes
15.
J Infect Dis ; 222(9): 1488-1497, 2020 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-32436943

RESUMEN

BACKGROUND: Ebola virus (EBOV) disease has killed thousands of West and Central Africans over the past several decades. Many who survive the acute disease later experience post-Ebola syndrome, a constellation of symptoms whose causative pathogenesis is unclear. METHODS: We investigated EBOV-specific CD8+ and CD4+ T-cell responses in 37 Sierra Leonean EBOV disease survivors with (n = 19) or without (n = 18) sequelae of arthralgia and ocular symptoms. Peripheral blood mononuclear cells were infected with recombinant vesicular stomatitis virus encoding EBOV antigens. We also studied the presence of EBOV-specific immunoglobulin G, antinuclear antibodies, anti-cyclic citrullinated peptide antibodies, rheumatoid factor, complement levels, and cytokine levels in these 2 groups. RESULTS: Survivors with sequelae had a significantly higher EBOV-specific CD8+ and CD4+ T-cell response. No differences in EBOV-specific immunoglobulin G, antinuclear antibody, or anti-cyclic citrullinated peptide antibody levels were found. Survivors with sequelae showed significantly higher rheumatoid factor levels. CONCLUSION: EBOV-specific CD8+ and CD4+ T-cell responses were significantly higher in Ebola survivors with post-Ebola syndrome. These findings suggest that pathogenesis may occur as an immune-mediated disease via virus-specific T-cell immune response or that persistent antigen exposure leads to increased and sustained T-cell responses.


Asunto(s)
Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD8-positivos/inmunología , Ebolavirus/inmunología , Fiebre Hemorrágica Ebola/inmunología , Adulto , Anticuerpos Antivirales/inmunología , Antígenos Virales/inmunología , Femenino , Técnica del Anticuerpo Fluorescente , Fiebre Hemorrágica Ebola/patología , Humanos , Inmunidad Celular , Masculino , Sierra Leona/epidemiología , Sobrevivientes
16.
Clin Infect Dis ; 71(7): 1749-1755, 2020 10 23.
Artículo en Inglés | MEDLINE | ID: mdl-31693114

RESUMEN

BACKGROUND: Cohort studies have reported a high prevalence of musculoskeletal, neurologic, auditory, and visual complications among Ebola virus disease (EVD) survivors. However, little is known about the host- and disease-related predictors of these symptoms and their etiological mechanisms. METHODS: The presence and patterns of 8 cardinal symptoms that are most commonly reported following EVD survival were assessed in the 326 EVD survivors who participated in the ongoing longitudinal Liberian EVD Survivor Study. At quarterly study visits, symptoms that developed since acute EVD were recorded and blood was collected for biomarkers of inflammation and immune activation. RESULTS: At baseline (mean 408 days from acute EVD), 75.5% of survivors reported at least 1 new cardinal symptom since surviving EVD, which in 85.8% was rated as highly interfering with life. Two or more incident symptoms were reported by 61.0% of survivors, with pairings of joint pain, headache, or fatigue the most frequent. Women were significantly more likely than men to report headache, while older age was significantly associated with musculoskeletal and visual symptoms. In analyses adjusted for multiple comparisons, no statistically significant association was found between any symptom and 26 markers of inflammation and immune activation. Symptom frequency remained largely unchanged during study follow-up. CONCLUSIONS: Post-EVD complications occur in a majority of survivors and remain present more than 4 years after acute infection. An association between markers of inflammation and immune activation and individual symptoms was not found, suggesting an alternative etiology for persistent post-EVD symptomatology.


Asunto(s)
Ebolavirus , Fiebre Hemorrágica Ebola , Anciano , Estudios de Cohortes , Brotes de Enfermedades , Femenino , Fiebre Hemorrágica Ebola/complicaciones , Fiebre Hemorrágica Ebola/epidemiología , Humanos , Inflamación/epidemiología , Masculino , Prevalencia , Sobrevivientes
17.
Emerg Infect Dis ; 26(11): 2625-2637, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-33079033

RESUMEN

Lassa fever (LF) causes multisystem disease and has a fatality rate <70%. Severe cases exhibit abnormal coagulation, endothelial barrier disruption, and dysfunctional platelet aggregation but the underlying mechanisms remain poorly understood. In Sierra Leone during 2015-2018, we assessed LF patients' day-of-admission plasma samples for levels of proteins necessary for coagulation, fibrinolysis, and platelet function. P-selectin, soluble endothelial protein C receptor, soluble thrombomodulin, plasminogen activator inhibitor 1, ADAMTS-13, von Willebrand factor, tissue factor, soluble intercellular adhesion molecule 1, and vascular cell adhesion molecule 1 were more elevated in LF patients than in controls. Endothelial protein C receptor, thrombomodulin, intercellular adhesion molecule 1, plasminogen activator inhibitor 1, D-dimer, and hepatocyte growth factor were higher in fatal than nonfatal LF cases. Platelet disaggregation occurred only in samples from fatal LF cases. The impaired homeostasis and platelet dysfunction implicate alterations in the protein C pathway, which might contribute to the loss of endothelial barrier function in fatal infections.


Asunto(s)
Plaquetas/patología , Endotelio/fisiopatología , Fiebre de Lassa , Adolescente , Adulto , Anciano , Coagulación Sanguínea , Niño , Preescolar , Femenino , Fibrinólisis , Humanos , Lactante , Fiebre de Lassa/diagnóstico , Fiebre de Lassa/epidemiología , Masculino , Persona de Mediana Edad , Sierra Leona , Adulto Joven
18.
Virol J ; 17(1): 188, 2020 11 26.
Artículo en Inglés | MEDLINE | ID: mdl-33243278

RESUMEN

BACKGROUND: Lassa fever and Ebola are characterized by non-specific initial presentations that can progress to severe multisystem illnesses with high fatality rates. Samples from additional subjects are examined to extend and corroborate biomarkers with prognostic value for these diseases. METHODS: Liquid Chromatography Mass Spectrometry metabolomics was used to identify and confirm metabolites disrupted in the blood of Lassa fever and Ebola patients. Authenticated standards are used to confirm the identify of key metabolites. RESULTS: We confirm prior results by other investigators that the amino acid L-threonine is elevated during Ebola virus infection. L-Threonine is also elevated during Lassa virus infection. We also confirmed that platelet-activating factor (PAF) and molecules with PAF moiety are reduced in the blood of patients with fatal Lassa fever. Similar changes in PAF and PAF-like molecules were not observed in the blood of Ebola patients. CONCLUSIONS: Metabolomics may provide tools to identify pathways that are differentially affected during viral hemorrhagic fevers and guide development of diagnostics to monitor and predict outcome.


Asunto(s)
Fiebre Hemorrágica Ebola/diagnóstico , Fiebre de Lassa/diagnóstico , Treonina/sangre , Adolescente , Adulto , Biomarcadores/sangre , Niño , Preescolar , Cromatografía Liquida/métodos , Estudios de Cohortes , Femenino , Fiebre Hemorrágica Ebola/sangre , Fiebre Hemorrágica Ebola/metabolismo , Humanos , Lactante , Fiebre de Lassa/sangre , Fiebre de Lassa/metabolismo , Masculino , Espectrometría de Masas/métodos , Metabolómica , Persona de Mediana Edad , Treonina/genética , Adulto Joven
19.
JAMA ; 319(21): 2202-2211, 2018 06 05.
Artículo en Inglés | MEDLINE | ID: mdl-29800114

RESUMEN

Importance: The quick Sequential (Sepsis-Related) Organ Failure Assessment (qSOFA) score has not been well-evaluated in low- and middle-income countries (LMICs). Objective: To assess the association of qSOFA with excess hospital death among patients with suspected infection in LMICs and to compare qSOFA with the systemic inflammatory response syndrome (SIRS) criteria. Design, Settings, and Participants: Retrospective secondary analysis of 8 cohort studies and 1 randomized clinical trial from 2003 to 2017. This study included 6569 hospitalized adults with suspected infection in emergency departments, inpatient wards, and intensive care units of 17 hospitals in 10 LMICs across sub-Saharan Africa, Asia, and the Americas. Exposures: Low (0), moderate (1), or high (≥2) qSOFA score (range, 0 [best] to 3 [worst]) or SIRS criteria (range, 0 [best] to 4 [worst]) within 24 hours of presentation to study hospital. Main Outcomes and Measures: Predictive validity (measured as incremental hospital mortality beyond that predicted by baseline risk factors, as a marker of sepsis or analogous severe infectious course) of the qSOFA score (primary) and SIRS criteria (secondary). Results: The cohorts were diverse in enrollment criteria, demographics (median ages, 29-54 years; males range, 36%-76%), HIV prevalence (range, 2%-43%), cause of infection, and hospital mortality (range, 1%-39%). Among 6218 patients with nonmissing outcome status in the combined cohort, 643 (10%) died. Compared with a low or moderate score, a high qSOFA score was associated with increased risk of death overall (19% vs 6%; difference, 13% [95% CI, 11%-14%]; odds ratio, 3.6 [95% CI, 3.0-4.2]) and across cohorts (P < .05 for 8 of 9 cohorts). Compared with a low qSOFA score, a moderate qSOFA score was also associated with increased risk of death overall (8% vs 3%; difference, 5% [95% CI, 4%-6%]; odds ratio, 2.8 [95% CI, 2.0-3.9]), but not in every cohort (P < .05 in 2 of 7 cohorts). High, vs low or moderate, SIRS criteria were associated with a smaller increase in risk of death overall (13% vs 8%; difference, 5% [95% CI, 3%-6%]; odds ratio, 1.7 [95% CI, 1.4-2.0]) and across cohorts (P < .05 for 4 of 9 cohorts). qSOFA discrimination (area under the receiver operating characteristic curve [AUROC], 0.70 [95% CI, 0.68-0.72]) was superior to that of both the baseline model (AUROC, 0.56 [95% CI, 0.53-0.58; P < .001) and SIRS (AUROC, 0.59 [95% CI, 0.57-0.62]; P < .001). Conclusions and Relevance: When assessed among hospitalized adults with suspected infection in 9 LMIC cohorts, the qSOFA score identified infected patients at risk of death beyond that explained by baseline factors. However, the predictive validity varied among cohorts and settings, and further research is needed to better understand potential generalizability.


Asunto(s)
Mortalidad Hospitalaria , Puntuaciones en la Disfunción de Órganos , Sepsis/clasificación , Síndrome de Respuesta Inflamatoria Sistémica/clasificación , Adulto , Área Bajo la Curva , Estudios de Cohortes , Países en Desarrollo , Femenino , Infecciones por VIH/complicaciones , Infecciones por VIH/epidemiología , Humanos , Infecciones/complicaciones , Masculino , Persona de Mediana Edad , Curva ROC , Estudios Retrospectivos , Factores de Riesgo , Sepsis/complicaciones , Síndrome de Respuesta Inflamatoria Sistémica/mortalidad
20.
N Engl J Med ; 371(22): 2092-100, 2014 Nov 27.
Artículo en Inglés | MEDLINE | ID: mdl-25353969

RESUMEN

BACKGROUND: Limited clinical and laboratory data are available on patients with Ebola virus disease (EVD). The Kenema Government Hospital in Sierra Leone, which had an existing infrastructure for research regarding viral hemorrhagic fever, has received and cared for patients with EVD since the beginning of the outbreak in Sierra Leone in May 2014. METHODS: We reviewed available epidemiologic, clinical, and laboratory records of patients in whom EVD was diagnosed between May 25 and June 18, 2014. We used quantitative reverse-transcriptase-polymerase-chain-reaction assays to assess the load of Ebola virus (EBOV, Zaire species) in a subgroup of patients. RESULTS: Of 106 patients in whom EVD was diagnosed, 87 had a known outcome, and 44 had detailed clinical information available. The incubation period was estimated to be 6 to 12 days, and the case fatality rate was 74%. Common findings at presentation included fever (in 89% of the patients), headache (in 80%), weakness (in 66%), dizziness (in 60%), diarrhea (in 51%), abdominal pain (in 40%), and vomiting (in 34%). Clinical and laboratory factors at presentation that were associated with a fatal outcome included fever, weakness, dizziness, diarrhea, and elevated levels of blood urea nitrogen, aspartate aminotransferase, and creatinine. Exploratory analyses indicated that patients under the age of 21 years had a lower case fatality rate than those over the age of 45 years (57% vs. 94%, P=0.03), and patients presenting with fewer than 100,000 EBOV copies per milliliter had a lower case fatality rate than those with 10 million EBOV copies per milliliter or more (33% vs. 94%, P=0.003). Bleeding occurred in only 1 patient. CONCLUSIONS: The incubation period and case fatality rate among patients with EVD in Sierra Leone are similar to those observed elsewhere in the 2014 outbreak and in previous outbreaks. Although bleeding was an infrequent finding, diarrhea and other gastrointestinal manifestations were common. (Funded by the National Institutes of Health and others.).


Asunto(s)
Ebolavirus/genética , Epidemias , Fiebre Hemorrágica Ebola/epidemiología , Dolor Abdominal , Adulto , Animales , Diarrea , Ebolavirus/aislamiento & purificación , Femenino , Fiebre , Fiebre Hemorrágica Ebola/complicaciones , Fiebre Hemorrágica Ebola/terapia , Fiebre Hemorrágica Ebola/virología , Humanos , Masculino , Persona de Mediana Edad , Mortalidad , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Sierra Leona/epidemiología , Carga Viral , Vómitos
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