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1.
J Infect Dis ; 225(11): 1923-1932, 2022 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-35079784

RESUMO

BACKGROUND: Additional severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines that are safe and effective as primary vaccines and boosters remain urgently needed to combat the coronavirus disease 2019 (COVID-19) pandemic. We describe safety and durability of immune responses following 2 primary doses and a homologous booster dose of an investigational DNA vaccine (INO-4800) targeting full-length spike antigen. METHODS: Three dosage strengths of INO-4800 (0.5 mg, 1.0 mg, and 2.0 mg) were evaluated in 120 age-stratified healthy adults. Intradermal injection of INO-4800 followed by electroporation at 0 and 4 weeks preceded an optional booster 6-10.5 months after the second dose. RESULTS: INO-4800 appeared well tolerated with no treatment-related serious adverse events. Most adverse events were mild and did not increase in frequency with age and subsequent dosing. A durable antibody response was observed 6 months following the second dose; a homologous booster dose significantly increased immune responses. Cytokine-producing T cells and activated CD8+ T cells with lytic potential were significantly increased in the 2.0-mg dose group. CONCLUSIONS: INO-4800 was well tolerated in a 2-dose primary series and homologous booster in all adults, including elderly participants. These results support further development of INO-4800 for use as primary vaccine and booster. CLINICAL TRIALS REGISTRATION: NCT04336410.


Assuntos
COVID-19 , Vacinas de DNA , Adulto , Idoso , Anticorpos Antivirais , Formação de Anticorpos , COVID-19/prevenção & controle , Vacinas contra COVID-19 , Humanos , Imunogenicidade da Vacina , SARS-CoV-2 , Vacinação/efeitos adversos , Vacinas de DNA/efeitos adversos
2.
NPJ Vaccines ; 6(1): 121, 2021 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-34650089

RESUMO

Global surveillance has identified emerging SARS-CoV-2 variants of concern (VOC) associated with broadened host specificity, pathogenicity, and immune evasion to vaccine-induced immunity. Here we compared humoral and cellular responses against SARS-CoV-2 VOC in subjects immunized with the DNA vaccine, INO-4800. INO-4800 vaccination induced neutralizing antibodies against all variants tested, with reduced levels detected against B.1.351. IFNγ T cell responses were fully maintained against all variants tested.

3.
EClinicalMedicine ; 31: 100689, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33392485

RESUMO

BACKGROUND: A vaccine against SARS-CoV-2 is of high urgency. Here the safety and immunogenicity induced by a DNA vaccine (INO-4800) targeting the full length spike antigen of SARS-CoV-2 are described. METHODS: INO-4800 was evaluated in two groups of 20 participants, receiving either 1.0 mg or 2.0 mg of vaccine intradermally followed by CELLECTRA® EP at 0 and 4 weeks. Thirty-nine subjects completed both doses; one subject in the 2.0 mg group discontinued trial participation prior to receiving the second dose. ClinicalTrials.gov identifier: NCT04336410. FINDINGS: The median age was 34.5, 55% (22/40) were men and 82.5% (33/40) white. Through week 8, only 6 related Grade 1 adverse events in 5 subjects were observed. None of these increased in frequency with the second administration. No serious adverse events were reported. All 38 subjects evaluable for immunogenicity had cellular and/or humoral immune responses following the second dose of INO-4800. By week 6, 95% (36/38) of the participants seroconverted based on their responses by generating binding (ELISA) and/or neutralizing antibodies (PRNT IC50), with responder geometric mean binding antibody titers of 655.5 [95% CI (255.6, 1681.0)] and 994.2 [95% CI (395.3, 2500.3)] in the 1.0 mg and 2.0 mg groups, respectively. For neutralizing antibody, 78% (14/18) and 84% (16/19) generated a response with corresponding geometric mean titers of 102.3 [95% CI (37.4, 280.3)] and 63.5 [95% CI (39.6, 101.8)], in the respective groups. By week 8, 74% (14/19) and 100% (19/19) of subjects generated T cell responses by IFN-É£ ELISpot assay with the median SFU per 106 PBMC of 46 [95% CI (21.1, 142.2)] and 71 [95% CI (32.2, 194.4)] in the 1.0 mg and 2.0 mg groups, respectively. Flow cytometry demonstrated a T cell response, dominated by CD8+ T cells co-producing IFN-É£ and TNF-α, without increase in IL-4. INTERPRETATION: INO-4800 demonstrated excellent safety and tolerability and was immunogenic in 100% (38/38) of the vaccinated subjects by eliciting either or both humoral or cellular immune responses. FUNDING: Coalition for Epidemic Preparedness Innovations (CEPI).

4.
Artigo em Inglês | MEDLINE | ID: mdl-31427299

RESUMO

VL-2397 is an antifungal drug with a novel mechanism of action, rapid fungicidal in vitro activity, and potent in vivo activity against Aspergillus fumigatus, including azole-resistant strains. VL2397-101, a phase 1 first-in-human, randomized, double-blind, placebo-controlled dose-escalation study, was conducted in healthy adults to determine the safety, tolerability, and pharmacokinetics (PK) of single and multiple ascending intravenous (i.v.) doses of VL-2397. All dosing cohorts were fully enrolled; all subjects completed the safety follow-up. A safety committee reviewed the safety data for each dosing cohort prior to recommending the initiation of each subsequent cohort. No serious adverse events (SAEs) occurred; the majority of treatment-emergent adverse events (TEAEs) were mild and self-limited. The most common drug-related TEAEs were infusion site reactions. No clinically concerning trends were noted in vital signs, electrocardiograms, physical examinations, or safety laboratory results. Following single infusions of VL-2397, the overall and maximum exposures rose less than proportionally with increasing doses from 3 mg to 1,200 mg as indicated by area under the concentration-time curve over 24 h (AUC24) and maximum concentration (Cmax). No signs of VL-2397 accumulation were observed following i.v. infusions of 300, 600, and 1,200 mg every 24 h (q24h) for 7 days. Renal elimination played a major role in total body clearance, with up to 47% of unmetabolized drug in urine 24 h after administration at single doses of >30 mg. Overall, VL-2397 dosing in the study appeared to be safe and well tolerated in the healthy subjects. The safety profile, consistent PK, and lack of drug accumulation support further development of VL-2397 in patients with invasive aspergillosis.


Assuntos
Antifúngicos/farmacocinética , Antifúngicos/uso terapêutico , Complexos de Coordenação/farmacocinética , Complexos de Coordenação/uso terapêutico , Peptídeos Cíclicos/farmacocinética , Peptídeos Cíclicos/uso terapêutico , Adulto , Relação Dose-Resposta a Droga , Método Duplo-Cego , Esquema de Medicação , Eletrocardiografia/métodos , Feminino , Voluntários Saudáveis , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
5.
Am J Trop Med Hyg ; 94(6): 1348-1358, 2016 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-27022153

RESUMO

We evaluated the safety and immunogenicity of two doses of a live-attenuated, tetravalent dengue virus vaccine (F17/Pre formulation) and a booster dose in a dengue endemic setting in two studies. Seven children (7- to 8-year-olds) were followed for 1 year after dose 2 and then given a booster dose (F17/Pre formulation), and followed for four more years (Child study). In the Infant study, 49 2-year-olds, vaccinated as infants, were followed for approximately 3.5 years after dose 2 and then given a booster dose (F17) and followed for one additional year. Two clinically notable events were observed, both in dengue vaccine recipients in the Infant study: 1 case of dengue approximately 2.7 years after dose 2 and 1 case of suspected dengue after booster vaccinations. The booster vaccinations had a favorable safety profile in terms of reactogenicity and adverse events reported during the 1-month follow-up periods. No vaccine-related serious adverse events were reported during the studies. Neutralizing antibodies against dengue viruses 1-4 waned during the 1-3 years before boosting, which elicited a short-lived booster response but did not provide a long-lived, multivalent antibody response in most subjects. Overall, this candidate vaccine did not elicit a durable humoral immune response.


Assuntos
Vacinas contra Dengue/normas , Dengue/prevenção & controle , Esquemas de Imunização , Anticorpos Antivirais/biossíntese , Anticorpos Antivirais/sangue , Criança , Pré-Escolar , Dengue/epidemiologia , Vacinas contra Dengue/administração & dosagem , Vacinas contra Dengue/imunologia , Humanos , Imunização Secundária , Lactente , Tailândia/epidemiologia , Vacinas Atenuadas/administração & dosagem , Vacinas Atenuadas/imunologia , Vacinas Atenuadas/normas
6.
Innovations (Phila) ; 10(5): 349-51, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26575381

RESUMO

Persistent paravalvular leak after aortic valve replacement prompted transcatheter closure with an Amplatzer VSD device. Although technically a successful procedure, aortic insufficiency persisted, leading to surgical reexploration and valve replacement.


Assuntos
Insuficiência da Valva Aórtica/etiologia , Bioprótese/efeitos adversos , Próteses Valvulares Cardíacas/efeitos adversos , Falha de Prótese/efeitos adversos , Substituição da Valva Aórtica Transcateter/efeitos adversos , Idoso , Humanos , Masculino
7.
BMC Public Health ; 15: 250, 2015 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-25886528

RESUMO

BACKGROUND: The effect of prior dengue virus (DENV) exposure on subsequent heterologous infection can be beneficial or detrimental depending on many factors including timing of infection. We sought to evaluate this effect by examining a large database of DENV infections captured by both active and passive surveillance encompassing a wide clinical spectrum of disease. METHODS: We evaluated datasets from 17 years of hospital-based passive surveillance and nine years of cohort studies, including clinical and subclinical DENV infections, to assess the outcomes of sequential heterologous infections. Chi square or Fisher's exact test was used to compare proportions of infection outcomes such as disease severity; ANOVA was used for continuous variables. Multivariate logistic regression was used to assess risk factors for infection outcomes. RESULTS: Of 38,740 DENV infections, two or more infections were detected in 502 individuals; 14 had three infections. The mean ages at the time of the first and second detected infections were 7.6 ± 3.0 and 11.2 ± 3.0 years. The shortest time between sequential infections was 66 days. A longer time interval between sequential infections was associated with dengue hemorrhagic fever (DHF) in the second detected infection (OR 1.3, 95% CI 1.2-1.4). All possible sequential serotype pairs were observed among 201 subjects with DHF at the second detected infection, except DENV-4 followed by DENV-3. Among DENV infections detected in cohort subjects by active study surveillance and subsequent non-study hospital-based passive surveillance, hospitalization at the first detected infection increased the likelihood of hospitalization at the second detected infection. CONCLUSIONS: Increasing time between sequential DENV infections was associated with greater severity of the second detected infection, supporting the role of heterotypic immunity in both protection and enhancement. Hospitalization was positively associated between the first and second detected infections, suggesting a possible predisposition in some individuals to more severe dengue disease.


Assuntos
Dengue/epidemiologia , Vigilância da População/métodos , Idade de Início , Anticorpos Antivirais/imunologia , Criança , Estudos de Coortes , Vírus da Dengue , Feminino , Hospitalização , Hospitais , Humanos , Masculino , Fatores de Risco , Dengue Grave/epidemiologia , Índice de Gravidade de Doença , Tailândia/epidemiologia , Fatores de Tempo
8.
PLoS Negl Trop Dis ; 8(9): e3138, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25211127

RESUMO

BACKGROUND: Dengue is endemic to the rural province of Kamphaeng Phet, Northern Thailand. A decade of prospective cohort studies has provided important insights into the dengue viruses and their generated disease. However, as elsewhere, spatial dynamics of the pathogen remain poorly understood. In particular, the spatial scale of transmission and the scale of clustering are poorly characterized. This information is critical for effective deployment of spatially targeted interventions and for understanding the mechanisms that drive the dispersal of the virus. METHODOLOGY/PRINCIPAL FINDINGS: We geocoded the home locations of 4,768 confirmed dengue cases admitted to the main hospital in Kamphaeng Phet province between 1994 and 2008. We used the phi clustering statistic to characterize short-term spatial dependence between cases. Further, to see if clustering of cases led to similar temporal patterns of disease across villages, we calculated the correlation in the long-term epidemic curves between communities. We found that cases were 2.9 times (95% confidence interval 2.7-3.2) more likely to live in the same village and be infected within the same month than expected given the underlying spatial and temporal distribution of cases. This fell to 1.4 times (1.2-1.7) for individuals living in villages 1 km apart. Significant clustering was observed up to 5 km. We found a steadily decreasing trend in the correlation in epidemics curves by distance: communities separated by up to 5 km had a mean correlation of 0.28 falling to 0.16 for communities separated between 20 km and 25 km. A potential explanation for these patterns is a role for human movement in spreading the pathogen between communities. Gravity style models, which attempt to capture population movement, outperformed competing models in describing the observed correlations. CONCLUSIONS: There exists significant short-term clustering of cases within individual villages. Effective spatially and temporally targeted interventions deployed within villages may target ongoing transmission and reduce infection risk.


Assuntos
Vírus da Dengue/isolamento & purificação , Dengue/epidemiologia , Análise por Conglomerados , Dengue/virologia , Geografia Médica , Humanos , Análise Espacial , Tailândia/epidemiologia
9.
Artigo em Inglês | MEDLINE | ID: mdl-24968673

RESUMO

We evaluated the differences in demographic, clinical, and laboratory findings between adult and pediatric patients hospitalized with dengue fever. Ninety patients with dengue infection admitted at San Lazaro Hospital (SLH), Manila from September 2005 to January 2006 were included in the study. The cases were laboratory-confirmed to have dengue infection. The majority of dengue cases (92%) had secondary dengue infection (median age = 18, age range: 2-37) while the remainder (8%) had a primary dengue infection (median age = 12, age range: 7-22). Nearly all the patients (99%) had dengue hemorrhagic fever (DHF). Sixty-five of the cases (72%) had serotype data: 2 (3%) were dengue virus serotype 1 (DENV-1) (median age = 17), 12 (18%) had DENV-2 (median age = 17.5), 38 (59%) had DENV-3 (median age = 16) and 13 (20%) had DENV-4 (median age = 18). The initial signs, symptoms and laboratory results except hematocrit (p = 0.02) and hemoglobin (p = 0.02) did not differ significantly between adults and children. During the study period, half the cases were adults (218 years; n = 45) and half were children (<18 years; n = 45). The ages of cases ranged from 2 to 37 years (median = 17 years) and the peak incidence was 15-19 years. Dengue is often considered as a pediatric disease. Additional studies are needed to determine if an age shift is occurring and where.


Assuntos
Dengue/epidemiologia , Adolescente , Adulto , Criança , Pré-Escolar , Demografia , Dengue/diagnóstico , Feminino , Humanos , Técnicas Imunoenzimáticas , Lactente , Masculino , Filipinas/epidemiologia , Vigilância da População , Estudos Prospectivos , Reação em Cadeia da Polimerase Via Transcriptase Reversa
10.
J Infect Dis ; 209(3): 360-8, 2014 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-23964110

RESUMO

BACKGROUND: Despite the strong association between secondary dengue virus (DENV) infections and dengue hemorrhagic fever (DHF), the majority of secondary infections are subclinical or mild. The determinants of clinical severity remain unclear, though studies indicate a titer-dependent and time-dependent role of cross-protective anti-DENV antibodies. METHODS: Data from 2 sequential prospective cohort studies were analyzed for subclinical and symptomatic DENV infections in schoolchildren in Kamphaeng Phet, Thailand (1998-2002 and 2004-2007). Children experiencing ≥ 1 DENV infection were selected as the population for analysis (contributing 2169 person-years of follow-up). RESULTS: In total, 1696 children had ≥ 1 DENV infection detected during their enrollment; 268 experienced 2 or more infections. A shorter time interval between infections was associated with subclinical infection in children seronegative for DENV at enrollment, for whom a second-detected DENV infection is more likely to reflect a true second infection (average of 2.6 years between infections for DHF, 1.9 for DF, and 1.6 for subclinical infections). CONCLUSIONS: These findings support a pathogenesis model where cross-reactive antibodies wane from higher-titer, protective levels to lower-titer, detrimental levels. This is one of the first studies of human subjects to suggest a window of cross-protection following DENV infection since Sabin's challenge studies in the 1940s.


Assuntos
Anticorpos Antivirais/sangue , Dengue/imunologia , Dengue/patologia , Adolescente , Criança , Pré-Escolar , Estudos de Coortes , Reações Cruzadas , Dengue/epidemiologia , Feminino , Humanos , Masculino , Estudos Prospectivos , Instituições Acadêmicas , Estudantes , Tailândia/epidemiologia , Fatores de Tempo
11.
Am J Trop Med Hyg ; 89(6): 1081-7, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24127167

RESUMO

A four-year longitudinal cohort and geographic cluster study in rural Thailand was conducted to characterize the clinical spectrum of dengue virus (DENV) infection. Symptomatic DENV infections in the cohort were detected by active school absence-based surveillance that triggered cluster investigations around ill cohort children. Data from 189 cohort children with symptomatic DENV infection and 126 contact children in the clusters with DENV infection were analyzed. Of infected contacts, only 19% were asymptomatic; 81% were symptomatic, but only 65.9% reported fever. Symptom-based case definitions were unreliable for diagnosis. Symptomatic infections in contacts were milder with lower DENV RNA levels than the cohort. Infections in contacts with fever history were more likely to have detectable DENV RNA than infections without fever history. Mild infections identified by cluster investigations account for a major proportion of all DENV infections. These findings are relevant for disease burden assessments, transmission modeling, and determination of vaccine impact.


Assuntos
Vírus da Dengue/isolamento & purificação , Dengue/epidemiologia , RNA Viral/sangue , Adolescente , Criança , Pré-Escolar , Análise por Conglomerados , Estudos de Coortes , Dengue/transmissão , Dengue/virologia , Vírus da Dengue/genética , Feminino , Febre , Humanos , Lactente , Estudos Longitudinais , Masculino , População Rural , Tailândia/epidemiologia
12.
Vaccine ; 31(41): 4487-500, 2013 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-23933334

RESUMO

This paper describes an international collaboration to carry out studies that contributed to the understanding of pathogenesis, diagnosis, treatment, and prevention of several diseases of public health importance for Thailand and the United States. In Kamphaeng Phet Province, Thailand, febrile syndromes, including encephalitis, hepatitis, hemorrhagic fever, and influenza-like illnesses, occurred commonly and were clinically diagnosed, but the etiology was rarely confirmed. Since 1982, the Kamphaeng Phet Provincial Hospital, the Thai Ministry of Public Health, and the US Army Component of the Armed Forces Research Institute of Medical Sciences, along with vaccine manufacturers and universities, have collaborated on studies that evaluated and capitalized on improved diagnostic capabilities for infections caused by Japanese encephalitis, hepatitis A, dengue, and influenza viruses. The collaboration clarified clinical and epidemiological features of these infections and, in large clinical trials, demonstrated that vaccines against Japanese encephalitis and hepatitis A viruses were over 90% efficacious, supporting licensure of both vaccines. With the introduction of Japanese encephalitis vaccines in Thailand's Expanded Program on Immunization, reported encephalitis rates dropped substantially. Similarly, in the US, particularly in the military populations, rates of hepatitis A disease have dropped with the use of hepatitis A vaccine. Studies of the pathogenesis of dengue infections have increased understanding of the role of cellular immunity in responding to these infections, and epidemiological studies have prepared the province for studies of dengue vaccines. Approximately 80 publications resulted from this collaboration. Studies conducted in Kamphaeng Phet provided experience that contributed to clinical trials of hepatitis E and HIV vaccines, conducted elsewhere. To provide a base for continuing studies, The Kamphaeng Phet-AFRIMS Virology Research Unit (KAVRU) was established. This paper reviews the origins of the collaboration and the scientific observations made between 1982 and 2012.


Assuntos
Cooperação Internacional , Vacinas Virais/administração & dosagem , Vacinas Virais/imunologia , Viroses/epidemiologia , Viroses/prevenção & controle , Humanos , Tailândia , Resultado do Tratamento , Estados Unidos , Viroses/diagnóstico , Viroses/patologia
13.
PLoS Negl Trop Dis ; 7(1): e1990, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23350000

RESUMO

Revealing the patterns and determinants of the spread of dengue virus (DENV) at local scales is central to understanding the epidemiology and evolution of this major human pathogen. We performed a phylogenetic analysis of the envelope (E) genes of DENV-1, -2, -3, and -4 isolates (involving 97, 23, 5, and 74 newly collected sequences, respectively) sampled from school-based cohort and village-based cluster studies in Kamphaeng Phet, Thailand, between 2004 and 2007. With these data, we sought to describe the spatial and temporal patterns of DENV spread within a rural population where a future vaccine efficacy trial is planned. Our analysis revealed considerable genetic diversity within the study population, with multiple lineages within each serotype circulating for various lengths of time during the study period. These results suggest that DENV is frequently introduced into both semi-urban and rural areas in Kamphaeng Phet from other populations. In contrast, the persistence of viral lineages across sampling years was observed less frequently. Analysis of phylogenetic clustering indicated that DENV transmission was highly spatially and temporally focal, and that it occurred in homes rather than at school. Overall, the strength of temporal clustering suggests that seasonal bottlenecks in local DENV populations facilitate the invasion and establishment of viruses from outside of the study area, in turn reducing the extent of lineage persistence.


Assuntos
Vírus da Dengue/classificação , Vírus da Dengue/isolamento & purificação , Dengue/epidemiologia , Dengue/transmissão , Emigração e Imigração , Adolescente , Criança , Pré-Escolar , Análise por Conglomerados , Dengue/virologia , Vírus da Dengue/genética , Feminino , Geografia , Humanos , Lactente , Recém-Nascido , Masculino , Epidemiologia Molecular , Dados de Sequência Molecular , Filogenia , RNA Viral/genética , População Rural , Análise de Sequência de DNA , Tailândia/epidemiologia , Fatores de Tempo , Proteínas do Envelope Viral/genética
14.
Transplant Proc ; 45(1): 360-3, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23267807

RESUMO

BACKGROUND: Recent limitations in Medicaid coverage of transplantation in Arizona jeopardized transplantation of potential recipients in that state and called attention to financial barriers inherent in the present organ allocation system. Policies of cardiac transplant centers regarding insurance requirements for transplantation have not been previously assessed. We sought to determine the policies of adult cardiac transplant programs nationwide regarding insurance requirements for evaluation and listing for cardiac transplantation. METHODS: From December 15, 2008 to November 16, 2010, all active adult cardiac transplant programs in the United States were surveyed regarding insurance requirements for evaluation and listing for cardiac transplantation. RESULTS: Surveys were completed by 62 of 101 programs, accounting for 71% of adult cardiac transplants in 2007. Only 2% of recipients were uninsured. Insurance was required by 48% of programs to evaluate and 84% to list for transplantation. For uninsured patients, 81% of programs required a large amount of money upfront (median, $200,000; interquartile range, $10,000-$300,000) to list for transplantation and often (84%) educated patients about fundraising to acquire these resources. CONCLUSIONS: Adult cardiac transplant programs generally require candidates to have adequate health insurance to undergo transplantation. Uninsured patients typically need a significant amount of money upfront to be listed for transplantation and often are advised to fundraise to gather such resources.


Assuntos
Insuficiência Cardíaca/economia , Insuficiência Cardíaca/cirurgia , Transplante de Coração/economia , Seguro Saúde , Cardiologia/economia , Cardiologia/normas , Transplante de Coração/normas , Humanos , Medicaid , Pessoas sem Cobertura de Seguro de Saúde/estatística & dados numéricos , Modelos Estatísticos , Obtenção de Tecidos e Órgãos/economia , Obtenção de Tecidos e Órgãos/métodos , Estados Unidos , Listas de Espera
15.
J Infect Dis ; 207(5): 700-8, 2013 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-23225894

RESUMO

BACKGROUND: Protection against dengue requires immunity against all 4 serotypes of dengue virus (DENV). Experimental challenge may be useful in evaluating vaccine-induced immunity. METHODS: Ten subjects previously vaccinated with a live attenuated tetravalent dengue vaccine (TDV) and 4 DENV-naive control subjects were challenged by subcutaneous inoculation of either 10(3) plaque-forming units (PFU) of DENV-1 or 10(5) PFU of DENV-3. Two additional subjects who did not develop DENV-3 neutralizing antibody (NAb) from TDV were revaccinated with 10(4) PFU of live attenuated DENV-3 vaccine to evaluate memory response. RESULTS: All 5 TDV recipients were protected against DENV-1 challenge. Of the 5 TDV recipients challenged with DENV-3, 2 were protected. All DENV-3-challenge subjects who developed viremia also developed elevated liver enzyme levels, and 2 had values that were >10 times greater than normal. Of the 2 subjects revaccinated with DENV-3 vaccine, 1 showed a secondary response to DENV-2, while neither showed such response to DENV-3. All 4 control subjects developed dengue fever from challenge. Protection was associated with presence of NAb, although 1 subject was protected despite a lack of measurable NAb at the time of DENV-1 challenge. CONCLUSIONS: Vaccination with TDV induced variable protection against subcutaneous challenge. DENV-3 experimental challenge was associated with transient but marked elevations of transaminases.


Assuntos
Vacinas contra Dengue/administração & dosagem , Vacinas contra Dengue/imunologia , Vírus da Dengue/imunologia , Vírus da Dengue/patogenicidade , Dengue/prevenção & controle , Adulto , Análise Química do Sangue , Dengue/patologia , Feminino , Humanos , Fígado/enzimologia , Testes de Função Hepática , Masculino , Vacinas Atenuadas/administração & dosagem , Vacinas Atenuadas/imunologia , Viremia/patologia , Viremia/prevenção & controle , Adulto Jovem
16.
PLoS Negl Trop Dis ; 6(7): e1730, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22816001

RESUMO

BACKGROUND: Based on spatiotemporal clustering of human dengue virus (DENV) infections, transmission is thought to occur at fine spatiotemporal scales by horizontal transfer of virus between humans and mosquito vectors. To define the dimensions of local transmission and quantify the factors that support it, we examined relationships between infected humans and Aedes aegypti in Thai villages. METHODOLOGY/PRINCIPAL FINDINGS: Geographic cluster investigations of 100-meter radius were conducted around DENV-positive and DENV-negative febrile "index" cases (positive and negative clusters, respectively) from a longitudinal cohort study in rural Thailand. Child contacts and Ae. aegypti from cluster houses were assessed for DENV infection. Spatiotemporal, demographic, and entomological parameters were evaluated. In positive clusters, the DENV infection rate among child contacts was 35.3% in index houses, 29.9% in houses within 20 meters, and decreased with distance from the index house to 6.2% in houses 80-100 meters away (p<0.001). Significantly more Ae. aegypti were DENV-infectious (i.e., DENV-positive in head/thorax) in positive clusters (23/1755; 1.3%) than negative clusters (1/1548; 0.1%). In positive clusters, 8.2% of mosquitoes were DENV-infectious in index houses, 4.2% in other houses with DENV-infected children, and 0.4% in houses without infected children (p<0.001). The DENV infection rate in contacts was 47.4% in houses with infectious mosquitoes, 28.7% in other houses in the same cluster, and 10.8% in positive clusters without infectious mosquitoes (p<0.001). Ae. aegypti pupae and adult females were more numerous only in houses containing infectious mosquitoes. CONCLUSIONS/SIGNIFICANCE: Human and mosquito infections are positively associated at the level of individual houses and neighboring residences. Certain houses with high transmission risk contribute disproportionately to DENV spread to neighboring houses. Small groups of houses with elevated transmission risk are consistent with over-dispersion of transmission (i.e., at a given point in time, people/mosquitoes from a small portion of houses are responsible for the majority of transmission).


Assuntos
Aedes/virologia , Vírus da Dengue/isolamento & purificação , Dengue/transmissão , Dengue/virologia , Transmissão de Doença Infecciosa , Adolescente , Animais , Anticorpos Antivirais/sangue , Criança , Pré-Escolar , Análise por Conglomerados , Estudos de Coortes , Dengue/epidemiologia , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Lactente , Estudos Longitudinais , Masculino , Reação em Cadeia da Polimerase , População Rural , Tailândia/epidemiologia
17.
J Infect Dis ; 206(3): 389-98, 2012 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-22615312

RESUMO

BACKGROUND: The understanding of dengue virus (DENV) transmission dynamics and the clinical spectrum of infection are critical to informing surveillance and control measures. Geographic cluster studies can elucidate these features in greater detail than cohort studies alone. METHODS: A 4-year longitudinal cohort and geographic cluster study was undertaken in rural Thailand. Cohort children underwent pre-/postseason serology and active school absence-based surveillance to detect inapparent and symptomatic dengue. Cluster investigations were triggered by cohort dengue and non-dengue febrile illnesses (positive and negative clusters, respectively). RESULTS: The annual cohort incidence of symptomatic dengue ranged from 1.3% to 4.4%. DENV-4 predominated in the first 2 years, DENV-1 in the second 2 years. The inapparent-to-symptomatic infection ratio ranged from 1.1:1 to 2.9:1. Positive clusters had a 16.0% infection rate, negative clusters 1.1%. Of 119 infections in positive clusters, 59.7% were febrile, 20.2% were afebrile with other symptoms, and 20.2% were asymptomatic. Of 16 febrile children detected during cluster investigations who continued to attend school, 9 had detectable viremia. CONCLUSIONS: Dengue transmission risk was high near viremic children in both high- and low-incidence years. Inapparent infections in the cohort overestimated the rate of asymptomatic infections. Ambulatory children with mild febrile viremic infections could represent an important component of dengue transmission.


Assuntos
Vírus da Dengue/isolamento & purificação , Dengue/epidemiologia , Viremia/epidemiologia , Adolescente , Criança , Pré-Escolar , Análise por Conglomerados , Estudos de Coortes , Dengue/diagnóstico , Dengue/virologia , Feminino , Habitação , Humanos , Incidência , Lactente , Estudos Longitudinais , Masculino , Estudos Prospectivos , População Rural , Instituições Acadêmicas , Tailândia/epidemiologia , Fatores de Tempo , Viremia/diagnóstico , Viremia/virologia
18.
Clin Vaccine Immunol ; 19(5): 804-10, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22441389

RESUMO

Seven commercial assays were evaluated to determine their suitability for the diagnosis of acute dengue infection: (i) the Panbio dengue virus Pan-E NS1 early enzyme-linked immunosorbent assay (ELISA), second generation (Alere, Australia); (ii) the Panbio dengue virus IgM capture ELISA (Alere, Australia); (iii) the Panbio dengue virus IgG capture ELISA (Alere, Australia); (iv) the Standard Diagnostics dengue virus NS1 antigen ELISA (Standard Diagnostics, South Korea); (v) the Standard Diagnostics dengue virus IgM ELISA (Standard Diagnostics, South Korea); (vi) the Standard Diagnostics dengue virus IgG ELISA (Standard Diagnostics, South Korea); and (vii) the Platelia NS1 antigen ELISA (Bio-Rad, France). Samples from 239 Thai patients confirmed to be dengue virus positive and 98 Sri Lankan patients negative for dengue virus infection were tested. The sensitivities and specificities of the NS1 antigen ELISAs ranged from 45 to 57% and 93 to 100% and those of the IgM antibody ELISAs ranged from 85 to 89% and 88 to 100%, respectively. Combining the NS1 antigen and IgM antibody results from the Standard Diagnostics ELISAs gave the best compromise between sensitivity and specificity (87 and 96%, respectively), as well as providing the best sensitivity for patients presenting at different times after fever onset. The Panbio IgG capture ELISA correctly classified 67% of secondary dengue infection cases. This study provides strong evidence of the value of combining dengue virus antigen- and antibody-based test results in the ELISA format for the diagnosis of acute dengue infection.


Assuntos
Anticorpos Antivirais/sangue , Antígenos Virais/sangue , Técnicas de Laboratório Clínico/métodos , Vírus da Dengue/imunologia , Dengue/diagnóstico , Kit de Reagentes para Diagnóstico , Adolescente , Adulto , Ensaio de Imunoadsorção Enzimática/métodos , Feminino , Humanos , Imunoglobulina G/sangue , Masculino , Sensibilidade e Especificidade , Fatores de Tempo , Adulto Jovem
19.
Indian J Pediatr ; 79 Suppl 1: S27-32, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21617912

RESUMO

The advent of pediatric psychopharmacology has enormously improved psychiatric care of children and adolescents. Nonetheless, our practice of diagnosis, treatment and referral in primary-care pediatric settings is not optimum as current evidence based knowledge is not regularly applied in the actual clinical circumstances. To help primary-care pediatricians minimise this in research-clinical practice, pharmacological treatment and referral in their clinical practice, they need to follow a two-tier diagnostic and multi axial treatment approach. The two-tier diagnostic approach of using a screening measure followed by confirmation of the screen positive cases with reference standard clinical criterion, improves the sensitivity and specificity. The multiaxial treatment has the advantage of offering a holistic approach to the intervention and improve prognosis from the interacting axes. The primary-care physician should be aware of the medications of choice for the Priority Mental Health Disorders and their drug interactions. Finally, referral of cases with atypical presentations, multiple comorbidities and poor response to the first-line of treatment needs referral to the next tier in the system.


Assuntos
Transtornos Mentais/diagnóstico , Serviços de Saúde Mental , Saúde Mental , Pediatria/métodos , Atenção Primária à Saúde/métodos , Psicofarmacologia/métodos , Adolescente , Serviços de Saúde do Adolescente , Criança , Serviços de Saúde da Criança , Humanos , Índia , Transtornos Mentais/tratamento farmacológico , Encaminhamento e Consulta , Sensibilidade e Especificidade
20.
Indian J Pediatr ; 79 Suppl 1: S19-26, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21660409

RESUMO

India has a huge child and adolescent population. Psychiatric disorders are widely prevalent and the mental health needs of these children are well recognized. Nonetheless, there are no country-centric and child specific mental health policies, plans or programs. There is also a significant lack of human resources for child and adolescent mental health in India. This combination of factors makes the primary care a critical setting for the early identification, treatment, consultation and referral of children and adolescents with mental health and developmental needs. Even though the importance of primary care as a system for addressing the mental health care has been recognized for decades, its potential requires further development in India as the Child and Adolescent Mental Health Services (CAMHS) emerge and evolve. A country and child specific mental health policy, plan and program needs to be formulated as well an integrated, multi-tier CAMHS with a focus on the primary-care physicians as care providers for this population has to be developed.


Assuntos
Serviços de Saúde do Adolescente , Serviços de Saúde da Criança , Transtornos Mentais/terapia , Serviços de Saúde Mental , Saúde Mental , Programas Nacionais de Saúde , Adolescente , Criança , Humanos , Índia , Pediatria , Atenção Primária à Saúde
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