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1.
Clin Infect Dis ; 71(2): 383-389, 2020 07 11.
Artigo em Inglês | MEDLINE | ID: mdl-31626692

RESUMO

BACKGROUND: Platelet transfusion is common in dengue patients with thrombocytopenia. We previously showed in a randomized clinical trial that prophylactic platelet transfusion did not reduce clinical bleeding. In this study, we aimed to characterize the predictors and clinical outcomes of poor platelet recovery in transfused and nontransfused participants. METHODS: We analyzed patients from the Adult Dengue Platelet Study with laboratory-confirmed dengue with ≤20 000 platelets/µL and without persistent mild bleeding or any severe bleeding in a post hoc analysis. Poor platelet recovery was defined as a platelet count of ≤20 000/µL on Day 2. We recruited 372 participants from 5 acute care hospitals located in Singapore and Malaysia between 29 April 2010 and 9 December 2014. Of these, 188 were randomly assigned to the transfusion group and 184 to the control group. RESULTS: Of 360 patients, 158 had poor platelet recovery. Age, white cell count, and day of illness at study enrollment were significant predictors of poor platelet recovery after adjustment for baseline characteristics and platelet transfusion. Patients with poor platelet recovery had longer hospitalizations but no significant difference in other clinical outcomes, regardless of transfusion. We found a significant interaction between platelet recovery and transfusion; patients with poor platelet recovery were more likely to bleed if given a prophylactic platelet transfusion (odds ratio 2.34, 95% confidence interval 1.18-4.63). CONCLUSIONS: Dengue patients with thrombocytopenia who were older or presented earlier and with lower white cell counts were more likely to have poor platelet recovery. In patients with poor platelet recovery, platelet transfusion does not improve outcomes and may actually increase the risk of bleeding. The mechanisms of poor platelet recovery need to be determined. CLINICAL TRIALS REGISTRATION: NCT01030211.


Assuntos
Dengue , Trombocitopenia , Adulto , Plaquetas , Dengue/complicações , Dengue/terapia , Humanos , Malásia , Transfusão de Plaquetas , Estudos Prospectivos , Singapura/epidemiologia
2.
Lancet ; 389(10079): 1611-1618, 2017 04 22.
Artigo em Inglês | MEDLINE | ID: mdl-28283286

RESUMO

BACKGROUND: Dengue is the commonest vector-borne infection worldwide. It is often associated with thrombocytopenia, and prophylactic platelet transfusion is widely used despite the dearth of robust evidence. We aimed to assess the efficacy and safety of prophylactic platelet transfusion in the prevention of bleeding in adults with dengue and thrombocytopenia. METHODS: We did an open-label, randomised, superiority trial in five hospitals in Singapore and Malaysia. We recruited patients aged at least 21 years who had laboratory-confirmed dengue (confirmed or probable) and thrombocytopenia (≤20 000 platelets per µL), without persistent mild bleeding or any severe bleeding. Patients were assigned (1:1), with randomly permuted block sizes of four or six and stratified by centre, to receive prophylactic platelet transfusion in addition to supportive care (transfusion group) or supportive care alone (control group). In the transfusion group, 4 units of pooled platelets were given each day when platelet count was 20 000 per µL or lower; supportive care consisted of bed rest, fluid therapy, and fever and pain medications. The primary endpoint was clinical bleeding (excluding petechiae) by study day 7 or hospital discharge (whichever was earlier), analysed by intention to treat. Safety outcomes were analysed according to the actual treatment received. This study was registered with ClinicalTrials.gov, number NCT01030211, and is completed. FINDINGS: Between April 29, 2010, and Dec 9, 2014, we randomly assigned 372 patients to the transfusion group (n=188) or the control group (n=184). The intention-to-treat analysis included 187 patients in the transfusion group (one patient was withdrawn immediately) and 182 in the control group (one was withdrawn immediately and one did not have confirmed or probable dengue). Clinical bleeding by day 7 or hospital discharge occurred in 40 (21%) patients in the transfusion group and 48 (26%) patients in the control group (risk difference -4·98% [95% CI -15·08 to 5·34]; relative risk 0·81 [95% CI 0·56 to 1·17]; p=0·16). 13 adverse events occurred in the transfusion group and two occurred in the control group (5·81% [-4·42 to 16·01]; 6·26 [1·43 to 27·34]; p=0·0064). Adverse events that were possibly, probably, or definitely related to transfusion included three cases of urticaria, one maculopapular rash, one pruritus, and one chest pain, as well as one case each of anaphylaxis, transfusion-related acute lung injury, and fluid overload that resulted in serious adverse events. No death was reported. INTERPRETATION: In adult patients with dengue and thrombocytopenia, prophylactic platelet transfusion was not superior to supportive care in preventing bleeding, and might be associated with adverse events. FUNDING: National Medical Research Council, Singapore.


Assuntos
Dengue/complicações , Hemorragia/prevenção & controle , Transfusão de Plaquetas , Trombocitopenia/complicações , Adulto , Estudos de Equivalência como Asunto , Feminino , Hemorragia/etiologia , Humanos , Malásia , Masculino , Pessoa de Meia-Idade , Singapura , Resultado do Tratamento
3.
Clin Infect Dis ; 64(suppl_2): S61-S67, 2017 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-28475790

RESUMO

BACKGROUND: We conducted a national point prevalence survey (PPS) to determine the prevalence of healthcare-associated infections (HAIs) and antimicrobial use (AMU) in Singapore acute-care hospitals. METHODS: Trained personnel collected HAI, AMU, and baseline hospital- and patient-level data of adult inpatients from 13 private and public acute-care hospitals between July 2015 and February 2016, using the PPS methodology developed by the European Centre for Disease Prevention and Control. Factors independently associated with HAIs were determined using multivariable regression. RESULTS: Of the 5415 patients surveyed, there were 646 patients (11.9%; 95% confidence interval [CI], 11.1%-12.8%) with 727 distinct HAIs, of which 331 (45.5%) were culture positive. The most common HAIs were unspecified clinical sepsis (25.5%) and pneumonia (24.8%). Staphylococcus aureus (12.9%) and Pseudomonas aeruginosa (11.5%) were the most common pathogens implicated in HAIs. Carbapenem nonsusceptibility rates were highest in Acinetobacter species (71.9%) and P. aeruginosa (23.6%). Male sex, increasing age, surgery during current hospitalization, and presence of central venous or urinary catheters were independently associated with HAIs. A total of 2762 (51.0%; 95% CI, 49.7%-52.3%) patients were on 3611 systemic antimicrobial agents; 462 (12.8%) were prescribed for surgical prophylaxis and 2997 (83.0%) were prescribed for treatment. Amoxicillin/clavulanate was the most frequently prescribed (24.6%) antimicrobial agent. CONCLUSIONS: This survey suggested a high prevalence of HAIs and AMU in Singapore's acute-care hospitals. While further research is necessary to understand the causes and costs of HAIs and AMU in Singapore, repeated PPSs over the next decade will be useful to gauge progress at controlling HAIs and AMU.


Assuntos
Antibacterianos/uso terapêutico , Infecção Hospitalar/epidemiologia , Infecção Hospitalar/microbiologia , Fatores Etários , Idoso , Combinação Amoxicilina e Clavulanato de Potássio/administração & dosagem , Combinação Amoxicilina e Clavulanato de Potássio/uso terapêutico , Carbapenêmicos/farmacologia , Infecção Hospitalar/tratamento farmacológico , Feminino , Cirurgia Geral , Inquéritos Epidemiológicos , Hospitais , Humanos , Pacientes Internados , Masculino , Pessoa de Meia-Idade , Padrões de Prática Médica/estatística & dados numéricos , Prevalência , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/isolamento & purificação , Fatores Sexuais , Singapura/epidemiologia , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/isolamento & purificação
4.
J Infect Dis ; 213(10): 1562-72, 2016 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-26704612

RESUMO

BACKGROUND: A safe, effective tetravalent dengue vaccine is a global health priority. The safety and immunogenicity of a live attenuated, recombinant tetravalent dengue vaccine candidate (TDV) were evaluated in healthy volunteers from dengue-endemic countries. METHODS: This multicenter, double-blind, phase 2 study was conducted in Puerto Rico, Colombia, Singapore, and Thailand. During stage I, 148 volunteers aged 1.5-45 years were sequentially enrolled into 4 age-descending groups and randomized at a ratio of 2:1 to receive TDV or placebo. In stage II (group 5), 212 children aged 1.5-11 years were randomized at a ratio of 3:1 to receive TDV or placebo. Participants received a subcutaneous injection of TDV or placebo on days 0 and 90 and were followed for analysis of safety, seropositivity, and neutralizing antibodies to DENV-1-4. RESULTS: Injection site pain, itching, and erythema (mostly mild) were the only solicited adverse events more frequently reported with TDV than with placebo in all age groups. After 2 TDV doses, seropositivity was >95% in all 5 groups for DENV-1-3 and 72.7%-100% for DENV-4; geometric mean titers ranged from 582 to 1187 for DENV-1, from 582 to 1187 for DENV-2, from 196 to 630 for DENV-3, and from 41 to 210 for DENV-4 among the 5 groups. CONCLUSIONS: TDV was well tolerated and immunogenic in volunteers aged 1.5-45 years, irrespective of prevaccination dengue exposure.


Assuntos
Anticorpos Antivirais/imunologia , Vacinas contra Dengue/imunologia , Vírus da Dengue/imunologia , Dengue/prevenção & controle , Adolescente , Adulto , Anticorpos Neutralizantes/imunologia , Criança , Pré-Escolar , Colômbia , Dengue/imunologia , Vacinas contra Dengue/administração & dosagem , Vacinas contra Dengue/normas , Método Duplo-Cego , Feminino , Humanos , Lactente , Injeções Subcutâneas , Masculino , Pessoa de Meia-Idade , Porto Rico , Segurança , Singapura , Tailândia , Vacinas Atenuadas/administração & dosagem , Vacinas Atenuadas/imunologia , Vacinas Atenuadas/normas , Adulto Jovem
5.
Expert Rev Vaccines ; 23(1): 16-26, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38047434

RESUMO

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causing COVID-19 has been a dynamically changing virus, requiring the development of adapted vaccines. This study estimated the potential public health impact alternative vaccination strategies for COVID-19 in Singapore. RESEARCH DESIGN AND METHODS: The outcomes of alternative vaccination strategies with a future adapted vaccine were estimated using a combined Markov decision tree model. The population was stratified by high- and standard-risk. Using age-specific inputs informed by local surveillance data and published sources, the model estimated health (case numbers, hospitalizations, and deaths) and economic (medical costs and productivity losses) outcomes in different age and risk subpopulations. RESULTS: Booster vaccination in only the elderly and high-risk subpopulation was estimated to avert 278,614 cases 21,558 hospitalizations, 239 deaths, Singapore dollars (SGD) 277 million in direct medical costs, and SGD 684 million in indirect medical costs. These benefits increased as vaccination was expanded to other subpopulations. Increasing the booster vaccination coverage to 75% of the standard-risk population averted more deaths (3%), hospitalizations (29%), infections (145%), direct costs (90%), and indirect costs (192%) compared to the base case. CONCLUSIONS: Broader vaccination strategies using an adapted booster vaccine could have substantial public health and economic impact in Singapore.


Assuntos
COVID-19 , Vacinas , Idoso , Humanos , Vacinas contra COVID-19 , Saúde Pública , Singapura/epidemiologia , COVID-19/epidemiologia , COVID-19/prevenção & controle , SARS-CoV-2 , Vacinação
6.
Am J Trop Med Hyg ; 111(1): 102-106, 2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-38806045

RESUMO

The profiles of vaccine-induced dengue antibodies may differ from those produced following natural infection and could potentially interfere with the interpretation of diagnostic tests. We assessed anti-dengue IgG and IgM antibodies, and nonstructural protein 1 antigen profiles in the serum of adults who received a single dose of the tetravalent dengue vaccine TAK-003 as either an initially developed high-dose formulation or the standard approved formulation in a phase 2 study in Singapore (#NCT02425098). Immunoglobulin G and IgM profiles during the first 30 days postvaccination varied by baseline serostatus (microneutralization assay). Nonstructural protein 1 antigen was not detected in the serum of any participants. Vaccine-induced IgG and IgM antibodies can affect serological confirmation of subsequent dengue infection in vaccinees. These results highlight the limitations of using serological tests for dengue diagnosis, particularly in a postvaccination setting, and emphasize the need for more sensitive antigen- and molecular-based testing for accurate dengue diagnosis.


Assuntos
Anticorpos Antivirais , Vacinas contra Dengue , Vírus da Dengue , Dengue , Imunoglobulina G , Imunoglobulina M , Proteínas não Estruturais Virais , Humanos , Vacinas contra Dengue/imunologia , Vacinas contra Dengue/administração & dosagem , Imunoglobulina M/sangue , Imunoglobulina G/sangue , Dengue/prevenção & controle , Dengue/imunologia , Dengue/diagnóstico , Proteínas não Estruturais Virais/imunologia , Anticorpos Antivirais/sangue , Adulto , Vírus da Dengue/imunologia , Masculino , Feminino , Singapura , Adulto Jovem , Pessoa de Meia-Idade , Adolescente
7.
N Engl J Med ; 358(24): 2573-84, 2008 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-18550874

RESUMO

BACKGROUND: Widespread infections of avian species with avian influenza H5N1 virus and its limited spread to humans suggest that the virus has the potential to cause a human influenza pandemic. An urgent need exists for an H5N1 vaccine that is effective against divergent strains of H5N1 virus. METHODS: In a randomized, dose-escalation, phase 1 and 2 study involving six subgroups, we investigated the safety of an H5N1 whole-virus vaccine produced on Vero cell cultures and determined its ability to induce antibodies capable of neutralizing various H5N1 strains. In two visits 21 days apart, 275 volunteers between the ages of 18 and 45 years received two doses of vaccine that each contained 3.75 microg, 7.5 microg, 15 microg, or 30 microg of hemagglutinin antigen with alum adjuvant or 7.5 microg or 15 microg of hemagglutinin antigen without adjuvant. Serologic analysis was performed at baseline and on days 21 and 42. RESULTS: The vaccine induced a neutralizing immune response not only against the clade 1 (A/Vietnam/1203/2004) virus strain but also against the clade 2 and 3 strains. The use of adjuvants did not improve the antibody response. Maximum responses to the vaccine strain were obtained with formulations containing 7.5 microg and 15 microg of hemagglutinin antigen without adjuvant. Mild pain at the injection site (in 9 to 27% of subjects) and headache (in 6 to 31% of subjects) were the most common adverse events identified for all vaccine formulations. CONCLUSIONS: A two-dose vaccine regimen of either 7.5 microg or 15 microg of hemagglutinin antigen without adjuvant induced neutralizing antibodies against diverse H5N1 virus strains in a high percentage of subjects, suggesting that this may be a useful H5N1 vaccine. (ClinicalTrials.gov number, NCT00349141.)


Assuntos
Virus da Influenza A Subtipo H5N1/imunologia , Vacinas contra Influenza/administração & dosagem , Influenza Humana/prevenção & controle , Adjuvantes Imunológicos/administração & dosagem , Adulto , Animais , Anticorpos Antivirais/sangue , Chlorocebus aethiops , Reações Cruzadas , Feminino , Humanos , Vacinas contra Influenza/efeitos adversos , Vacinas contra Influenza/imunologia , Influenza Humana/imunologia , Injeções Intramusculares/efeitos adversos , Masculino , Testes de Neutralização , Células Vero
8.
BMC Infect Dis ; 11: 123, 2011 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-21569427

RESUMO

BACKGROUND: Dengue re-emerges in Singapore despite decades of effective vector control; the infection predominantly afflicts adults. Severe dengue not fulfilling dengue hemorrhagic fever (DHF) criteria according to World Health Organization (WHO) 1997 guideline was increasingly reported. A new WHO 2009 guideline emphasized warning signs and a wider range of severe dengue manifestations. We aim to evaluate the utility of these two guidelines in confirmed adult dengue fatalities. METHODS: We conducted a multi-center retrospective chart review of all confirmed adult dengue deaths in Singapore from 1 January 2004 to 31 December 2008. RESULTS: Of 28 adult dengue deaths, median age was 59 years. Male gender comprised 67.9% and co-morbidities existed in 75%. From illness onset, patients presented for admission at a median of 4 days and death occurred at a median of 12 days. Intensive care admission was required in 71.4%. Probable dengue was diagnosed in 32.1% by WHO 1997 criteria and 78.6% by WHO 2009. The earliest warning sign was persistent vomiting at a median of 1.5 days. Hematocrit change ≥20% concurrent with platelet count <20 × 10^9/L was associated with the shortest interval to death at a median of 3 days. Only 35.7% of death cases fulfilled DHF criteria by WHO 1997 versus severe dengue in 100.0% by WHO 2009 criteria. Deaths were due to shock and organ failure. Acute renal impairment occurred in 71.4%, impaired consciousness 57.1% and severe hepatitis 53.6%. CONCLUSIONS: In our adult fatal dengue cohort, WHO 2009 criteria had higher sensitivity in diagnosing probable dengue and severe dengue compared with WHO 1997. As warning signs, persistent vomiting occurred early and hematocrit change ≥20% concurrent with platelet count <20 × 10^9/L preceded death most closely.


Assuntos
Dengue/epidemiologia , Dengue/mortalidade , Adulto , Estudos de Coortes , Dengue/diagnóstico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Singapura/epidemiologia , Organização Mundial da Saúde
9.
Vaccine ; 38(6): 1513-1519, 2020 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-31843269

RESUMO

BACKGROUND: Early formulations of Takeda's tetravalent dengue vaccine candidate (TAK-003) have demonstrated notably higher neutralizing antibody responses against serotype 2 than other serotypes. Here, we assessed the immunogenicity and tolerability in adults living in Singapore of two TAK-003 formulations: an early formulation, referred to as HD-TDV, and a new formulation with 10-fold lower serotype 2 potency, referred to as TDV (NCT02425098). METHODS: Subjects aged 21-45 years were stratified by baseline dengue serostatus and randomised 1:1 to receive a single dose of either HD-TDV or TDV. Immunogenicity was evaluated at Days 15, 30, 90, 180, and 365 post-vaccination as geometric mean titres (GMTs) of neutralising antibodies and seropositivity rates. Viremia was assessed per vaccine strain. Solicited and unsolicited adverse events (AEs) were assessed by severity and causality. RESULTS: Of 351 subjects randomised, 176 received HD-TDV and 175 received TDV. Peak GMTs against all serotypes were observed at Day 30, with highest GMTs against DENV-2 in both groups. In subjects seronegative at baseline, the response to DENV-2 was less dominant with TDV (Day 30 GMTs: 813 for TDV, 10,966 for HD-TDV). In these subjects, DENV-4 seropositivity rates and GMTs were higher with TDV (Day 30 GMTs: 58 for TDV, 21 for HD-TDV; seropositivity rates: 76% for TDV, 60% for HD-TDV). Viremia mainly occurred for TDV-2 in both vaccine groups, with a lower incidence in TDV recipients, and mostly resolved by Day 30. Both vaccine formulations showed an acceptable safety profile with similar overall rates of solicited and unsolicited AEs across vaccine groups. CONCLUSIONS: These results suggest a more balanced immune response with the new formulation TDV compared with the early formulation HD-TDV, particularly in subjects who were seronegative prior to vaccination, and support the choice of the new formulation for the phase 3 efficacy assessment.


Assuntos
Vacinas contra Dengue/imunologia , Dengue , Imunogenicidade da Vacina , Adulto , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Dengue/prevenção & controle , Vacinas contra Dengue/efeitos adversos , Método Duplo-Cego , Humanos , Pessoa de Meia-Idade , Sorogrupo , Singapura , Vacinas Combinadas/efeitos adversos , Vacinas Combinadas/imunologia , Adulto Jovem
10.
Vaccine ; 35(51): 7127-7132, 2017 12 18.
Artigo em Inglês | MEDLINE | ID: mdl-29174316

RESUMO

BACKGROUND: Human Rabies infection continues to be potentially fatal despite the availability of post-exposure prophylaxis with rabies vaccine. The PIKA Rabies vaccine adjuvant is a TLR3 agonist and has been shown to be safe and immunogenic in clinical phase I studies. METHODS: We conducted a phase II, open label, randomized study in healthy adults to assess the safety and immunogenicity of the PIKA rabies vaccine under an accelerated regimen. 126 subjects were randomized into two groups: control vaccine classic regimen ("control-classic") and PIKA vaccine accelerated regimen ("PIKA-accelerated"). Subjects were followed up for safety and rabies virus neutralizing antibodies (RVNA). RESULTS: Both the control and PIKA vaccines were generally well tolerated. 57.6% of subjects in the PIKA vaccine group, compared with 43.8% of subjects in the control-classic group, achieved the target RVNA titer of ≥0.5 IU/mL by Day 7. All subjects achieved the target RVNA titer by Day 14. The RVNA geometric mean titer at Day 7 was 0.60 IU/ml in the PIKA vaccine group and 0.39 IU/ml in the control-classic group. At Day 14, the RVNA geometric mean titer was 18.25 IU/ml in the PIKA-accelerated group and 19.24 IU/ml in the control-classic group. The median time taken to reach the target RVNA titer level of ≥0.5 IU/mL was 7.0 days (95% CI: 7.0-42.0 days) in the PIKA-accelerated group and 14.0 days (95% CI: 7.0-42.0 days) in the control-classic group. CONCLUSION: The accelerated regimen using the investigational PIKA Rabies vaccine was well-tolerated and demonstrated non-inferior immunogenicity compared to the classic regimen using the commercially available vaccine in healthy adults. Clinical trial registry: The study was registered with clinicaltrials.gov (NCT02956421).


Assuntos
Adjuvantes Imunológicos/administração & dosagem , Imunogenicidade da Vacina , Vacina Antirrábica/efeitos adversos , Vacina Antirrábica/imunologia , Raiva/prevenção & controle , Adjuvantes Imunológicos/química , Adulto , Idoso , Animais , Anticorpos Neutralizantes/biossíntese , Anticorpos Neutralizantes/sangue , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Chlorocebus aethiops , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Feminino , Voluntários Saudáveis , Humanos , Masculino , Pessoa de Meia-Idade , Profilaxia Pós-Exposição , Vacina Antirrábica/administração & dosagem , Vírus da Raiva/imunologia , Receptor 3 Toll-Like/agonistas , Receptor 3 Toll-Like/imunologia , Células Vero , Adulto Jovem
11.
J Clin Virol ; 57(1): 91-4, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23415634

RESUMO

Neurological manifestations due to Dengue virus (DENV) infection are atypical and uncommon. Genomic information of clinically characterised, neurotrophic DENV in humans is extremely limited albeit their importance in deciphering the pathogenicity is substantial. Here, we report a rare case of fatal DENV-4 infection complicated with encephalitis and multi-organ failure. The clinical presentation was unusual due to its rapid onset of encephalitis despite a very low virus titre. Full genomes of serum and CSF-derived viruses shared 99.99% similarity, indicating the virus dissemination across blood-brain barrier. Even though virus genomes did not reveal any of the neurotrophic substitutions of DENV documented so far, case isolates possessed a combination of 8 novel amino acid alterations, predominantly distributed in non-structural genes of DENV-4.


Assuntos
Vírus da Dengue/classificação , Dengue/virologia , Encefalite Viral/virologia , Insuficiência de Múltiplos Órgãos/virologia , Adulto , Anticorpos Antivirais/sangue , Dengue/complicações , Dengue/imunologia , Vírus da Dengue/genética , Vírus da Dengue/isolamento & purificação , Encefalite Viral/complicações , Evolução Fatal , Feminino , Humanos , Insuficiência de Múltiplos Órgãos/complicações , Filogenia , Proteínas do Envelope Viral/genética
12.
PLoS One ; 8(11): e81060, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24278377

RESUMO

OBJECTIVES: To identify demographic, clinical and laboratory risk factors for death due to dengue fever in adult patients in Singapore. METHODS: Multi-center retrospective study of hospitalized adult patients with confirmed dengue fever in Singapore between 1 January 2004 and 31 December 2008. Non-fatal controls were selected by matching age and year of infection with fatal cases. World Health Organization 1997, 2009 criteria were applied to define dengue hemorrhagic fever (DHF), warning signs and severe dengue. Statistical significance was assessed by conditional logistic regression modeling. RESULTS: Significantly more fatal cases than matched controls had pre-existing co-morbid conditions, and presented with abdominal pain/tenderness. Median pulse rates were significantly higher while myalgia was significantly less frequent in cases. . Fatal cases also had higher leucocyte counts, platelet counts, serum sodium, potassium, urea, creatine and bilirubin levels on admission compared to controls. There was no statistical significant difference between the prevalence of DHF and hematocrit level among cases and controls. Multivariate analysis showed myalgia and leucocyte count at presentation were independent predictors of fatality (adjusted odds ratios 0.09 and 2.94 respectively). None of the controls was admitted to intensive care unit (ICU) or given blood transfusion, while 71.4% and 28.6% of fatal cases received ICU admission and blood transfusion. CONCLUSIONS: Absence of myalgia and leucocytosis on admission were independently associated with fatality in our matched case-control study. Fatalities were also commonly associated with co-morbidities and clinicians should be alarmed if dengue patients fulfilled severe dengue case definition on admission.


Assuntos
Dengue/epidemiologia , Mortalidade Hospitalar , Pacientes Internados , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Comorbidade , Dengue/mortalidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Razão de Chances , Estudos Retrospectivos , Fatores de Risco , Singapura/epidemiologia , Adulto Jovem
13.
Vaccine ; 30(2): 329-35, 2012 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-22080174

RESUMO

A successful vaccine development strategy for areas with clustered H5N1 events requires conduct of vaccine trials in potentially non-naïve subjects and evaluation of post-vaccination responsiveness. An open-label, randomized, phase I/II study therefore assessed the immunogenicity and safety of two different dose levels of an inactivated, non-adjuvanted, whole virus clade 2.1 (A/Indonesia/05/2005) H5N1 Vero cell-derived influenza vaccine in healthy adults (21-45 years) from a region where the virus has been circulating (Hong Kong) as well as Singapore. Subjects (N=110) were randomized 1:1 to receive two vaccinations with either 3.75 µg or 7.5 µg H5N1 haemagglutinin antigen 21 days apart. Safety, immunogenicity (microneutralization [MN] and single radial haemolysis [SRH] at baseline and post-vaccination) and cross-reactivity against a heterologous clade 1 strain (A/Vietnam/1203/2004) of the vaccine were assessed. Pre-existing immunity to the vaccine strain was 14% which is higher than previously reported for these regions. Two vaccinations with either vaccine formulation induced high seroprotection rates (MN titre ≥ 1:20) against the vaccine strain A/Indonesia/05/2005: 82.7% and 86.5% in the 3.75 µg and 7.5 µg dose groups. Seroconversion rates and fold increase exceeded the CPMP criterion of >40% and >2.5 for MN and SRH in both dose groups after the second vaccination, while the seroprotection rate in the 7.5 µg dose group determined by SRH was only marginally lower (69.2%) than the CPMP criterion of >70%. Thus, 11 of 12 CHMP criteria were fulfilled. A cross-reactive antibody response against the heterologous A/Vietnam/1203/2004 strain was demonstrated after the second vaccination (>21% by MN and ≥ 25% by SRH). Persistence of antibodies against the vaccine strain was also demonstrated 6 months after the first vaccination, indicating that a booster vaccination would be effective in those who have received two priming doses. No serious adverse events were reported. The H5N1 influenza vaccine against clade 2.1 strain A/Indonesia/05/2005 was well tolerated and immunogenic after two vaccinations, and induced a cross-neutralizing antibody response, with no dose effect.


Assuntos
Virus da Influenza A Subtipo H5N1/imunologia , Vacinas contra Influenza/efeitos adversos , Vacinas contra Influenza/imunologia , Influenza Humana/prevenção & controle , Vacinação/métodos , Adulto , Animais , Anticorpos Antivirais/sangue , Chlorocebus aethiops , Reações Cruzadas , Hong Kong , Humanos , Imunoensaio , Virus da Influenza A Subtipo H5N1/crescimento & desenvolvimento , Vacinas contra Influenza/administração & dosagem , Influenza Humana/imunologia , Pessoa de Meia-Idade , Singapura , Vacinação/efeitos adversos , Células Vero
14.
Ann Acad Med Singap ; 39(6): 460-5, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20625622

RESUMO

INTRODUCTION: Urinary tract infections remain one of the most frequently encountered acquired complications in an intensive care unit (ICU). The objective of this study was to determine the incidence, risk factors, microbial sensitivity patterns, and clinical outcomes of patients with UTIs acquired during their admission to an ICU in an acute care hospital in Singapore. MATERIALS AND METHODS: This was a 14-week prospective study. All ICU patients > or =18 years who remained in the ICU for > or =48 hours were eligible for this study. Patients were reviewed daily and the presence of an ICU-acquired UTI was identified via urinary microscopic examination or culture results. Other data collected included patient demographics, ICU admission criteria, concomitant illnesses, presence of invasive lines, microbial sensitivity and treatment outcomes. RESULTS: Thirty-fi ve (13.7%) cases of ICU-acquired UTI occurred in 256 separate ICU admissions. The most common micro-organisms isolated were Candida spp. (34%). Female gender and prior exposure to antibiotics were independent risk factors for developing an ICU-acquired UTI (P <0.01). Both mean length of ICU stay and duration of catheterisation were significantly longer for patients with ICU-acquired UTI (P <0.001). The mortality rate of patients with ICU-acquired UTIs (12.1%) was slightly higher than those without (9.9%). CONCLUSIONS: The incidence of ICU-acquired UTIs was similar to figures reported for nosocomial UTIs from the previous studies. Significant risk factors for developing an ICU-acquired UTI were female gender and history of antibiotic exposure prior to ICU admission. The insignificant link between ICU-acquired UTI and mortality requires further investigation in larger cohorts.


Assuntos
Infecção Hospitalar , Unidades de Terapia Intensiva , Infecções Urinárias/epidemiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Avaliação de Resultados em Cuidados de Saúde , Estudos Prospectivos , Fatores de Risco , Singapura/epidemiologia , Infecções Urinárias/etiologia , Infecções Urinárias/fisiopatologia , Adulto Jovem
15.
J Infect Dis ; 200(7): 1113-8, 2009 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-19712040

RESUMO

Novel strategies are required to provide rapid vaccine coverage in the event of an influenza pandemic. A phase I/II dose finding/formulation study was performed with a whole-virus H5N1 clade 1 A/Vietnam vaccine (2-dose priming regimen) to evaluate safety and immunogenicity. Seventy-seven of 141 subjects in this study received a booster (12-17 months after priming) with a 7.5-microg dose of a clade 2.1 A/Indonesia vaccine. The prime-boost regimen resulted in antibody responses against clade 1, 2.1, 2.2, and 2.3 viruses that were significantly higher than those after the priming regimen. These findings demonstrate that a prime-boost regimen may alleviate vaccine supply constraints in a pandemic.


Assuntos
Virus da Influenza A Subtipo H5N1/imunologia , Vacinas contra Influenza/imunologia , Animais , Anticorpos Antivirais , Chlorocebus aethiops , Relação Dose-Resposta Imunológica , Humanos , Imunização Secundária , Memória Imunológica , Vacinas contra Influenza/administração & dosagem , Influenza Humana/prevenção & controle , Células Vero
16.
Scand J Infect Dis ; 39(4): 357-9, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17454903

RESUMO

Melioidosis is a bacterial infection caused by the Gram-negative bacillus Burkholderia pseudomallei. We report an unusual case of melioidosis that presented as a pyrexia of unknown origin complicated by pericardial effusion. Our patient received a 6-week course of intravenous antibiotics, followed by 8 months of oral antibiotics, and made a complete recovery. This report illustrates the diagnostic and therapeutic challenge that clinicians may encounter when faced with this potentially fatal infection.


Assuntos
Burkholderia pseudomallei/patogenicidade , Melioidose/complicações , Pericardite/etiologia , Combinação Amoxicilina e Clavulanato de Potássio/uso terapêutico , Antibacterianos/uso terapêutico , Burkholderia pseudomallei/efeitos dos fármacos , Doxiciclina/uso terapêutico , Quimioterapia Combinada , Ecocardiografia , Humanos , Imipenem/uso terapêutico , Masculino , Melioidose/imunologia , Melioidose/microbiologia , Pessoa de Meia-Idade , Pericardite/microbiologia , Pericardite/patologia
17.
Emerg Infect Dis ; 10(2): 261-4, 2004 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15030694

RESUMO

We describe an atypical presentation of severe acute respiratory syndrome (SARS) in a geriatric patient with multiple coexisting conditions. Interpretation of radiographic changes was confounded by cardiac failure, with resolution of fever causing delayed diagnosis and a cluster of cases. SARS should be considered even if a contact history is unavailable, during an ongoing outbreak.


Assuntos
Síndrome Respiratória Aguda Grave/diagnóstico , Idoso , Idoso de 80 Anos ou mais , Busca de Comunicante , Surtos de Doenças , Feminino , Humanos , Masculino , Radiografia Torácica , Síndrome Respiratória Aguda Grave/diagnóstico por imagem , Síndrome Respiratória Aguda Grave/epidemiologia , Síndrome Respiratória Aguda Grave/transmissão , Singapura
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