Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 77
Filtrar
1.
Lancet Infect Dis ; 23(12): 1383-1394, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37660711

RESUMO

BACKGROUND: A vaccine that prevents cytomegalovirus (CMV) infection in women could reduce the incidence of congenital CMV infection, a major cause of neurodevelopmental disability. We aimed to assess the safety and efficacy of a replication-defective investigational CMV vaccine, V160, in CMV-seronegative women. METHODS: This phase 2b, randomised, double-blind, placebo-controlled study was conducted at 90 sites in seven countries (USA, Finland, Canada, Israel, Spain, Russia, and Australia). Eligible participants were generally healthy, CMV-seronegative, non-pregnant, 16-35-year-old women of childbearing potential with exposure to children aged 5 years or younger. Participants were randomly assigned using central randomisation via an interactive response technology system 1:1:1 to one of three groups: V160 three-dose regimen (V160 at day 1, month 2, and month 6), V160 two-dose regimen (V160 on day 1, placebo at month 2, and V160 at month 6), or placebo (saline solution at day 1, month 2, and month 6). The primary outcomes were the efficacy of three doses of V160 in reducing the incidence of primary CMV infection during the follow-up period starting 30 days after the last dose of vaccine using a fixed event rate design, and the safety and tolerability of the two-dose and three-dose V160 regimens. We planned to test the efficacy of a two-dose regimen of V160 in reducing the incidence of primary CMV infection only if the primary efficacy hypothesis was met. Analyses for the primary efficacy endpoint were performed on the per-protocol efficacy population; safety analyses included all randomly assigned participants who received study vaccine. The primary efficacy hypothesis was tested at prespecified interim and final analyses. The study was ongoing and efficacy data continued to accrue at the time of final testing of the primary efficacy hypothesis. Vaccine efficacy was re-estimated after final testing of the primary efficacy hypothesis based on all available efficacy data at end of study. This trial is registered at ClinicalTrials.gov (NCT03486834) and EudraCT (2017-004233-86) and is complete. FINDINGS: Between April 30, 2018, and Aug 30, 2019, 7458 participants were screened, of whom 2220 were randomly assigned to the V160 three-dose group (n=733), V160 two-dose group (n=733), or placebo group (n=734). A total of 523 participants in the V160 three-dose group and 519 in the placebo group were included in the final hypothesis testing. Of these, there were 11 cases of CMV infection in the V160 three-dose group and 20 cases in the placebo group. The vaccine efficacy for the V160 three-dose group was 44·6% (95% CI -15·2 to 74·8) at the final testing of the primary efficacy hypothesis, a result corresponding to failure to demonstrate the primary efficacy hypothesis. On the basis of this result, the study was terminated for futility. The re-estimate of vaccine efficacy for the V160 three-dose group based on all available efficacy data at end of study (556 participants in the V160 three-dose group and 543 in the placebo group) was 42·4% (95% CI -13·5 to 71·1). A total of 728 participants in the V160 three-dose group, 729 in the V160 two-dose group, and 732 in the placebo group were included in the safety analyses. The most common solicited injection-site adverse event was injection-site pain (680 [93%] in the V160 three-dose group, 659 [90%] in the V160 two-dose group, and 232 [32%] in the placebo group). The most common solicited systemic adverse event was fatigue (457 [63%] in the V160 three-dose group, 461 [63%] in the V160 two-dose group, and 357 [49%] in the placebo group). No vaccine-related serious adverse events or deaths were reported. INTERPRETATION: V160 was generally well tolerated and immunogenic; however, three doses of the vaccine did not reduce the incidence of primary CMV infection in CMV-seronegative women compared with placebo. This study provides insights into the design of future CMV vaccine efficacy trials, particularly for the identification of CMV infection using molecular assays. FUNDING: Merck Sharp & Dohme, a subsidiary of Merck & Co, Rahway, NJ, USA (MSD).


Assuntos
Infecções por Citomegalovirus , Vacinas contra Citomegalovirus , Vacinas , Criança , Humanos , Feminino , Adolescente , Adulto Jovem , Adulto , Citomegalovirus , Imunização , Infecções por Citomegalovirus/prevenção & controle , Método Duplo-Cego , Imunogenicidade da Vacina
2.
Am J Trop Med Hyg ; 107(5): 1114-1128, 2022 11 14.
Artigo em Inglês | MEDLINE | ID: mdl-36162442

RESUMO

The objective of this study was to determine the etiology of febrile illnesses among patients from October 1, 1993 through September 30, 1999, in the urban community of Iquitos in the Amazon River Basin of Peru. Epidemiological and clinical data as well as blood samples were obtained from consenting patients at hospitals, health clinics and private residences. Samples were tested for arboviruses in cell cultures and for IgM and IgG antibodies by ELISA. Blood smears were examined for malaria, and sera were tested for antibodies to Leptospira spp. by ELISA and microscopic agglutination. Among 6,607 febrile patients studied, dengue viruses caused 14.6% of the cases, and Venezuelan equine encephalitis virus caused 2.5%, Oropouche virus 1.0%, Mayaro virus 0.4%, and other arboviruses caused 0.2% of the cases. Also, 22.9% of 4,844 patients tested were positive for malaria, and of 400 samples tested, 9% had evidence of acute leptospirosis. Although the study was not designed to assess the importance of these pathogens as a cause of human morbidity in the total population, these results indicate that arboviruses, leptospirosis, and malaria were the cause of approximately 50% of the febrile cases. Although the arboviruses that were diagnosed can produce asymptomatic infections, our findings increased the overall understanding of the relative health burden of these infections, as well as baseline knowledge needed for designing and implementing further studies to better assess the health impact and threat of these pathogens in the Amazon Basin of Peru.


Assuntos
Arbovírus , Vírus da Encefalite Equina Venezuelana , Leptospirose , Malária , Humanos , Peru/epidemiologia , Rios , Leptospirose/epidemiologia , Febre/epidemiologia
3.
Hum Vaccin Immunother ; 18(5): 2046960, 2022 11 30.
Artigo em Inglês | MEDLINE | ID: mdl-35290152

RESUMO

Dengue (DENV) is a mosquito-borne virus with four serotypes causing substantial morbidity in tropical and subtropical areas worldwide. V181 is an investigational, live, attenuated, quadrivalent dengue vaccine. In this phase 1 double-blind, placebo-controlled study, the safety, tolerability, and immunogenicity of V181 in baseline flavivirus-naïve (BFN) and flavivirus-experienced (BFE) healthy adults were evaluated in two formulations: TV003 and TV005. TV005 contains a 10-fold higher DENV2 level than TV003. Two-hundred adults were randomized 2:2:1 to receive TV003, TV005, or placebo on Days 1 and 180. Immunogenicity against the 4 DENV serotypes was measured using a Virus Reduction Neutralization Test (VRNT60) after each vaccination and out to 1 year after the second dose. There were no discontinuations due to adverse events (AE) or serious vaccine-related AEs in the study. Most common AEs after TV003 or TV005 were headache, rash, fatigue, and myalgia. Tri- or tetravalent vaccine-viremia was detected in 63.9% and 25.6% of BFN TV003 and TV005 participants, respectively, post-dose 1 (PD1). Tri- or tetravalent dengue VRNT60 seropositivity was demonstrated in 92.6% of BFN TV003, 74.2% of BFN TV005, and 100% of BFE TV003 and TV005 participants PD1. Increases in VRNT60 GMTs were observed after the first vaccination with TV003 and TV005 in both flavivirus subgroups for all dengue serotypes, and minimal increases were measured PD2. GMTs in the TV003 and TV005 BFE and BFN groups remained above the respective baselines and placebo through 1-year PD2. These data support further development of V181 as a single-dose vaccine for the prevention of dengue disease.


Assuntos
Vacinas contra Dengue , Vírus da Dengue , Dengue , Flavivirus , Adulto , Anticorpos Antivirais , Dengue/prevenção & controle , Método Duplo-Cego , Humanos , Imunogenicidade da Vacina , Vacinas Atenuadas , Vacinas Combinadas
4.
J Infect Dis ; 216(suppl_1): S114-S121, 2017 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-28838173

RESUMO

Background: Introduction of inactivated polio vaccine creates challenges in maintaining the cold chain for vaccine storage and distribution. Methods: We evaluated the cold chain in 23 health facilities and 36 outreach vaccination sessions in 8 districts and cities of Bangladesh, using purposive sampling during August-October 2015. We interviewed immunization and cold-chain staff, assessed equipment, and recorded temperatures during vaccine storage and transportation. Results: All health facilities had functioning refrigerators, and 96% had freezers. Temperature monitors were observed in all refrigerators and freezers but in only 14 of 66 vaccine transporters (21%). Recorders detected temperatures >8°C for >60 minutes in 5 of 23 refrigerators (22%), 3 of 6 cold boxes (50%) transporting vaccines from national to subnational depots, and 8 of 48 vaccine carriers (17%) used in outreach vaccination sites. Temperatures <2°C were detected in 4 of 19 cold boxes (21%) transporting vaccine from subnational depots to health facilities and 14 of 48 vaccine carriers (29%). Conclusions: Bangladesh has substantial cold-chain storage and transportation capacity after inactivated polio vaccine introduction, but temperature fluctuations during vaccine transport could cause vaccine potency loss that could go undetected. Bangladesh and other countries should strive to ensure consistent and sufficient cold-chain storage and monitor the cold chain during vaccine transportation at all levels.


Assuntos
Programas de Imunização , Vacina Antipólio de Vírus Inativado , Refrigeração , Bangladesh , Estabilidade de Medicamentos , Humanos , Programas de Imunização/organização & administração , Programas de Imunização/normas , Programas de Imunização/estatística & dados numéricos , Poliomielite/prevenção & controle , Vacina Antipólio de Vírus Inativado/química , Vacina Antipólio de Vírus Inativado/provisão & distribuição , Refrigeração/métodos , Refrigeração/normas , Refrigeração/estatística & dados numéricos , Meios de Transporte
6.
Clin Microbiol Rev ; 28(3): 743-800, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26085551

RESUMO

This comprehensive review outlines the impact of military-relevant respiratory infections, with special attention to recruit training environments, influenza pandemics in 1918 to 1919 and 2009 to 2010, and peacetime operations and conflicts in the past 25 years. Outbreaks and epidemiologic investigations of viral and bacterial infections among high-risk groups are presented, including (i) experience by recruits at training centers, (ii) impact on advanced trainees in special settings, (iii) morbidity sustained by shipboard personnel at sea, and (iv) experience of deployed personnel. Utilizing a pathogen-by-pathogen approach, we examine (i) epidemiology, (ii) impact in terms of morbidity and operational readiness, (iii) clinical presentation and outbreak potential, (iv) diagnostic modalities, (v) treatment approaches, and (vi) vaccine and other control measures. We also outline military-specific initiatives in (i) surveillance, (ii) vaccine development and policy, (iii) novel influenza and coronavirus diagnostic test development and surveillance methods, (iv) influenza virus transmission and severity prediction modeling efforts, and (v) evaluation and implementation of nonvaccine, nonpharmacologic interventions.


Assuntos
Militares , Infecções Respiratórias/epidemiologia , Infecções Respiratórias/prevenção & controle , Surtos de Doenças/estatística & dados numéricos , Humanos , Infecções Respiratórias/terapia , Estados Unidos , Vacinação/normas
7.
J Infect Dis ; 212(6): 871-80, 2015 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-25748322

RESUMO

BACKGROUND: The circulation of human adenovirus type 21 (HAdV21) in the United States has been documented since the 1960s in association with outbreaks of febrile respiratory illness (FRI) in military boot camps and civilian cases of respiratory disease. METHODS: To describe the molecular epidemiology of HAdV21 respiratory infections across the country, 150 clinical respiratory isolates obtained from continuous surveillance of military recruit FRI, and 23 respiratory isolates recovered from pediatric and adult civilian cases of acute respiratory infection were characterized to compile molecular typing data spanning 37 years (1978-2014). RESULTS: Restriction enzyme analysis and genomic sequencing identified 2 clusters of closely related genomic variants readily distinguishable from the prototype and designated 21a-like and 21b-like. A-like variants predominated until 1999. A shift to b-like variants was noticeable by 2007 after a 7-year period (2000-2006) of cocirculation of the 2 genome types. US strains are phylogenetically more closely related to European and Asian strains isolated over the last 4 decades than to the Saudi Arabian prototype strain AV-1645 isolated in 1956. CONCLUSIONS: Knowledge of circulating HAdV21 variants and their epidemic behavior will be of significant value to local and global FRI surveillance efforts.


Assuntos
Infecções por Adenoviridae/epidemiologia , Infecções por Adenoviridae/virologia , Adenovírus Humanos/classificação , Militares , Infecções Respiratórias/epidemiologia , Infecções Respiratórias/virologia , Adenovírus Humanos/genética , Adenovírus Humanos/isolamento & purificação , DNA Viral/genética , Surtos de Doenças , Variação Genética , Humanos , Epidemiologia Molecular , Reação em Cadeia da Polimerase , Vigilância da População , Fatores de Tempo , Estados Unidos/epidemiologia
8.
Vaccine ; 33(9): 1182-7, 2015 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-25579777

RESUMO

BACKGROUND: Streptococcus pneumoniae infections have periodically caused significant morbidity and outbreaks among military personnel, especially trainees. This study evaluated the effectiveness of the 23-valent polysaccharide pneumococcal vaccine (PPV23) in reducing pneumonia in healthy military trainees. METHODS: From 2000-2003, 152723 military trainees from 5 US training camps were enrolled in a double-blind, placebo-controlled trial of PPV23. Participants were closely monitored during basic training for radiographically confirmed pneumonia etiology and loss-of-training days. Participants were also followed using electronic medical encounter data until 1 June 2007 for three additional outcomes: any-cause pneumonia, any acute respiratory disease, and meningitis. RESULTS: Comparison of demographic data by study arm suggested the randomization procedures were sound. During basic training, 371 study participants developed radiographically confirmed pneumonia. None had evidence of S. pneumoniae infection, but other etiologies included adenovirus (38%), Chlamydophila pneumoniae (9%), and Mycoplasma pneumoniae (8%). During the follow-up period, many study participants, in both the vaccine and placebo groups, had clinical encounters for the medical outcomes of interest. However, Cox's proportional hazard modeling revealed no evidence of a protective vaccine effect during recruit training (radiographically confirmed pneumonia) or up to 6.7 years after enrollment (any-cause pneumonia, any acute respiratory disease, or meningitis). CONCLUSIONS: Data from this large, double-blind, placebo controlled trial do not support routine use of PPV23 among healthy new military trainees. This clinical trial was registered at clinicaltrials.gov (registration number NCT02079701, http://www.clinicaltrials.gov/ct2/show/NCT02079701?term=NCT02079701&rank=1).


Assuntos
Militares , Vacinas Pneumocócicas/administração & dosagem , Pneumonia/epidemiologia , Pneumonia/prevenção & controle , Adolescente , Adulto , Estudos de Coortes , Método Duplo-Cego , Feminino , Humanos , Incidência , Masculino , Placebos/administração & dosagem , Adulto Jovem
9.
PLoS One ; 9(10): e111222, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25329886

RESUMO

Electronic event-based biosurveillance systems (EEBS's) that use near real-time information from the internet are an increasingly important source of epidemiologic intelligence. However, there has not been a systematic assessment of EEBS evaluations, which could identify key uncertainties about current systems and guide EEBS development to most effectively exploit web-based information for biosurveillance. To conduct this assessment, we searched PubMed and Google Scholar to identify peer-reviewed evaluations of EEBS's. We included EEBS's that use publicly available internet information sources, cover events that are relevant to human health, and have global scope. To assess the publications using a common framework, we constructed a list of 17 EEBS attributes from published guidelines for evaluating health surveillance systems. We identified 11 EEBS's and 20 evaluations of these EEBS's. The number of published evaluations per EEBS ranged from 1 (Gen-Db, GODsN, MiTAP) to 8 (GPHIN, HealthMap). The median number of evaluation variables assessed per EEBS was 8 (range, 3-15). Ten published evaluations contained quantitative assessments of at least one key variable. No evaluations examined usefulness by identifying specific public health decisions, actions, or outcomes resulting from EEBS outputs. Future EEBS assessments should identify and discuss critical indicators of public health utility, especially the impact of EEBS's on public health response.


Assuntos
Biovigilância , Internet , Vigilância em Saúde Pública , Humanos , PubMed
10.
Clin Infect Dis ; 59(7): 962-8, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24991024

RESUMO

BACKGROUND: In late 2011, after a 12-year hiatus, oral vaccines against adenovirus types 4 (Ad4) and 7 (Ad7) were again produced and administered to US military recruits. This study examined the impact of the new adenovirus vaccines on febrile respiratory illness (FRI) and adenovirus rates and investigated if new serotypes emerged. FRI rates and their associated hospitalizations had markedly risen since vaccine production ceased in 1999. METHODS: From 1996 to 2013, the Naval Health Research Center conducted FRI surveillance at 8 military recruit training centers in the United States. During this period, 58 103 FRI pharyngeal swab specimens were studied, yielding 37 048 adenovirus-positive cases, among which 64% were typed. RESULTS: During the 2 years after reintroduction of the vaccines, military trainees experienced a 100-fold decline in adenovirus disease burden (from 5.8 to 0.02 cases per 1000 person-weeks, P < .0001), without evidence that vaccine pressure had increased the impact of adenovirus types other than Ad4 and Ad7. Although the percentage of type 14 increased following reintroduction of the vaccination, the actual number of cases decreased. We estimate that the vaccines prevent approximately 1 death, 1100-2700 hospitalizations, and 13 000 febrile adenovirus cases each year among the trainees. CONCLUSIONS: These data strongly support the continued production and use of Ad4 and Ad7 vaccines in controlling FRI among US military trainees. Continued surveillance for emerging adenovirus subtypes is warranted.


Assuntos
Vacinas contra Adenovirus/administração & dosagem , Vacinas contra Adenovirus/imunologia , Militares , Infecções Respiratórias/epidemiologia , Infecções Respiratórias/prevenção & controle , Humanos , Incidência , Estados Unidos/epidemiologia
12.
US Army Med Dep J ; : 7-18, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23584903

RESUMO

In its 15th year, the Global Emerging Infections Surveillance and Response System (GEIS) continued to make significant contributions to global public health and emerging infectious disease surveillance worldwide. As a division of the US Department of Defense's Armed Forces Health Surveillance Center since 2008, GEIS coordinated a network of surveillance and response activities through collaborations with 33 partners in 76 countries. The GEIS was involved in 73 outbreak responses in fiscal year 2011. Significant laboratory capacity-building initiatives were undertaken with 53 foreign health, agriculture and/or defense ministries, as well as with other US government entities and international institutions, including support for numerous national influenza centers. Equally important, a variety of epidemiologic training endeavors reached over 4,500 individuals in 96 countries. Collectively, these activities enhanced the ability of partner countries and the US military to make decisions about biological threats and design programs to protect global public health as well as global health security.


Assuntos
Controle de Doenças Transmissíveis/organização & administração , Doenças Transmissíveis Emergentes/epidemiologia , Surtos de Doenças , Saúde Global , Medicina Militar/organização & administração , Vigilância de Evento Sentinela , Fortalecimento Institucional , Humanos , Laboratórios , Objetivos Organizacionais , Prevalência , Estados Unidos , United States Department of Defense
13.
Vaccine ; 31(28): 2963-71, 2013 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-23623865

RESUMO

Adenovirus (ADV) types 4 (ADV-4) and 7 (ADV-7) are presently the major cause of febrile acute respiratory disease (ARD) in U.S. military recruits. We conducted a multi-center, randomized, double-blind, placebo-controlled phase 3 study of the new vaccine to assess its safety and efficacy. Healthy adults at two basic training sites were randomly assigned to receive either vaccine (two enteric-coated tablets consisting of no less than 4.5 log10 TCID50 of live ADV-4 or ADV-7) or placebo in a 3:1 ratio. Volunteers were observed throughout the approximate eight weeks of their basic training and also returned for four scheduled visits. The primary endpoints were prevention of febrile ARD due to ADV-4 and seroconversion of neutralizing serum antibodies to ADV-7, which was not expected to circulate in the study population during the course of the trial. A total of 4151 volunteers were enrolled and 4040 (97%) were randomized and included in the primary analysis (110 were removed prior to randomization and one was removed after randomization due to inability to swallow tablets). A total of 49 ADV-4 febrile ARD cases were identified with 48 in the placebo group and 1 in the vaccine group (attack rates of 4.76% and 0.03%, respectively). Vaccine efficacy was 99.3% (95% CI, 96.0-99.9; P<0.001). Seroconversion rates for vaccine recipients for ADV-4 and ADV-7 were 94.5% (95% CI, 93.4-95.5%) and 93.8% (95% CI: 93.4-95.2%), respectively. The vaccine was well tolerated as compared to placebo. We conclude that the new live, oral ADV-4 and ADV-7 vaccine is safe and effective for use in groups represented by the study population.


Assuntos
Infecções por Adenovirus Humanos/prevenção & controle , Vacinas contra Adenovirus/imunologia , Adenovírus Humanos/imunologia , Infecções Respiratórias/prevenção & controle , Doença Aguda , Infecções por Adenovirus Humanos/imunologia , Vacinas contra Adenovirus/administração & dosagem , Vacinas contra Adenovirus/efeitos adversos , Administração Oral , Adulto , Método Duplo-Cego , Feminino , Humanos , Masculino , Militares , Infecções Respiratórias/imunologia , Adulto Jovem
14.
PLoS One ; 7(7): e41435, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22859985

RESUMO

INTRODUCTION: Following the 2009 influenza A/H1N1 (pH1N1) pandemic, both seasonal and pH1N1 viruses circulated in the US during the 2010-2011 influenza season; influenza vaccine effectiveness (VE) may vary between live attenuated (LAIV) and trivalent inactivated (TIV) vaccines as well as by virus subtype. MATERIALS AND METHODS: Vaccine type and virus subtype-specific VE were determined for US military active component personnel for the period of September 1, 2010 through April 30, 2011. Laboratory-confirmed influenza-related medical encounters were compared to matched individuals with a non-respiratory illness (healthy controls), and unmatched individuals who experienced a non-influenza respiratory illness (test-negative controls). Odds ratios (OR) and VE estimates were calculated overall, by vaccine type and influenza subtype. RESULTS: A total of 603 influenza cases were identified. Overall VE was relatively low and similar regardless of whether healthy controls (VE = 26%, 95% CI: -1 to 45) or test-negative controls (VE = 29%, 95% CI: -6 to 53) were used as comparison groups. Using test-negative controls, vaccine type-specific VE was found to be higher for TIV (53%, 95% CI: 25 to 71) than for LAIV (VE = -13%, 95% CI: -77 to 27). Influenza subtype-specific analyses revealed moderate protection against A/H3 (VE = 58%, 95% CI: 21 to 78), but not against A/H1 (VE = -38%, 95% CI: -211 to 39) or B (VE = 34%, 95% CI: -122 to 80). CONCLUSION: Overall, a low level of protection against clinically-apparent, laboratory-confirmed, influenza was found for the 2010-11 seasonal influenza vaccines. TIV immunization was associated with higher protection than LAIV, however, no protection against A/H1 was noted, despite inclusion of a pandemic influenza strain as a vaccine component for two consecutive years. Vaccine virus mismatch or lower immunogenicity may have contributed to these findings and deserve further examination in controlled studies. Continued assessment of VE in military personnel is essential in order to better inform vaccination policy decisions.


Assuntos
Vírus da Influenza A/imunologia , Vacinas contra Influenza/administração & dosagem , Influenza Humana/prevenção & controle , Militares , Adulto , Estudos de Casos e Controles , Feminino , Humanos , Influenza Humana/imunologia , Influenza Humana/virologia , Masculino , Vacinação em Massa , Estados Unidos , Vacinas Atenuadas/administração & dosagem , Vacinas de Produtos Inativados/administração & dosagem , Adulto Jovem
15.
PLoS Negl Trop Dis ; 6(1): e1465, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22292093

RESUMO

BACKGROUND: Recent clusters of outbreaks of mosquito-borne diseases (Rift Valley fever and chikungunya) in Africa and parts of the Indian Ocean islands illustrate how interannual climate variability influences the changing risk patterns of disease outbreaks. Although Rift Valley fever outbreaks have been known to follow periods of above-normal rainfall, the timing of the outbreak events has largely been unknown. Similarly, there is inadequate knowledge on climate drivers of chikungunya outbreaks. We analyze a variety of climate and satellite-derived vegetation measurements to explain the coupling between patterns of climate variability and disease outbreaks of Rift Valley fever and chikungunya. METHODS AND FINDINGS: We derived a teleconnections map by correlating long-term monthly global precipitation data with the NINO3.4 sea surface temperature (SST) anomaly index. This map identifies regional hot-spots where rainfall variability may have an influence on the ecology of vector borne disease. Among the regions are Eastern and Southern Africa where outbreaks of chikungunya and Rift Valley fever occurred 2004-2009. Chikungunya and Rift Valley fever case locations were mapped to corresponding climate data anomalies to understand associations between specific anomaly patterns in ecological and climate variables and disease outbreak patterns through space and time. From these maps we explored associations among Rift Valley fever disease occurrence locations and cumulative rainfall and vegetation index anomalies. We illustrated the time lag between the driving climate conditions and the timing of the first case of Rift Valley fever. Results showed that reported outbreaks of Rift Valley fever occurred after ∼3-4 months of sustained above-normal rainfall and associated green-up in vegetation, conditions ideal for Rift Valley fever mosquito vectors. For chikungunya we explored associations among surface air temperature, precipitation anomalies, and chikungunya outbreak locations. We found that chikungunya outbreaks occurred under conditions of anomalously high temperatures and drought over Eastern Africa. However, in Southeast Asia, chikungunya outbreaks were negatively correlated (p<0.05) with drought conditions, but positively correlated with warmer-than-normal temperatures and rainfall. CONCLUSIONS/SIGNIFICANCE: Extremes in climate conditions forced by the El Niño/Southern Oscillation (ENSO) lead to severe droughts or floods, ideal ecological conditions for disease vectors to emerge, and may result in epizootics and epidemics of Rift Valley fever and chikungunya. However, the immune status of livestock (Rift Valley fever) and human (chikungunya) populations is a factor that is largely unknown but very likely plays a role in the spatial-temporal patterns of these disease outbreaks. As the frequency and severity of extremes in climate increase, the potential for globalization of vectors and disease is likely to accelerate. Understanding the underlying patterns of global and regional climate variability and their impacts on ecological drivers of vector-borne diseases is critical in long-range planning of appropriate disease and disease-vector response, control, and mitigation strategies.


Assuntos
Infecções por Alphavirus/epidemiologia , Infecções por Alphavirus/veterinária , Clima , Surtos de Doenças , Febre do Vale de Rift/epidemiologia , Febre do Vale de Rift/veterinária , África Oriental/epidemiologia , África Austral/epidemiologia , Animais , Febre de Chikungunya , Humanos , Telemetria
16.
PLoS Negl Trop Dis ; 6(2): e1472, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22363822

RESUMO

BACKGROUND: Knowledge of spatial patterns of dengue virus (DENV) infection is important for understanding transmission dynamics and guiding effective disease prevention strategies. Because movement of infected humans and mosquito vectors plays a role in the spread and persistence of virus, spatial dimensions of transmission can range from small household foci to large community clusters. Current understanding is limited because past analyses emphasized clinically apparent illness and did not account for the potentially large proportion of inapparent infections. In this study we analyzed both clinically apparent and overall infections to determine the extent of clustering among human DENV infections. METHODOLOGY/PRINCIPAL FINDINGS: We conducted spatial analyses at global and local scales, using acute case and seroconversion data from a prospective longitudinal cohort in Iquitos, Peru, from 1999-2003. Our study began during a period of interepidemic DENV-1 and DENV-2 transmission and transitioned to epidemic DENV-3 transmission. Infection status was determined by seroconversion based on plaque neutralization testing of sequential blood samples taken at approximately six-month intervals, with date of infection assigned as the middate between paired samples. Each year was divided into three distinct seasonal periods of DENV transmission. Spatial heterogeneity was detected in baseline seroprevalence for DENV-1 and DENV-2. Cumulative DENV-3 seroprevalence calculated by trimester from 2001-2003 was spatially similar to preexisting DENV-1 and DENV-2 seroprevalence. Global clustering (case-control Ripley's K statistic) appeared at radii of ∼200-800 m. Local analyses (Kuldorf spatial scan statistic) identified eight DENV-1 and 15 DENV-3 clusters from 1999-2003. The number of seroconversions per cluster ranged from 3-34 with radii from zero (a single household) to 750 m; 65% of clusters had radii >100 m. No clustering was detected among clinically apparent infections. CONCLUSIONS/SIGNIFICANCE: Seroprevalence of previously circulating DENV serotypes can be a predictor of transmission risk for a different invading serotype and, thus, identify targets for strategically placed surveillance and intervention. Seroprevalence of a specific serotype is also important, but does not preclude other contributing factors, such as mosquito density, in determining where transmission of that virus will occur. Regardless of the epidemiological context or virus serotype, human movement appears to be an important factor in defining the spatial dimensions of DENV transmission and, thus, should be considered in the design and evaluation of surveillance and intervention strategies.


Assuntos
Análise por Conglomerados , Vírus da Dengue/classificação , Vírus da Dengue/isolamento & purificação , Dengue/epidemiologia , Dengue/transmissão , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Criança , Pré-Escolar , Estudos de Coortes , Dengue/virologia , Vírus da Dengue/genética , Feminino , Geografia , Humanos , Lactente , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Testes de Neutralização , Peru/epidemiologia , Estudos Prospectivos , Estudos Soroepidemiológicos , Sorotipagem , Ensaio de Placa Viral , Adulto Jovem
17.
Am J Prev Med ; 41(6): 573-80, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22099233

RESUMO

BACKGROUND: Respiratory illnesses can cause substantial morbidity during military deployments. Bordetella pertussis, Chlamydia pneumoniae, Mycoplasma pneumoniae, adenovirus, parainfluenza, and respiratory syncytial virus (RSV) are hypothesized causes. PURPOSE: To determine pathogen-specific seroprevalence prior to and after deployment in support of Operation Enduring Freedom (OEF). METHODS: A retrospective cohort study of 1000 service members deployed between June 30, 2004, and June 30, 2007, was conducted from 2008 through 2009. Pre- and post-deployment sera were tested for the presence of antibody to each pathogen. RESULTS: Pre-deployment IgG seropositivity was high for adenovirus, RSV, and parainfluenza (98.7%, 97.8%, and 81.6%, respectively), whereas seropositivity for B. pertussis, M. pneumoniae, and C. pneumoniae was 14.2%, 21.9%, and 65.1%, respectively. As defined by seroconversion in 1000 subjects, the following were identified: 43 new parainfluenza infections (24% of susceptibles); 37 new pertussis infections (4% of susceptibles); 33 new C. pneumoniae infections (10% of susceptibles); and 29 new M. pneumoniae infections (4% of susceptibles). B. pertussis seroconversion was two to four times higher than reports for the general U.S. population. Overall, 14.2% of the service members seroconverted to at least one of these six pathogens; this increased to 30.1% seroconversion when influenza was included. However, serologic testing was not clearly associated with clinical illness in this report. CONCLUSIONS: Serologic evidence for respiratory infections was common among the 2004-2007 OEF-deployed military, sometimes at a higher rate than the general U.S. population. Awareness of this risk and implementation of preventive measures should be emphasized by leadership prior to and during deployment.


Assuntos
Campanha Afegã de 2001- , Militares , Infecções Respiratórias/epidemiologia , Adolescente , Adulto , Estudos de Coortes , Feminino , Humanos , Imunoglobulina G/sangue , Masculino , Infecções Respiratórias/microbiologia , Infecções Respiratórias/virologia , Estudos Retrospectivos , Estudos Soroepidemiológicos , Testes Sorológicos , Estados Unidos/epidemiologia , Adulto Jovem
18.
PLoS One ; 6(10): e25308, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21991307

RESUMO

When introduced in the 1950s, benzathine penicillin G (BPG) was shown to be effective in eradicating group A beta-hemolytic streptococcus (GAS) for at least 3 weeks after administration. Several studies since the 1990s suggest that at 3-4 weeks serum penicillin G levels are less than adequate (below MIC(90) of 0.016 µg/ml). We studied these levels for 4 weeks after the recommended dose of BPG in military recruits, for whom it is used as prophylaxis against GAS. The 329 subjects (mean age 20 years) each received 1.2 million units BPG IM and gave sera 1 day post injection and twice more at staggered time points over 4 weeks. Serum penicillin G levels were measured by liquid chromatography/tandem mass spectometry. The half-life of serum penicillin G was 4.1 days. By day 11, mean levels were <0.02 µg/ml, and by day 15<0.01 µg/ml. Levels in more than 50% of the subjects were below 0.02 µg/ml on day 9, and <.01 µg/ml on day 16. There was no demonstrable effect of subject body-surface area nor of the four different lots of BPG used. These data indicate that in healthy young adults serum penicillin G levels become less than protective <2½ weeks after injection of 1.2 million units of BPG. The findings require serious consideration in future medical and public health recommendations for treatment and prophylaxis of GAS upper respiratory tract infections.


Assuntos
Penicilina G/administração & dosagem , Penicilina G/sangue , Adolescente , Adulto , Intervalos de Confiança , Demografia , Relação Dose-Resposta a Droga , Humanos , Injeções Intramusculares , Masculino , Adulto Jovem
20.
BMC Public Health ; 11 Suppl 2: S2, 2011 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-21388562

RESUMO

The Armed Forces Health Surveillance Center, Global Emerging Infections Surveillance and Response System (AFHSC-GEIS) has the mission of performing surveillance for emerging infectious diseases that could affect the United States (U.S.) military. This mission is accomplished by orchestrating a global portfolio of surveillance projects, capacity-building efforts, outbreak investigations and training exercises. In 2009, this portfolio involved 39 funded partners, impacting 92 countries. This article discusses the current biosurveillance landscape, programmatic details of organization and implementation, and key contributions to force health protection and global public health in 2009.


Assuntos
Controle de Doenças Transmissíveis , Surtos de Doenças/prevenção & controle , Medicina Militar , Saúde Pública , Vigilância de Evento Sentinela , Controle de Doenças Transmissíveis/métodos , Controle de Doenças Transmissíveis/organização & administração , Órgãos Governamentais , Humanos , Medicina Militar/organização & administração , Militares , Vigilância da População , Administração em Saúde Pública , Estados Unidos , United States Department of Defense
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...