Dengue is the most prevalent arboviral disease of humans. The host and virus variables associated with dengue virus (DENV) transmission from symptomatic dengue cases (n = 208) to Aedes aegypti mosquitoes during 407 independent exposure events was defined. The 50% mosquito infectious dose for each of DENV-1-4 ranged from 6.29 to 7.52 log10 RNA copies/mL of plasma. Increasing day of illness, declining viremia, and rising antibody titers were independently associated with reduced risk of DENV transmission. High early DENV plasma viremia levels in patients were a marker of the duration of human infectiousness, and blood meals containing high concentrations of DENV were positively associated with the prevalence of infectious mosquitoes 14 d after blood feeding. Ambulatory dengue cases had lower viremia levels compared with hospitalized dengue cases but nonetheless at levels predicted to be infectious to mosquitoes. These data define serotype-specific viremia levels that vaccines or drugs must inhibit to prevent DENV transmission.engue is globally the most important mosquito-borne viral disease of humans, with a global burden of ∼100 million cases per annum (1, 2). Aedes aegypti mosquitoes are the primary mosquito vectors of dengue viruses (DENV), of which there are four virus types (DENV-1-4). Multiple factors influence the likelihood of infection and dissemination of DENV in Ae. aegypti and include the amplitude of daily temperature fluctuations (3), mean temperature (4), and the genotype of mosquito and virus (5), among others (6). The extrinsic incubation period (EIP), a critical determinant of vector competence (7,8), is widely accepted to be 7-14 d for DENV in Ae. aegypti, although a recent modeling analysis of historical DENV transmission data has suggested a wider range of 2-15 d at 30°C (9). A major caveat to many of these observations is that they stem from laboratory experiments with artificially generated virus-spiked blood meals and often in-bred colony mosquitoes.The temporal and virological variables associated with the transmission of DENV from a naturally infected human to a biting Ae. aegypti mosquito are poorly understood. Natural history studies of experimental DENV infection of small cohorts of human volunteers in the 1920s by Siler et al. (10,11), likely using DENV-4 (12), and subsequent studies by Simmons et al. (13), likely using DENV-1 (12), suggested that the window of time before the onset of clinical symptoms that DENV-1 or DENV-4 could be transmitted to Ae. aegypti mosquitoes was 6-18 h or 2 d, respectively (14). After fever onset, the duration of infectiousness was 4-5 d for DENV-1 and up to 2 d for DENV-4, with an EIP in the mosquito of 10 d or more. Consistent with this, mosquitobiting studies by Gubler et al. in the 1960s (15-18) collectively estimated that dengue cases were infectious for 4-5 d after illness onset (range, 2-12 d). The human viremia level required to infect Ae. aegypti mosquitoes is unknown, and therefore it is uncertain what percentage of symptomatic (or asymptomatic...

Background-Coronary heart disease is the leading cause of morbidity and mortality in American men and women.Although there have been dramatic changes in the management of patients hospitalized with acute myocardial infarction (AMI) over the past several decades, a considerable proportion of patients with AMI continue to delay seeking medical care in a timely manner. This review provides an overview of the published literature that has examined age and sex differences in extent of prehospital delay in patients hospitalized with AMI. Methods and Results-A systematic review of the literature from 1960 to 2008, including publications that provided data on duration of prehospital delay in patients hospitalized with AMI, was conducted. A total of 44 articles (42 studies) were included in the present analysis. The majority of studies showed that in patients hospitalized with AMI, women and older persons were more likely to arrive at the hospital later than men and younger persons. Several factors associated with duration of prehospital delay, including sociodemographic, medical history, clinical, and contextual characteristics differed according to sex. Conclusions-The elderly and women were more likely to exhibit longer delays in seeking medical care after the development of symptoms suggestive of AMI compared with other groups. Further research is needed to more fully understand the reasons for delay in these vulnerable groups. (Circ Cardiovasc Qual Outcomes. 2010;3:82-92.)

Each year, ~800 000 people undergo CABG worldwide; >264 000 will develop post-CABG AF. Onset is typically 2-3 days post-CABG and episodes last, on average, several hours. Effective prophylaxis and management is urgently needed to reduce associated risks of adverse outcomes.

BackgroundVietnam is experiencing an epidemiologic transition with an increased prevalence of non-communicable diseases. Novel, large-scale, effective, and sustainable interventions to control hypertension in Vietnam are needed. We report the results of a cluster-randomized feasibility trial at 3 months follow-up conducted in Hung Yen province, Vietnam, designed to evaluate the feasibility and acceptability of two community-based interventions to improve hypertension control: a “storytelling” intervention, “We Talk about Our Hypertension,” and a didactic intervention.MethodsThe storytelling intervention included stories about strategies for coping with hypertension, with patients speaking in their own words, and didactic content about the importance of healthy lifestyle behaviors including salt reduction and exercise. The didactic intervention included only didactic content. The storytelling intervention was delivered by two DVDs at 3-month intervals; the didactic intervention included only one installment. The trial was conducted in four communes, equally randomized to the two interventions.ResultsThe mean age of the 160 study patients was 66 years, and 54% were men. Most participants described both interventions as understandable, informative, and motivational. Between baseline and 3 months, mean systolic blood pressure declined by 8.2 mmHg (95% CI 4.1–12.2) in the storytelling group and by 5.5 mmHg (95% CI 1.4–9.5) in the didactic group. The storytelling group also reported a significant increase in hypertension medication adherence.ConclusionsBoth interventions were well accepted in several rural communities and were shown to be potentially effective in lowering blood pressure. A large-scale randomized trial is needed to compare the effectiveness of the two interventions in controlling hypertension.Trial registrationClinicalTrials.gov, NCT02483780

Background-The prompt administration of coronary reperfusion therapy for patients with an evolving acute myocardial infarction (AMI) is crucial in reducing mortality and the risk of serious clinical complications in these patients. However, long-term trends in extent of prehospital delay and factors affecting patient's care-seeking behavior remain relatively unexplored, especially in men and women of different ages. The objectives of this study were to examine the overall magnitude and 20-year trends (1986 to 2005) in duration of prehospital delay in middle-aged and elderly men and women hospitalized with AMI. Methods and Results-The study sample consisted of 5967 residents of the Worcester, Mass, metropolitan area hospitalized at all greater Worcester medical centers for AMI between 1986 and 2005 who had information available about duration of prehospital delay. Compared with men Ͻ65 years, patients in other age-sex strata exhibited longer prehospital delays over the 20-year period under study. The multivariable-adjusted medians of prehospital delay were 1.96, 2.07, and 2.57 hours for men Ͻ65 years, men 65 to 74 years, and men Ն75 years and 2.08, 2.33, and 2.27 hours for women Ͻ65 years, women 65 to 74 years, and women Ն75 years, respectively. These age and sex differences have narrowed over time, which has been largely explained by changes in patient's comorbidity profile and AMI-associated characteristics. Conclusions-Our results suggest that duration of prehospital delay in persons with symptoms of AMI has remained essentially unchanged during the 20-year period under study and elderly individuals are more likely to delay seeking timely medical care than younger persons. (Circ Cardiovasc Qual Outcomes. 2010;3:590-598.)Key Words: prehospital delay Ⅲ acute myocardial infarction Ⅲ age and sex differences T he prompt administration of reperfusion therapy to patients with an evolving acute myocardial infarction (AMI) can be crucial to reducing mortality and serious complications in these patients. Results from prior studies have shown that reperfusion treatment is most effective if patients with ST-segment elevation-myocardial infarction are treated promptly, particularly within 1 hour of acute symptom onset. 1,2 Although an association between extent of prehospital delay and outcomes after non-ST-segment elevationmyocardial infarction has not been firmly established, it is assumed that earlier evaluation and treatment of these patients would be preferable.Despite the importance of seeking medical care as soon as possible after the onset of acute coronary symptoms, upward of one half of patients with AMI delay seeking medical care by more than 2 hours, 3,4 and upward of one quarter of patients with AMI delay seeking care by more than 6 hours. [3][4][5] Several previous studies have also suggested that extent of prehospital delay is associated with delays in the receipt of effective hospital therapies, 4,6 primarily coronary reperfusion therapy.Although considerable efforts have been expended to educate patients ...

Background:National Malaria Control Programmes (NMCPs) currently make limited use of parasite genetic data. We have developed GenRe-Mekong, a platform for genetic surveillance of malaria in the Greater Mekong Subregion (GMS) that enables NMCPs to implement large-scale surveillance projects by integrating simple sample collection procedures in routine public health procedures.Methods:Samples from symptomatic patients are processed by SpotMalaria, a high-throughput system that produces a comprehensive set of genotypes comprising several drug resistance markers, species markers and a genomic barcode. GenRe-Mekong delivers Genetic Report Cards, a compendium of genotypes and phenotype predictions used to map prevalence of resistance to multiple drugs.Results:GenRe-Mekong has worked with NMCPs and research projects in eight countries, processing 9623 samples from clinical cases. Monitoring resistance markers has been valuable for tracking the rapid spread of parasites resistant to the dihydroartemisinin-piperaquine combination therapy. In Vietnam and Laos, GenRe-Mekong data have provided novel knowledge about the spread of these resistant strains into previously unaffected provinces, informing decision-making by NMCPs.Conclusions:GenRe-Mekong provides detailed knowledge about drug resistance at a local level, and facilitates data sharing at a regional level, enabling cross-border resistance monitoring and providing the public health community with valuable insights. The project provides a rich open data resource to benefit the entire malaria community.Funding:The GenRe-Mekong project is funded by the Bill and Melinda Gates Foundation (OPP11188166, OPP1204268). Genotyping and sequencing were funded by the Wellcome Trust (098051, 206194, 203141, 090770, 204911, 106698/B/14/Z) and Medical Research Council (G0600718). A proportion of samples were collected with the support of the UK Department for International Development (201900, M006212), and Intramural Research Program of the National Institute of Allergy and Infectious Diseases.

BackgroundThe objectives of this community-based study were to examine the overall and changing (1990–2007) frequency and impact on 30-day and 1-year death rates from multiple cardiovascular comorbidities in adults from a large central New England metropolitan area hospitalized with acute myocardial infarction (AMI).MethodsThe study population consisted of 9581 patients hospitalized with AMI at all 11 medical centers in the metropolitan area of Worcester, MA, during 10 annual periods between 1990 and 2007. The comorbidities examined included atrial fibrillation, diabetes, heart failure, hypertension, and stroke.ResultsThirty-five percent of participants had a single diagnosed cardiovascular comorbidity, 25% had two, 12% had three, and 5% had four or more comorbidities. Between 1990 and 2007, the proportion of patients without any of these comorbidities decreased significantly, while the proportion of patients with multiple comorbidities increased significantly during the years under study. An increasing number of comorbidities was associated with higher 30-day and 1-year postadmission death rates in patients hospitalized with AMI.ConclusionPatients hospitalized with AMI carry a significant burden of comorbid cardiovascular disease that adversely impacts their 30-day and longer-term survival. Increased attention to the management of AMI patients with multiple cardiovascular comorbidities is warranted.

Aedes albopictus is secondary to Aedes aegypti as a vector of dengue viruses (DENVs) in settings of endemicity, but it plays an important role in areas of dengue emergence. This study compared the susceptibility of these 2 species to DENV infection by performing 232 direct blood-feeding experiments on 118 viremic patients with dengue in Vietnam. Field-derived A. albopictus acquired DENV infections as readily as A. aegypti after blood feeding. Once infected, A. albopictus permitted higher concentrations of DENV RNA to accumulate in abdominal tissues, compared with A. aegypti. However, the odds of A. albopictus having infectious saliva were lower than the odds observed for A. aegypti (odds ratio, 0.70; 95% confidence interval, .52–.93). These results quantitate the susceptibility of A. albopictus to DENV infection and will assist parameterization of models for predicting disease risk in settings where A. albopictus is present.