Zika virus evolution and spread in the Americas.

Although the recent Zika virus (ZIKV) epidemic in the Americas and its link to birth defects have attracted a great deal of attention, much remains unknown about ZIKV disease epidemiology and ZIKV evolution, in part owing to a lack of genomic data. Here we address this gap in knowledge by using multiple sequencing approaches to generate 110 ZIKV genomes from clinical and mosquito samples from 10 countries and territories, greatly expanding the observed viral genetic diversity from this outbreak. We analysed the timing and patterns of introductions into distinct geographic regions; our phylogenetic evidence suggests rapid expansion of the outbreak in Brazil and multiple introductions of outbreak strains into Puerto Rico, Honduras, Colombia, other Caribbean islands, and the continental United States. We find that ZIKV circulated undetected in multiple regions for many months before the first locally transmitted cases were confirmed, highlighting the importance of surveillance of viral infections. We identify mutations with possible functional implications for ZIKV biology and pathogenesis, as well as those that might be relevant to the effectiveness of diagnostic tests.

Symptomatic Dengue in Children in 10 Asian and Latin American Countries.

BACKGROUND: The control groups in two phase 3 trials of dengue vaccine efficacy included two large regional cohorts that were followed up for dengue infection. These cohorts provided a sample for epidemiologic analyses of symptomatic dengue in children across 10 countries in Southeast Asia and Latin America in which dengue is endemic. METHODS: We monitored acute febrile illness and virologically confirmed dengue (VCD) in 3424 healthy children, 2 to 16 years of age, in Asia (Indonesia, Malaysia, the Philippines, Thailand, and Vietnam) from June 2011 through December 2013 and in 6939 children, 9 to 18 years of age, in Latin America (Brazil, Colombia, Honduras, Mexico, and Puerto Rico) from June 2011 through April 2014. Acute febrile episodes were determined to be VCD by means of a nonstructural protein 1 antigen immunoassay and reverse-transcriptase-polymerase-chain-reaction assays. Dengue hemorrhagic fever was defined according to 1997 World Health Organization criteria. RESULTS: Approximately 10% of the febrile episodes in each cohort were confirmed to be VCD, with 319 VCD episodes (4.6 episodes per 100 person-years) occurring in the Asian cohort and 389 VCD episodes (2.9 episodes per 100 person-years) occurring in the Latin American cohort; no trend according to age group was observed. The incidence of dengue hemorrhagic fever was less than 0.3 episodes per 100 person-years in each cohort. The percentage of VCD episodes requiring hospitalization was 19.1% in the Asian cohort and 11.1% in the Latin American cohort. In comparable age groups (9 to 12 years and 13 to 16 years), the burden of dengue was higher in Asia than in Latin America. CONCLUSIONS: The burdens of dengue were substantial in the two regions and in all age groups. Burdens varied widely according to country, but the rates were generally higher and the disease more frequently severe in Asian countries than in Latin American countries. (Funded by Sanofi Pasteur; CYD14 and CYD15 ClinicalTrials.gov numbers, NCT01373281 and NCT01374516.).

Study protocol for the multicentre cohorts of Zika virus infection in pregnant women, infants, and acute clinical cases in Latin America and the Caribbean: the ZIKAlliance consortium.

BACKGROUND: The European Commission (EC) Horizon 2020 (H2020)-funded ZIKAlliance Consortium designed a multicentre study including pregnant women (PW), children (CH) and natural history (NH) cohorts. Clinical sites were selected over a wide geographic range within Latin America and the Caribbean, taking into account the dynamic course of the ZIKV epidemic. METHODS: Recruitment to the PW cohort will take place in antenatal care clinics. PW will be enrolled regardless of symptoms and followed over the course of pregnancy, approximately every 4 weeks. PW will be revisited at delivery (or after miscarriage/abortion) to assess birth outcomes, including microcephaly and other congenital abnormalities according to the evolving definition of congenital Zika syndrome (CZS). After birth, children will be followed for 2 years in the CH cohort. Follow-up visits are scheduled at ages 1-3, 4-6, 12, and 24 months to assess neurocognitive and developmental milestones. In addition, a NH cohort for the characterization of symptomatic rash/fever illness was designed, including follow-up to capture persisting health problems. Blood, urine, and other biological materials will be collected, and tested for ZIKV and other relevant arboviral diseases (dengue, chikungunya, yellow fever) using RT-PCR or serological methods. A virtual, decentralized biobank will be created. Reciprocal clinical monitoring has been established between partner sites. Substudies of ZIKV seroprevalence, transmission clustering, disabilities and health economics, viral kinetics, the potential role of antibody enhancement, and co-infections will be linked to the cohort studies. DISCUSSION: Results of these large cohort studies will provide better risk estimates for birth defects and other developmental abnormalities associated with ZIKV infection including possible co-factors for the variability of risk estimates between other countries and regions. Additional outcomes include incidence and transmission estimates of ZIKV during and after pregnancy, characterization of short and long-term clinical course following infection and viral kinetics of ZIKV. STUDY REGISTRATIONS: clinicaltrials.gov NCT03188731 (PW cohort), June 15, 2017; clinicaltrials.gov NCT03393286 (CH cohort), January 8, 2018; clinicaltrials.gov NCT03204409 (NH cohort), July 2, 2017.

Impact of Dengue Vaccination on Serological Diagnosis: Insights From Phase III Dengue Vaccine Efficacy Trials.

Background: We previously reported that vaccination with the tetravalent dengue vaccine (CYD-TDV; Dengvaxia) may bias the diagnosis of dengue based on immunoglobulin M (IgM) and immunoglobulin G (IgG) assessments. Methods: We undertook a post hoc pooled analysis of febrile episodes that occurred during the active surveillance phase (the 25 months after the first study injection) of 2 pivotal phase III, placebo-controlled CYD-TDV efficacy studies that involved ≥31000 children aged 2-16 years across 10 countries in Asia and Latin America. Virologically confirmed dengue (VCD) episode was defined with a positive test for dengue nonstructural protein 1 antigen or dengue polymerase chain reaction. Probable dengue episode was serologically defined as (1) IgM-positive acute- or convalescent-phase sample, or (2) IgG-positive acute-phase sample and ≥4-fold IgG increase between acute- and convalescent-phase samples. Results: There were 1284 VCD episodes (575 and 709 in the CYD-TDV and placebo groups, respectively) and 17673 other febrile episodes (11668 and 6005, respectively). Compared with VCD, the sensitivity and specificity of probable dengue definition were 93.1% and 77.2%, respectively. Overall positive and negative predictive values were 22.9% and 99.5%, respectively, reflecting the much lower probability of correctly confirming probable dengue in a population including a vaccinated cohort. Vaccination-induced bias toward false-positive diagnosis was more pronounced among individuals seronegative at baseline. Conclusions: Caution will be required when interpreting IgM and IgG data obtained during routine surveillance in those vaccinated with CYD-TDV. There is an urgent need for new practical, dengue-specific diagnostic algorithms now that CYD-TDV is approved in a number of dengue-endemic countries. Clinical Trials Registration: NCT01373281 and NCT01374516.

Efficacy of a tetravalent dengue vaccine in children in Latin America.

BACKGROUND: In light of the increasing rate of dengue infections throughout the world despite vector-control measures, several dengue vaccine candidates are in development. METHODS: In a phase 3 efficacy trial of a tetravalent dengue vaccine in five Latin American countries where dengue is endemic, we randomly assigned healthy children between the ages of 9 and 16 years in a 2:1 ratio to receive three injections of recombinant, live, attenuated, tetravalent dengue vaccine (CYD-TDV) or placebo at months 0, 6, and 12 under blinded conditions. The children were then followed for 25 months. The primary outcome was vaccine efficacy against symptomatic, virologically confirmed dengue (VCD), regardless of disease severity or serotype, occurring more than 28 days after the third injection. RESULTS: A total of 20,869 healthy children received either vaccine or placebo. At baseline, 79.4% of an immunogenicity subgroup of 1944 children had seropositive status for one or more dengue serotypes. In the per-protocol population, there were 176 VCD cases (with 11,793 person-years at risk) in the vaccine group and 221 VCD cases (with 5809 person-years at risk) in the control group, for a vaccine efficacy of 60.8% (95% confidence interval [CI], 52.0 to 68.0). In the intention-to-treat population (those who received at least one injection), vaccine efficacy was 64.7% (95% CI, 58.7 to 69.8). Serotype-specific vaccine efficacy was 50.3% for serotype 1, 42.3% for serotype 2, 74.0% for serotype 3, and 77.7% for serotype 4. Among the severe VCD cases, 1 of 12 was in the vaccine group, for an intention-to-treat vaccine efficacy of 95.5%. Vaccine efficacy against hospitalization for dengue was 80.3%. The safety profile for the CYD-TDV vaccine was similar to that for placebo, with no marked difference in rates of adverse events. CONCLUSIONS: The CYD-TDV dengue vaccine was efficacious against VCD and severe VCD and led to fewer hospitalizations for VCD in five Latin American countries where dengue is endemic. (Funded by Sanofi Pasteur; ClinicalTrials.gov number, NCT01374516.).

Burden of dengue among febrile patients at the time of chikungunya introduction in Piedecuesta, Colombia.

OBJECTIVE: To estimate the age-specific incidence of symptomatic dengue and chikungunya in Colombia. METHOD: A passive facility-based fever surveillance study was conducted among individuals with undifferentiated fever. Confirmatory diagnostics included serological and molecular tests in paired samples, and surveillance's underreporting was assessed using capture-recapture methods. RESULTS: Of 839 febrile participants 686 completed the study. There were 33.2% (295/839) dengue infections (51% primary infections), and 35.9% (191/532) of negative dengue cases there were chikungunya cases. On average, dengue cases were younger (median = 18 years) than chikungunya cases (median = 25 years). Thrombocytopaenia and abdominal pain were the main dengue predictors, while presence of rash was the main predictor for chikungunya diagnosis. Underreporting of dengue was 31%; the estimated expansion factors indicate an underreporting rate of dengue cases of threefold for all cases and of almost sixfold for inpatients. CONCLUSIONS: These findings highlight the ongoing coexistence of both arboviruses, a distinct clinical profile of each condition in the study area that could be used by clinicians to generate a differential diagnosis, and the presence of underreporting, mostly among hospitalised cases.

Serum fatty acids and progression from dengue fever to dengue haemorrhagic fever/dengue shock syndrome.

PUFA might modulate inflammatory responses involved in the development of severe dengue. We aimed to examine whether serum PUFA concentrations in patients diagnosed with dengue fever (DF) were related to the risk of progression to dengue haemorrhagic fever/dengue shock syndrome (DHF/DSS). A secondary aim was to assess correlations between fatty acids (FA) and inflammatory biomarkers in patients with DF. We conducted a prospective case-control study nested within a cohort of patients who were diagnosed with DF and followed during the acute episode. We compared the distribution of individual FA (% of total FA) at onset of fever between 109 cases who progressed to DHF/DSS and 235 DF non-progressing controls using unconditional logistic regression. We estimated correlations between baseline FA and cytokine concentrations and compared FA concentrations between the acute episode and >1 year post-convalescence in a subgroup. DHA was positively related to progression to DHF/DSS (multivariable adjusted OR (AOR) for DHA in quintile 5 v. 1=5·34, 95 % CI 2·03, 14·1; P trend=0·007). Dihomo-γ-linolenic acid (DGLA) was inversely associated with progression (AOR for quintile 5 v. 1=0·30, 95 % CI 0·13, 0·69; P trend=0·007). Pentadecanoic acid concentrations were inversely related to DHF/DSS. Correlations of PUFA with cytokines at baseline were low. PUFA were lower during the acute episode than in a disease-free period. In conclusion, serum DHA in patients with DF predicts higher odds of progression to DHF/DSS whereas DGLA and pentadecanoic acid predict lower odds.

Early warning signal for dengue outbreaks and identification of high risk areas for dengue fever in Colombia using climate and non-climate datasets.

BACKGROUND: Dengue has been prevalent in Colombia with high risk of outbreaks in various locations. While the prediction of dengue epidemics will bring significant benefits to the society, accurate forecasts have been a challenge. Given competing health demands in Colombia, it is critical to consider the effective use of the limited healthcare resources by identifying high risk areas for dengue fever. METHODS: The Climate Risk Factor (CRF) index was constructed based upon temperature, precipitation, and humidity. Considering the conditions necessary for vector survival and transmission behavior, elevation and population density were taken into account. An Early Warning Signal (EWS) model was developed by estimating the elasticity of the climate risk factor function to detect dengue epidemics. The climate risk factor index was further estimated at the smaller geographical unit (5 km by 5 km resolution) to identify populations at high risk. RESULTS: From January 2007 to December 2015, the Early Warning Signal model successfully detected 75% of the total number of outbreaks 1 ~ 5 months ahead of time, 12.5% in the same month, and missed 12.5% of all outbreaks. The climate risk factors showed that populations at high risk are concentrated in the Western part of Colombia where more suitable climate conditions for vector mosquitoes and the high population level were observed compared to the East. CONCLUSIONS: This study concludes that it is possible to detect dengue outbreaks ahead of time and identify populations at high risk for various disease prevention activities based upon observed climate and non-climate information. The study outcomes can be used to minimize potential societal losses by prioritizing limited healthcare services and resources, as well as by conducting vector control activities prior to experiencing epidemics.

Screening for parasite infections in immigrant children from low-income countries.

INTRODUCTION: In Spain, minors represent approximately 20% of the immigration flow. Many of these immigrants come from countries in the tropics and sub-tropics where intestinal parasitic infections caused by helminths and protozoa are one of the major causes of human disease. The main objective of the present work was to describe parasite infections in a group of immigrant children. METHODS: A prospective evaluation was performed in 373 minors from Sub-Saharan Africa, North Africa, and Latin America. Details were collected from the medical records and physical examination. Urine, stool and peripheral blood samples were obtained for serological and routine laboratory tests. Direct and indirect parasitological tests were also performed. RESULTS: At least 1 parasitic disease was diagnosed in 176 (47.1%) immigrant children, while 77 (20.6%) minors were infected with two or more parasites. The number of parasites was highest in children from Sub-Saharan Africa compared with the rest of the areas of origin (p<.001), and in children from urban areas compared with those from rural areas (OR 1.27 [1.059-1.552], p=.011). The most frequent causes of multiple parasite infection were filariasis plus strongyloidiasis and filariasis plus schistosomiasis. Intestinal parasite infection was diagnosed in 38 cases (13.8%). Logistic regression analysis revealed that for each month of stay, the probability of a positive finding in the stool sample decreased by 0.02% [ß=-0.020, (p=.07)]. CONCLUSIONS: The high infection rates of parasite diseases in immigrant children point to the need for screening protocols for certain infectious diseases in these children according to their country of origin and their length of residence in Spain.

Why are people with dengue dying? A scoping review of determinants for dengue mortality.

BACKGROUND: Dengue is a viral disease whose clinical spectrum ranges from unapparent to severe forms and fatal outcomes. Although dengue death is 99% avoidable, every year around 20,000 deaths are estimated to occur in more than 100 countries. We consider that, along with biological factors, social determinants of health (SDHs) are related to dengue deaths as well. METHODS: A scoping review was conducted to explore what has been written about the role of SDHs in dengue mortality. The inclusion criteria were that documents (grey or peer-reviewed) had to include information about dengue fatal cases in humans and be published between 1997 and 2013 and written in English, Spanish, Portuguese or French. The search was conducted using a set of key words related to dengue mortality in several electronic databases: PubMed, LILACS, COCHRANE, Scielo, Science Direct, WHOLIS, OpenGrey, OpenSingle and Google Scholar. Information on SDHs was categorized under individual, social and environmental, and health systems dimensions. A summative content analysis using QDA Miner was conducted to assess the frequency of information on SDHs and its contextual meaning in the reviewed literature. The role of each SDH in dengue mortality was assessed using content analysis results. RESULTS: From a total of 971 documents retrieved, 78 met the criteria. Those documents were published in the Americas region (50.0%), Asia (38.4%), Europe (9.0%) and Africa (2.6%). The described SDHs related to dengue deaths included, in the individual dimension: age, ethnicity, education, type of infection and immunological status; and in the social dimension: poverty and care-seeking behavior. The health systems dimension included access, opportunity, and quality of care, as well as health staff knowledge. Ethnicity was considered a determinant that depends on cultural and socioeconomic conditions. CONCLUSIONS: Along with biological factors, there are several SDHs related to dengue mortality. However, only a few of these have been systematically analyzed, suggesting the need for more studies on this subject to inform the design and implementation of sustainable interventions to decrease dengue mortality. These findings nevertheless provide a better understanding of the non-biological factors involved in dengue mortality.

A Fasciola hepatica-derived fatty acid binding protein induces protection against schistosomiasis caused by Schistosoma bovis using the adjuvant adaptation (ADAD) vaccination system.

Several efforts have been made to identify anti-schistosomiasis vaccine candidates and new vaccination systems. The fatty acid binding protein (FAPB) has been shown to induce a high level of protection in trematode infection. The adjuvant adaptation (ADAD) vaccination system was used in this study, including recombinant FABP, a natural immunomodulator and saponins. Mice immunised with the ADAD system were able to up-regulate proinflammatory cytokines (IL-1 and IL-6) and induce high IgG2a levels. Moreover, there was a significant reduction in worm burden, egg liver and hepatic lesion in vaccinated mice in two independent experiments involving Schistosoma bovis infected mice. The foregoing data shows that ADAD system using FABP provide a good alternative for triggering an effective immune response against animal schistosomiasis.

Increased threat of urban arboviral diseases from Aedes aegypti mosquitoes in Colombia.

Objectives: Our study targets the potential of the local urban mosquito Aedes aegypti to experimentally transmit chikungunya virus (CHIKV), dengue virus (DENV), yellow fever virus (YFV), and Zika virus (ZIKV). Methods: We collected eggs and adults of Ae. aegypti in Medellín, Colombia (from February to March 2020) for mosquito experimental infections with DENV, CHIKV, YFV and ZIKV and viral detection using the BioMark Dynamic arrays system. Results: We show that Ae. aegypti from Medellín was more prone to become infected, to disseminate and transmit CHIKV and ZIKV than DENV and YFV. Conclusions: Thus, in Colombia, chikungunya is the most serious threat to public health based on our vector competence data.

Dietary Patterns and Anti-Flavivirus IgG Seroconversion in Colombian Children.

The burden of flaviviral infections, especially dengue and Zika, is high in the Americas. Malnutrition affects the risk and response to infections, but the role of diet on flaviviral infection risk is uncertain. The objective of this study was to investigate the relations between dietary patterns adherence and anti-flavivirus IgG seroconversion in children during a Zika epidemic in a dengue-endemic area of Colombia. In 2015-2016, we followed 424 anti-flavivirus IgG seronegative children aged 2 to 12 years for 1 year. Baseline data included children's sociodemographic, anthropometric, and dietary information collected through a 38-item food frequency questionnaire (FFQ). IgG testing was repeated at the end of follow-up. The primary exposure was adherence to each of four dietary patterns (animal foods, traditional, ultraprocessed foods, and prudent) that were identified from the FFQ through principal component analysis. Secondary exposures were intake frequencies of foods contributing to relevant patterns. We estimated risk of seroconversion by quartiles of adherence scores and compared them using relative risks (RR) and 95% CI from Poisson regression adjusted for sex, age, and socioeconomic status indicators. Seroconversion risk was 32.1%. Adherence to the traditional pattern was positively related to seroconversion. RR comparing fourth versus first quartiles of adherence was 1.52 (95% CI: 1.04-2.21; P trend = 0.02). Of the most representative foods in this pattern, potato and sugarcane water intake frequencies were related to increased seroconversion risk. In conclusion, adherence to a traditional foods pattern, including potatoes and sugarcane water, was positively associated with anti-flavivirus IgG seroconversion.

Neurodevelopmental outcome of infants without central nervous system anomalies born to symptomatic RT-PCR ZIKV positive women.

An epidemic of Zika virus (ZIKV) infection began in Colombia in October 2015. Previous studies have identified a cause-effect relationship between fetal exposure to the ZIKV and the development of microcephaly and other central nervous system (CNS) anomalies with variable degrees of neurodevelopmental delay. Less is known about the neurodevelopmental outcome of infants without CNS anomalies born to symptomatic ZIKV RT-PCR-positive women. We aimed to compare the neurodevelopmental outcome of these infants to a control group of infants without CNS anomalies born to asymptomatic ZIKV RT-PCR negative women who did not seroconvert during pregnancy. Participating infants were categorized according to ZIKV maternal exposure. Women with symptomatology suggestive of ZIKV infection and a positive RT-PCR for ZIKV were categorized as ZIKV-exposed. Maternal controls (ZIKV unexposed) from the same geographic area were subsequently captured during the tail end of the epidemic through a partner project, the ZIKAlliance, whose aim was to determine the prevalence of ZIKV in pregnant women. Infant survivors from these two groups of pregnant women had a neurodevelopmental evaluation at 12, 18, and 24 months corrected age (CA). The ZIKV-exposed women were found to be older, had less subsidized health care, had a higher percentage of women in middle-class socioeconomic strata, had higher technical and university education, were less likely to be living with a partner, and had higher rates of pregnancy comorbidity and premature births than ZIKV unexposed women. Compared to infants born to ZIKV unexposed women (unexposed), infants born to ZIKV exposed women (exposed) were of lower gestational age and required more speech and occupational therapy services. No differences between groups were observed in the proportion of cut-off scores <70 on the Bayley-III Scale at 12, 18, and 24 months for motor, language, and cognitive domains. When a cut-off of <85 was used, a higher percentage of motor and cognitive impairment was observed in unexposed infants at 12 and 24 months CA, respectively. Median and IQR score on the Bayley-III scale showed higher scores in favor of exposed infants for motor development at 12 and 18 months CA, language at 12 months, and cognitive domain at 12, 18, and 24 months. The adjusted median and IQR compound score of the difference between exposed and unexposed was higher in favor of exposed infants at 12 to 24 months CA for motor (3.8 [95% CI 1.0 to 6.7]) and cognitive domains (10.6 [95% CI 7.3 to 13.9]). We observed no differences in the language domain (1.9 [95% CI -1.2 to 5.0]). We conclude that infants with no evidence of microcephaly or other CNS anomalies born to ZIKV-exposed women had normal neurodevelopment up to 24 months of CA, supporting an all-or-nothing effect with maternal ZIKV exposure. Long-term follow-up to evaluate school performance is required. Clinical Trial Registration: www.clinicaltrials.gov, NCT02943304.

Seroprevalence of anti-SARS-CoV-2 antibodies in Colombia, 2020: A population-based study.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to cause very high morbidity and mortality throughout Latin American countries. However, few population-based seroprevalence surveys have been conducted to quantify attack rates and characterize drivers of transmission. METHODS: We conducted a population-based cross-sectional study to assess the seroprevalence of antibodies against SARS-CoV-2 in ten cities in Colombia between September and December 2020. The study involved multi-stage cluster sampling at each city. Participants provided a serum sample and answered a demographic and risk factor questionnaire. Prior infection by SARS-CoV-2 was ascertained using the "SARS-CoV-2 Total (COV2T) Advia Centaur - Siemens" chemiluminescence assay. FINDINGS: A total of 17863 participants from 7320 households participated in the study. Seroprevalence varied substantially between cities, ranging from 26% (95%CI 23-29 %) in Medellín to 68% (95%CI 62-74 %) in Guapi. There were no differences in seroprevalence by sex, but seropositivity was higher in certain ethnic groups. There was substantial heterogeneity in seroprevalence within cities, driven to a large extent by a strong association between socioeconomic stratum and seropositivity. INTERPRETATION: Colombia has been one of the Latin American countries most affected by the COVID-19 pandemic. This study documented very high attack rates in several Colombian cities by the end of 2020 and identified key drivers of heterogeneities including ethnicity and socioeconomic stratum. Few studies of seroprevalence of SARS-CoV-2 have been conducted in Latin America, and therefore this study contributes to the fundamental understanding of the pandemic in the region. FUNDING: The study was sponsored by, Ministerio de Ciencia y Tecnología e Innovación -CT361/2020, Ministerio de Salud y Protección Social, Fundación Universitaria del Norte, Imperial College of London, Universidad Nacional de Colombia (Sede Medellín), Universidad de Córdoba, California University, Unidad Nacional de Gestión del Riesgo, Centro de Atención y Diagnóstico de Enfermedades Infecciosas -CDI-, Centro Internacional de Entrenamiento e Investigaciones Médicas -CIDEIM-, Departamento Administrativo Nacional de Estadística - DANE, Fondo Nacional de Turismo -FONTUR-, Secretarías de Salud Departamentales, Distritales y Municipales and Instituto Nacional de Salud.

Illness Process and Recovery From the Perspective of the Alcoholic Patient.

The aim of this work was to gain understanding, using the self-transcendence theory, of the perspective of the alcoholic patient. This was a qualitative study using the grounded theory method. Eight semistructured interviews were conducted with alcohol-dependent individuals. Eleven categories emerged that allowed for understanding the process of becoming alcohol dependent to later seeking help and maintaining abstinence through the intervention program developed by Alcoholics Anonymous.

Comparison of the diagnostic accuracy of commercial NS1-based diagnostic tests for early dengue infection.

BACKGROUND: We compared the diagnostic accuracy and reproducibility of commercially available NS1-based dengue tests and explored factors influencing their sensitivities. METHODS: Paired analysis of 310 samples previously characterized as positive (n = 218) and negative (n = 92) for viral isolation and/or RT-PCR and/or IgM seroconversion. Masked samples were tested by two observers with Platelia™ Dengue NS1 Ag, second generation Pan-E™ Dengue Early ELISA, SD Dengue NS1 Ag ELISA, Dengue NS1 Ag STRIP™, and SD BIOLINE™ Dengue Duo (NS1/IgM/IgG). RESULTS: SD BIOLINE™ NS1/IgM/IgG had the highest sensitivity (80.7% 95%CI 75-85.7) with likelihood ratios of 7.4 (95%CI 4.1-13.8) and 0.21 (95%CI 0.16-0.28). The ELISA-format tests showed comparable sensitivities; all below 75%. STRIP™ and SD NS1 had even lower sensitivities (<65%). The sensitivities significantly decreased in samples taken after 3 days of fever onset, in secondary infections, viral serotypes 2 and 4, and severe dengue. Adding IgM or IgG to SD NS1 increased its sensitivity in all these situations. CONCLUSIONS: The simultaneous detection of NS1/IgM/IgG would be potentially useful for dengue diagnosis in both endemic and non endemic areas. A negative result does not rule out dengue. Further studies are required to assess the performance and impact of early laboratory diagnosis of dengue in the routine clinical setting.

Comparative transcriptomic analysis reveals novel roles of transcription factors and hormones during the flowering induction and floral bud differentiation in sweet cherry trees (Prunus avium L. cv. Bing).

In sweet cherry trees, flowering is commercially important because the flowers, after fertilization, will generate the fruits. In P. avium, the flowering induction and flower organogensis are the first developmental steps towards flower formation and they occur within specialized organs known as floral buds during the summer, nine months before blooming. During this period the number of floral buds per tree and the bud fruitfulness (number of flowers per bud) are stablished affecting the potential yield of orchards and the plant architecture. The floral bud development is sensitive to any type of stress and the hotter and drier summers will interfere with this process and are calling for new adapted cultivars. A better understanding of the underlying molecular and hormonal mechanisms would be of help, but unlike the model plant Arabidopsis, very little is known about floral induction in sweet cherry. To explore the molecular mechanism of floral bud differentiation, high-throughput RNA sequencing was used to detect differences in the gene expression of P. avium floral buds at five differentiation stages. We found 2,982 differentially expressed genes during floral bud development. We identified genes associated with floral initiation or floral organ identity that appear to be useful biomarkers of floral development and several transcription factor families (ERF, MYB, bHLH, MADS-box and NAC gene family) with novel potential roles during floral transition in this species. We analyzed in deep the MADS-box gene family and we shed light about their key role during floral bud and organs development in P. avium. Furthermore, the hormonal-related signatures in the gene regulatory networks and the dynamic changes of absicic acid, zeatin and indolacetic acid contents in buds suggest an important role for these hormones during floral bud differentiation in sweet cherry. These data provide a rich source of novel informacion for functional and evolutionary studies about floral bud development in sweet cherry and new tools for biotechnology and breeding.

Serotype-specific detection of dengue viruses in a nonstructural protein 1-based enzyme-linked immunosorbent assay validated with a multi-national cohort.

BACKGROUND: Dengue virus (DENV) infections pose one of the largest global barriers to human health. The four serotypes (DENV 1-4) present different symptoms and influence immune response to subsequent DENV infections, rendering surveillance, risk assessments, and disease control particularly challenging. Early diagnosis and appropriate clinical management is critical and can be achieved by detecting DENV nonstructural protein 1 (NS1) in serum during the acute phase. However, few NS1-based tests have been developed that are capable of differentiating DENV serotypes and none are currently commercially available. METHODOLOGY/PRINCIPLE FINDINGS: We developed an enzyme-linked immunosorbent assay (ELISA) to distinguish DENV-1-4 NS1 using serotype-specific pairs of monoclonal antibodies. A total of 1,046 antibodies were harvested from DENV-immunized mice and screened for antigen binding affinity. ELISA clinical performance was evaluated using 408 polymerase chain reaction-confirmed dengue samples obtained from patients in Brazil, Honduras, and India. The overall sensitivity of the test for pan-DENV was 79.66% (325/408), and the sensitivities for DENV-1-4 serotyping were 79.1% (38/48), 80.41% (78/97), 100% (45/45), and 79.6% (98/123), respectively. Specificity reached 94.07-100%. SIGNIFICANCE: Our study demonstrates a robust antibody screening strategy that enabled the development of a serotype NS1-based ELISA with maximized specific and sensitive antigen binding. This sensitive and specific assay also utilized the most expansive cohort to date, and of which about half are from Latin America, a geographic region severely underrepresented in previous similar studies. This ELISA test offers potential enhanced diagnostics during the acute phase of infection to help guide patient care and disease control. These results indicate that this ELISA is a promising aid in early DENV-1-4 diagnosis and surveillance in regions of endemicity in addition to offer convenient monitoring for future vaccine interventions.

Genetic risk for dengue hemorrhagic fever and dengue fever in multiple ancestries.

BACKGROUND: Genetic risk factors for dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS) and dengue fever (DF) are limited, in particular there are sparse data on genetic risk across diverse populations. METHODS: We conducted a genome-wide association study (GWAS) in a derivation and validation sample of 7, 460 participants of Latin American, South Asian, and South East Asian ancestries. We then developed a weighted polygenic risk score (PRS) for each participant in each of the validation cohorts of the three ancestries to predict the risk of DHF/DSS compared to DF, DHF/DSS compared to controls, and, DF compared to controls. FINDINGS: The risk of DHF/DSS was significantly increased, odds ratio [OR] 1.84 (95%CI 1.47 to 2.31) (195 SNPs), compared to DF, fourth PRS quartile versus first quartile, in the validation cohort. The risk of DHF/DSS compared to controls was increased (OR=3.94; 95% CI 2.84 to 5.45) (278 SNPs), as was the risk of DF compared to controls (OR=1.97; 95%CI 1.63 to 2.39) (251 SNPs). Risk increased in a dose-dependent manner with increase in quartiles of PRS across comparisons. Significant associations persisted for PRS built within ancestries and applied to the same or different ancestries as well as for PRS built for one outcome (DHF/DSS or DF) and applied to the other. INTERPRETATION: There is a strong genetic effect that predisposes to risk of DHF/DSS and DF. The genetic risk for DHF/DSS is higher than that for DF when compared to controls, and this effect persists across multiple ancestries.