Direct mosquito feedings on dengue-2 virus-infected people reveal dynamics of human infectiousness.

Dengue virus (DENV) transmission from humans to mosquitoes is a poorly documented, but critical component of DENV epidemiology. Magnitude of viremia is the primary determinant of successful human-to-mosquito DENV transmission. People with the same level of viremia, however, can vary in their infectiousness to mosquitoes as a function of other factors that remain to be elucidated. Here, we report on a field-based study in the city of Iquitos, Peru, where we conducted direct mosquito feedings on people naturally infected with DENV and that experienced mild illness. We also enrolled people naturally infected with Zika virus (ZIKV) after the introduction of ZIKV in Iquitos during the study period. Of the 54 study participants involved in direct mosquito feedings, 43 were infected with DENV-2, two with DENV-3, and nine with ZIKV. Our analysis excluded participants whose viremia was detectable at enrollment but undetectable at the time of mosquito feeding, which was the case for all participants with DENV-3 and ZIKV infections. We analyzed the probability of onward transmission during 50 feeding events involving 27 participants infected with DENV-2 based on the presence of infectious virus in mosquito saliva 7-16 days post blood meal. Transmission probability was positively associated with the level of viremia and duration of extrinsic incubation in the mosquito. In addition, transmission probability was influenced by the day of illness in a non-monotonic fashion; i.e., transmission probability increased until 2 days after symptom onset and decreased thereafter. We conclude that mildly ill DENV-infected humans with similar levels of viremia during the first two days after symptom onset will be most infectious to mosquitoes on the second day of their illness. Quantifying variation within and between people in their contribution to DENV transmission is essential to better understand the biological determinants of human infectiousness, parametrize epidemiological models, and improve disease surveillance and prevention strategies.

Quantifying heterogeneities in arbovirus transmission: Description of the rationale and methodology for a prospective longitudinal study of dengue and Zika virus transmission in Iquitos, Peru (2014-2019).

Current knowledge of dengue virus (DENV) transmission provides only a partial understanding of a complex and dynamic system yielding a public health track record that has more failures than successes. An important part of the problem is that the foundation for contemporary interventions includes a series of longstanding, but untested, assumptions based on a relatively small portion of the human population; i.e., people who are convenient to study because they manifest clinically apparent disease. Approaching dengue from the perspective of people with overt illness has produced an extensive body of useful literature. It has not, however, fully embraced heterogeneities in virus transmission dynamics that are increasingly recognized as key information still missing in the struggle to control the most important insect-transmitted viral infection of humans. Only in the last 20 years have there been significant efforts to carry out comprehensive longitudinal dengue studies. This manuscript provides the rationale and comprehensive, integrated description of the methodology for a five-year longitudinal cohort study based in the tropical city of Iquitos, in the heart of the Peruvian Amazon. Primary data collection for this study was completed in 2019. Although some manuscripts have been published to date, our principal objective here is to support subsequent publications by describing in detail the structure, methodology, and significance of a specific research program. Our project was designed to study people across the entire continuum of disease, with the ultimate goal of quantifying heterogeneities in human variables that affect DENV transmission dynamics and prevention. Because our study design is applicable to other Aedes transmitted viruses, we used it to gain insights into Zika virus (ZIKV) transmission when during the project period ZIKV was introduced and circulated in Iquitos. Our prospective contact cluster investigation design was initiated by detecttion of a person with a symptomatic DENV infection and then followed that person's immediate contacts. This allowed us to monitor individuals at high risk of DENV infection, including people with clinically inapparent and mild infections that are otherwise difficult to detect. We aimed to fill knowledge gaps by defining the contribution to DENV transmission dynamics of (1) the understudied majority of DENV-infected people with inapparent and mild infections and (2) epidemiological, entomological, and socio-behavioral sources of heterogeneity. By accounting for factors underlying variation in each person's contribution to transmission we sought to better determine the type and extent of effort needed to better prevent virus transmission and disease.

Two-year outcomes of Faith in Action/Fe en Acción: a randomized controlled trial of physical activity promotion in Latinas.

BACKGROUND: Latina women are less likely to report engaging in leisure-time physical activity (PA) than non-Latina white women. This study evaluated the 24-month impact of a faith-based PA intervention targeting Latinas. METHODS: The study is a cluster randomized controlled trial of a PA intervention or cancer screening comparison condition, with churches as the randomization unit. A total of 436 Latinas (aged 18-65 years) from 16 churches who engaged in low levels of self-report and accelerometer-based PA were enrolled. The experimental condition was a 24-month PA intervention, with in-person classes, social support, and environmental changes, led by community health workers (i.e., promotoras). At baseline, 12-, and 24 months, we assessed changes in accelerometer-based and self-reported moderate to vigorous physical activity (MVPA; primary outcomes). Secondary outcomes were light intensity activity, sedentary time, body mass index (BMI), and waist circumference. RESULTS: After adjusting for sociodemographic factors, a mixed effects analysis found significant increases in self-reported leisure time MVPA (p < 0.005) and marginal increases in accelerometer-assessed MVPA (p < 0.08) 24 months post-baseline in the intervention compared to the attention-control condition. Data showed significant associations between PA class attendance and engaging in MVPA as assessed by self-report and accelerometry. No significant changes were found for light activity, sedentary time, BMI, or waist circumference. CONCLUSIONS: Participants who attended the PA classes at least once a month engaged in significantly higher MVPA compared to those who did not. Maximizing engagement and maintenance strategies to enhance PA maintenance could contribute to important long-term health benefits. TRIAL REGISTRATION: NCT01776632 , Registered March 18, 2011.

Body image and disordered eating behaviors in Hispanic/Latino Youth: Findings from the Hispanic Community Health Study/Study of Latino Youth.

BACKGROUND: Prevalence of certain disordered eating behaviors is higher among Hispanic youth compared to non-Hispanics. Understanding the role of body image and social attitudes towards weight in disordered eating may inform treatment in Hispanic youth. METHODS: We analyzed data from the Hispanic Community Health Study/Study of Latino Youth (SOL Youth). Our sample included 1,463 children aged 8-16 years from four sites (Bronx, Chicago, Miami, San Diego) assessed in 2011-2014. Body image discrepancy score was calculated as the difference between perceived ideal body image and actual body image using two numbered visual graphs: adolescent (n = 728) or child (n = 735), each with slightly different scales. Questionnaires measured influences from social attitudes toward weight and disordered eating behaviors. Three disordered eating behaviors (dieting, overeating, and compensatory behaviors) were analyzed as the dependent variable. Logistic regression models adjusted for age, sex, acculturative stress, and field center to estimate adjusted odds ratios (aOR) and 95% confidence intervals (CI). RESULTS: Mean body image discrepancy score was -0.79 for adolescents (SE = 0.08) and -0.50 for children (SE = 0.05), with a negative score signifying a perceived actual body image larger than their ideal. Body image discrepancy was strongly associated with dieting (dieting ≥5 times/year aOR = 0.64, 95% CI 0.53, 0.77) and compensatory behaviors (aOR = 0.65, 95% CI 0.50, 0.85) among adolescents, and was strongly associated with overeating among children (aOR = 0.74, 95% CI 0.61, 0.91). Significant associations were not observed with social attitudes towards weight. CONCLUSIONS: Associations observed with body image discrepancy and disordered eating behaviors can inform interventions in Hispanic/Latino youth, which should consider acculturative stress.

The El Valor de Nuestra Salud clustered randomized controlled trial store-based intervention to promote fruit and vegetable purchasing and consumption.

BACKGROUND: Modifying the environment to promote healthy foods is a population-based approach for improving diet. This study evaluated the outcome effectiveness of a food store intervention that used structural and social change strategies to promote fruits and vegetables. It was hypothesized that intervention versus control store customers would improve their consumption of fruits and vegetables at 6 months. TRIAL DESIGN: Clustered randomized controlled trial METHODS: Sixteen pair-matched stores were randomized to an intervention or wait-list control condition. With the research team's support, intervention stores modified the availability, accessibility, and promotion of fruits and vegetables, including augmenting produce displays within the store and building employees' capacity to place and promote fruits and vegetables throughout the store (Phase 1), followed by the delivery of a customer-directed marketing campaign for 6 months (Phase 2). From months 7 to 12, stores were encouraged to maintain strategies on their own (Phase 3). Customer-reported daily fruit and vegetable consumption (cups/day) were collected by blinded research assistants at three time-points (baseline, 6 months and 12 months post-baseline) from 369 participating customers (an average of 23/store). Secondary outcomes included customer-reported fruit and vegetable purchasing and other behaviors. RESULTS: The study retained the 16 stores and most customers at 6 (91%) and 12 (89%) months. Although significant differences were not observed in the overall sample for vegetable consumption, male customers of intervention versus control stores consumed significantly more fruit daily at 6 months [mean (standard deviation) cups at baseline and six months; intervention: 1.6 (1.5) to 1.6 (1.5) vs. control: 1.4 (1.2) to 1.1 (0.8)]. However, this difference was not observed at 12 months, or among females. There was an overall increase in dollars spent at the targeted store in the intervention versus control condition among male versus female customers at 6 months; however, no change was observed in the percent of dollars spent on fruits and vegetables at the targeted store. Frequency of shopping at the targeted store did not modify intervention effects. CONCLUSIONS: Structural and social change interventions can modify customers' behavior in the short-term. Future research should consider methods for achieving longer-term changes, and potential generalizability to other products (e.g., energy-dense sweet and savory products). TRIAL REGISTRATION: NCT01475526.

The impact of dengue illness on social distancing and caregiving behavior.

BACKGROUND: Human mobility among residential locations can drive dengue virus (DENV) transmission dynamics. Recently, it was shown that individuals with symptomatic DENV infection exhibit significant changes in their mobility patterns, spending more time at home during illness. This change in mobility is predicted to increase the risk of acquiring infection for those living with or visiting the ill individual. It has yet to be considered, however, whether social contacts are also changing their mobility, either by socially distancing themselves from the infectious individual or increasing contact to help care for them. Social, or physical, distancing and caregiving could have diverse yet important impacts on DENV transmission dynamics; therefore, it is necessary to better understand the nature and frequency of these behaviors including their effect on mobility. METHODOLOGY AND PRINCIPAL FINDINGS: Through community-based febrile illness surveillance and RT-PCR infection confirmation, 67 DENV positive (DENV+) residents were identified in the city of Iquitos, Peru. Using retrospective interviews, data were collected on visitors and home-based care received during the illness. While 15% of participants lost visitors during their illness, 22% gained visitors; overall, 32% of all individuals (particularly females) received visitors while symptomatic. Caregiving was common (90%), particularly caring by housemates (91%) and caring for children (98%). Twenty-eight percent of caregivers changed their behavior enough to have their work (and, likely, mobility patterns) affected. This was significantly more likely when caring for individuals with low "health-related quality of well-being" during illness (Fisher's Exact, p = 0.01). CONCLUSIONS/SIGNIFICANCE: Our study demonstrates that social contacts of individuals with dengue modify their patterns of visitation and caregiving. The observed mobility changes could impact a susceptible individual's exposure to virus or a presymptomatic/clinically inapparent individual's contribution to onward transmission. Accounting for changes in social contact mobility is imperative in order to get a more accurate understanding of DENV transmission.

Disease-driven reduction in human mobility influences human-mosquito contacts and dengue transmission dynamics.

Heterogeneous exposure to mosquitoes determines an individual's contribution to vector-borne pathogen transmission. Particularly for dengue virus (DENV), there is a major difficulty in quantifying human-vector contacts due to the unknown coupled effect of key heterogeneities. To test the hypothesis that the reduction of human out-of-home mobility due to dengue illness will significantly influence population-level dynamics and the structure of DENV transmission chains, we extended an existing modeling framework to include social structure, disease-driven mobility reductions, and heterogeneous transmissibility from different infectious groups. Compared to a baseline model, naïve to human pre-symptomatic infectiousness and disease-driven mobility changes, a model including both parameters predicted an increase of 37% in the probability of a DENV outbreak occurring; a model including mobility change alone predicted a 15.5% increase compared to the baseline model. At the individual level, models including mobility change led to a reduction of the importance of out-of-home onward transmission (R, the fraction of secondary cases predicted to be generated by an individual) by symptomatic individuals (up to -62%) at the expense of an increase in the relevance of their home (up to +40%). An individual's positive contribution to R could be predicted by a GAM including a non-linear interaction between an individual's biting suitability and the number of mosquitoes in their home (>10 mosquitoes and 0.6 individual attractiveness significantly increased R). We conclude that the complex fabric of social relationships and differential behavioral response to dengue illness cause the fraction of symptomatic DENV infections to concentrate transmission in specific locations, whereas asymptomatic carriers (including individuals in their pre-symptomatic period) move the virus throughout the landscape. Our findings point to the difficulty of focusing vector control interventions reactively on the home of symptomatic individuals, as this approach will fail to contain virus propagation by visitors to their house and asymptomatic carriers.

Heterogeneity of Dengue Illness in Community-Based Prospective Study, Iquitos, Peru.

Measuring heterogeneity of dengue illness is necessary to define suitable endpoints in dengue vaccine and therapeutic trials and will help clarify behavioral responses to illness. To quantify heterogeneity in dengue illness, including milder cases, we developed the Dengue Illness Perceptions Response (IPR) survey, which captured detailed symptom data, including intensity, duration, and character, and change in routine activities caused by illness. During 2016-2019, we collected IPR data daily during the acute phase of illness for 79 persons with a positive reverse transcription PCR result for dengue virus RNA. Most participants had mild ambulatory disease. However, we measured substantial heterogeneity in illness experience, symptom duration, and maximum reported intensity of individual symptoms. Symptom intensity was a more valuable predicter of major activity change during dengue illness than symptom presence or absence alone. These data suggest that the IPR measures clinically useful heterogeneity in dengue illness experience and its relation to altered human behavior.

Measuring health related quality of life for dengue patients in Iquitos, Peru.

Previous studies measuring the health-related quality of life (HRQoL) of individuals with dengue focused on treatment seeking populations. However, the vast majority of global dengue cases are unlikely to be detected by health systems. Representative measurements of HRQoL should therefore include patients with disease not likely to trigger treatment-seeking behavior. This study based in Iquitos, Peru used the Quality of Wellbeing Scale-Self Administered, a survey that enquires about not only physical health, but also psychological health, self-care, mobility, and usual social activities, and rates HRQoL between 0 (death) and 1 (optimum function), to evaluate the impact of dengue on HRQoL. In order to enroll treatment and non treatment-seeking participants, three modalities of participant recruitment were used. In addition to clinic and community-based febrile surveillance, a contact-cluster methodology was also employed to identify infected individuals less likely to seek treatment. We measured changes in HRQoL and identified common areas of health impairment in 73 virologically confirmed dengue cases at 3 time points during the participant's illness; the early-acute (days 0-6 post symptom onset), late-acute (days 7-20), and convalescent illness phases (days 21 +). Participants reported HRQoL related impairments at significantly higher frequency during the early-acute versus convalescent illness phase (Fisher's exact: P<0.01). There was substantial heterogeneity in scores during each illness phase with median scores in the early-acute, late-acute and convalescent phases of 0.56 (IQR: 0.41-0.64), 0.70 (IQR: 0.57-0.94), and 1 (IQR: 0.80-1.00), respectively. In all illness phases participants recruited in clinics had on average the lowest HRQoL scores where as those recruited in the contact clusters had the highest. Only 1 individual who was recruited in the contact-clusters had no reduction in HRQoL score during their illness. These data illustrate that dengue should be considered as a disease that may have significant implications for not only physical health but also psychological health and social functioning. The impact of dengue on the HRQoL of non-treatment-seeking individuals, although lower than the impact among treatment-seeking individuals, is not necessarily trivial.

Correction: Dengue illness impacts daily human mobility patterns in Iquitos, Peru.

[This corrects the article DOI: 10.1371/journal.pntd.0007756.].

The impact of insecticide treated curtains on dengue virus transmission: A cluster randomized trial in Iquitos, Peru.

Dengue is one of the most important vector-borne diseases, resulting in an estimated hundreds of millions of infections annually throughout the tropics. Control of dengue is heavily dependent upon control of its primary mosquito vector, Aedes aegypti. Innovative interventions that are effective at targeting the adult stage of the mosquito are needed to increase the options for effective control. The use of insecticide-treated curtains (ITCs) has previously been shown to significantly reduce the abundance of Ae. aegypti in and around homes, but the impact of ITCs on dengue virus (DENV) transmission has not been rigorously quantified. A parallel arm cluster-randomized controlled trial was conducted in Iquitos, Peru to quantify the impact of ITCs on DENV seroconversion as measured through plaque-reduction neutralization tests. Seroconversion data showed that individuals living in the clusters that received ITCs were at greater risk to seroconverting to DENV, with an average seroconversion rate of 50.6 per 100 person-years (PY) (CI: 29.9-71.9), while those in the control arm had an average seroconversion rate of 37.4 per 100 PY (CI: 15.2-51.7). ITCs lost their insecticidal efficacy within 6 months of deployment, necessitating re-treatment with insecticide. Entomological indicators did not show statistically significant differences between ITC and non-ITC clusters. It's unclear how the lack of protective efficacy reported here is attributable to simple failure of the intervention to protect against Ae. aegypti bites, or the presence of a faulty intervention during much of the follow-up period. The higher risk of dengue seroconversion that was detected in the ITC clusters may have arisen due to a false sense of security that inadvertently led to less routine protective behaviors on the part of households that received the ITCs. Our study provides important lessons learned for conducting cluster randomized trials for vector control interventions against Aedes-transmitted virus infections.

Examining Mexican-Heritage Mothers' Perceptions of Their Children's Weight: Comparison of Silhouette and Categorical Survey Methods.

Background: Failure to recognize children's overweight status by parents may contribute to children's risk for obesity. We examined two methods of measuring mothers' perceptions of children's weight and factors associated with weight perception inaccuracy. Methods: Cross-sectional analyses of clinical and self-report data from 287 Mexican-heritage mother-child dyads. Mothers identified their child's weight category using a scale (e.g., "normal/overweight/obese") and a visual silhouette scale (11 child gender-specific weight-varying images). Children's height and weight were measured to calculate body mass index (BMI). Chi-square tests examined associations between categorical, silhouette, and BMI percentile categories of children's weight. Bivariate logistic regression analyses examined factors associated with mothers' inaccuracy of their children's weight. Results: Only 13% of mothers accurately classified their child as obese using the categorical scale, while 78% accurately classified their child as obese using the silhouette scale. Mothers were more likely to underestimate their child's weight using BMI categories (62%) compared to using the silhouette scale (23%). Predictors of mothers' underestimation using the categorical method were child sex [female] (adjusted odds ratio [AOR] = 1.99; 95% CI: 1.02-3.86), child age [younger age] (AOR = 10.39; 95% CI: 4.16-25.92 for ages 5-6 years), and mother's weight status (overweight AOR = 2.99; 95% CI: 1.05-8.51; obese AOR = 5.19; 95% CI: 1.89-14.18). Child BMI was the only predictor of mothers' overestimation (AOR = 0.89; 95% CI: 0.85-0.94) using the silhouette method. Conclusions: Using silhouette scales to identify children's body weight may be a more accurate tool for clinicians and interventionists to activate parents' awareness of unhealthy weight in children compared to using traditional categorical weight-labeling methods.

Evaluation of Store Environment Changes of an In-Store Intervention to Promote Fruits and Vegetables in Latino/Hispanic-Focused Food Stores.

Implementing interventions that manipulate food store environments are one potential strategy for improving dietary behaviors. The present study evaluated intervention effects, from the El Valor de Nuestra Salud (The Value of Our Health) study, on in-store environmental changes within Latino/Hispanic-focused food stores (tiendas). Sixteen tiendas were randomly assigned to either: a six-month structural and social food store intervention or a wait-list control condition. Store-level environmental measures of product availability, placement, and promotion were assessed monthly from baseline through six-months post-baseline using store audits. Linear mixed effects models tested for condition-by-time interactions in store-level environmental measures. Results demonstrated that the intervention was successful at increasing the total number of fruit and vegetable (FV) promotions (p < 0.001) and the number of FV promotions outside the produce department (p < 0.001) among tiendas in the intervention versus control condition. No changes in product availability or placement were observed. Results suggests changing the marketing mix element of promotions within small stores is measurable and feasible in an in-store intervention. Difficulties in capturing changes in product availability and placement may be due to intervention implementation methods chosen by tiendas. It is important to build upon the lessons learned from these types of interventions to disseminate evidence-based in-store interventions.

Dengue illness impacts daily human mobility patterns in Iquitos, Peru.

BACKGROUND: Human mobility plays a central role in shaping pathogen transmission by generating spatial and/or individual variability in potential pathogen-transmitting contacts. Recent research has shown that symptomatic infection can influence human mobility and pathogen transmission dynamics. Better understanding the complex relationship between symptom severity, infectiousness, and human mobility requires quantification of movement patterns throughout infectiousness. For dengue virus (DENV), human infectiousness peaks 0-2 days after symptom onset, making it paramount to understand human movement patterns from the beginning of illness. METHODOLOGY AND PRINCIPAL FINDINGS: Through community-based febrile surveillance and RT-PCR assays, we identified a cohort of DENV+ residents of the city of Iquitos, Peru (n = 63). Using retrospective interviews, we measured the movements of these individuals when healthy and during each day of symptomatic illness. The most dramatic changes in mobility occurred during the first three days after symptom onset; individuals visited significantly fewer locations (Wilcoxon test, p = 0.017) and spent significantly more time at home (Wilcoxon test, p = 0.005), compared to when healthy. By 7-9 days after symptom onset, mobility measures had returned to healthy levels. Throughout an individual's symptomatic period, the day of illness and their subjective sense of well-being were the most significant predictors for the number of locations and houses they visited. CONCLUSIONS/SIGNIFICANCE: Our study is one of the first to collect and analyze human mobility data at a daily scale during symptomatic infection. Accounting for the observed changes in human mobility throughout illness will improve understanding of the impact of disease on DENV transmission dynamics and the interpretation of public health-based surveillance data.

Diet, physical activity, obesity and related cancer risk: strategies to reduce cancer burden in the Americas / Dieta, actividad física, obesidad y riesgo de cáncer: estrategias para reducir la carga del cáncer en las Américas

Abstract: With increased globalization, Latin America is experiencing transitions from traditional lifestyle and dietary practices to those found in higher income countries. Healthy diets, physical activity and optimal body fat can prevent approximately 15% of cancers in low-income and 20% in high-income countries. We discuss links between diet, obesity, physical activity and cancer, emphasizing strategies targeting children to decrease risk of obesity, control obesity-related risk factors, and reduce sedentary lifestyles, as this will have high impact on adult cancer risk. We focus on individual behaviors, economic, cultural and societal changes that may guide future interventions in the Americas.

Resumen: América Latina está experimentando transiciones desde estilos de vida tradicional y prácticas dietéticas a las de países de ingresos altos. Las dietas saludables, la actividad física y la grasa corporal óptima pueden prevenir aproximadamente el 15% de cánceres en países de bajos ingresos y 20% en países de ingresos altos. Discutimos los vínculos entre la dieta, obesidad, actividad física y cáncer; haciendo hincapié en estrategias dirigidas a niños, para disminuir el riesgo de obesidad y reducir la vida sedentaria. Nos enfocamos en comportamientos individuales, cambios económicos, culturales y sociales que pueden guiar futuras intervenciones en las Américas.

Diet, physical activity, obesity and related cancer risk: strategies to reduce cancer burden in the Americas.

With increased globalization, Latin America is experiencing transitions from traditional lifestyle and dietary practices to those found in higher income countries. Healthy diets, physical activity and optimal body fat can prevent approximately 15% of cancers in low-income and 20% in high-income countries. We discuss links between diet, obesity, physical activity and cancer, emphasizing strategies targeting children to decrease risk of obesity, control obesity-related risk factors, and reduce sedentary lifestyles, as this will have high impact on adult cancer risk. We focus on individual behaviors, economic, cultural and societal changes that may guide future interventions in the Americas.

América Latina está experimentando transiciones desde estilos de vida tradicional y prácticas dietéticas a las de países de ingresos altos. Las dietas saludables, la actividad física y la grasa corporal óptima pueden prevenir aproximadamente el 15% de cánceres en países de bajos ingresos y 20% en países de ingresos altos. Discutimos los vínculos entre la dieta, obesidad, actividad física y cáncer; haciendo hincapié en estrategias dirigidas a niños, para disminuir el riesgo de obesidad y reducir la vida sedentaria. Nos enfocamos en comportamientos individuales, cambios económicos, culturales y sociales que pueden guiar futuras intervenciones en las Américas.

Correlates of low-adherence to oral hypoglycemic medications among Hispanic/Latinos of Mexican heritage with Type 2 Diabetes in the United States.

AIMS: We examined psychosocial- and social/economic factors related to low medication adherence, and sex differences, among 279 adults of Mexican heritage with Type 2 Diabetes. METHODS: Self-report and health record data were used for cross-sectional analyses. Bivariate analyses tested the association of demographic, psychosocial (depression, anxiety, stress) and social/economic factors (insurance type, health literacy, social support) and medication adherence measured by proportion of days covered. Hierarchical regression analyses examined associations between demographic, psychosocial- and social/economic- related factors and low medication adherence stratified by sex. RESULTS: More males than females demonstrated low adherence to hypoglycemic medications (75.0.% vs. 70.3%) (p < 0.05). We found significant differences between levels social support and medication adherence (p < 0.05). In hierarchical models, being US born and higher levels of social support were associated with low adherence among males (p < 0.05, and p < 0.001). CONCLUSIONS: Approximately 72% of Mexican heritage adults demonstrated low adherence (PDC ≤ 0.50) to their hypoglycemic regimen, and gender differences exist. Interventions should address gender differences in preferences for social support to improve medication-taking behaviors among Mexican heritage males.

An agent-based model of dengue virus transmission shows how uncertainty about breakthrough infections influences vaccination impact projections.

Prophylactic vaccination is a powerful tool for reducing the burden of infectious diseases, due to a combination of direct protection of vaccinees and indirect protection of others via herd immunity. Computational models play an important role in devising strategies for vaccination by making projections of its impacts on public health. Such projections are subject to uncertainty about numerous factors, however. For example, many vaccine efficacy trials focus on measuring protection against disease rather than protection against infection, leaving the extent of breakthrough infections (i.e., disease ameliorated but infection unimpeded) among vaccinees unknown. Our goal in this study was to quantify the extent to which uncertainty about breakthrough infections results in uncertainty about vaccination impact, with a focus on vaccines for dengue. To realistically account for the many forms of heterogeneity in dengue virus (DENV) transmission, which could have implications for the dynamics of indirect protection, we used a stochastic, agent-based model for DENV transmission informed by more than a decade of empirical studies in the city of Iquitos, Peru. Following 20 years of routine vaccination of nine-year-old children at 80% coverage, projections of the proportion of disease episodes averted varied by a factor of 1.76 (95% CI: 1.54-2.06) across the range of uncertainty about breakthrough infections. This was equivalent to the range of vaccination impact projected across a range of uncertainty about vaccine efficacy of 0.268 (95% CI: 0.210-0.329). Until uncertainty about breakthrough infections can be addressed empirically, our results demonstrate the importance of accounting for it in models of vaccination impact.

Latina mothers as agents of change in children's eating habits: findings from the randomized controlled trial Entre Familia: Reflejos de Salud.

BACKGROUND: Few children consume sufficient servings of fruits and vegetables. Interventions aiming to improve children's dietary intake often target parent level factors, but limited research has examined the mediating role of parental factors on children's dietary intake. This study examined 10-month follow up data from the Entre Familia: Reflejos de Salud (Within the Family: Reflections of Health) trial to investigate (1) intervention effects on children's dietary intake, both sustained and new changes, and (2) whether changes in mothers' dietary intake, her parenting strategies, and behavioral strategies to promoting healthy eating in the home mediated changes in children's dietary intake. METHODS: Participants were 361 Mexican-origin families living in Imperial County, California. Families were randomly assigned to a 4-month dietary intervention or a delayed treatment control group. The intervention was delivered by promotoras (community health workers) via home visits and telephone calls. Assessments occurred at baseline, and 4- and 10-months post-baseline. RESULTS: At 10-months post-baseline, sustained intervention effects were observed on children's reported intake of varieties of vegetables, with differences getting larger over time. However, differential intervention effects on fast food were not sustained due to significant reductions in the control group compared with smaller changes in the intervention group. New intervention effects were observed on servings of sugar-sweetened beverages. However, the intervention continued to have no effect on children's reported fruit and vegetable servings, and varieties of fruits consumed. Mother-reported behavioral strategies to increase fiber and lower fat mediated the relationship between the intervention and children's intake of varieties of vegetables. Mothers' percent energy from fat and behavioral strategies to lower fat were mediators of children's daily servings of sugar-sweetened beverages. CONCLUSIONS: This study suggests that a promotora-led family based intervention can provide mothers with skills to promote modest changes in children's diet. Examining the parent related mechanisms of change will inform future interventions on important targets for improving children's diet. TRIAL REGISTRATION: https://clinicaltrials.gov/ . NCT02441049 . Retrospectively registered 05.06.2015.

A Mediation Analysis of Mothers' Dietary Intake: The Entre Familia: Reflejos de Salud Randomized Controlled Trial.

AIMS: Examine intervention effects among mothers involved in a healthy eating randomized controlled trial. Furthermore, examine the mediating roles of individual and familial influences on observed outcomes. METHODS: Between 2009 and 2011, 361 families were recruited; half were assigned to an 11-session community health worker-delivered family-based intervention targeting Spanish-speaking Latino families in Imperial County, California. The intervention was delivered over a 4-month period. Home visits and telephone calls were delivered approximately weekly, with tapering near the end of the intervention to promote independence from the promotora. In this article, mothers' self-reported dietary intake was the primary outcome. Evaluation measures were taken at baseline, 4 months, and 10 months. RESULTS: Daily servings of fruits were higher among intervention versus control mothers (mean = 1.86 vs. mean = 1.47; effect size [ES] = 0.22) at 10 months post-baseline. Mothers in the intervention versus control condition also reported consuming a lower percent energy from fat (mean = 30.0% vs. 31.0%; ES = 0.30) and a higher diet quality (mean = 2.93 vs. mean = 2.67; ES = 0.29). Mediators of improvements were behavioral strategies to increase fiber and lower fat intake, family support for vegetable purchasing, and decreased unhealthy eating behaviors and perceived family barriers to healthy eating. DISCUSSION AND CONCLUSION: Family-based behavioral interventions are effective for changing the skills and family system needed to improve diet among Latina mothers. Health care providers and other practitioners are encouraged to target skill development and fostering a socially supportive environment.