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.

Predictors and Effects of Participation in Peer Support: A Prospective Structural Equation Modeling Analysis.

BACKGROUND: Peer support provides varied health benefits, but how it achieves these benefits is not well understood. PURPOSE: Examine a) predictors of participation in peer support interventions for diabetes management, and b) relationship between participation and glycemic control. METHODS: Seven peer support interventions funded through Peers for Progress provided pre/post data on 1,746 participants' glycemic control (hemoglobin A1c), contacts with peer supporters as an indicator of participation, health literacy, availability/satisfaction with support for diabetes management from family and clinical team, quality of life (EQ-Index), diabetes distress, depression (PHQ-8), BMI, gender, age, education, and years with diabetes. RESULTS: Structural equation modeling indicated a) lower levels of available support for diabetes management, higher depression scores, and older age predicted more contacts with peer supporters, and b) more contacts predicted lower levels of final HbA1c as did lower baseline levels of BMI and diabetes distress and fewer years living with diabetes. Parallel effects of contacts on HbA1c, although not statistically significant, were observed among those with baseline HbA1c values > 7.5% or > 9%. Additionally, no, low, moderate, and high contacts showed a significant linear, dose-response relationship with final HbA1c. Baseline and covariate-adjusted, final HbA1c was 8.18% versus 7.86% for those with no versus high contacts. CONCLUSIONS: Peer support reached/benefitted those at greater disadvantage. Less social support for dealing with diabetes and higher PHQ-8 scores predicted greater participation in peer support. Participation in turn predicted lower HbA1c across levels of baseline HbA1c, and in a dose-response relationship across levels of participation.

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.

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.

A unique variant of lymphocytic choriomeningitis virus that induces pheromone binding protein MUP: Critical role for CTL.

Lymphocytic choriomeningitis virus (LCMV) WE variant 2.2 (v2.2) generated a high level of the major mouse urinary protein: MUP. Mice infected with LCMV WE v54, which differed from v2.2 by a single amino acid in the viral glycoprotein, failed to generate MUP above baseline levels found in uninfected controls. Variant 54 bound at 2.5 logs higher affinity to the LCMV receptor α-dystroglycan (α-DG) than v2.2 and entered α-DG-expressing but not α-DG-null cells. Variant 2.2 infected both α-DG-null or -expressing cells. Variant 54 infected more dendritic cells, generated a negligible CD8 T cell response, and caused a persistent infection, while v2.2 generated cytotoxic T lymphocytes (CTLs) and cleared virus within 10 days. By 20 days postinfection and through the 80-day observation period, significantly higher amounts of MUP were found in v2.2-infected mice. Production of MUP was dependent on virus-specific CTL as deletion of such cells aborted MUP production. Furthermore, MUP production was not elevated in v2.2 persistently infected mice unless virus was cleared following transfer of virus-specific CTL.

HIV induces synaptic hyperexcitation via cGMP-dependent protein kinase II activation in the FIV infection model.

Over half of individuals infected with human immunodeficiency virus (HIV) suffer from HIV-associated neurocognitive disorders (HANDs), yet the molecular mechanisms leading to neuronal dysfunction are poorly understood. Feline immunodeficiency virus (FIV) naturally infects cats and shares its structure, cell tropism, and pathology with HIV, including wide-ranging neurological deficits. We employ FIV as a model to elucidate the molecular pathways underlying HIV-induced neuronal dysfunction, in particular, synaptic alteration. Among HIV-induced neuron-damaging products, HIV envelope glycoprotein gp120 triggers elevation of intracellular Ca2+ activity in neurons, stimulating various pathways to damage synaptic functions. We quantify neuronal Ca2+ activity using intracellular Ca2+ imaging in cultured hippocampal neurons and confirm that FIV envelope glycoprotein gp95 also elevates neuronal Ca2+ activity. In addition, we reveal that gp95 interacts with the chemokine receptor, CXCR4, and facilitates the release of intracellular Ca2+ by the activation of the endoplasmic reticulum (ER)-associated Ca2+ channels, inositol triphosphate receptors (IP3Rs), and synaptic NMDA receptors (NMDARs), similar to HIV gp120. This suggests that HIV gp120 and FIV gp95 share a core pathological process in neurons. Significantly, gp95's stimulation of NMDARs activates cGMP-dependent protein kinase II (cGKII) through the activation of the neuronal nitric oxide synthase (nNOS)-cGMP pathway, which increases Ca2+ release from the ER and promotes surface expression of AMPA receptors, leading to an increase in synaptic activity. Moreover, we culture feline hippocampal neurons and confirm that gp95-induced neuronal Ca2+ overactivation is mediated by CXCR4 and cGKII. Finally, cGKII activation is also required for HIV gp120-induced Ca2+ hyperactivation. These results thus provide a novel neurobiological mechanism of cGKII-mediated synaptic hyperexcitation in HAND.

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.

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.

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.

Type 1 diabetes pathogenesis is modulated by spontaneous autoimmune responses to endogenous retrovirus antigens in NOD mice.

Secreted microvesicles (MVs) are potent inflammatory triggers that stimulate autoreactive B and T cells, causing Type 1 Diabetes in non-obese diabetic (NOD) mice. Proteomic analysis of purified MVs released from islet cells detected the presence of endogenous retrovirus (ERV) antigens, including Env and Gag sequences similar to the well-characterized murine leukemia retroviruses. This raises the possibility that ERV antigens may be expressed in the pancreatic islets via MV secretion. Using virus-like particles produced by co-expressing ERV Env and Gag antigens, and a recombinant gp70 Env protein, we demonstrated that NOD but not diabetes-resistant mice developed anti-Env autoantibodies that increase in titer as disease progresses. A lentiviral-based RNA interference knockdown of Gag revealed that Gag contributes to the MV-induced T-cell response, whose diabetogenic function can be demonstrated via cell-transfer into immune-deficient mice. Finally, we observed that Gag and Env are expressed in NOD islet-derived primary mesenchymal stem cells (MSCs). However, MSCs derived from the islets of diabetes-resistant mice do not express the antigens. Taken together, abnormal ERV activation and secretion of MVs may induce anti-retroviral responses to trigger autoimmunity.

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.

The Alapahoochee watershed microgeographic structure and its potential influence on metal concentrations and genetic structure in the Florida cottonmouth, Agkistrodon piscivorus conanti, within the watershed.

This study examines the microgeographic structure of the Alapahoochee watershed, part of the Suwannee River basin, south-central GA, USA, and relates it to variations in liver metal concentrations and genetic structure of the Florida cottonmouth, Agkistrodon piscivorus conanti. One objective was to determine if liver metal concentrations in A. piscivorus differ between Grand Bay and Mud creeks, which form the watershed's upper portion. Grand Bay Creek is relatively pristine, whereas Mud Creek is polluted with various metals. Genetic analyses were used to assess possible migration patterns between the creeks indicating whether the basin possesses a single population or two populations. Collections occurred in 2008 and 2009. Specimens were captured, euthanized, or collected as road kills, and liver metal concentrations were analyzed and DNA extracted. No differences in metal concentrations were detected between the creeks, except for nickel in females. Metal concentrations in A. piscivorus were not significantly different between males and females nor show a relationship to body size. Genetic analyses were limited to three primer sets, which amplified informative loci. Locus, CH4B, was highly divergent between the putative populations and particularly informative. Genetic structure indicates potential population isolation within the two creeks. Results suggest that two distinct A. piscivorus populations were present and those populations did not differ in their liver metal concentrations (exception being nickel), despite the differences in environmental metal concentrations in the areas. These findings provide new insight into metal accumulation and detoxification in these animals.

Fe en Acción: Promoting Physical Activity Among Churchgoing Latinas.

OBJECTIVES: To evaluate the impact of a faith-based intervention to promote physical activity in Latinas. METHODS: We randomized 16 churches in San Diego County, California, to a physical activity intervention or cancer screening comparison condition (n = 436). The intervention followed an ecological framework and involved promotoras. We examined 12-month intervention effects, including accelerometer-based moderate-to-vigorous physical activity (MVPA; primary outcome) and secondary outcomes. We conducted the study from 2010 to 2016. RESULTS: Mixed effects analyses showed significant increases in accelerometer-based MVPA (effect size = 0.25) and self-report leisure-time MVPA (effect size = 0.38) among Latinas in the intervention versus comparison condition. Participants in the intervention condition had about 66% higher odds of meeting the 2008 Physical Activity Guidelines, had reduced body mass index (effect size = 0.23), and used more behavioral strategies for engaging in physical activity (effect size = 0.42). Program attendance was associated with increased self-reported leisure-time MVPA and the number of motivational interviewing calls was associated with meeting the 2008 Physical Activity Guidelines. CONCLUSIONS: A faith-based intervention was effective in increasing MVPA and decreasing body mass index among participants. Process analyses showed the value of program attendance and motivational interviewing calls.

Time-varying, serotype-specific force of infection of dengue virus.

Infectious disease models play a key role in public health planning. These models rely on accurate estimates of key transmission parameters such as the force of infection (FoI), which is the per-capita risk of a susceptible person being infected. The FoI captures the fundamental dynamics of transmission and is crucial for gauging control efforts, such as identifying vaccination targets. Dengue virus (DENV) is a mosquito-borne, multiserotype pathogen that currently infects ∼390 million people a year. Existing estimates of the DENV FoI are inaccurate because they rely on the unrealistic assumption that risk is constant over time. Dengue models are thus unreliable for designing vaccine deployment strategies. Here, we present to our knowledge the first time-varying (daily), serotype-specific estimates of DENV FoIs using a spline-based fitting procedure designed to examine a 12-y, longitudinal DENV serological dataset from Iquitos, Peru (11,703 individuals, 38,416 samples, and 22,301 serotype-specific DENV infections from 1999 to 2010). The yearly DENV FoI varied markedly across time and serotypes (0-0.33), as did daily basic reproductive numbers (0.49-4.72). During specific time periods, the FoI fluctuations correlated across serotypes, indicating that different DENV serotypes shared common transmission drivers. The marked variation in transmission intensity that we detected indicates that intervention targets based on one-time estimates of the FoI could underestimate the level of effort needed to prevent disease. Our description of dengue virus transmission dynamics is unprecedented in detail, providing a basis for understanding the persistence of this rapidly emerging pathogen and improving disease prevention programs.

Enrolling African-American and Latino patients with asthma in comparative effectiveness research: Lessons learned from 8 patient-centered studies.

BACKGROUND: African-American and Latino patients are often difficult to recruit for asthma studies. This challenge is a barrier to improving asthma care and outcomes for these populations. OBJECTIVES: We sought to examine the recruitment experiences of 8 asthma comparative effectiveness studies that specifically targeted African-American and Latino patients, and identify the solutions they developed to improve recruitment. METHODS: Case report methodology was used to gather and evaluate information on study design, recruitment procedures and outcomes from study protocols and annual reports, and in-depth interviews with each research team. Data were analyzed for themes, commonalities, and differences. RESULTS: There were 4 domains of recruitment challenges: individual participant, institutional, research team, and study intervention. Participants had competing demands for time and some did not believe they had asthma. Institutional challenges included organizational policies governing monetary incentives and staff hiring. Research team challenges included ongoing training needs of recruitment staff, and intervention designs often were unappealing to participants because of inconveniences. Teams identified a host of strategies to address these challenges, most importantly engagement of patients and other stakeholders in study design and troubleshooting, and flexibility in data collection and intervention application to meet the varied needs of patients. CONCLUSIONS: Asthma researchers may have greater success with recruitment by addressing uncertainty among patients about asthma diagnosis, engaging stakeholders in all aspects of study design and implementation, and maximizing flexibility of study and intervention protocols. However, even with such efforts, engagement of African-American and Latino patients in asthma research may remain low. Greater investment in research on engaging these populations in asthma research may ultimately be needed to improve their asthma care and outcomes.

Calling in sick: impacts of fever on intra-urban human mobility.

Pathogens inflict a wide variety of disease manifestations on their hosts, yet the impacts of disease on the behaviour of infected hosts are rarely studied empirically and are seldom accounted for in mathematical models of transmission dynamics. We explored the potential impacts of one of the most common disease manifestations, fever, on a key determinant of pathogen transmission, host mobility, in residents of the Amazonian city of Iquitos, Peru. We did so by comparing two groups of febrile individuals (dengue-positive and dengue-negative) with an afebrile control group. A retrospective, semi-structured interview allowed us to quantify multiple aspects of mobility during the two-week period preceding each interview. We fitted nested models of each aspect of mobility to data from interviews and compared models using likelihood ratio tests to determine whether there were statistically distinguishable differences in mobility attributable to fever or its aetiology. Compared with afebrile individuals, febrile study participants spent more time at home, visited fewer locations, and, in some cases, visited locations closer to home and spent less time at certain types of locations. These multifaceted impacts are consistent with the possibility that disease-mediated changes in host mobility generate dynamic and complex changes in host contact network structure.

Sex Differences in Cardiometabolic Risk Factors among Hispanic/Latino Youth.

OBJECTIVE: To determine the prevalence of obesity and cardiometabolic risk in US Hispanic/Latino youth and examine whether there are disparities by sex in cardiometabolic risk factors. STUDY DESIGN: Study of Latino Youth is a population-based cross-sectional study of 1466 Hispanic/Latino youth (8-16 years old) who were recruited from 4 urban US communities (Bronx, NY, Chicago, IL, Miami, FL, and San Diego, CA) in 2012-2014. The majority of children were US-born (78%) and from low-income and immigrant families. Cardiometabolic risk factors were defined by the use of national age- and sex-specific guidelines. RESULTS: The prevalence of obesity was 26.5%. The prevalence of class II-III obesity, diabetes, and dyslipidemia was high (9.7%, 16.5%, and 23.3%, respectively). The prevalence of cardiometabolic risk factors increased with severity of obesity in both boys and girls. Boys had a greater prevalence of diabetes and of elevated blood pressure than girls (20.9% vs 11.8% and 8.5% vs 3.3%). In multivariable analyses, younger boys were more likely to have obesity class II-III than girls (OR 3.59; 95% CI 1.44-8.97). Boys were more likely to have prediabetes than girls (OR 2.02; 95% CI 1.35-3.02), and the association was stronger at older ages. CONCLUSIONS: The prevalence of cardiometabolic risk factors was high in this sample of Hispanic youth. Boys had a more adverse cardiometabolic profile compared with girls that may put them at higher risk of diabetes and cardiovascular disease later in life. Reasons for this disparity and the long-term clinical implications remain to be elucidated.

Experiences with insecticide-treated curtains: a qualitative study in Iquitos, Peru.

BACKGROUND: Dengue is an arthropod-borne viral disease responsible for approximately 400 million infections annually; the only available method of prevention is vector control. It has been previously demonstrated that insecticide treated curtains (ITCs) can lower dengue vector infestations in and around houses. As part of a larger trial examining whether ITCs could reduce dengue transmission in Iquitos, Peru, the objective of this study was to characterize the participants' experience with the ITCs using qualitative methods. METHODS: Knowledge, attitudes, and practices (KAP) surveys (at baseline, and 9 and 27 months post-ITC distribution, with n = 593, 595 and 511, respectively), focus group discussions (at 6 and 12 months post-ITC distribution, with n = 18 and 33, respectively), and 11 one-on-one interviews (at 12 months post-distribution) were conducted with 605 participants who received ITCs as part of a cluster-randomized trial. RESULTS: Focus groups at 6 months post-ITC distribution revealed that individuals had observed their ITCs to function for approximately 3 months, after which they reported the ITCs were no longer working. Follow up revealed that the ITCs required re-treatment with insecticide at approximately 1 year post-distribution. Over half (55.3 %, n = 329) of participants at 9 months post-ITC distribution and over a third (34.8 %, n = 177) at 27 months post-ITC distribution reported perceiving a decrease in the number of mosquitoes in their home. The percentage of participants who would recommend ITCs to their family or friends in the future remained high throughout the study (94.3 %, n = 561 at 9 months and 94.6 %, n = 488 at 27 months post-distribution). When asked why, participants reported that ITCs were effective at reducing mosquitoes (81.6 and 37.8 %, at 9 and 27 months respectively), that they prevent dengue (5.7 and 51.2 %, at 9 and 27 months), that they are "beautiful" (5.9 and 3.1 %), as well as other reasons (6.9 and 2.5 %). CONCLUSION: ITCs have substantial potential for long term dengue vector control because they are liked by users, both for their perceived effectiveness and for aesthetic reasons, and because they require little proactive behavioral effort on the part of the users. Our results highlight the importance of gathering process (as opposed to outcome) data during vector control studies, without which researchers would not have become aware that the ITCs had lost effectiveness early in the trial.

Decreased Anemia Prevalence Among Women and Children in Rural Baja California, Mexico: A 6-Year Comparative Study.

Anemia is a public health problem in Mexico. This study sought to determine the prevalence and correlates of anemia among women and children residing in a rural farming region of Baja California, Mexico. An existing partnership between universities, non-governmental organizations, and an underserved Mexican community was utilized to perform cross-sectional data collection in 2004-2005 (Wave 1) and in 2011-2012 (Wave 2) among women (15-49 years) and their children (6-59 months). All participants completed a survey and underwent anemia testing. Blood smears were obtained to identify etiology. Nutrition education interventions and clinical health evaluations were offered between waves. Participants included 201 women and 99 children in Wave 1, and 146 women and 77 children in Wave 2. Prevalence of anemia significantly decreased from 42.3 to 23.3 % between Waves 1 and 2 in women (p < 0.001), from 46.5 to 30.2 % in children 24-59 months (p = 0.066), and from 71.4 to 45.8 % in children 6-23 months (p = 0.061). Among women in Wave 1, consumption of iron absorption enhancing foods (green vegetables and fruits high in vitamin C) was protective against anemia (p = 0.043). Women in Wave 2 who ate ≥4 servings of green, leafy vegetables per week were less likely to be anemic (p = 0.034). Microscopic examination of blood smears revealed microcytic, hypochromic red blood cells in 90 % of anemic children and 68.8 % of anemic women, consistent with iron deficiency anemia.