BACKGROUND:COVID-19 has disproportionately affected underserved communities, such as Latinos living in the U.S. Promotoras (Community Health Workers) may be effective at delivering tailored and culturally relevant strategies to prevent household spread and the burden of SARS-CoV-2 among Latinos and other minority groups. PURPOSE:To develop, implement, and test the clinic-based promotora-led COVID-19 Prevention Program (CPP) to reduce transmission of SARS-CoV-2 in 256 Latino households and the community. DESIGN:CPP is a two-group randomized controlled trial designed to test the immediate, mid-term, and long-term effectiveness of the promotora-led intervention, as well as test its effectiveness on short- and long-term behavioral, mental, and physical health outcomes. The primary outcome is household infection rate assessed at 6 weeks and 6-, 12-, and 24-months based on a binary indicator (yes vs. no) of evidence of a new infection via antigen, real-time reverse transcriptase-polymerase chain reaction (RT-PCR), or antibody SARS-CoV-2 test results within household members. Patients in the intervention group will receive enhanced standard-of-care, including tailored, real-time text messaging and virtual counseling, delivered by promotoras. Patients in the control group will receive the clinical standard of care. Analyses will test for household-level group differences in new infections related to an identified index case. DISCUSSION:Preventing household spread of SARS-CoV-2 is an important strategy to reduce the overall burden of SARS-CoV-2 among Latinos. The CPP is a scalable and tailored approach that has the potential to serve as a model to address future respiratory disease outbreaks, especially among uninsured, low-income, and medically underserved communities. TRIAL REGISTRATION:Clinicaltrials.gov Identifier NCT05697068 (1/20/2023).

Objectives: Prevention of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the disease COVID-19 is a public health priority. The efficacy of non-pharmaceutical interventions such as wearing face masks to prevent SARS-CoV-2 infection has been well established in controlled settings. However, evidence for the effectiveness of face masks in preventing SARS-CoV-2 transmission within real-world settings is limited and mixed. The present systematic review evaluated the effectiveness of face mask policies and mask wearing to prevent SARS-CoV-2 transmission and COVID-19 in real-world settings. Methods: Following PRISMA guidelines, scientific databases, and gray literature, were searched through June 2023. Inclusion criteria were as follows: (1) studies/reports written in or translated to English; (2) prospectively assessed incidence of SARS-CoV-2 or COVID-19; (3) assessed the behavior and/or policy of mask-wearing; and (4) conducted in community/public settings (i.e., not laboratory). Studies were excluded if they did not parse out data specific to the effect of mask wearing (behavior and/or policy) and subsequent SARS-CoV-2 transmission or COVID-19 disease or if they relied solely on statistical models to estimate the effects of mask wearing on transmission. A total of 2616 studies were initially identified, and 470 met inclusion and exclusion criteria for full-text review. The vote counting method was used to evaluate effectiveness, and risk of bias was assessed using JBI critical appraisal tools. Results: A total of 79 unique studies met the final inclusion criteria, and their data were abstracted and evaluated. Study settings included community/neighborhood settings (n = 34, 43%), healthcare settings (n = 30, 38%), and school/universities (n = 15, 19%). A majority of studies (n = 61, 77%) provided evidence to support the effectiveness of wearing face masks and/or face mask policies to reduce the transmission of SARS-CoV-2 and/or prevention of COVID-19. Effectiveness of mask wearing did not vary substantially by study design (67–100%), type of mask (77–100%), or setting (80–91%), while 85% of masking policies specifically reported a benefit. Conclusions: This systematic literature review supports public health recommendations and policies that encourage the public to wear face masks to reduce the risk of SARS-CoV-2 infection and COVID-19 in multiple real-world settings. Effective communication strategies are needed to encourage and support the use of face masks by the general public, particularly during peak infection cycles.

Objectives: The purpose of this study was to examine middle and high school students’ cognitive and affective attitude and their cognitive-affective attitudinal structures toward physical education (PE). The effects of cognitive and affective attitude and attitudinal structures on physical activity (PA) in PE and outside of school were also examined. Methods: 1773 Chinese middle and high-school students participated in this study. SEM, Chi-square test, ANOVAs, and Contingency tables were adopted to address the research questions. Results: The results showed that most students (>90%) were holding positive cognitive and affective attitude toward PE. Students’ affective attitude significantly influences their PA in PE and outside of school. Most students were holding the positive cognitive-positive negative attitudinal structure toward PE. Conclusions: All these findings lay important foundations for future theoretical advancement about attitude toward PE and provide guidance for PE teachers on attitude intervention and PA promotion.

Background: Viaje Interinstitucional de Integración Docente, Asistencial y de Investigación (VIIDAI) is a binational community health collaboration involving transdisciplinary education, field training, and research efforts that promotes health and provides services to underserved populations in rural Mexico, while also fostering cultural competency in medical and public health students from the Mexico-U.S. border region. Purpose: This paper describes the development and operation of the VIIDAI academic-community-service organization partnership and clinical and public health training program, and highlights the impact, challenges, road map, and powerful lessons of this binational effort. Methods and Approaches: The VIIDAI partnership is a collaboration between San Diego State University, School of Public Health; Universidad Autónoma de Baja California Tijuana, School of Medicine and Psychology; University of California San Diego, School of Medicine; and Old Mission Rotary. Since 1998, VIIDAI has cooperatively implemented projects using a community-based participatory research approach, integrating community members with faculty, students, and health practitioners from the three universities alongside the Rotary to balance research and action for the mutual benefit of all partners involved. Epidemiologic investigations and interventions, health promotion, and clinical care are conducted with active community engagement during semiannual trips. Field activities are conducted in San Quintín, Baja California, Mexico within a rural, predominately indigenous community, targeting a variety of population-specific public health issues. Results: Since its inception, over 3,300 faculty and students have participated in VIIDAI. The community has responded enthusiastically, with over 14,000 clinic visits and broad participation in health promotion interactions. These efforts have led to improvements in multiple indicators of community health, such as decreased prevalence of anemia; improved access to free potable water; increased numbers of students advancing to secondary schools; reduced family sizes and older age of first pregnancy; increased community interest and engagement in health issues and disease prevention; and increased visibility and empowerment among community leaders. Conclusion: The success of the VIIDAI partnership can be attributed to five key elements: (1) stable, long-term leadership; (2) guidance from the host country; (3) equal partnership with the local community; (4) support from a non-academic service organization to help fulfill unmet needs; and (5) mutually beneficial involvement across all participants.

Abstract Background. Since its emergence, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused an unprecedented global pandemic. Evidence regarding the effectiveness of mask wearing is important to support guidelines for public health practice and implementation of infection-control strategies. Previous systematically reviews within controlled settings suggest wearing face masks are ‘efficacious’ at preventing COVID-19. However, a comprehensive review of the ‘effectiveness’ of face masks in preventing COVID-19 transmission in real-world settings is needed in order to generalize findings. The present study reviewed literature on the effectiveness of wearing face masks in preventing COVID-19 transmission in real-world settings. Methods. Following PRISMA guidelines, three databases and gray literature sources were searched up until January 2022. Inclusion criteria for studies were: 1) written in or translated into English; 2) assess the SARS-CoV-2 transmission; 3) assess the behavior of mask wearing and 4) study conducted in a non-laboratory-controlled setting (e.g., worksites, schools etc.). All 2,240 search results were reviewed for inclusion. Two reviewers extracted study characteristics. Three reviewers independently assessed quality of evidence and risk of bias using JBI critical appraisal tools. Results. This review identified 48 unique studies that met the criteria. Most studies investigated the effect of face masks in a healthcare setting (n=21, 43%). The majority (n=44; 91.6%) of studies showed that wearing face masks led to a reduction in transmission or risk of transmission of COVID-19, and the protective effect of masks was increased when combined with other preventive measures. The findings support that face masks may be up to 79% effective in preventing transmission in non-controlled real-life settings. Conclusions. The results of this systematic review strongly support public health recommendations for wearing a mask to reduce the risk of COVID-19 infection in real-world settings. Effective communication efforts are needed to inform the general public of the benefits of wearing face masks to prevent COVID-19.

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.

Transmission heterogeneity, whereby a disproportionate fraction of pathogen transmission events result from a small number of individuals or geographic locations, is an inherent property of many, if not most, infectious disease systems. For vector-borne diseases, transmission heterogeneity is inferred from the distribution of the number of vectors per host, which could lead to significant bias in situations where vector abundance and transmission risk at the household do not correlate, as is the case with dengue virus (DENV). We used data from a contact tracing study to quantify the distribution of DENV acute infections within human activity spaces (AS), the collection of residential locations an individual routinely visits, and quantified measures of virus transmission heterogeneity from two consecutive dengue outbreaks (DENV-4 and DENV-2) that occurred in the city of Iquitos, Peru. Negative-binomial distributions and Pareto fractions showed evidence of strong overdispersion in the number of DENV infections by AS and identified super-spreading units (SSUs): i.e. AS where most infections occurred. Approximately 8% of AS were identified as SSUs, contributing to more than 50% of DENV infections. SSU occurrence was associated more with DENV-2 infection than with DENV-4, a predominance of inapparent infections (74% of all infections), households with high Aedes aegypti mosquito abundance, and high host susceptibility to the circulating DENV serotype. Marked heterogeneity in dengue case distribution, and the role of inapparent infections in defining it, highlight major challenges faced by reactive interventions if those transmission units contributing the most to transmission are not identified, prioritized, and effectively treated.

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.

Objective Examine the relationship between alcohol consumption and alcohol related consequences (ARCs) for college students at a Hispanic Serving Institution (HSI). Participants Random sample of 375 students at a large university in the pacific south-west. Methods Cross sectional study using an online version of the ACHA-NCHA II survey. Chi-square tests and stepped logistic regression models were conducted to explore the relationship between race/ethnicity and the experience of any alcohol-related consequence, adjusting for covariates. Results Among heavy drinkers, Hispanic students, compared to White students, were 65.9% less likely to report one or more ARC (OR= 0.34, 95%CI = 0.15, 0.79). Conclusions Given the severity of alcohol related consequences in the college population, the potential protective environmental effects of attending a HSI warrant further study.

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 & GE;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.

Background The effects of stakeholder engagement, particularly in comparative effectiveness trials, have not been widely reported. In 2014, eight comparative effectiveness studies targeting African Americans and Hispanics/Latinos with uncontrolled asthma were funded by the Patient-Centered Outcomes Research Institute (PCORI) as part of its Addressing Disparities Program. Awardees were required to meaningfully involve patients and other stakeholders. Using specific examples, we describe how these stakeholders substantially changed the research protocols and in other ways participated meaningfully as full partners in the development and conduct of the eight studies. Methods Using the method content analysis of cases, we identified themes regarding the types of stakeholders, methods of engagement, input from the stakeholders, changes made to the research protocols and processes, and perceived benefits and challenges of the engagement process. We used summaries from meetings of the eight teams, results from an engagement survey, and the final research reports as our data source to obtain detailed information. The descriptive data were assessed by multiple reviewers using inductive and deductive qualitative methods and discussed in the context of engagement literature. Results Stakeholders participated in the planning, conduct, and dissemination phases of all eight asthma studies. All the studies included clinicians and community representatives as stakeholders. Other stakeholders included patients with asthma, their caregivers, advocacy organizations, and health-system representatives. Engagement was primarily by participation in advisory boards, although six of the eight studies (75%) also utilized focus groups and one-on-one interviews. Difficulty finding a time and location to meet was the most reported challenge to engagement, noted by four of the eight teams (50%). Other reported challenges and barriers to engagement included recruitment of stakeholders, varying levels of enthusiasm among stakeholders, controlling power dynamics, and ensuring that stakeholder involvement was reflected and had true influence on the project. Conclusion Engagement-driven modifications led to specific changes in study design and conduct that were felt to have increased enrollment and the general level of trust and support of the targeted communities. The level of interaction described, between investigators and stakeholders in each study and between investigator-stakeholder groups, is—we believe—unprecedented and may provide useful guidance for other studies seeking to improve the effectiveness of community-driven research.

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.

Asthma is a common illness that makes it hard to breathe.When children's asthma is not well controlled, they may need to miss school or limit their daily activities in other ways.Latino children are more likely to have asthma than are non-Latino White children.

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.

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.

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.

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.

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.

Declining levels of physical activity probably contribute to the increasing prevalence of overweight in US youth. In this study, the authors examined cross-sectional and longitudinal associations between physical activity and body composition in sixthand eighth-grade girls. In 2003, girls were recruited from six US states as part of the Trial of Activity for Adolescent Girls. Physical activity was measured using 6 days of accelerometry, and percentage of body fat was calculated using an ageand ethnicity-specific prediction equation. Sixth-grade girls with an average of 12.8 minutes of moderate-to-vigorous physical activity (MVPA) per day (15th percentile) were 2.3 times (95% confidence interval: 1.52, 3.44) more likely to be overweight than girls with 34.7 minutes of MVPA per day (85th percentile), and their percent body fat was 2.64 percentage points greater (95% confidence interval: 1.79, 3.50). Longitudinal analyses showed that percent body fat increased 0.28 percentage points less in girls with a 6.2-minute increase in MVPA than in girls with a 4.5-minute decrease (85th and 15th percentiles of change). Associations between MVPA in sixth grade and incidence of overweight in eighth grade were not detected. More population-based research using Correspondence to Dr. June Stevens, CB 7400, Department of Nutrition, School of Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599 (e-mail: June_stevens@unc.edu).. NIH Public Access Author Manuscript Am J Epidemiol. Author manuscript; available in PMC 2008 June 1. Published in final edited form as: Am J Epidemiol. 2007 December 1; 166(11): 1298–1305. N IH PA Athor M anscript N IH PA Athor M anscript N IH PA Athor M anscript objective physical activity and body composition measurements is needed to make evidence-based physical activity recommendations for US youth.