70 research outputs found

    Spatiotemporal modeling of schistosomiasis in Ghana: linking remote sensing data to infectious disease

    Full text link
    More than 90% of the worldwide schistosomiasis burden falls on sub-Saharan Africa. Control efforts are often based on infrequent, small-scale health surveys, which are expensive and logistically difficult to conduct. The use of satellite imagery to predictively model infectious disease transmission has great potential for public health applications. The transmission of schistosomiasis, a disease acquired from contact with contaminated surface water, requires specific environmental conditions to sustain freshwater snails. If a connection between schistosomiasis and remotely sensed environmental variables can be established, then cost effective and current disease risk predictions can be made available. Schistosomiasis transmission has unknown seasonality, and the disease is difficult to study due to a long lag between infection and clinical symptoms. To overcome these challenges, we employed a comprehensive 15-year time-series built from remote sensing feeds, which is the longest environmental dataset to be used in the application of remote sensing to schistosomiasis. The following environmental variables will be used in the model: accumulated precipitation, land surface temperature, vegetative growth indices, and climate zones created from a novel climate regionalization technique. This technique, improves upon the conventional Köppen-Geiger method, which has been the primary climate classification system in use the past 100 years. These predictor variables will be regressed against 8 years of national health data in Ghana, the largest health dataset of its kind to be used in this context, and acquired from freely available satellite imagery data. A benefit of remote sensing processing is that it only requires training and time in terms of resources. The results of a fixed effects model can be used to develop a decision support framework to design treatment schemes and direct scarce resources to areas with the highest risk of infection. This framework can be applied to diseases sensitive to climate or to locations where remote sensing would be better suited than health surveys.Published versio

    The use of remotely sensed environmental parameters for spatial and temporal schistosomiasis prediction across climate zones in Ghana

    Full text link
    Schistosomiasis control in sub-Saharan Africa is enacted primarily through preventive chemotherapy. Predictive models can play an important role in filling knowledge gaps in the distribution of the disease and help guide the allocation of limited resources. Previous modeling approaches have used localized cross-sectional survey data and environmental data typically collected at a discrete point in time. In this analysis, 8 years (2008-2015) of monthly schistosomiasis cases reported into Ghana's national surveillance system were used to assess temporal and spatial relationships between disease rates and three remotely sensed environmental variables: land surface temperature (LST), normalized difference vegetation index (NDVI), and accumulated precipitation (AP). Furthermore, the analysis was stratified by three major and nine minor climate zones, defined using a new climate classification method. Results showed a downward trend in reported disease rates (~ 1% per month) for all climate zones. Seasonality was present in the north with two peaks (March and September), and in the middle of the country with a single peak (July). Lowest disease rates were observed in December/January across climate zones. Seasonal patterns in the environmental variables and their associations with reported schistosomiasis infection rates varied across climate zones. Precipitation consistently demonstrated a positive association with disease outcome, with a 1-cm increase in rainfall contributing a 0.3-1.6% increase in monthly reported schistosomiasis infection rates. Generally, surveillance of neglected tropical diseases (NTDs) in low-income countries continues to suffer from data quality issues. However, with systematic improvements, our approach demonstrates a way for health departments to use routine surveillance data in combination with publicly available remote sensing data to analyze disease patterns with wide geographic coverage and varying levels of spatial and temporal aggregation.Accepted manuscrip

    Depressive Symptoms and Weight Status Among Women Recently Immigrating to the US

    Get PDF
    Objectives Depressive symptoms have been associated with obesity. Little is known about this relationship among immigrants. We examined relationships between depressive symptoms and weight status in immigrant women from three ethnic groups. Methods Participants were Brazilian, Haitian, and Latina women (n = 345) enrolled in Live Well, a community-based, randomized intervention designed to prevent weight gain in recent immigrants. Study data are from baseline when participants completed the Center for Epidemiological Studies Depression Scale (CES-D), Perceived Stress Scale, a physical activity questionnaire, and socio-demographic questions; BMI was calculated from measured height and weight. Results Forty-four percent of participants (36 % of Brazilians, 66 % of Haitians, 30 % of Latinas) had high depressive symptoms (CES-D ≥ 16), and 38 % (26 % of Brazilians, 49 % of Haitians, 42 % of Latinas) were obese (BMI ≥ 30.0). Those reporting more depressive symptoms were more likely to be obese (Wald Chi square = 4.82, p \u3c .05). An interaction between depressive symptoms, ethnic group, and income was revealed (F(4,340) = 2.91, p \u3c .05), such that higher depressive symptoms were associated with higher BMI among Brazilians earning ≥30,000peryearandwithlowerBMIamongBraziliansearning3˘c30,000 per year and with lower BMI among Brazilians earning \u3c30,000. The relationship between depressive symptoms and obesity did not differ by income among Haitians or Latinas. Conclusions Depressive symptoms and obesity were highly prevalent among these recently-immigrated women. Positive relationships between these variables were consistent across ethnic and income groups, with the exception of lower-income Brazilians. While these findings suggest similar patterns and health needs across several groups of immigrants, cultural differences should be considered when addressing these health conditions

    Population Vulnerability to Biannual Cholera Outbreaks and Associated Macro-Scale Drivers in the Bengal Delta

    Get PDF
    The highly populated floodplains of the Bengal Delta have a long history of endemic and epidemic cholera outbreaks, both coastal and inland. Previous studies have not addressed the spatio-temporal dynamics of population vulnerability related to the influence of underlying large-scale processes. We analyzed spatial and temporal variability of cholera incidence across six surveillance sites in the Bengal Delta and their association with regional hydroclimatic and environmental drivers. More specifically, we use salinity and flood inundation modeling across the vulnerable districts of Bangladesh to test earlier proposed hypotheses on the role of these environmental variables. Our results show strong influence of seasonal and interannual variability in estuarine salinity on spring outbreaks and inland flooding on fall outbreaks. A large segment of the population in the Bengal Delta floodplains remain vulnerable to these biannual cholera transmission mechanisms that provide ecologic and environmental conditions for outbreaks over large geographic regions

    Low demanding parental feeding style is associated with low consumption of whole grains among children of recent immigrants

    Get PDF
    We explored the influence of immigrant mothers feeding style on their children\u27s fruit, vegetable and whole grain intake and how this relationship differed by mother\u27s time in the U.S. Baseline data were collected on mother-child (3–12 yrs) dyads enrolled in Live Well (n = 313), a community-based, participatory, randomized controlled lifestyle intervention (2008–2013). Socio-demographics, years of residence in the U.S., behavioral data, and responses to the Caregiver\u27s Feeding Styles Questionnaire (CFSQ) were obtained from the mother. Measured heights and weights were obtained for both mother and child. Child dietary intake was assessed using the Block Food Screener. Separate multiple linear regression models were run, adjusting for child and mother covariates. Interactions between feeding styles and years in the U.S. (\u3c5 and ≥ 5 years), ethnicity, and child age were tested. Sixty-nine percent of mothers were overweight or obese, 46% of the children were overweight or obese. For mothers in the U.S. for \u3c 5 years, having a low demanding/high responsive style was associated with lower child intake of whole grains in adjusted models vs. a high demanding/high responsive style (p \u3c 0.05). This was not seen for mothers in the U.S. for ≥ 5 years. Thus, the influence of feeding style on dietary intake may change with length of time in the U.S. These hypotheses-generating findings call for future research to understand how broader socio-cultural factors influence the feeding dynamic among immigrants

    Feeding styles and child weight status among recent immigrant mother-child dyads

    Get PDF
    Background: Research has shown that parental feeding styles may influence children’s food consumption, energy intake, and ultimately, weight status. We examine this relationship, among recent immigrants to the US. Given that immigrant parents and children are at greater risk for becoming overweight/obese with increased time in the US, identification of risk factors for weight gain is critical. Methods: Baseline data was collected on 383 mother-child dyads enrolled in Live Well, a community-based, participatory, randomized controlled lifestyle intervention to prevent weight gain in recent immigrant mothers. Socio-demographic information together with heights and weights were collected for both mother and child. Acculturation, behavioral data, and responses to the Caregiver’s Feeding Styles Questionnaire (CFSQ) were also obtained from the mother. Results: The children’s average age was 6.2 ± 2.7 years, 58% male. Mothers had been in the country for an average of 6.0 ± 3.3 years, and are Brazilian (36%), Haitian (34%) and Latino (30%). Seventy-two percent of the mothers were overweight/obese, while 43% of the children were overweight/obese. Fifteen percent of mothers reported their feeding style as being high demanding/high responsive; 32% as being high demanding/low responsive; 34% as being low demanding/high responsive and 18% as being low demanding/low responsive. In bivariate analyses, feeding styles significantly differed by child BMIz-score, ethnic group, and mother’s perceived stress. In multiple linear regression, a low demanding/high responsive feeding style was found to be positively associated (ß = 0.56) with a higher child weight as compared to high demanding/high responsive, controlling for known covariates (p = 0.01). Conclusions: Most mothers report having a low demanding/high responsive feeding style, which is associated with higher child weight status in this diverse immigrant population. This finding adds to the growing literature that suggests this type of feeding style may be a risk factor for childhood obesity. Further research is needed to help understand the larger socio-cultural context and its influence on feeding dynamics among immigrant families and families of lower incomes. How parents establish a certain feeding style in their home country compared to when they move to the US “obesogenic” environment, should also be explored

    Feeding styles and evening family meals among recent immigrants

    Get PDF
    The protective effect of family meals on unhealthy weight gain and diet has been shown across multiple age groups; however, it is unknown whether a similar effect is present among diverse immigrant populations. In addition, little research has focused on factors associated with the frequency of evening family meals, such as feeding styles (how parents interact with their child around feeding). Therefore the goals of this paper are to explore the 1) association between the frequency of evening family meals and child weight status among new immigrant families, and 2) influence of immigrant mothers’ feeding styles on the frequency of evening family meals. Baseline self-reported socio-demographic information and measured heights and weights were collected for both mother and child (age range: 3–12 years) among 387 mother-child dyads enrolled in Live Well, a community-based, participatory-research, randomized controlled lifestyle intervention to prevent excessive weight gain in recent (U.S.) immigrant mothers and children. For children, height and weight measurements were transformed into BMI z-scores using age-and sex-specific CDC standards and categorized as overweight (85th–94th percentile) and obese (≥95th percentile); mothers’ BMI was calculated. Frequency of evening family meals, eating dinner in front of the TV, acculturation and responses to the Caregiver’s Feeding Styles Questionnaire (CFSQ) were also obtained from the mother. Children were categorized as “eating evening family meals regularly” if they had an evening family meal ≥5 times per week. Overall, 20% of children were overweight and 25% were obese. Less than half (40.9%) of families had regular evening family meals. In multivariate analyses, adjusting for covariates, children who were overweight/obese were significantly less likely to have ≥5 evening family meals/week compared with normal weight children (OR = 0.51, 95% CI 0.32-0.82) . Mothers who had a low demanding/high responsive or a low demanding/low responsive feeding style, were less likely to have ≥5 evening family meals/week compared to mothers with a high demanding/high responsive feeding style (OR = 0.41, 95% CI 0.18-0.0.96, OR = 0.33, 95% CI 0.13-0.87, respectively). Future interventions and programs that seek to help parents establish healthy household routines, such as family meals, may consider tailoring to specific maternal feeding styles

    Effective Control of Schistosoma haematobium Infection in a Ghanaian Community following Installation of a Water Recreation Area

    Get PDF
    BackgroundUrogenital schistosomiasis caused by Schistosoma haematobium was endemic in Adasawase, Ghana in 2007. Transmission was reported to be primarily through recreational water contact.MethodsWe designed a water recreation area (WRA) to prevent transmission to school-aged children. The WRA features a concrete pool supplied by a borehole well and a gravity-driven rainwater collection system; it is 30 m2 and is split into shallow and deep sections to accommodate a variety of age groups. The WRA opened in 2009 and children were encouraged to use it for recreation as opposed to the local river. We screened children annually for S. haematobium eggs in their urine in 2008, 2009, and 2010 and established differences in infection rates before (2008–09) and after (2009–10) installation of the WRA. After each annual screening, children were treated with praziquantel and rescreened to confirm parasite clearance.Principal FindingsInitial baseline testing in 2008 established that 105 of 247 (42.5%) children were egg-positive. In 2009, with drug treatment alone, the pre-WRA annual cumulative incidence of infection was 29 of 216 (13.4%). In 2010, this incidence rate fell significantly (p<0.001, chi-squared) to 9 of 245 (3.7%) children after installation of the WRA. Logistic regression analysis was used to determine correlates of infection among the variables age, sex, distance between home and river, minutes observed at the river, low height-for-age, low weight-for-age, low Body Mass Index (BMI)-for-age, and previous infection status.Conclusion/SignificanceThe installation and use of a WRA is a feasible and highly effective means to reduce the incidence of schistosomiasis in school-aged children in a rural Ghanaian community. In conjunction with drug treatment and education, such an intervention can represent a significant step towards the control of schistosomiasis. The WRA should be tested in other water-rich endemic areas to determine whether infection prevalence can be substantially reduced.Author SummaryUrogenital schistosomiasis is a disease caused by the parasite Schistosoma haematobium; it is often characterized by bloody urine and tends to disproportionately affect school-aged children in rural tropical regions. The parasite is transmitted via skin contact with surface water that is contaminated by human waste. The disease was endemic in Adasawase, a rural Ghanaian community, in 2007. Transmission occurred mainly through recreational water contact. We collaborated with community members to design a water recreation area (WRA) featuring a concrete pool supplied by a borehole well and a rainwater collection system. We opened the pool in 2009 and local officials encouraged children to use the WRA for recreation. We screened local children annually (2008, 2009, 2010) for S. haematobium infection. After each screening, children were treated with praziquantel and rescreened. Baseline testing in 2008 established that at least 105 of 247 (42.5%) children were infected. In 2009, 29 of 216 (13.4%) children were infected, reflecting annual cumulative incidence. In 2010, a significantly smaller percentage of children (9 of 245, 3.7%) were infected. We conclude that the WRA effectively reduced infection in Adasawase, and that it should be tested in other water-rich endemic areas

    Measurement of Angular Distributions and R= sigma_L/sigma_T in Diffractive Electroproduction of rho^0 Mesons

    Full text link
    Production and decay angular distributions were extracted from measurements of exclusive electroproduction of the rho^0(770) meson over a range in the virtual photon negative four-momentum squared 0.5< Q^2 <4 GeV^2 and the photon-nucleon invariant mass range 3.8< W <6.5 GeV. The experiment was performed with the HERMES spectrometer, using a longitudinally polarized positron beam and a ^3He gas target internal to the HERA e^{+-} storage ring. The event sample combines rho^0 mesons produced incoherently off individual nucleons and coherently off the nucleus as a whole. The distributions in one production angle and two angles describing the rho^0 -> pi+ pi- decay yielded measurements of eight elements of the spin-density matrix, including one that had not been measured before. The results are consistent with the dominance of helicity-conserving amplitudes and natural parity exchange. The improved precision achieved at 47 GeV, reveals evidence for an energy dependence in the ratio R of the longitudinal to transverse cross sections at constant Q^2.Comment: 15 pages, 15 embedded figures, LaTeX for SVJour(epj) document class Revision: Fig. 15 corrected, recent data added to Figs. 10,12,14,15; minor changes to tex
    corecore