60,418 research outputs found
Malaria parasite detection increases during pregnancy in wild chimpanzees
Background: The diversity of malaria parasites (Plasmodium sp.) infecting chimpanzees (Pan troglodytes) and their close relatedness with those infecting humans is well documented. However, their biology is still largely unexplored and there is a need for baseline epidemiological data. Here, the effect of pregnancy, a well-known risk factor for malaria in humans, on the susceptibility of female chimpanzees to malaria infection was investigated.
Methods: A series of 384 faecal samples collected during 40 pregnancies and 36 post-pregnancies from three habituated groups of wild chimpanzees in the Tai National Park, Cote d'Ivoire, were tested. Samples were tested for malaria parasites by polymerase chain reaction (PCR) and sequencing. Data were analysed using a generalized linear mixed model.
Results: Probability of malaria parasite detection significantly increased towards the end of pregnancy and decreased with the age of the mother.
Conclusions: This study provides evidence that susceptibility to malaria parasite infection increases during pregnancy, and, as shown before, in younger individuals, which points towards similar dynamics of malaria parasite infection in human and chimpanzee populations and raises questions about the effects of such infections on pregnancy outcome and offspring morbidity/mortality
Predictors and Consequences of Anaemia Among Antiretroviral-Naïve HIV-Infected and HIV-Uninfected Children in Tanzania.
Predictors and consequences of childhood anaemia in settings with high HIV prevalence are not well known. The aims of the present study were to identify maternal and child predictors of anaemia among children born to HIV-infected women and to study the association between childhood anaemia and mortality. Prospective cohort study. Maternal characteristics during pregnancy and Hb measurements at 3-month intervals from birth were available for children. Information was also collected on malaria and HIV infection in the children, who were followed up for survival status until 24 months after birth. Dar es Salaam, Tanzania. The study sample consisted of 829 children born to HIV-positive women. Advanced maternal clinical HIV disease (relative risk (RR) for stage > or =2 v. stage 1: 1.31, 95 % CI 1.14, 1.51) and low CD4 cell counts during pregnancy (RR for <350 cells/mm3 v. > or =350 cells/mm3: 1.58, 95 % CI 1.05, 2.37) were associated with increased risk of anaemia among children. Birth weight <2500 g, preterm birth (<34 weeks), malaria parasitaemia and HIV infection in the children also increased the risk of anaemia. Fe-deficiency anaemia in children was an independent predictor of mortality in the first two years of life (hazard ratio 1.99, 95 % CI 1.06, 3.72). Comprehensive care including highly active antiretroviral therapy to eligible HIV-infected women during pregnancy could reduce the burden of anaemia in children. Programmes for the prevention of mother-to-child transmission of HIV and antimalarial treatment to children could improve child survival in settings with high HIV prevalence
Timescale effect estimation in time-series studies of air pollution and health: A Singular Spectrum Analysis approach
A wealth of epidemiological data suggests an association between
mortality/morbidity from pulmonary and cardiovascular adverse events and air
pollution, but uncertainty remains as to the extent implied by those
associations although the abundance of the data. In this paper we describe an
SSA (Singular Spectrum Analysis) based approach in order to decompose the
time-series of particulate matter concentration into a set of exposure
variables, each one representing a different timescale. We implement our
methodology to investigate both acute and long-term effects of
exposure on morbidity from respiratory causes within the urban area of Bari,
Italy.Comment: Published in at http://dx.doi.org/10.1214/07-EJS123 the Electronic
Journal of Statistics (http://www.i-journals.org/ejs/) by the Institute of
Mathematical Statistics (http://www.imstat.org
Effectiveness of a Faith-placed Cardiovascular Health Promotion Intervention for Rural Adults
Introduction: Cardiovascular disease (CVD) is the leading cause of mortality in the US. Further, rural US adults experience disproportionately high CVD prevalence and mortality compared to non-rural. Cardiovascular risk-reduction interventions for rural adults have shown short-term effectiveness, but long-term maintenance of outcomes remains a challenge. Faith organizations offer promise as collaborative partners for translating evidence-based interventions to reduce CVD.
Methods: We adapted and implemented a collaborative, faith-placed, CVD risk-reduction intervention in rural Illinois. We used a quasi-experimental, pre-post design to compare changes in dietary and physical activity among participants. Intervention components included Heart Smart for Women (HSFW), an evidence-based program implemented weekly for 12 weeks followed by Heart Smart Maintenance (HSM), implemented monthly for two years. Participants engaged in HSFW only, HSM only, or both. We used regression and generalized estimating equations models to examine changes in outcomes after one year.
Results: Among participants who completed both baseline and one-year surveys (n = 131), HSFW+HSM participants had significantly higher vegetable consumption (p = .007) and combined fruit/vegetable consumption (p = .01) compared to the HSM-only group at one year. We found no differences in physical activity.
Conclusion: Improving and maintaining CVD-risk behaviors is a persistent challenge in rural populations. Advancing research to improve our understanding of effective translation of CVD risk-reduction interventions in rural populations is critical
Dynamic Modelling of Child Mortality in Developing Countries: Application for Zambia
In this paper, we analyse the causes of under five mortality in Zambia, with a particular emphasis on assessing possible time-variations in the effects of covariates, i.e. whether the effects of certain covariates vary with the age of the child. The analysis is based on micro data from the 1992 Demographic and health Survey. Employing a Bayesian dynamic logit model for discrete time survival data and Markov-Chain Monte Carlo methods, we find that there are several variables, including the age of the mother and the breastfeeding duration whose effects exhibit distinct age-dependencies. In the case of breastfeeding, this age dependency is intimately linked with the reasons for stopping breastfeeding. Incorporating such age dependencies greatly improves the explanatory power of the model and yields new insights on the differential role of covariates on child survival
Air pollution and mortality : results from Santiago, Chile
Heavy outdoor pollution is found in developing country cities such as Jakarta, Katowice, Mexico City, and Santiago. But most epidemiological studies of dose-response relationships between particulate air pollution (PM10) and premature deaths are from Western industrial nations. This study of such relationships in developing countries by the authors fills an important gap. It is also one of the few based on monitored PM10 values, or small particles, which is likely to be a more relevant measure of exposure to air pollution than the more traditional measure of total suspended particulates. Over several years, daily measures of ambient PM10 were collected in Santiago. Data were collected for all deaths, as well as for deaths for all men, all women, and all people over 64. Deaths from respiratory and cardiovascular disease were recorded separately, and accidental deaths were excluded. Multiple regression analysis was used to explain mortality, with particular attention to the influence of season and temperature. The association persists after controlling for daily minimum temperature and binary variables indicating temperature extremes the day of the week, the month, and the year. Additional sensitivity analysis suggests robust relationships. A change equal to 10-microgram-per-cubic-meter in daily PM10 (about 9 percent) averaged over three days was associatedwith a 1.1 percent increase in mortality (95 percent confidence interval: 0.6 to 1.5 percent). Death from respiratory and cardiovascular disease was more responsive to changes in PM10 than total mortality was. The same holds for mortality among men and mortality among individuals older than 64. The results are surprising consistent with results from industrial countries.Public Health Promotion,Air Quality&Clean Air,Health Monitoring&Evaluation,Montreal Protocol,Statistical&Mathematical Sciences,Statistical&Mathematical Sciences,Montreal Protocol,Airports and Air Services,Health Economics&Finance,Health Monitoring&Evaluation
Low uptake of antiretroviral therapy after admission with human immunodeficiency virus and tuberculosis in KwaZulu-Natal, South Africa.
A prospective cohort study was conducted among human immunodeficiency virus (HIV) infected in-patients with tuberculosis (TB) or other opportunistic infections (OIs) in South Africa to estimate subsequent antiretroviral therapy (ART) uptake and survival
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