Bayesian modelling of the effect of climate on malaria in Burundi

<p>Abstract</p> <p>Background</p> <p>In Burundi, malaria is a major public health issue in terms of both morbidity and mortality with around 2.5 million clinical cases and more than 15,000 deaths each year. It is the single main cause of mortality in pregnant women and children below five years of age. Due to the severe health and economic cost of malaria, there is still a growing need for methods that will help to understand the influencing factors. Several studies have been done on the subject yielding different results as which factors are most responsible for the increase in malaria. The purpose of this study has been to undertake a spatial/longitudinal statistical analysis to identify important climatic variables that influence malaria incidences in Burundi.</p> <p>Methods</p> <p>This paper investigates the effects of climate on malaria in Burundi. For the period 1996-2007, real monthly data on both malaria epidemiology and climate in the area of Burundi are described and analysed. From this analysis, a mathematical model is derived and proposed to assess which variables significantly influence malaria incidences in Burundi. The proposed modelling is based on both generalized linear models (GLM) and generalized additive mixed models (GAMM). The modelling is fully Bayesian and inference is carried out by Markov Chain Monte Carlo (MCMC) techniques.</p> <p>Results</p> <p>The results obtained from the proposed models are discussed and it is found that malaria incidence in a given month in Burundi is strongly positively associated with the minimum temperature of the previous month. In contrast, it is found that rainfall and maximum temperature in a given month have a possible negative effect on malaria incidence of the same month.</p> <p>Conclusions</p> <p>This study has exploited available real monthly data on malaria and climate over 12 years in Burundi to derive and propose a regression modelling to assess climatic factors that are associated with monthly malaria incidence. The results obtained from the proposed models suggest a strong positive association between malaria incidence in a given month and the minimum temperature (night temperature) of the previous month. An open question is, therefore, how to cope with high temperatures at night.</p

Improving knowledge and practices of mitigating green house gas emission through waste recycling in a community, Ibadan, Nigeria

Throughout the world, waste sector has been implicated in significant contribution to anthropogenic greenhouse gas (GHG) emissions. Involving communities in recycling their solid waste would ensure climate change effect mitigation and resilience. This study was carried out to improve waste management practices through a community-led intervention at Kube-Atenda community in Ibadan, Nigeria. The study adopted a quasi-experimental design, comprising mixed method of data collection such as semi- structured questionnaire and a life-cycle-based model for calculating greenhouse gas generation potentials of various waste management practices in the area. A systematic random sampling was used to select sixty (60) households for a survey on knowledge, attitude and practices of waste management through Recovery, Reduction, Reuse and Recycling (4Rs) before and after the training intervention. Data collected were summarised using descriptive statistics, chi-square test, t-test and ANOVA at p = 0.05. The mean age of the respondent was 49.7 ± 16.7 and 68.3% were females. Respondents' knowledge scores before and after the intervention were significantly different: 7.07 ± 1.48 and 11.6 ± 1.6 while attitude scores were: 8.2 ± 2.3 and 13.5 ± 0.8. There were significant differences in the major waste disposal practices in the community before and after the intervention. All (100%) the participants were willing to participate in waste recycling business and the model predicted that adoption of 4Rs strategy had a great potential in saving greenhouse gas emissions in the community. The behaviour of the community people has changed towards waste management that promote climate change mitigation and adaptation through waste reduction, reuse, and resource recovery

The effects of aflatoxin exposure on Hepatitis B-vaccine induced immunity in Kenyan children

Background: Globally, approximately three million children die each year from vaccine preventable infectious diseases mainly in developing countries. Despite the success of the expanded immunization program, not all infants and children around the world develop the same protective immune response to the same vaccine. A vaccine must induce a response over the basal immune response that may be driven by population-specific, environmental or socio-economic factors. Mycotoxins like aflatoxins are immune suppressants that are confirmed to interfere with both cell-mediated and acquired immunity. The mechanism of aflatoxin toxicity is through the binding of the bio-activated AFB1-8, 9-epoxide to cellular macromolecules. Methods: We studied Hepatitis B surface antibodies [anti-HBs] levels to explore the immune modulation effects of dietary exposure to aflatoxins in children aged between one and fourteen years in Kenya. Hepatitis B vaccine was introduced for routine administration for Kenyan infants in November 2001. To assess the effects of aflatoxin on immunogenicity of childhood vaccines Aflatoxin B1-lysine in blood serum samples were determined using High Performance Liquid Chromatography with Fluorescence detection while anti-HBs were measured using Bio-ELISA anti-HBs kit. Results: The mean ± SD of AFB1-lysine adducts in our study population was 45.38 ± 87.03 pg/mg of albumin while the geometric mean was 20.40 pg/mg. The distribution of AFB1-lysine adducts was skewed to the right. Only 98/205 (47.8%) of the study population tested positive for Hepatitis B surface antibodies. From regression analysis, we noted that for every unit rise in serum aflatoxin level, anti-HBs dropped by 0.91 mIU/ml (−0.9110038; 95% C.I −1.604948, −0.21706). Conclusion: Despite high coverage of routine immunization, less than half of the study population had developed immunity to HepB. Exposure to aflatoxin was high and weakly associated with low anti-HBs antibodies. These findings highlight a potentially significant role for environmental factors that may contribute to vaccine effectiveness warranting further research