The global spread and the increased frequency and magnitude of epidemic dengue in the last 50 years underscore the urgent need for effective tools for surveillance, prevention, and control. This review aims at providing a systematic overview of what predictors are critical and which spatial and spatio-temporal modeling approaches are useful in generating risk maps for dengue. A systematic search was undertaken, using the PubMed, Web of Science, WHOLIS, Centers for Disease Control and Prevention (CDC) and OvidSP databases for published citations, without language or time restrictions. A manual search of the titles and abstracts was carried out using predefined criteria, notably the inclusion of dengue cases. Data were extracted for pre-identified variables, including the type of predictors and the type of modeling approach used for risk mapping. A wide variety of both predictors and modeling approaches was used to create dengue risk maps. No specific patterns could be identified in the combination of predictors or models across studies. The most important and commonly used predictors for the category of demographic and socio-economic variables were age, gender, education, housing conditions and level of income. Among environmental variables, precipitation and air temperature were often significant predictors. Remote sensing provided a source of varied land cover data that could act as a proxy for other predictor categories. Descriptive maps showing dengue case hotspots were useful for identifying high-risk areas. Predictive maps based on more complex methodology facilitated advanced data analysis and visualization, but their applicability in public health contexts remains to be established. The majority of available dengue risk maps was descriptive and based on retrospective data. Availability of resources, feasibility of acquisition, quality of data, alongside available technical expertise, determines the accuracy of dengue risk maps and their applicability to the field of public health. A large number of unknowns, including effective entomological predictors, genetic diversity of circulating viruses, population serological profile, and human mobility, continue to pose challenges and to limit the ability to produce accurate and effective risk maps, and fail to support the development of early warning systems.

Climate change strongly impacts the agricultural sector in West Africa, threatening food security and nutrition, particularly for populations with the least adaptive capacity. Little is known about national climate change policies in the region. This systematic review identifies and analyses climate change policy documents in all 16 West African countries: (1) What are the existing climate change adaptation policies publicly available? (2) Which topics are addressed? (3) How are agriculture and food security framed and addressed? Following PRISMA guidelines, PubMed and Google scholar as key databases were searched with an extensive grey literature search. Keywords for searches were combinations of “Africa”, “Climate Change”, and “National Policy/Plan/Strategy/Guideline”. Fifteen countries have at least one national policy document on climate change in the frame of our study. Nineteen policy documents covered seven key sectors (energy, agriculture, water resources, health, forestry, infrastructure, and education), and eight thematic areas (community resilience, disaster risk management, institutional development, industry development, research and development, policy making, economic investment, and partnerships/collaboration). At the intersection of these sectors/areas, effects of changing climate on countries/populations were evaluated and described. Climate change adaptation strategies emerged including development of local risk/disaster plans, micro-financing and insurance schemes (public or private), green energy, and development of community groups/farmers organizations. No clear trend emerged when analysing the adaptation options, however, climate change adaptation in the agriculture sector was almost always included. Analysing agriculture, nutrition, and food security, seven agricultural challenges were identified: The small scale of West African farming, information gaps, missing infrastructure, poor financing, weak farmer/community organizations, a shifting agricultural calendar, and deteriorating environmental ecology. They reflect barriers to adaptation especially for small-scale subsistence farmers with increased climate change vulnerabilities. The study has shown that most West African countries have climate change policies. Nevertheless, key questions remain unanswered, and demand for further research, e.g., on evaluating the implementation in the respective countries, persists.

Among the many challenges faced by the people of Bangladesh, the effects of climate change are discernibly threatening, impacting on human settlement, agricultural production, economic development, and human health. Bangladesh is a low-income country with limited resources; its vulnerability to climate change has influenced individuals to seek out health coping strategies. The objectives of the study were to explore the different strategies/measures people employ to cope with climate sensitive diseases and sickness. A cross-sectional study was conducted among 450 households from Rajshahi and Khulna districts of Bangladesh selected through multi-stage sampling techniques, using a semi-structured questionnaire supplemented by 12 focus group discussions and 15 key informant interviews. Respondents applied 22 types of primary health coping strategies to prevent climate related diseases and sickness. To cope with health problems, 80.8% used personal treatment experiences and 99.3% sought any treatments available at village level. The percentage of respondents that visited unqualified health providers to cope with climate induced health problems was quite high, namely 92.7% visited village doctors, 75.9% drug stores, and 67.3% self-medicated. Ninety per cent of the respondents took treatment from unqualified providers as their first choice. Public health facilities were the first choice of treatment for only 11.0% of respondents. On average, every household spent Bangladesh Currency Taka 9,323 per year for the treatment of climate sensitive diseases and sickness. Only 46% of health expenditure was managed from their savings. The rest, 54% expenditure, was supported by using 24 different sources, such as social capital and the selling of family assets. The rate of out-of-pocket payment was almost 100%. People are concerned about climate induced diseases and sickness and sought preventive as well as curative measures to cope with health problems. The most common and widely used climate health coping strategies among the respondents included self-medicating and seeking the health service of unqualified private health care providers. Per family spending to cope with such health problems is expensive and completely based on out of pocket payment. There is no fund pooling, community funding or health insurance program in rural areas to support the health coping of the people. Policies are needed to reduce out-of-pocket payment, to improve the quality of the unqualified providers and to extend public health services at rural areas and support climate related health coping. Collection of such knowledge on climate related health coping strategies can allow researchers to study any specific issue on health coping, and policy makers to initiate effective climate related health coping strategies for climate vulnerable people.

In Sub Saharan Africa malaria remains one of the major health problems and its control represents an important public health measure. Integrated malaria control comprises the use of impregnated mosquito nets and indoor residual spraying. The use of drugs to treat patients can create additional pressure on the equation of malaria transmission. Vector control may target the adult mosquitoes or their aquatic larval stages. Biological larvicides such as Bacillus thuringiensis israelensis (Bti) represent a promising approach to support malaria control programs by creating additional pressure on the equation of malaria transmission. In this study we examined the efficacy of a water-dispersible granule formulation (WDG) of the biological larvicide Bti (VectoBac®) against wild Anopheles spp. larvae. Different concentrations of the larvicide were tested in standardized plastic tubs in the field against untreated controls. In weekly intervals tubs were treated with fixed concentrations of larvicide and the percentage reduction of larvae and pupae was calculated. All used concentrations successfully killed 100 percent of the larvae within 24 hours, while the higher concentrations showed a slightly prolonged residual effect. Natural reconolization of larvae took place after two and three days respectively, late instar larvae were not found before 5 days after treatment. For the higher concentrations, up to three days no new larvae were found, implicating that the residual effect of WDG in tropical conditions is approximately one to two days. The overall pupae reduction in treated tubs was 98.5%. Biological larviciding with Bti can be a promising, additional tool in the fight against malaria in Africa. Environmental particularities in tropical Africa, first and foremost the rapid development of mosquitoes from oviposition to imago have to be taken into account before implementing such counter measures in national or international vector control programs. Nonetheless biological larviciding seems to be an appropriate measure for selected conditions, offering a significant contribution to the future of malaria control.

Dengue is the major public health burden in Sri Lanka. Kalutara is one of the highly affected districts. Understanding the drivers of dengue is vital in controlling and preventing the disease spread. This study focuses on quantifying the influence of weather variability on dengue incidence over 10 Medical Officer of Health (MOH) divisions of Kalutara district. Weekly weather variables and data on dengue notifications, measured at 10 MOH divisions in Kalutara from 2009 to 2013, were retrieved and analysed. Distributed lag non-linear model and hierarchical-analysis was used to estimate division specific and overall relationships between weather and dengue. We incorporated lag times up to 12 weeks and evaluated models based on the Akaike Information Criterion. Consistent exposure-response patterns between different geographical locations were observed for rainfall, showing increasing relative risk of dengue with increasing rainfall from 50 mm per week. The strongest association with dengue risk centred around 6 to 10 weeks following rainfalls of more than 300 mm per week. With increasing temperature, the overall relative risk of dengue increased steadily starting from a lag of 4 weeks. We found similarly a strong link between the Oceanic Niño Index to weather patterns in the district in Sri Lanka and to dengue at a longer latency time confirming these relationships. Part of the influences of rainfall and temperature can be seen as mediator in the causal pathway of the Ocean Niño Index, which may allow a longer lead time for early warning signals. Our findings describe a strong association between weather, El Niño-Southern Oscillation and dengue in Sri Lanka.

Background: Effective and timely treatment is an essential aspect of malaria control, but remains a challenge in many parts of sub-Saharan Africa. The objective of this study was to describe young children's access to malaria treatment in Nouna Health District, Burkina Faso. Methods: In February/March 2006, a survey was conducted in a representative sample of 1,052 households. Results: Overall 149/1052 (14%) households reported the current possession of anti-malarial medicine, which was significantly associated with urban area, literacy of household head, having young children, and high socio-economic status. Out of a total of 802 children under five years, at least one malaria episode was reported for 239 (30%) within the last month. Overall 95% of children received treatment, either modern (72%), traditional (18%) or mixed (5%). Most of the medicines were provided as home treatment by the caregiver and half of children received some type of modern treatment within 24 hours of the occurrence of first symptoms. Despite a recent policy change to artemisinin-based combination therapy, modern anti-malarials consisted mainly of chloroquine (93%). Modern drugs were obtained more often from a health facility in localities with a health facility compared to those without (60% vs. 25.6%, p < 0.001). In contrast, beside informal providers, volunteer community health workers (CHW) were the main source of modern medicine in localities without a health centre (28% vs. 3%, p < 0.001). Conclusion: Access to modern health services providing quality controlled effective combination therapies against malaria needs to be strengthened in rural Africa, which should include a re-investigation of the role of CHW 30 years after Alma Ata.