Integrated malaria vector control with microbial larvicides and insecticide-treated nets in western Kenya: a controlled trial

Objective

To assess the contributions of both microbial larvicides and insecticide-treated nets (ITNs) in terms of reducing malaria incidence in an integrated vector management programme in an area moderately endemic for malaria in the western Kenyan highlands.

Methods

A pre-post, control group design was used. Larval and adult vector populations were surveyed weekly in six separate valley communities. The incidence of Plasmodium infections in children 6 months to 13 years of age was measured during the long and short rainy seasons each year. Baseline data were collected for 17 months, after which Bacillus-based larvicides were applied weekly to aquatic habitats in three of the valleys for another 19 months. At around the same time the larviciding was initiated, ITNs were introduced gradually into all study communities by the National Malaria Control Programme. The effect of larviciding, ITNs and other determinants of malaria risk was assessed by means of generalized estimating equations.

Findings

The risk of acquiring new parasite infections in children was substantially and independently reduced by ITN use (odds ratio, OR: 0.69; 95% confidence interval, CI: 0.48–0.99) and larvicide application (OR: 0.44; 95% CI: 0.23–0.82), after adjusting for confounders.

Conclusion

Vector control with microbial larvicides enhanced the malaria control achieved with ITNs alone. Anti-larval measures are a promising complement to ITN distribution in the economically important highland areas and similar transmission settings in Africa.     

Alcohol questionnaires and HDL: Screening scores as scaled markers of alcohol consumption

Improving the quality of alcohol-related care requires practical approaches to assessing alcohol consumption to guide management and monitor outcomes. Given the increasing use of alcohol screening questionnaires to identify alcohol misuse it would be ideal if scores on screening questionnaires were also indicators of average alcohol consumption. However, the questionnaires were not designed for this purpose and include dimensions of drinking that may not reflect average consumption (e.g. heavy episodic drinking, alcohol-related problems). In a general population sample, scores on the AUDIT-C screen correlated with reports of alcohol consumption in detailed interviews, but the relationship is unknown for clinical populations and other questionnaires. Serum high-density lipoprotein cholesterol (HDL) is a biomarker routinely obtained in clinical care and is known to rise with average alcohol consumption. This cross-sectional study of 11,175 male U.S. Veterans Affairs patients enrolled in a primary care study used HDL as an objective biomarker to evaluate whether average alcohol consumption increased as scores increased on 3 brief alcohol screens – the AUDIT-C, AUDIT Question #3 (a single-item screen), and the CAGE questionnaire. Mean HDL progressively increased as screening scores increased for the AUDIT-C and AUDIT Question #3: about 12 mg/dL from the lowest to the highest scores. The association was much weaker for the CAGE questionnaire. Results were minimally affected by adjustment for covariates (e.g. age, race, medical comorbidity, smoking, medication count, and depression) but the association was modified (p = 0.008) and mildly attenuated by adherent use of lipid-lowering medications. This study using HDL as a biomarker of average alcohol consumption adds to evidence that some alcohol screening scores may also serve as scaled markers of average alcohol consumption.     

'Whatever you say . . . say nothing'. Youth for youth, reflections on a 2-year youth participation project

From January 2000 to December 2002 save the Children worked in partnership with a group of young people, concerning their experience of the conflict and their invisibility within the new political context in Northern Ireland. This paper will consider the learning realised through this partnership with children and young people, reflecting first on the difficulties in working directly with the issues of experience and identity within the context of ongoing conflict, second on the expectations of young people and organisations working for change within this problematic and sensitive context, and finally on the barriers young people experience working for change within a fluctuating political environment.

Despite the fact that the number of young people involved in this initiative was small, it is hoped that the reflections and learning within this paper may be of use to those interested in exploring the challenges of partnership approaches with young people.     

Embryotoxicity of weathered crude oil from the Gulf of Mexico in mallard ducks (Anas platyrhynchos)

Weathered crude oil in the Gulf of Mexico can result from oil spills such as the Deepwater Horizon incident that occurred on April 20, 2010 or from natural seeps. Adult waterbirds of the Gulf Coast region may become exposed to weathered crude oil while foraging, wading, or resting, and residues can then be transferred to nests, eggs, and hatchlings. Although the toxicity of many types of crude oil to avian embryos has been thoroughly studied, the effects of weathered crude oil on developing avian embryos are not well characterized. The objective of the present study was to examine embryotoxicity of weathered crude oil collected from the Gulf of Mexico in June 2010 using mallard ducks (Anas platyrhynchos) as a model species. Weathered crude oil was applied to fertilized mallard duck eggs by paintbrush in masses ranging from 0.1 to 99.9?mg on day 3 of incubation. Mortality occurred as early as day 7 and the conservatively derived median lethal application of weathered crude oil was 30.8?mg/egg (0.5?mg/g egg) or 30.7?μl/egg (0.5?μl/g egg). Body mass, liver and spleen mass, crown-rump and bill lengths, and frequency of deformities were not significantly different among hatchlings from oiled and control eggs. In comparison to published reports of fresh crude oil embryotoxicity, weathered crude oil was considerably less toxic. We conclude that avian toxicity varies according to the degree of crude oil weathering and the stage of embryonic development at the time of exposure. Results indicate bird eggs exposed to weathered crude oil from the Gulf of Mexico during summer 2010 may have had reduced hatching success.     

Solution structure and dynamics of a de novo designed three-helix bundle protein

Although de novo protein design is an important endeavor with implications for understanding protein folding, until now, structures have been determined for only a few 25- to 30-residue designed miniproteins. Here, the NMR solution structure of a complex 73-residue three-helix bundle protein, alpha3D, is reported. The structure of alpha3D was not based on any natural protein, and yet it shows thermodynamic and spectroscopic properties typical of native proteins. A variety of features contribute to its unique structure, including electrostatics, the packing of a diverse set of hydrophobic side chains, and a loop that incorporates common capping motifs. Thus, it is now possible to design a complex protein with a well defined and predictable three-dimensional structure.