Rapid assessment for prioritisation of trachoma control at community level in one district of the Kaolack Region, Senegal.

The objective of this study was to use a modified Lot Quality Assurance Sampling methodology to classify communities according to prevalence of active trachoma and to estimate the prevalence of trachoma and trichiasis in Nioro department, Kaolack Region, Senegal. A survey was conducted using two-stage cluster sampling to select 50 children aged 2-5 years in each of 33 clusters. In total 1,648 children were examined for active trachoma. Information on trachoma risk factors was collected through interviews with the mother or the household head of the child. Adults (>40 years) with trichiasis were identified through case finding. Nineteen clusters had a low prevalence of active trachoma in children aged 2-5 years (40%). The prevalence of active trachoma in children aged 2-5 years was 17.4% (95% CI 12.9-21.8%). Multivariate-adjusted predictors of active trachoma were: age, facial cleanliness, hygiene practices and keeping cattle in the household. The prevalence of trichiasis in adults aged over 40 years was 1.77% (95% CI 1.24-2.51), equating to 985 adults (95% CI 765-1250) with trichiasis in Nioro department. In conclusion, a survey using rapid methodology showed that trachoma is a problem of public significance in Nioro department, Senegal

On trial: agricultural biotechnology in Africa

Increasing agricultural productivity and adapting farming to climate change are central to Africa’s development prospects. There are important opportunities to enhance yields and increase resilience through the adoption of improved crop varieties. In some cases, biotechnology, and in particular genetic modification (GM), offers advantages over conventional plant-breeding approaches. Accordingly there are a various projects under way to develop new GM varieties for African farmers, ranging from drought-resistant maize to varieties of cassava, banana, sorghum, cowpea and sweet potato with resistance to pests and disease. In addition to government funds, these projects have also attracted the support of influential donor agencies and philanthropic foundations. However, despite the expenditure of considerable resources, the potential of GM in Africa is not being realized. So far no GM trait developed for African farmers has been put to use. Multiple barriers inhibit the development and adoption of pro-poor GM varieties in Africa. On the demand side, farmers may be reluctant to adopt GM varieties owing to a lack of export opportunities and distrust of the technology among local consumers. Farmers may also be concerned about exploitation by transnational seed companies (despite the fact that development of new GM technologies in Africa is dominated by the public sector). On the supply side, donor funding struggles to match the long timescales of research and development, while incentives among research scientists may be poorly aligned with farmer outcomes. Non-existent, poorly functioning or overly punitive regulatory regimes discourage investment. The most important barriers – such as regulatory constraints, consumer distrust and weak farmer demand – must be understood in the context of wider social and political dynamics surrounding GM, typified by misinformation, polarized public discourse, and dysfunctional and opportunistic politics. The result is most GM projects becoming ‘stuck’ at the field trial stage without ever progressing to release. This ‘convenient deadlock’ of continual field trials allows governments to manage political risks by effectively balancing the demands of pro-GM and anti-GM lobbies – proponents of GM have a pipeline of technologies, while opponents are appeased by the failure of any to gain approval. The disabling socio-political environment for GM development in Africa greatly reduces the efficacy of investment in this technology. This has two important implications. First, technology development needs to be located within a wider project of transformation that engages key actors – most notably politicians, policy-makers and farmers – as stakeholders from the outset, and includes strategies to address multiple demand- and supply-side barriers. Second, successful adoption is more likely in countries with less disabling political conditions, characterized by lower levels of consumer distrust and opposition, genuine farmer demand and demonstrable commitment from government. Focusing efforts and resources on a small number of ‘best bet’ countries will also allow donors and technology providers to support more ambitious, transformational projects led by national governments

Design and characterization of a research electrohydraulic lithotripter patterned after the Dornier HM3

An electrohydraulic lithotripter has been designed that mimics the behavior of the Dornier HM3 extracorporeal shock wave lithotripter. The key mechanical and electrical properties of a clinical HM3 were measured and a design implemented to replicate these parameters. Three research lithotripters have been constructed on this design and are being used in a multi-institutional, multidisciplinary research program to determine the physical mechanisms of stone fragmentation and tissue damage in shock wave lithotripsy. The acoustic fields of the three research lithotripters and of two clinical Dornier HM3 lithotripters were measured with a PVDF membrane hydrophone. The peak positive pressure, peak negative pressure, pulse duration, and shock rise time of the focal waveforms were compared. Peak positive pressures varied from 25 MPa at a voltage setting of 12 kV to 40 MPa at 24 kV. The magnitude of the peak negative pressure varied from -7 to -12 MPa over the same voltage range. The spatial variations of the peak positive pressure and peak negative pressure were also compared. The focal region, as defined by the full width half maximum of the peak positive pressure, was 60 mm long in the axial direction and 10 mm wide in the lateral direction. The performance of the research lithotripters was found to be consistent at clinical firing rates (up to 3 Hz). The results indicated that pressure fields in the research lithotripters are equivalent to those generated by a clinical HM3 lithotripter

An outbreak of acute haemorrhagic conjunctivitis associated with coxsackievirus A24 variant in The Gambia, West Africa.

OBJECTIVE: An outbreak of acute haemorrhagic conjunctivitis occurred in The Gambia, West Africa in 2011. Affected individuals presented with conjunctival haemorrhages, swelling and ocular discharge. In an effort to identify a causative agent of the disease, ocular swabs were taken from patients during the acute and convalescent phases. Total RNA was extracted from all samples and reverse-transcriptase PCR performed using primers specific for all enteroviruses. Resulting amplicons were sequenced and data compared to known sequences using the BLAST algorithm. RESULTS: Forty-eight swabs were included in the analysis. Of these, 21 acute and 9 convalescent swabs (65% of the total) gave positive PCR results. Sequence analysis of the resulting amplicons indicated 99% sequence identity with coxsackievirus A24 variant identified during independent outbreaks of acute haemorrhagic conjunctivitis around the world and suggest the Gambian outbreak was due to this virus

Clustering in 18O - absolute determination of branching ratios via high-resolution particle spectroscopy

The determination of absolute branching ratios for high-energy states in light nuclei is an important and useful tool for probing the underlying nuclear structure of individual resonances: for example, in establishing the tendency of an excited state towards α -cluster structure. Difficulty arises in measuring these branching ratios due to similarities in available decay channels, such as ( 18 O, n ) and ( 18 O, 2 n ), as well as differences in geometric efficiencies due to population of bound excited levels in daughter nuclei. Methods are presented using Monte Carlo techniques to overcome these issues

The prevalence and risk factors for acute respiratory infections in children aged 0-59 months in rural Malawi: A cross-sectional study.

BACKGROUND: Acute Respiratory Infections (ARI) are a leading cause of childhood mortality and morbidity. Malawi has high childhood mortality but limited data on the prevalence of disease in the community. METHODS: A cross-sectional study of children aged 0-59 months. Health passports were examined for ARI diagnoses in the preceding 12 months. Children were physically examined for malnutrition or current ARI. RESULTS: 828 children participated. The annual prevalence of ARI was 32.6% (95% CI 29.3-36.0%). Having a sibling with ARI (OR 1.44, P = .01), increasing household density (OR 2.17, P = .02) and acute malnutrition (OR 1.69, P = .01) were predictors of infection in the last year. The point prevalence of ARI was 8.3% (95% CI 6.8-10.4%). Risk factors for current ARI were acute-on-chronic malnutrition (OR 3.06, P = .02), increasing household density (OR1.19, P = .05) and having a sibling with ARI (OR 2.30, P = .02). CONCLUSION: This study provides novel data on the high prevalence of ARI in Malawi. This baseline data can be used in the monitoring and planning of future interventions in this population

Towards a safe and effective chlamydial vaccine: lessons from the eye.

As well as being the most common bacterial sexually transmitted infection, Chlamydia trachomatis (Ct) is the leading infectious cause of blindness. The pathogenesis of ocular chlamydial infection (trachoma) is similar to that of genital infection. In the 1960s the efficacy of Ct vaccines against ocular infection was evaluated in major field trials in Saudi Arabia, Taiwan, The Gambia, India and Ethiopia. These trials showed that it was possible to induce short term immunity to ocular infection, and to reduce the incidence of inflammatory trachoma, by parenteral immunisation with killed or live whole organism vaccines. In one study, it was also shown that the incidence of scarring sequelae was reduced in vaccinated children. Detailed studies in non-human primates conducted at this time suggested that vaccination could lead to more severe inflammatory disease on subsequent challenge. Since that time there have been many studies on the immunological correlates of protective immunity and immunopathology in ocular Ct infection in humans and non-human primates, and on host genetic polymorphisms associated with protection from adverse sequelae. These have provided important information to guide the development and evaluation of a human Ct vaccine

Best Practices for Conducting Observational Research to Assess the Relation between Nutrition and Bone: An International Working Group Summary

Diet is a modifiable factor that can affect bone strength and integrity, and the risk of fractures. Currently, a hierarchy of scientific evidence contributes to our understanding of the role of diet on bone health and fracture risk. The strength of evidence is generally based on the type of study conducted, the quality of the methodology employed, the rigor and integrity of the data collected and analysis plan, and the transparency and completeness of the results. Randomized controlled trials (RCTs) are considered to be the gold standard from a clinical research paradigm, but there is a dearth of high-quality diet-related intervention trials with bone as the primary outcome, forcing the use of observational research to inform research and clinical practices. However, for observational research to be of the most utility, standardization and optimization of the study design, accurate and reliable measurement of key variables, and appropriate data analysis and data reporting are paramount. Although there have been recommendations made in relation to RCTs in the field of nutrition, no clear rubric exists for best practices in conducting observational research with regard to nutrition and bone health. Therefore, the purpose of this paper is to describe the best practices and considerations for designing, conducting, analyzing, interpreting, and reporting observational research specifically for understanding the role of nutrition in bone health, amassed by a global panel of scientific experts with strengths in bone, nutrition epidemiology, physical activity, public health, clinical and translational trials, and observational study methods. The global panel of scientific experts represents the leadership and selected participants from the 10th annual International Symposium for the Nutritional Aspects of Osteoporosis. The topics selected and best practices presented reflect expert opinion and areas of scientific expertise of the authors rather than a systematic or comprehensive literature review or professional reporting guidelines

Non-Chlamydial Bacterial Infection and Progression of Conjunctival Scarring in Trachoma.

Purpose: The purpose of this study was to assess whether non-chlamydial bacterial infection is associated with progression of trachomatous scarring in adults. Methods: This was a cohort study involving 800 participants in northern Tanzania who underwent clinical examination, photography, and conjunctival swab collection for microbiology over a 24-month period. Samples for microbiology were inoculated onto blood and chocolate agar, and Chlamydia trachomatis was detected by PCR. Progression was determined by comparison of baseline to 24-month photographs. Results: C. trachomatis was detected in only four participants at baseline. At 24 months, 617 participants (77.1%) were followed up. Of those seen at 24 months, 452 could be reliably assessed. Definite scarring progression (progressors) was seen in 345 (55.9%); there was no progression (nonprogressors) in 107 (17.3%). Using combined baseline and 12-month microbiology results, progressors had significantly higher levels of commensal and pathogenic bacterial organisms detected compared with nonprogressors. After adjusting for age, baseline scarring, and ethnicity, there was weak evidence (P = 0.07) that the bacteria category was associated with scarring progression (commensal organisms only: odds ratio [OR] = 1.61; 95% confidence interval [CI]: 0.90 to 2.89; pathogenic organisms either with or without commensal: OR = 2.39; 95% CI: 1.10 to 5.16). Conclusion: The findings were consistent with the possibility that trachomatous scarring in adults is associated with the presence of non-chlamydial bacterial organisms, particularly pathogenic organisms. C. trachomatis was detected very infrequently and may not be an important factor in the pathogenesis of scarring progression in adults. This has implications for trachoma control programs, which largely concentrate on reducing C. trachomatis levels and transmission