39 research outputs found

    Historical environmental change in Africa drives divergence and admixture of Aedes aegypti mosquitoes: a precursor to successful worldwide colonization?

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    Article PurchasedIncreasing globalization has promoted the spread of exotic species, including disease vectors. Understanding the evolutionary processes involved in such colonizations is both of intrinsic biological interest and important to predict and mitigate future disease risks. The Aedes aegypti mosquito is a major vector of dengue, chikungunya and Zika, the worldwide spread of which has been facilitated by Ae. aegypti's adaption to human-modified environments. Understanding the evolutionary processes involved in this invasion requires characterization of the genetic make-up of the source population(s). The application of approximate Bayesian computation (ABC) to sequence data from four nuclear and one mitochondrial marker revealed that African populations of Ae. aegypti best fit a demographic model of lineage diversification, historical admixture and recent population structuring. As ancestral Ae. aegypti were dependent on forests, this population history is consistent with the effects of forest fragmentation and expansion driven by Pleistocene climatic change. Alternatively, or additionally, historical human movement across the continent may have facilitated their recent spread and mixing. ABC analysis and haplotype networks support earlier inferences of a single out-of-Africa colonization event, while a cline of decreasing genetic diversity indicates that Ae. aegypti moved first from Africa to the Americas and then to Asia. ABC analysis was unable to verify this colonization route, possibly because the genetic signal of admixture obscures the true colonization pathway. By increasing genetic diversity and forming novel allelic combinations, divergence and historical admixture within Africa could have provided the adaptive potential needed for the successful worldwide spread of Ae. aegypti

    Strategies for specialty training of healthcare professionals in low-resource settings: a systematic review on evidence from stroke care

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    Background: The greatest mortality and disability from stroke occurs in low- and middle-income countries. A significant barrier to implementation of best stroke care practices in these settings is limited availability of specialized healthcare training. We conducted a systematic review to determine the most effective methods for the provision of speciality stroke care education for hospital-based healthcare professionals in low-resource settings. Methods: We followed the PRISMA guidelines for systematic reviews and searched PubMed, Web of Science and Scopus for original clinical research articles that described or evaluated stroke care education for hospital-based healthcare professionals in low-resource settings. Two reviewers screened titles/abstracts and then full text articles. Three reviewers critically appraised the articles selected for inclusion. Results: A total of 1,182 articles were identified and eight were eligible for inclusion in this review; three were randomized controlled trials, four were non-randomized studies, and one was a descriptive study. Most studies used several approaches to education. A “train-the-trainer” approach to education was found to have the most positive clinical outcomes (lower overall complications, lengths of stay in hospital, and clinical vascular events). When used for quality improvement, the “train-the-trainer” approach increased patient reception of eligible performance measures. When technology was used to provide stroke education there was an increased frequency in diagnosis of stroke and use of antithrombotic treatment, reduced door-to-needle times, and increased support for decision making in medication prescription was reported. Task-shifting workshops for non-neurologists improved knowledge of stroke and patient care. Multidimensional education demonstrated an overall care quality improvement and increased prescriptions for evidence-based therapies, although, there were no significant differences in secondary prevention efforts, stroke reoccurrence or mortality rates. Conclusions: The “train the trainer” approach is likely the most effective strategy for specialist stroke education, while technology is also useful if resources are available to support its development and use. If resources are limited, basic knowledge education should be considered at a minimum and multidimensional training may not be as beneficial. Research into communities of practice, led by those in similar settings, may be helpful to develop educational initiatives with relevance to local contexts

    A phase 2b randomized, controlled trial of the efficacy of the GMZ2 malaria vaccine in African children.

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    : GMZ2 is a recombinant protein malaria vaccine, comprising two blood-stage antigens of Plasmodium falciparum, glutamate-rich protein and merozoite surface protein 3. We assessed efficacy of GMZ2 in children in Burkina Faso, Gabon, Ghana and Uganda. : Children 12-60months old were randomized to receive three injections of either 100ÎŒg GMZ2 adjuvanted with aluminum hydroxide or a control vaccine (rabies) four weeks apart and were followed up for six months to measure the incidence of malaria defined as fever or history of fever and a parasite density â©Ÿ5000/ÎŒL. : A cohort of 1849 children were randomized, 1735 received three doses of vaccine (868 GMZ2, 867 control-vaccine). There were 641 malaria episodes in the GMZ2/Alum group and 720 in the control group. In the ATP analysis, vaccine efficacy (VE), adjusted for age and site was 14% (95% confidence interval [CI]: 3.6%, 23%, p-value=0.009). In the ITT analysis, age-adjusted VE was 11.3% (95% CI 2.5%, 19%, p-value=0.013). VE was higher in older children. In GMZ2-vaccinated children, the incidence of malaria decreased with increasing vaccine-induced anti-GMZ2 IgG concentration. There were 32 cases of severe malaria (18 in the rabies vaccine group and 14 in the GMZ2 group), VE 27% (95% CI -44%, 63%). : GMZ2 is the first blood-stage malaria vaccine to be evaluated in a large multicenter trial. GMZ2 was well tolerated and immunogenic, and reduced the incidence of malaria, but efficacy would need to be substantially improved, using a more immunogenic formulation, for the vaccine to have a public health role.<br/

    A Survey of Nematode Infection in Oreochromis niloticus (L.) (Teleostei: Cichlidae) in Lake Kyoga, Uganda

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    The incidence and intensity of nematode infection was investigated in Nile tilapia Oreochromis niloticus from Lake Kyoga, Uganda and 11% of the 406 fish examined were parasitized by nematodes of the genus Contracaecum. The prevalence of these parasites was greatest in the smallest and largest size classes, but this may reflect their small sample sizes. The prevalence of Contracaecum was similar to that in tilapias from a reservoir in India but much lower than in fish from South Africa and Ethiopia.

    Influence of physicochemical parameters on storage stability: Microbiological quality of fresh unpasteurized fruit juices

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    Fresh juices rich in health and nutritional benefits are valued for their fresh flavor, taste, and aroma. These juices' quality however is affected by factors like temperature, light, and microbiological contamination significantly changing physicochemical parameters and storage stability. Physicochemical and microbiological analyses of passion fruit, pineapple, and mango juices in dark and light bottles at 24°C and 4°C were conducted in Kampala, Uganda for 12 days. Physicochemical parameters significantly reduced (p &lt; .05) storage stability of fresh juices, while no significant changes (p &gt; .05) were observed for the microbiological analyses. pH values ranged from 3.0 to 4.2 (dark) bottles and 2.9 to 4.0 (light) bottles for juices at 24°C and 4°C. °Brix values were from 1.0 to 5.5 for dark and clear bottles at 24°C and 4°C. TTA (%) values ranged from 1.1 to 7.2 (dark) bottles and 1.1 to 7.4 for (light) bottles at 24°C and 4°C. Ascorbic acid content ranged from 3.5 to 61.0 mg/ 100 ml and 5.5 to 56.7 mg/100 ml for juices in dark and clear bottles, respectively. total plate counts ranged from 1.3 × 10___ to 3.3 × 107 CFU/ml (dark bottles at 24°C) to 3.5 × 10³ to 3.3 × 108 CFU/ml (dark bottles at 4°C). For juices in light bottles, total plate counts ranged from 1.8 × 10___ to 8.0 × 107 CFU/ml (24°C) and 2.7 × 10___ to 1.5 × 108 CFU/ml (4°C). High microbial loads suggest the use of poor processing techniques and lack of good hygiene which lower quality and reduce storage stability of juices. Storage temperature greatly reduces physicochemical parameters both at ambient and refrigeration temperatures. This implies that temperature control for unpasteurized juices is critical in order to inhibit microorganism metabolic activities which accelerate biodeterioration leading to spoilage and short shelf life. Fresh unpasteurized juices stored at 24°C and 4°C may safely be consumed within 1 and 2 days, respectively

    Assessment of the Knowledge and Attitude Towards Dementia Among Undergraduate University Students in Uganda

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    Phillip Musoke,1 Ronald Olum,1 Shallon Kembabazi,1 Brandy Nantaayi,1 Felix Bongomin,2 Mark Kaddumukasa3 1School of Medicine, College of Health Sciences, Makerere University, Kampala, Uganda; 2Department of Medical Microbiology and Immunology, Faculty of Medicine, Gulu University, Gulu, Uganda; 3Department of Medicine, School of Medicine, College of Health Sciences, Makerere University, Kampala, UgandaCorrespondence: Phillip MusokeSchool of Medicine, College of Health Sciences, Makerere University, Kampala, UgandaEmail [email protected]: Dementia remains a public health concern and a leading cause of disability and dependency among older people worldwide. However, the knowledge and attitudes towards dementia among university students remain unknown. This study assessed the knowledge and attitude towards dementia among university students in Uganda.Methods: An online descriptive, cross-sectional study was undertaken from August to November 2020, among undergraduate students from 11 Ugandan universities. A validated study questionnaire was used to collect data on socio-demographic characteristics, knowledge, and attitudes of dementia. A score &lt; 60% was considered poor knowledge while &ge; 80% good knowledge and more than 80% reflected positive attitudes.Results: Overall, 1005 participants with a median age of 23 (interquartile range: 18 to 35) years participated in the study. The majority of the students were male (56.5%, n=568) and nearly half were pursuing human sciences/medicine-related programs. The mean knowledge score was 65.5% (SD&plusmn; 18.5). Thirty-two percent of the study participants had poor knowledge and only 26.8% (n=269) had good knowledge of dementia. More than half of the study participants believed that dementia is a normal part of aging and that memory loss happens to all people as they age. Attitudes towards patients with dementia were positive with a mean score of 81.9% (SD&plusmn; 19.6) and 65.2% of the study participants had positive dementia attitudes. Those aged more than 24 years were significantly associated with positive attitudes (adjusted odds ratio (AOR): 1.5, 95% CI: 1.1&ndash; 2.0, p=0.019). There was a weak correlation between knowledge and attitude scores (&rho;=0.341, p&lt; 0.001).Conclusion: Whereas the majority of university students have positive attitudes towards patients with dementia, a significant number still have poor knowledge of the same. Continuous health education is suggested to improve knowledge of dementia in this population. Further studies to understand the perception in the general population are recommended.Keywords: dementia, Alzheimer&rsquo;s disease, knowledge, attitude, Ugand

    Microsatellite‐based analysis reveals Aedes aegypti populations in the Kingdom of Saudi Arabia result from colonization by both the ancestral African and the global domestic forms

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    Abstract The Aedes aegypti (Linnaeus, 1762) mosquito is the main vector of dengue, chikungunya and Zika and is well established today all over the world. The species comprises two forms: the ancestral form found throughout Africa and a global domestic form that spread to the rest of the tropics and subtropics. In Saudi Arabia, A. aegypti has been known in the southwest since 1956, and previous genetic studies clustered A. aegypti from Saudi Arabia with the global domestic form. The purpose of this study was to assess the genetic structure of A. aegypti in Saudi Arabia and determine their geographic origin. Genetic data for 17 microsatellites were collected for A. aegypti ranging from the southwestern highlands of Saudi Arabia on the border of Yemen to the north‐west in Madinah region as well as from Thailand and Uganda populations (as representatives of the ancestral African and global domestic forms, respectively). The low but significant level of genetic structuring in Saudi Arabia was consistent with long‐distance dispersal capability possibly through road connectivity and human activities, that is, passive dispersal. There are two main genetic groupings in Saudi Arabia, one of which clusters with the Ugandan population and the other with the Thailand population with many Saudi Arabian individuals having mixed ancestry. The hypothesis of genetic admixture of the ancestral African and global domestic forms in Saudi Arabia was supported by approximate Bayesian computational analyses. The extent of admixture varied across Saudi Arabia. African ancestry was highest in the highland area of the Jazan region followed by the lowland Jazan and Sahil regions. Conversely, the western (Makkah, Jeddah and Madinah) and Najran populations corresponded to the global domesticated form. Given potential differences between the forms in transmission capability, ecology and behaviour, the findings here should be taken into account in vector control efforts in Saudi Arabia
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