104 research outputs found

    Achieving high coverage of larval-stage mosquito surveillance: challenges for a community-based mosquito control programme in urban Dar es Salaam, Tanzania

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    Background: Preventing malaria by controlling mosquitoes in their larval stages requires regular sensitive monitoring of vector populations and intervention coverage. The study assessed the effectiveness of operational, community-based larval habitat surveillance systems within the Urban Malaria Control Programme (UMCP) in urban Dar es Salaam, Tanzania. Methods: Cross-sectional surveys were carried out to assess the ability of community-owned resource persons (CORPs) to detect mosquito breeding sites and larvae in areas with and without larviciding. Potential environmental and programmatic determinants of habitat detection coverage and detection sensitivity of mosquito larvae were recorded during guided walks with 64 different CORPs to assess the accuracy of data each had collected the previous day. Results: CORPs reported the presence of 66.2% of all aquatic habitats (1,963/2,965), but only detected Anopheles larvae in 12.6% (29/230) of habitats that contained them. Detection sensitivity was particularly low for late-stage Anopheles (2.7%, 3/111), the most direct programmatic indicator of malaria vector productivity. Whether a CORP found a wet habitat or not was associated with his/her unfamiliarity with the area (Odds Ratio (OR) [95% confidence interval (CI)] = 0.16 [0.130, 0.203], P < 0.001), the habitat type (P < 0.001) or a fence around the compound (OR [95% CI] = 0.50 [0.386, 0.646], P < 0.001). The majority of mosquito larvae (Anophelines 57.8% (133/230) and Culicines 55.9% (461/825) were not reported because their habitats were not found. The only factor affecting detection of Anopheline larvae in habitats that were reported by CORPs was larviciding, which reduced sensitivity (OR [95% CI] = 0.37 [0.142, 0.965], P = 0.042). Conclusions: Accessibility of habitats in urban settings presents a major challenge because the majority of compounds are fenced for security reasons. Furthermore, CORPs under-reported larvae especially where larvicides were applied. This UMCP system for larval surveillance in cities must be urgently revised to improve access to enclosed compounds and the sensitivity with which habitats are searched for larvae

    Integrating plant- and animal-based perspectives for more effective restoration of biodiversity

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    Ecological restoration of modified and degraded landscapes is an important challenge for the 21st century, with potential for major gains in the recovery of biodiversity. However, there is a general lack of agreement between plant- and animal-based approaches to restoration, both in theory and practice. Here, we review these approaches, identify limitations from failing to effectively integrate their different perspectives, and suggest ways to improve outcomes for biodiversity recovery in agricultural landscapes. We highlight the need to strengthen collaboration between plant and animal ecologists, to overcome disciplinary and cultural differences, and to achieve a more unified approach to restoration ecology. Explicit consideration of key ecosystem functions, the need to plan at multiple spatial and temporal scales, and the importance of plant–animal interactions can provide a bridge between plant- and animal-based methods. A systematic approach to restoration planning is critical to achieving effective biodiversity outcomes while meeting long-term social and economic needs

    Assessment and comparative analysis of a rapid diagnostic test (Tubex®) for the diagnosis of typhoid fever among hospitalized children in rural Tanzania

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    Background: Typhoid fever remains a significant health problem in many developing countries. A rapid test with a performance comparable to that of blood culture would be highly useful. A rapid diagnostic test for typhoid fever, Tubex&reg;, is commercially available that uses particle separation to detect immunoglobulin M directed towards Salmonella Typhi O9 lipopolysaccharide in sera.Methods: We assessed the sensitivity and specificity of the Tubex test among Tanzanian children hospitalized with febrile illness using blood culture as gold standard. Evaluation was done considering blood culture confirmed S. Typhi with non-typhi salmonella (NTS) and non - salmonella isolates as controls as well as with non-salmonella isolates only.Results: Of 139 samples tested with Tubex, 33 were positive for S. Typhi in blood culture, 49 were culture-confirmed NTS infections, and 57 were other non-salmonella infections. Thirteen hemolyzed samples were excluded. Using all non - S. Typhi isolates as controls, we showed a sensitivity of 79% and a specificity of 89%. When the analysis was repeated excluding NTS from the pool of controls we showed a sensitivity of 79% and a specificity of 97%. There was no significant difference in the test performance using the two different control groups (p &gt; 0.05).Conclusion: This first evaluation of the Tubex test in an African setting showed a similar performance to those seen in some Asian settings. Comparison with the earlier results of a Widal test using the same samples showed no significant difference (p &gt; 0.05) for any of the performance indicators, irrespective of the applied control group

    Pond research and management in Europe: "Small is Beautiful"

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    The phrase "Small is Beautiful" was first used by the talented scholar Leopold Kohr (1909 131994), but it becames more popular thanks to the essays of one of his students, the British economist E. F. Schumacher, and it was coined as a response to the socially established idea that "Big is Powerful". It could be argued that this desire for "bigness" explains why current legal frameworks and the conservation planning and management related to standing waters often overlook ponds, despite their well-known value in terms of biodiversity and socio-economic benefits (Oertli et al., 2004; Cereghino et al., 2008). Of course, this is only one of several possible explanations, but it is important to understand that such long-established ideas can have a lasting effect upon the efficiency of our conservation actions. Beyond this social perspective, the history of science can also provide some explanation as to why ponds have been undervalued for so long

    Evaluation of the Widal tube agglutination test for the diagnosis of typhoid fever among children admitted to a rural hdospital in Tanzania and a comparison with previous studies

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    BACKGROUND: The diagnosis of typhoid fever is confirmed by culture of Salmonella enterica serotype Typhi (S. typhi). However, a more rapid, simpler, and cheaper diagnostic method would be very useful especially in developing countries. The Widal test is widely used in Africa but little information exists about its reliability. METHODS: We assessed the performance of the Widal tube agglutination test among febrile hospitalized Tanzanian children. We calculated the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of various anti-TH and -TO titers using culture-confirmed typhoid fever cases as the "true positives" and all other febrile children with blood culture negative for S. typhi as the "true negatives." RESULTS: We found that 16 (1%) of 1,680 children had culture-proven typhoid fever. A single anti-TH titer of 1:80 and higher was the optimal indicator of typhoid fever. This had a sensitivity of 75%, specificity of 98%, NPV of 100%, but PPV was only 26%. We compared our main findings with those from previous studies. CONCLUSION: Among febrile hospitalized Tanzanian children with a low prevalence of typhoid fever, a Widal titer of > or = 1:80 performed well in terms of sensitivity, specificity, and NPV. However a test with improved PPV that is similarly easy to apply and cost-efficient is desirable

    Beyond climate envelopes: effects of weather on regional population trends in butterflies

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    Although the effects of climate change on biodiversity are increasingly evident by the shifts in species ranges across taxonomical groups, the underlying mechanisms affecting individual species are still poorly understood. The power of climate envelopes to predict future ranges has been seriously questioned in recent studies. Amongst others, an improved understanding of the effects of current weather on population trends is required. We analysed the relation between butterfly abundance and the weather experienced during the life cycle for successive years using data collected within the framework of the Dutch Butterfly Monitoring Scheme for 40 species over a 15-year period and corresponding climate data. Both average and extreme temperature and precipitation events were identified, and multiple regression was applied to explain annual changes in population indices. Significant weather effects were obtained for 39 species, with the most frequent effects associated with temperature. However, positive density-dependence suggested climatic independent trends in at least 12 species. Validation of the short-term predictions revealed a good potential for climate-based predictions of population trends in 20 species. Nevertheless, data from the warm and dry year of 2003 indicate that negative effects of climatic extremes are generally underestimated for habitat specialists in drought-susceptible habitats, whereas generalists remain unaffected. Further climatic warming is expected to influence the trends of 13 species, leading to an improvement for nine species, but a continued decline in the majority of species. Expectations from climate envelope models overestimate the positive effects of climate change in northwestern Europe. Our results underline the challenge to include population trends in predicting range shifts in response to climate change

    Women's views and postpartum follow-up in the CHIPS Trial (Control of Hypertension in Pregnancy Study).

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    OBJECTIVE: To compare women's views about blood pressure (BP) control in CHIPS (Control of Hypertension In Pregnancy Study) (NCT01192412). DESIGN: Quantitative and qualitative analysis of questionnaire responses. SETTING: International randomised trial (94 sites, 15 countries). POPULATION/SAMPLE: 911 (92.9%) women randomised to 'tight' (target diastolic blood pressure, 85mmHg) or 'less tight' (target diastolic blood pressure, 100mmHg) who completed questionnaires. METHODS: A questionnaire was administered at ∼6-12 weeks postpartum regarding post-discharge morbidity and views about trial participation. Questionnaires were administered by the site co-ordinator, and contact was made by phone, home or clinic visit; rarely, data was collected from medical records. Quantitative analyses were Chi-square or Fisher's exact test for categorical variables, mixed effects multinomial logistic regression to adjust for confounders, and p<0.001 for statistical significance. NVivo software was used for thematic analysis of women's views. MAIN OUTCOME MEASURES: Satisfaction, measured as willingness to have the same treatment in another pregnancy or recommend that treatment to a friend. RESULTS: Among the 533 women in 'tight' (N=265) vs. 'less tight' (N=268) control who provided comments for qualitative analysis, women in 'tight' (vs. 'less tight') control made fewer positive comments about the amount of medication taken (5 vs. 28 women, respectively) and intensity of BP monitoring (7 vs. 17, respectively). However, this did not translate into less willingness to either have the same treatment in another pregnancy (434, 95.8% vs. 423, 92.4%, respectively; p=0.14) or recommend that treatment to a friend (435, 96.0% and 428, 93.4%, respectively; p=0.17). Importantly, although satisfaction remained high among women with an adverse outcome, those in 'tight' control who suffered an adverse outcome (vs. those who did not) were not consistently less satisfied, whereas this was not the case among women in 'less tight' control among whom satisfaction was consistently lower for the CHIPS primary outcome (p<0.001), severe hypertension (p≤0.01), and pre-eclampsia (p<0.001). CONCLUSIONS: Women in 'tight' (vs. 'less tight') control were equally satisfied with their care, and more so in the face of adverse perinatal or maternal outcomes

    Lack of effective communication between communities and hospitals in Uganda: a qualitative exploration of missing links

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    <p>Abstract</p> <p>Background</p> <p>Community members are stakeholders in hospitals and have a right to participate in the improvement of quality of services rendered to them. Their views are important because they reflect the perspectives of the general public. This study explored how communities that live around hospitals pass on their views to and receive feedback from the hospitals' management and administration.</p> <p>Methods</p> <p>The study was conducted in eight hospitals and the communities around them. Four of the hospitals were from three districts from eastern Uganda and another four from two districts from western Uganda. Eight key informant interviews (KIIs) were conducted with medical superintendents of the hospitals. A member from each of three hospital management boards was also interviewed. Eight focus group discussions (FGDs) were conducted with health workers from the hospitals. Another eight FGDs (four with men and four with women) were conducted with communities within a five km radius around the hospitals. Four of the FGDs (two with men and two with women) were done in western Uganda and the other four in eastern Uganda. The focus of the KIIs and FGDs was exploring how hospitals communicated with the communities around them. Analysis was by manifest content analysis.</p> <p>Results</p> <p>Whereas health unit management committees were supposed to have community representatives, the representatives never received views from the community nor gave them any feed back from the hospitals. Messages through the mass media like radio were seen to be non specific for action. Views sent through suggestion boxes were seen as individual needs rather than community concerns. Some community members perceived they would be harassed if they complained and had reached a state of resignation preferring instead to endure the problems quietly.</p> <p>Conclusion</p> <p>There is still lack of effective communication between the communities and the hospitals that serve them in Uganda. This deprives the communities of the right to participate in the improvement of the services they receive, to assume their position as stakeholders. Various avenues could be instituted including using associations in communities, rapid appraisal methods and community meetings.</p

    Influence of gestational age at initiation of antihypertensive therapy: Secondary analysis of CHIPS trial data (control of hypertension in pregnancy study).

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    For hypertensive women in CHIPS (Control of Hypertension in Pregnancy Study), we assessed whether the maternal benefits of tight control could be achieved, while minimizing any potentially negative effect on fetal growth, by delaying initiation of antihypertensive therapy until later in pregnancy. For the 981 women with nonsevere, chronic or gestational hypertension randomized to less-tight (target diastolic blood pressure, 100 mm Hg), or tight (target, 85 mm Hg) control, we used mixed-effects logistic regression to examine whether the effect of less-tight (versus tight) control on major outcomes was dependent on gestational age at randomization, adjusting for baseline factors as in the primary analysis and including an interaction term between gestational age at randomization and treatment allocation. Gestational age was considered categorically (quartiles) and continuously (linear or quadratic form), and the optimal functional form selected to provide the best fit to the data based on the Akaike information criterion. Randomization before (but not after) 24 weeks to less-tight (versus tight) control was associated with fewer babies with birth weight 48 hours (Pinteraction=0.354). For the mother, less-tight (versus tight) control was associated with more severe hypertension at all gestational ages but particularly so before 28 weeks (Pinteraction=0.076). In women with nonsevere, chronic, or gestational hypertension, there seems to be no gestational age at which less-tight (versus tight) control is the preferred management strategy to optimize maternal or perinatal outcomes
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