74 research outputs found
Pathogenicity of Metarhizium anisopliae (Metch) Sorok and Beauveria bassiana (Bals) Vuill to adult Phlebotomus duboscqi (Neveu-Lemaire) in the laboratory
Background & objectives: Biological control of sandflies using entomopathogenic fungi is a possible alternativeto the expensive synthetic chemical control. It is potentially sustainable, less hazardous, and relatively inexpensiveand merits further investigations. The objective of this study was to identify the most pathogenic fungal isolate(s)to sandflies in the laboratory.Methods: Isolates of entomopathogenic fungi Metarhizium anisopliae and Beauveria bassiana were screenedfor their pathogenicity against Phlebotomus duboscqi. Adult flies were contaminated using the technique describedby Migiro et al (2010). Briefly, flies were exposed to 0.1 g of dry conidia evenly spread on a cotton velvet clothcovering the inner side of a cylindrical plastic tube (95 mm long × 48 mm diam). In all 25 sandflies weretransferred into the cylindrical tube and allowed to walk on the velvet for one minute, after which they weretransferred from the velvet into the cages in Perplex. Insects in the control treatments were exposed to fungusfree velvet cloth before being transferred into similar cages. The treatments were maintained at 25 ± 2°C,60–70% RH and 12L: 12D photoperiod. The experiment was replicated 5 times. The most pathogenic isolateswere selected for further studies.Results: A total of 19 isolates were screened against adult sandflies in the laboratory. Mortality in the controlswas approximately 16.8 ± 1.7 %. All the isolates were found to be pathogenic to P. duboscqi. Mortality rangedbetween 76.8 and 100% on all the fungal isolates tested. The lethal time taken to 50% (LT50) and 90% (LT90(mortality ranged from 3.0–7.8 days and from 5.3–16.2 days, respectively. The virulent isolates, causing mortalitiesof 97.5–100%, were selected for further studies.Interpretation & conclusion: The high susceptibility of sandflies to entomopathogenic fungi suggests that fungiare potential alternatives to chemical control methods. We conclude that application of entomopathogenic fungicould result in acute mortalities of sandflies and reduction of parasite transmission and subsequently, reductionof leishmaniasis risk. This method of biological control has great potential as a new strategy for leishmaniasiscontro
Comparative performance of the Mbita trap, CDC light trap and the human landing catch in the sampling of Anopheles arabiensis, An. funestus and culicine species in a rice irrigation in western Kenya
BACKGROUND: Mosquitoes sampling is an important component in malaria control. However, most of the methods used have several shortcomings and hence there is a need to develop and calibrate new methods. The Mbita trap for capturing host-seeking mosquitoes was recently developed and successfully tested in Kenya. However, the Mbita trap is less effective at catching outdoor-biting Anopheles funestus and Anopheles arabiensis in Madagascar and, thus, there is need to further evaluate this trap in diverse epidemiological settings. This study reports a field evaluation of the Mbita trap in a rice irrigation scheme in Kenya METHODS: The mosquito sampling efficiency of the Mbita trap was compared to that of the CDC light trap and the human landing catch in western Kenya. Data was analysed by Bayesian regression of linear and non-linear models. RESULTS: The Mbita trap caught about 17%, 60%, and 20% of the number of An. arabiensis, An. funestus, and culicine species caught in the human landing collections respectively. There was consistency in sampling proportionality between the Mbita trap and the human landing catch for both An. arabiensis and the culicine species. For An. funestus, the Mbita trap portrayed some density-dependent sampling efficiency that suggested lowered sampling efficiency of human landing catch at low densities. The CDC light trap caught about 60%, 120%, and 552% of the number of An. arabiensis, An. funestus, and culicine species caught in the human landing collections respectively. There was consistency in the sampling proportionality between the CDC light trap and the human landing catch for both An. arabiensis and An. funestus, whereas for the culicines, there was no simple relationship between the two methods. CONCLUSIONS: The Mbita trap is less sensitive than either the human landing catch or the CDC light trap. However, for a given investment of time and money, it is likely to catch more mosquitoes over a longer (and hence more representative) period. This trap can therefore be recommended for use by community members for passive mosquito surveillance. Nonetheless, there is still a need to develop new sampling methods for some epidemiological settings. The human landing catch should be maintained as the standard reference method for use in calibrating new methods for sampling the human biting population of mosquitoes
Social support for students with visual impairments in educational institutions : an integrative literature review
Students with visual impairments often experience emotional problems and encounter difficulties in forming and maintaining social relationships. Research indicates that the social support provided to these students by staff members and their peers in educational institutions may have a positive impact on their academic learning and socioemotional development. The purpose of this integrative literature review was to synthesise the results from 17 academic articles published during 1998 and 2018, which examined the topic of social support for students with visual impairments in educational institutions. This review reveals that for students with visual impairments cooperation, empathetic behaviour, and practical assistance are the main components of social support. These students actively seek social support from staff members and peers, but they face many challenges, such as the lack of training and awareness. Support from staff members contributes to students’ academic learning and social inclusion, whereas peers’ social support enhances their self-esteem and social acceptance. The outlined positive effects of educational interventions on students’ social skills and social interaction support the need for implementing more interventions. The limitations of the studies reviewed and recommendations for future research are discussed
The potential of agroecology to build climate-resilient livelihoods and food systems
Climate change has severe negative impacts on livelihoods and food systems worldwide. Our future climate according to latest scenarios seriously undermine current efforts to improve the state of food security and nutrition, especially in sub-Sahara Africa. To address this to its full extent, there is an urgent need for transformational change of our food systems towards more sustainability and resilience. Agroecology could play a vital role here. As a response to FAO’s governing bodies’ call for increased evidence-based work on agroecology, this study aims to elaborate on existing links between agroecology and climate change. It provides evidence on the technical and policy potential of agroecology to build resilient food systems. Inspired by the idea that transformation will only happen through a coordinated approach among all levels, this study was jointly developed by a broad set of actors from UN agencies (FAO), research institutes (FIBL, Bioversity, ISRA) and CSOs (Biovision, Enda Pronat, ICE) and thus combines evidence from a broad range of backgrounds and perspectives.
The overall research question of this study was: How can agroecology foster climate change adaptation, mitigation and resilience through practices and policies?
To provide a robust and evidence based answer to this we analysed three different dimensions:
1. International policy arena, in particular in the United Nations Framework Convention on Climate Change and the Koronivia Joint Work on Agriculture;
2. Peer-reviewed scientific studies on agroecology applying a meta-analysis; and
3. Two case studies in Kenya and Senegal that assess both, the policy potential of agroecology in respective national settings and the technical potential of agroecology to foster climate resilience on farm-level.
The main findings of the study are:
- Robust scientific evidence demonstrates that agroecology increases climate resilience. Success factors for this are that agroecology builds on:
a) ecological principles, in particular on biodiversity, overall diversity and healthy soils (meta-analysis and case studies results);
b) social aspects, in particular on the co-creation and sharing of knowledge and fostering traditions (case study results).
- More than ten percent of the nationally determined contributions (NDCs) by UNFCCC member states mention agroecology and consider it a valid approach to address climate change. The climate potential of agroecology is furthermore backed by the IPCC Special Report on Climate Change and Land and the 2019 HLPE report of the Committee on World Food Security (CFS) (int. policy analysis result).
- The interdisciplinary and systemic nature of agroecology is key for its true transformational power. However these characteristics are also the main challenges for both, conducting comprehensive research and policy revisions: typically research concepts and policy processes focus on the productive dimension with selective sectorial views (meta-analysis and policy analysis results).
The key recommendations from this study are:
- Given the sound knowledge base, fostering agroecology to build resilience should be recognized as a viable climate change adaptation strategy.
- Barriers to the scaling-up of agroecology need to be addressed: amongst others, improved access to knowledge and understanding of systemic approaches should be fostered across sectors, stakeholders and scales.
- Further comparative research on the multidimensional effects of agroecology is needed.
- Agroecology’s transformative resilience-building potential depends on its holistic and systemic nature which goes beyond a set of practices and includes: a social movement for producers’ empowerment and a multidisciplinary scientific paradigm
Facility and home based HIV Counseling and Testing: a comparative analysis of uptake of services by rural communities in southwestern Uganda
<p>Abstract</p> <p>Background</p> <p>In Uganda, public human immunodeficiency virus (HIV) Voluntary Counseling and Testing (VCT) services are mainly provided through the facility based model, although the home based approach is being promoted as a strategy for improving access to VCT. However the uptake of VCT varies according to service delivery model and is influenced by a number of factors. The aim of this study therefore, was to compare predictors for uptake of facility and home based VCT in a rural context.</p> <p>Methods</p> <p>A longitudinal study with cross-sectional investigative phases was conducted at two sites (Rugando and Kabingo) in southwestern Uganda between November 2007 (baseline) and March 2008 (follow up). During the baseline visit, facility based VCT was offered at the main health centre in Rugando while home based VCT was offered at the household level in Kabingo and a mixed survey questionnaire administered to the respondents. The results presented in this paper are derived from only the baseline data.</p> <p>Results</p> <p>Nine hundred ninety four (994) respondents were interviewed, of whom 500 received facility based VCT in Rugando and 494 home based VCT in Kabingo during the baseline visit. The respondents had a mean age of 32.2 years (SD 10.9) and were mainly female (68 percent). Clients who received facility based VCT were less likely to be residents of the more rural households (adjusted Odds Ratio (aOR) = 0.14, 95% CI 0.07, 0.22). The clients who received home based VCT were less likely to report having an STI symptom (aOR = 0.63, 95% CI 0.46, 0.86), and more likely to be worried about discrimination if they contracted AIDS (aOR = 1.78, 95% CI 1.22, 2.61).</p> <p>Conclusion</p> <p>The uptake of VCT provided through either the facility or home based models is influenced by client characteristics such as proximity to service delivery points, HIV related symptoms, and fear of discrimination in rural Uganda. Interventions that seek to improve uptake of VCT should provide potential clients with both facility and home based VCT options within a given setting. The clients are then able to select a model for VCT that best fits their characteristics. This is likely to have positive implications for both service coverage and uptake by different sub-groups within particular communities.</p
Conducting Violence and Mental Health Research with Female Sex Workers during the COVID-19 Pandemic: Ethical Considerations, Challenges, and Lessons Learned from the Maisha Fiti Study in Nairobi, Kenya
Conducting violence and mental health research during the COVID-19 pandemic with vulnerable groups such as female sex workers (FSWs) required care to ensure that participants and the research team were not harmed. Potential risks and harm avoidance needed to be considered as well as ensuring data reliability. In March 2020, COVID-19 restrictions were imposed in Kenya during follow-up data collection for the Maisha Fiti study (n = 1003); hence data collection was paused. In June 2020, the study clinic was re-opened after consultations with violence and mental health experts and the FSW community. Between June 2020 and January 2021, data were collected in person and remotely following ethical procedures. A total of 885/1003 (88.2%) FSWs participated in the follow-up behavioural–biological survey and 47/47 (100%) participated in the qualitative in-depth interviews. A total of 26/885 (2.9%) quantitative surveys and 3/47 (6.4%) qualitative interviews were conducted remotely. Researching sensitive topics like sex work, violence, and mental health must guarantee study participants’ safety and privacy. Collecting data at the height of COVID-19 was crucial in understanding the relationships between the COVID-19 pandemic, violence against women, and mental health. Relationships established with study participants during the baseline survey—before the pandemic—enabled us to complete data collection. In this paper, we discuss key issues involved in undertaking violence and mental health research with a vulnerable population such as FSWs during a pandemic. Lessons learned could be useful to others researching sensitive topics such as violence and mental health with vulnerable populations
Host choice and multiple blood feeding behaviour of malaria vectors and other anophelines in Mwea rice scheme, Kenya
<p>Abstract</p> <p>Background</p> <p>Studies were conducted between April 2004 and February 2006 to determine the blood-feeding pattern of <it>Anopheles </it>mosquitoes in Mwea Kenya.</p> <p>Methods</p> <p>Samples were collected indoors by pyrethrum spay catch and outdoors by Centers for Disease Control light traps and processed for blood meal analysis by an Enzyme-linked Immunosorbent Assay.</p> <p>Results</p> <p>A total of 3,333 blood-fed <it>Anopheles </it>mosquitoes representing four <it>Anopheles </it>species were collected and 2,796 of the samples were assayed, with <it>Anopheles arabiensis </it>comprising 76.2% (n = 2,542) followed in decreasing order by <it>Anopheles coustani </it>8.9% (n = 297), <it>Anopheles pharoensis </it>8.2% (n = 272) and <it>Anopheles funestus </it>6.7% (n = 222). All mosquito species had a high preference for bovine (range 56.3–71.4%) over human (range 1.1–23.9%) or goat (0.1–2.2%) blood meals. Some individuals from all the four species were found to contain mixed blood meals. The bovine blood index (BBI) for <it>An. arabiensis </it>was significantly higher for populations collected indoors (71.8%), than populations collected outdoors (41.3%), but the human blood index (HBI) did not differ significantly between the two populations. In contrast, BBI for indoor collected <it>An. funestus </it>(51.4%) was significantly lower than for outdoor collected populations (78.0%) and the HBI was significantly higher indoors (28.7%) than outdoors (2.4%). Anthropophily of <it>An. funestus </it>was lowest within the rice scheme, moderate in unplanned rice agro-ecosystem, and highest within the non-irrigated agro-ecosystem. Anthropophily of <it>An. arabiensis </it>was significantly higher in the non-irrigated agro-ecosystem than in the other agro-ecosystems.</p> <p>Conclusion</p> <p>These findings suggest that rice cultivation has an effect on host choice by <it>Anopheles </it>mosquitoes. The study further indicate that zooprophylaxis may be a potential strategy for malaria control, but there is need to assess how domestic animals may influence arboviruses epidemiology before adapting the strategy.</p
Prevalence and correlates of common mental health problems and recent suicidal thoughts and behaviours among female sex workers in Nairobi, Kenya
Background: Adverse childhood experiences (ACEs), poverty, violence and harmful alcohol/substance use are associated with poor mental health outcomes, but few studies have examined these risks among Female Sex Workers (FSWs). We examine the prevalence and correlates of common mental health problems including suicidal thoughts and behaviours among FSWs in Kenya. Methods: Maisha Fiti is a longitudinal study among FSWs randomly selected from Sex Worker Outreach Programme (SWOP) clinics across Nairobi. Baseline behavioural-biological survey (n = 1003) data were collected June–December 2019. Mental health problems were assessed using the Patient Health Questionnaire (PHQ-9) for depression, the Generalised Anxiety Disorder tool (GAD-7) for anxiety, the Harvard Trauma Questionnaire (HTQ-17) for Post-Traumatic Stress Disorder (PTSD) and a two-item tool to measure recent suicidal thoughts/behaviours. Other measurement tools included the WHO Adverse Childhood Experiences (ACE) score, WHO Violence Against Women questionnaire, and the Alcohol, Smoking and Substance Involvement Screening Test (ASSIST). Descriptive statistics and multivariable logistic regression were conducted using a hierarchical modelling approach. Results: Of 1039 eligible FSWs, 1003 FSWs participated in the study (response rate: 96%) with mean age 33.7 years. The prevalence of moderate/severe depression was 23.2%, moderate/severe anxiety 11.0%, PTSD 14.0% and recent suicidal thoughts/behaviours 10.2% (2.6% suicide attempt, 10.0% suicidal thoughts). Depression, anxiety, PTSD and recent suicidal thoughts/behaviours were all independently associated with higher ACE scores, recent hunger (missed a meal in last week due to financial difficulties), recent sexual/physical violence and increased harmful alcohol/substance. PTSD was additionally associated with increased chlamydia prevalence and recent suicidal thoughts/behaviours with low education and low socio-economic status. Mental health problems were less prevalent among women reporting social support. Conclusions: The high burden of mental health problems indicates a need for accessible services tailored for FSWs alongside structural interventions addressing poverty, harmful alcohol/substance use and violence. Given the high rates of ACEs, early childhood and family interventions should be considered to prevent poor mental health outcomes
Comparison of HPLC/ESI-FTICR MS versus MALDI-TOF/TOF MS for glycopeptide analysis of a highly glycosylated HIV envelope glycoprotein
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