Early morning anopheline mosquito biting, a potential driver of malaria transmission in Busia County, western Kenya.

BACKGROUND: Insecticide-treated nets (ITNs) contributed significantly to the decline in malaria since 2000. Their protective efficacy depends not only on access, use, and net integrity, but also location of people within the home environment and mosquito biting profiles. Anopheline mosquito biting and human location data were integrated to identify potential gaps in protection and better understand malaria transmission dynamics in Busia County, western Kenya. METHODS: Direct observation of human activities and human landing catches (HLC) were performed hourly between 1700 to 0700 h. Household members were recorded as home or away; and, if at home, as indoors/outdoors, awake/asleep, and under a net or not. Aggregated data was analysed by weighting hourly anopheline biting activity with human location. Standard indicators of human-vector interaction were calculated using a Microsoft Excel template. RESULTS: There was no significant difference between indoor and outdoor biting for Anopheles gambiae sensu lato (s.l.) (RR = 0.82; 95% CI 0.65-1.03); significantly fewer Anopheles funestus were captured outdoors than indoors (RR = 0.41; 95% CI 0.25-0.66). Biting peaked before dawn and extended into early morning hours when people began to awake and perform routine activities, between 0400-0700 h for An. gambiae and 0300-0700 h for An. funestus. The study population away from home peaked at 1700-1800 h (58%), gradually decreased and remained constant at 10% throughout the night, before rising again to 40% by 0600-0700 h. When accounting for resident location, nearly all bites within the peri-domestic space (defined as inside household structures and surrounding outdoor spaces) occurred indoors for unprotected people (98%). Using an ITN while sleeping was estimated to prevent 79% and 82% of bites for An. gambiae and An. funestus, respectively. For an ITN user, most remaining exposure to bites occurred indoors in the hours before bed and early morning. CONCLUSION: While use of an ITN was estimated to prevent most vector bites in this context, results suggest gaps in protection, particularly in the early hours of the morning when biting peaks and many people are awake and active. Assessment of additional human exposure points, including outside of the peri-domestic setting, are needed to guide supplementary interventions for transmission reduction.

Screening of malaria infections in human blood samples with varying parasite densities and anaemic conditions using AI-Powered mid-infrared spectroscopy.

BACKGROUND: Effective testing for malaria, including the detection of infections at very low densities, is vital for the successful elimination of the disease. Unfortunately, existing methods are either inexpensive but poorly sensitive or sensitive but costly. Recent studies have shown that mid-infrared spectroscopy coupled with machine learning (MIRs-ML) has potential for rapidly detecting malaria infections but requires further evaluation on diverse samples representative of natural infections in endemic areas. The aim of this study was, therefore, to demonstrate a simple AI-powered, reagent-free, and user-friendly approach that uses mid-infrared spectra from dried blood spots to accurately detect malaria infections across varying parasite densities and anaemic conditions. METHODS: Plasmodium falciparum strains NF54 and FCR3 were cultured and mixed with blood from 70 malaria-free individuals to create various malaria parasitaemia and anaemic conditions. Blood dilutions produced three haematocrit ratios (50%, 25%, 12.5%) and five parasitaemia levels (6%, 0.1%, 0.002%, 0.00003%, 0%). Dried blood spots were prepared on Whatman™ filter papers and scanned using attenuated total reflection-Fourier Transform Infrared (ATR-FTIR) for machine-learning analysis. Three classifiers were trained on an 80%/20% split of 4655 spectra: (I) high contrast (6% parasitaemia vs. negative), (II) low contrast (0.00003% vs. negative) and (III) all concentrations (all positive levels vs. negative). The classifiers were validated with unseen datasets to detect malaria at various parasitaemia levels and anaemic conditions. Additionally, these classifiers were tested on samples from a population survey in malaria-endemic villages of southeastern Tanzania. RESULTS: The AI classifiers attained over 90% accuracy in detecting malaria infections as low as one parasite per microlitre of blood, a sensitivity unattainable by conventional RDTs and microscopy. These laboratory-developed classifiers seamlessly transitioned to field applicability, achieving over 80% accuracy in predicting natural P. falciparum infections in blood samples collected during the field survey. Crucially, the performance remained unaffected by various levels of anaemia, a common complication in malaria patients. CONCLUSION: These findings suggest that the AI-driven mid-infrared spectroscopy approach holds promise as a simplified, sensitive and cost-effective method for malaria screening, consistently performing well despite variations in parasite densities and anaemic conditions. The technique simply involves scanning dried blood spots with a desktop mid-infrared scanner and analysing the spectra using pre-trained AI classifiers, making it readily adaptable to field conditions in low-resource settings. In this study, the approach was successfully adapted to field use, effectively predicting natural malaria infections in blood samples from a population-level survey in Tanzania. With additional field trials and validation, this technique could significantly enhance malaria surveillance and contribute to accelerating malaria elimination efforts.

Zyxin protects from hypertension-induced cardiac dysfunction.

Arterial hypertension causes left ventricular hypertrophy leading to dilated cardiomyopathy. Following compensatory cardiomyocyte hypertrophy, cardiac dysfunction develops due to loss of cardiomyocytes preceded or paralleled by cardiac fibrosis. Zyxin acts as a mechanotransducer in vascular cells that may promote cardiomyocyte survival. Here, we analyzed cardiac function during experimental hypertension in zyxin knockout (KO) mice. In zyxin KO mice, made hypertensive by way of deoxycorticosterone acetate (DOCA)-salt treatment telemetry recording showed an attenuated rise in systolic blood pressure. Echocardiography indicated a systolic dysfunction, and isolated working heart measurements showed a decrease in systolic elastance. Hearts from hypertensive zyxin KO mice revealed increased apoptosis, fibrosis and an upregulation of active focal adhesion kinase as well as of integrins α5 and ß1. Both interstitial and perivascular fibrosis were even more pronounced in zyxin KO mice exposed to angiotensin II instead of DOCA-salt. Stretched microvascular endothelial cells may release collagen 1α2 and TGF-ß, which is characteristic for the transition to an intermediate mesenchymal phenotype, and thus spur the transformation of cardiac fibroblasts to myofibroblasts resulting in excessive scar tissue formation in the heart of hypertensive zyxin KO mice. While zyxin KO mice per se do not reveal a cardiac phenotype, this is unmasked upon induction of hypertension and owing to enhanced cardiomyocyte apoptosis and excessive fibrosis causes cardiac dysfunction. Zyxin may thus be important for the maintenance of cardiac function in spite of hypertension.

A retail audit of mosquito control products in Busia County, western Kenya.

BACKGROUND: Approximately 70% of Kenya's population is at risk for malaria. The core vector control methods in Kenya are insecticide-treated mosquito nets (ITNs) and indoor residual spraying, with supplementary larval source management. In 2015, 21% of ITNs were accessed through the private retail sector. Despite the private sector role in supplying mosquito control products (MCPs), there is little evidence on the availability, sales trends, and consumer preferences for MCPs other than ITNs. This study, a component of a larger research programme focused on evaluating a spatial repellent intervention class for mosquito-borne disease control, addressed this evidence gap on the role of the private sector in supplying MCPs. METHODS: A cross-sectional survey was deployed in a range of retail outlets in Busia County to characterize MCP availability, sales trends, and distribution channels. The questionnaire included 32 closed-ended and four open-ended questions with short answer responses. Descriptive analysis of frequency counts and percentages was carried out to glean insights about commercially available MCPs and the weighted average rank was used to determine consumer preferences for MCPs. Open-ended data was analysed thematically. RESULTS: Retail outlets that stocked MCPs commonly stocked mosquito coils (73.0%), topical repellents (38.1%), aerosol insecticide sprays (23.8%) and ITNs (14.3%). Overall, retailers reported the profits from selling MCPs were adequate and they overwhelmingly planned to continue stocking the products. Of respondents who stocked MCPs, 96.8% responded that sales increased during long rains and 36.5% that sales also surged during short rains. ITNs and baby-size nets were often delivered by the wholesaler. Retailers of aerosol sprays, mosquito coils, and topical repellents either collected stock from the wholesaler or products were delivered to them. Other commercially available MCPs included insecticide incense sticks, electric mosquito strikers, insecticide soaps, electrically heated insecticide mats, and electric insecticide emanators, indicating a well-established market. CONCLUSIONS: The wide range of MCPs in local retail outlets within the study area suggests the need and demand for mosquito control tools, in addition to ITNs, that are affordable, easy to use and effective. The presence of a wide range of MCPs, is a promising sign for the introduction of a spatial repellent intervention class of products that meets consumer needs and preferences.

In vitro and in vivo studies on anti-malarial activity of Commiphora africana and Dichrostachys cinerea used by the Maasai in Arusha region, Tanzania.

BACKGROUND: Traditional medicinal plants are one of the potential sources of anti-malarial drugs and there is an increasing interest in the use and development of traditional herbal remedies for the treatment of malaria and other ailments. This study was carried out with the aim to investigate the phytochemical screening, cytotoxic effect and antiplasmodial activities of Dichrostachys cinerea and Commiphora africana. Both plants are used by the Maasai in Tanzania in suspected malaria and other diseases. No previous work appears to have investigated the potential anti-malarial activity of the two plants. METHODS: This study aimed to investigate the in vitro anti-malarial activity of methanol and dichloromethane extracts of the two plants against chloroquine sensitive (D6) and chloroquine resistant (Dd2) strains of Plasmodium falciparum. The anti-malarial property was assessed by the lactate dehydrogenase method (pLDH). The in vivo anti-malarial study was carried out using the Peters' 4-day suppressive test in Plasmodium berghei in Balb/c mice. Cytotoxic tests were carried out using monkey kidney epithelial cell line in [3(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] (MTT) assay. Qualitative phytochemical screening was carried out using standard methods of analysis. RESULTS: The phytochemical screening of plant extracts revealed the presence of alkaloids, flavonoids, tannins, steroids, triterpenoids, glycosides and saponins. However, alkaloids were absent in most plant extracts. The dichloromethane extracts of C. africana (stem bark); D. cinerea (stem bark) and methanol extracts of D. cinerea (whole stem) all showed promising in vitro anti-malarial activities. All other extracts did not show any significant anti-malarial activity. The two most promising extracts based on in vitro studies, DCM extracts of C. africana (stem bark) and D. cinerea (stems bark), equally exhibited very significant anti-malarial activities in the mouse model. They exhibited parasite suppression rates of 64.24 and 53.12%, respectively, and considerable improvement in weight and survival rate. Most plant extracts were not cytotoxic except for DCM extract of D. cinerea (whole stem) CC50 (29.44 µg/mL). CONCLUSION: The findings of this study provide scientific evidence supporting the traditional use of the plants in the treatment of malaria by the Maasai in Arusha region, Tanzania. Consequently, further work including bioassay-guided fractionation and advanced toxicity testing may yield new anti-malarial drug candidates from the two plants.

Options for sustaining solar-powered mosquito trapping systems on Rusinga Island, Western Kenya: a social dilemma analysis.

BACKGROUND: In 2012, a donor-supported proof of principle study was launched to eliminate malaria from Rusinga Island, western Kenya, using solar-powered mosquito trapping systems (SMoTS). SMoTS, which also provided power for room lighting and charging mobile telephones, were installed in houses. In view of the involvement of individual and collective benefits, as well as individual and collective maintenance solutions, this study qualitatively examined preferences of some project stakeholders towards SMoTS sustainability components to see if and how they related to social dilemma factors. METHODS: The data were collected through participant observation, semi-structured interviews and focus group discussions. RESULTS: The results show that respondents largely preferred individual solutions to various aspects of maintenance. Selective collective solutions such as table banking groups were considered positively for mobilising financial resources for maintenance, but respondents were hardly willing to contribute financially to a collective entity. Few people saw a meaningful role for a collective governing body; people preferred to rely on individual household responsibility and private service delivery for repairs and stocking spare parts. An overriding concern was that people lacked trust in other community members, leaders and/or technicians who would be employed by a governing body. Respondents also had little confidence that a governing body or saving group could effectively impose sanctions to misappropriation of funds, poor leadership, defecting group members or technicians that might abuse a salaried position. CONCLUSION: There seemed to be linkages between preferences towards organising various components of SMoTS sustainability and known hindrances to addressing social dilemmas. This posed considerable challenges to organising the sustainability of this innovative malaria control strategy. TRIAL REGISTRATION: NTR3496 .

Impact of MPH programs: contributing to health system strengthening in low- and middle-income countries?

BACKGROUND: The "health workforce" crisis has led to an increased interest in health professional education, including MPH programs. Recently, it was questioned whether training of mid- to higher level cadres in public health prepared graduates with competencies to strengthen health systems in low- and middle-income countries. Measuring educational impact has been notoriously difficult; therefore, innovative methods for measuring the outcome and impact of MPH programs were sought. Impact was conceptualized as "impact on workplace" and "impact on society," which entailed studying how these competencies were enacted and to what effect within the context of the graduates' workplaces, as well as on societal health. METHODS: This is part of a larger six-country mixed method study; in this paper, the focus is on the qualitative findings of two English language programs, one a distance MPH program offered from South Africa, the other a residential program in the Netherlands. Both offer MPH training to students from a diversity of countries. In-depth interviews were conducted with 10 graduates (per program), working in low- and middle-income health systems, their peers, and their supervisors. RESULTS: Impact on the workplace was reported as considerable by graduates and peers as well as supervisors and included changes in management and leadership: promotion to a leadership position as well as expanded or revitalized management roles were reported by many participants. The development of leadership capacity was highly valued amongst many graduates, and this capacity was cited by a number of supervisors and peers. Wider impact in the workplace took the form of introducing workplace innovations such as setting up an AIDS and addiction research center and research involvement; teaching and training, advocacy, and community engagement were other ways in which graduates' influence reached a wider target grouping. Beyond the workplace, an intersectoral approach, national reach through policy advisory roles to Ministries of Health, policy development, and capacity building, was reported. Work conditions and context influenced conduciveness for innovation and the extent to which graduates were able to have effect. Self-selection of graduates and their role in selecting peers and supervisors may have resulted in some bias, some graduates could not be traced, and social acceptability bias may have influenced findings. CONCLUSIONS: There was considerable impact at many levels; graduates were perceived to be able to contribute significantly to their workplaces and often had influence at the national level. Much of the impact described was in line with public health educational aims. The qualitative method study revealed more in-depth understanding of graduates' impact as well as their career pathways.

Combining malaria control with house electrification: adherence to recommended behaviours for proper deployment of solar-powered mosquito trapping systems, Rusinga Island, western Kenya.

OBJECTIVE: To investigate community adherence to recommended behaviours for proper deployment of solar-powered mosquito trapping systems (SMoTS) after 3- to 10-week use. METHODS: Solar-powered mosquito trapping system, which also provided power for room lighting and charging mobile phones, were installed in houses in Rusinga Island, western Kenya. We used a structured checklist for observations and a semi-structured questionnaire for interviews in 24 homesteads. We also analysed the subject of 224 community calls to the project team for technical maintenance of SMoTS. RESULTS: Most respondents cared for SMoTS by fencing, emptying and cleaning the trap. Our observations revealed that most traps were fenced, clean and in good working condition. A significantly higher proportion of community calls was lighting-related. Lighting was the main reason respondents liked SMoTS because it reduced or eliminated expenditure on kerosene. However, some respondents observed they no longer heard sounds of mosquitoes inside their houses. All respondents reportedly slept under insecticide-treated nets (ITNs) before receiving SMoTS. After receiving SMoTS, most respondents reportedly continued to use ITNs citing that the project advised them to do so. Some beach residents stopped using ITNs because they no longer heard mosquitoes or due to heat discomfort caused by lights. CONCLUSION: Electricity-related incentives played a greater role in encouraging adherence to recommended behaviours for proper deployment of SMoTS than the potential health benefits in the early stages of the intervention. Although energy-related financial incentives may play a role, they are insufficient to ensure adherence to health advice, even in the short term. Ongoing community engagement and research monitors and addresses adherence to recommended behaviours including continuation of current malaria control strategies.

Outcome and impact of Master of Public Health programs across six countries: education for change.

BACKGROUND: The human resources for health crisis has highlighted the need for high-level public health education to add specific capacities to the workforce. Recently, it was questioned whether Master of Public Health (MPH) training prepared graduates with competencies relevant to low- and middle-income countries (LMICs). This study aims to examine the influence of the MPH programs geared towards LMICs offered in Vietnam, China, South Africa, Mexico, Sudan, and the Netherlands on graduates' careers, application of acquired competencies, performance at the workplace, and their professional contribution to society. METHODS: A self-administered questionnaire was sent to graduates from six MPH programs. Frequency distributions of the answers were calculated, and a bivariate analysis and logistic regression of certain variables was performed. RESULTS: The response rate was 37.5%. Graduates reported change in leadership (69%), in technical position (69%), acquiring new responsibilities (80%), and increased remuneration (63%); they asserted that MPH programs contributed significantly to this. Graduates' attribution of their application of 7 key competencies 'substantially to the MPH program' ranged from 33% to 48%. Of the 26 impact variables, graduates attributed the effect they had on their workplace substantially to the MPH program; the highest rated variable ranged from 31% to 73% and the lowest ranged from 9% to 43%. Of the 10 impact variables on society, graduates attributed the effect they had on society substantially to the MPH program; for the highest rated variable (13% to 71%); for the lowest rated variable (4% to 42%). Candidates' attribution of their application of acquired competencies as well as their impact at the workplace varied significantly according to institution of study and educational background. CONCLUSIONS: This study concludes that these MPH programs contribute to improving graduates' careers and to building leadership in public health. The MPH programs contribute to graduates' application of competencies. MPH programs contribute substantially towards impact variables on the workplace, such as development of research proposals and reporting on population health needs, and less substantially to their impact on society, such as contributing equitable access to quality services. Differences reported between MPH programs merit further study. The results can be used for curriculum reform.

Visual outcomes from pars plana vitrectomy versus combined pars plana vitrectomy, phacoemulsification, and intraocular lens implantation in patients with diabetes.

PURPOSE: To compare visual acuity outcomes and diabetic retinopathy progression after pars plana vitrectomy (PPV) versus combined pars plana vitrectomy and phacoemulsification (PPVCE) in patients with diabetes. METHODS: Retrospective review of 222 consecutive diabetic patients undergoing PPV or PPVCE. RESULTS: A total of 251 eyes of 222 patients were evaluated (PPV = 122, PPVCE = 129). Four-year follow-up was 64% (161 eyes). Overall, patients undergoing PPVCE had better preoperative visual acuity (PPVCE = 20/80, PPV = 20/160, P = 0.03). At 4-year follow-up, visual acuity improved (PPV = +22, PPVCE = +11 letters) compared with baseline in both groups. After correcting for baseline differences in visual acuity, no statistically significant difference in final visual acuity was observed (PPVCE = 20/32, PPV = 20/50, P = 0.09). Results did not differ substantially by surgical indication (vitreous hemorrhage, traction retinal detachment, epiretinal membrane, and/or diabetic macular edema). Cataract progression occurred in 64%, and cataract surgery was performed in 39% of phakic eyes undergoing PPV. Rates of diabetic retinopathy progression, vitreous hemorrhage, and retinal detachment were not statistically different. Neovascular glaucoma developed in 2 patients (2%) after PPV and 6 patients (8%) after PPVCE (P = 0.07). CONCLUSION: In diabetic patients, equivalent visual acuity improvement over 4 years was observed after PPV or PPVCE. Visual outcomes and retinopathy progression rates were not significantly different after either intervention, suggesting that PPVCE may be appropriate when indicated in patients with diabetes.

Reagent-free detection of Plasmodium falciparum malaria infections in field-collected mosquitoes using mid-infrared spectroscopy and machine learning.

Field-derived metrics are critical for effective control of malaria, particularly in sub-Saharan Africa where the disease kills over half a million people yearly. One key metric is entomological inoculation rate, a direct measure of transmission intensities, computed as a product of human biting rates and prevalence of Plasmodium sporozoites in mosquitoes. Unfortunately, current methods for identifying infectious mosquitoes are laborious, time-consuming, and may require expensive reagents that are not always readily available. Here, we demonstrate the first field-application of mid-infrared spectroscopy and machine learning (MIRS-ML) to swiftly and accurately detect Plasmodium falciparum sporozoites in wild-caught Anopheles funestus, a major Afro-tropical malaria vector, without requiring any laboratory reagents. We collected 7178 female An. funestus from rural Tanzanian households using CDC-light traps, then desiccated and scanned their heads and thoraces using an FT-IR spectrometer. The sporozoite infections were confirmed using enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR), to establish references for training supervised algorithms. The XGBoost model was used to detect sporozoite-infectious specimen, accurately predicting ELISA and PCR outcomes with 92% and 93% accuracies respectively. These findings suggest that MIRS-ML can rapidly detect P. falciparum in field-collected mosquitoes, with potential for enhancing surveillance in malaria-endemic regions. The technique is both fast, scanning 60-100 mosquitoes per hour, and cost-efficient, requiring no biochemical reactions and therefore no reagents. Given its previously proven capability in monitoring key entomological indicators like mosquito age, human blood index, and identities of vector species, we conclude that MIRS-ML could constitute a low-cost multi-functional toolkit for monitoring malaria risk and evaluating interventions.

Additional blood meals increase sporozoite infection in Anopheles mosquitoes but not Plasmodium falciparum genetic diversity.

The availability of nutrients from mosquito blood meals accelerates the development of Plasmodium falciparum laboratory strains in artificially infected Anopheles gambiae mosquitoes. The impact of multiple blood meals on the number of P. falciparum genotypes developing from polyclonal natural human malaria infections (field-isolates) remains unexplored. Here, we experimentally infect An. gambiae with P. falciparum field-isolates and measure the impact of an additional non-infectious blood meal on parasite development. We also assess parasite genetic diversity at the blood stage level of the parasite in the human host and of the sporozoites in the mosquito. Additional blood meals increase the sporozoite infection prevalence and intensity, but do not substantially affect the genetic diversity of sporozoites in the mosquito. The most abundant parasite genotypes in the human blood were transmitted to mosquitoes, suggesting that there was no preferential selection of specific genotypes. This study underlines the importance of additional mosquito blood meals for the development of parasite field-isolates in the mosquito host.

Quality assurance in transnational higher education: a case study of the tropEd network.

INTRODUCTION: Transnational or cross-border higher education has rapidly expanded since the 1980s. Together with that expansion issues on quality assurance came to the forefront. This article aims to identify key issues regarding quality assurance of transnational higher education and discusses the quality assurance of the tropEd Network for International Health in Higher Education in relation to these key issues. METHODS: Literature review and review of documents. RESULTS: From the literature the following key issues regarding transnational quality assurance were identified and explored: comparability of quality assurance frameworks, true collaboration versus erosion of national education sovereignty, accreditation agencies and transparency. The tropEd network developed a transnational quality assurance framework for the network. The network accredits modules through a rigorous process which has been accepted by major stakeholders. This process was a participatory learning process and at the same time the process worked positive for the relations between the institutions. DISCUSSION: The development of the quality assurance framework and the process provides a potential example for others.

A systematic review of outcome and impact of master's in health and health care.

BACKGROUND: The 'human resources for health' crisis has highlighted the need for more health (care) professionals and led to an increased interest in health professional education, including master's degree programmes. The number of these programmes in low- and middle-income countries (LMIC) is increasing, but questions have been raised regarding their relevance, outcome and impact. We conducted a systematic review to evaluate the outcomes and impact of health-related master's degree programmes. METHODS: We searched the databases Scopus, Pubmed, Embase, CINAHL, ERIC, Psychinfo and Cochrane (1999 - November 2011) and selected websites. All papers describing outcomes and impact of health-related Master programmes were included. Three reviewers, two for each article, extracted data independently. The articles were categorised by type of programme, country, defined outcomes and impact, study methods used and level of evidence, and classified according to outcomes: competencies used in practice, graduates' career progression and impact on graduates' workplaces and sector/society. RESULTS: Of the 33 articles included in the review, most originated from the US and the UK, and only one from a low-income country. The programmes studied were in public health (8), nursing (8), physiotherapy (5), family practice (4) and other topics (8). Outcomes were defined in less than one third of the articles, and impact was not defined at all. Outcomes and impact were measured by self-reported alumni surveys and qualitative methods. Most articles reported that competencies learned during the programme were applied in the workplace and alumni reported career progression or specific job changes. Some articles reported difficulties in using newly gained competencies in the workplace. There was limited evidence of impact on the workplace. Only two articles reported impact on the sector. Most studies described learning approaches, but very few described a mechanism to ensure outcome and impact of the programme. CONCLUSIONS: Evidence suggests that graduates apply newly learned competencies in the field and that they progress in their career. There is a paucity of well-designed studies assessing the outcomes and impact of health-related master's degree programmes in low- and middle-income countries. Studies of such programmes should consider the context and define outcomes and impact.

Malaria rapid diagnostic tests reliably detect asymptomatic Plasmodium falciparum infections in school-aged children that are infectious to mosquitoes.

BACKGROUND: Asymptomatic malaria infections (Plasmodium falciparum) are common in school-aged children and represent a disease transmission reservoir as they are potentially infectious to mosquitoes. To detect and treat such infections, convenient, rapid and reliable diagnostic tools are needed. In this study, malaria rapid diagnostic tests (mRDT), light microscopy (LM) and quantitative polymerase chain reaction (qPCR) were used to evaluate their performance detecting asymptomatic malaria infections that are infectious to mosquitoes. METHODS: One hundred seventy asymptomatic school-aged children (6-14 years old) from the Bagamoyo district in Tanzania were screened for Plasmodium spp. infections using mRDT (SD BIOLINE), LM and qPCR. In addition, gametocytes were detected using reverse transcription quantitative polymerase chain reaction (RT-qPCR) for all qPCR-positive children. Venous blood from all P. falciparum positive children was fed to female Anopheles gambiae sensu stricto mosquitoes via direct membrane feeding assays (DMFAs) after serum replacement. Mosquitoes were dissected for oocyst infections on day 8 post-infection. RESULTS: The P. falciparum prevalence in study participants was 31.7% by qPCR, 18.2% by mRDT and 9.4% by LM. Approximately one-third (31.2%) of asymptomatic malaria infections were infectious to mosquitoes in DMFAs. In total, 297 infected mosquitoes were recorded after dissections, from which 94.9% (282/297) were derived from infections detected by mRDT and 5.1% (15/297) from subpatent mRDT infections. CONCLUSION: The mRDT can be used reliably to detect children carrying gametocyte densities sufficient to infect high numbers of mosquitoes. Subpatent mRDT infections contributed marginally to the pool of oocyts-infected mosquitoes.

Sub-lethal exposure to chlorfenapyr reduces the probability of developing Plasmodium falciparum parasites in surviving Anopheles mosquitoes.

BACKGROUND: Pyrethroid resistance in the key malaria vectors threatens the success of pyrethroid-treated nets. To overcome pyrethroid resistance, Interceptor® G2 (IG2), a 'first-in-class' dual insecticidal net that combines alpha-cypermethrin with chlorfenapyr, was developed. Chlorfenapyr is a pro-insecticide, requiring bio-activation by oxidative metabolism within the insect's mitochondria, constituting a mode of action preventing cross-resistance to pyrethroids. Recent epidemiological trials conducted in Benin and Tanzania confirm IG2's public health value in areas with pyrethroid-resistant Anopheles mosquitoes. As chlorfenapyr might also interfere with the metabolic mechanism of the Plasmodium parasite, we hypothesised that chlorfenapyr may provide additional transmission-reducing effects even if a mosquito survives a sub-lethal dose. METHODS: We tested the effect of chlorfenapyr netting to reduce Plasmodium falciparum transmission using a modified WHO tunnel test with a dose yielding sub-lethal effects. Pyrethroid-resistant Anopheles gambiae s.s. with L1014F and L1014S knockdown resistance alleles and expression levels of pyrethroid metabolisers CYP6P3, CYP6M2, CYP4G16 and CYP6P1 confirmed by quantitative reverse transcription polymerase chain reaction (RT-qPCR) prior to conducting experiments were exposed to untreated netting and netting treated with 200 mg/m3 chlorfenapyr for 8 h overnight and then fed on gametocytemic blood meals from naturally infected individuals. Prevalence and intensity of oocysts and sporozoites were determined on day 8 and day 16 after feeding. RESULTS: Both prevalence and intensity of P. falciparum infection in the surviving mosquitoes were substantially reduced in the chlorfenapyr-exposed mosquitoes compared to untreated nets. The odds ratios in the prevalence of oocysts and sporozoites were 0.33 (95% confidence interval; 95% CI 0.23-0.46) and 0.43 (95% CI 0.25-0.73), respectively, while only the incidence rate ratio for oocysts was 0.30 (95% CI 0.22-0.41). CONCLUSION: We demonstrated that sub-lethal exposure of pyrethroid-resistant mosquitoes to chlorfenapyr substantially reduces the proportion of infected mosquitoes and the intensity of the P. falciparum infection. This will likely also contribute to the reduction of malaria in communities beyond the direct killing of mosquitoes.

Prevalence of substance use among college students in Eldoret, western Kenya.

BACKGROUND: Substance use among college and university students predicts substance related problems in later life. Few studies on this phenomenon have been carried out in low income countries, and most focus on primary and secondary school students. This study therefore aimed to establish the prevalence and factors associated with drug use among university and college students in a low income country. DESIGN: A descriptive cross-sectional survey using the Self-Administered WHO Model Core Questionnaire to collect information on use of various drugs among students in colleges and university campuses within Eldoret Municipality in Western Kenya. SETTING: Four tertiary learning institutions in Eldoret Municipality were randomly selected for inclusion in the study- three tertiary level non-university institutions and one university campus. SUBJECTS: Five hundred students who gave consent to participate in the study, 125 from each of the four participating institutions. The mean age was 22.9 years (18-32, s.d. 2.5), and males made up 52.2% of the sample. RESULTS: Lifetime prevalence rate of any substance use was 69.8%, and none of the socio-demographic factors was significantly associated with this. Lifetime prevalence rate of alcohol use was 51.9%, and 97.6% of alcohol users had consumed alcohol in the week prior to the study. The prevalence rate of cigarette use was 42.8%, with males having statistically significantly higher rates than females (p < 0.05). Other substances used were cannabis (2%) and cocaine (0.6%). Among those who admitted to using substances, 75.1% were introduced by a friend while 23.5% were introduced by a relative other than a member of the nuclear family. Majority of those using substances wanted to relax (62.2%) or relieve stress (60.8%). Problems associated with alcohol use included quarrelling and fights, loss and damage to property, problems with parents, medical problems and unplanned unprotected sex. CONCLUSION: The prevalence of substance use among college and university students in Eldoret is high and causes significant physical and psychosocial problems in this population. A large proportion of those using alcohol reported serious adverse effects, raising the necessity of targeted interventions to reduce the risk of subsequent substance dependence and other deleterious consequences.

Factors influencing medical students' motivation to practise in rural areas in low-income and middle-income countries: a systematic review.

OBJECTIVES: There is a shortage of doctors working in rural areas all over the world, especially in low-income and middle-income countries. The choice to practise medicine in a rural area is influenced by many factors. Motivation developed as a medical student is one key determinant of this choice. This study explores influences on medical students' motivation to practise in rural areas of low-income and middle-income countries following graduation. DESIGN: A systematic review was conducted to identify influences on medical students' motivation to work in rural areas in low-income and middle-income countries. Papers reporting influences on motivation were included, and content analysis was conducted to select the articles. Articles not published in English were excluded from this review. RESULTS: A rural background (ie, being brought up in a rural area), training in rural areas with a community-based curriculum, early exposure to the community during medical training and rural location of medical school motivate medical students to work in rural areas. Perceived lack of infrastructure, high workload, poor hospital management and isolation are among the health facility factors that demotivate medical students for medical practice in rural areas. CONCLUSIONS: Medical school selection criteria focusing on a rural background factor and medical education curriculum focusing on rural area are more relevant factors in low-income and middle-income countries. The factors identified in this review may assist the planners, medical educators and policymakers in low-income and middle-income countries in designing relevant interventions to positively influence rural choices where the shortage of rural physicians is an ongoing and increasing concern.

Mass mosquito trapping for malaria control in western Kenya: study protocol for a stepped wedge cluster-randomised trial.

BACKGROUND: Increasing levels of insecticide resistance as well as outdoor, residual transmission of malaria threaten the efficacy of existing vector control tools used against malaria mosquitoes. The development of odour-baited mosquito traps has led to the possibility of controlling malaria through mass trapping of malaria vectors. Through daily removal trapping against a background of continued bed net use it is anticipated that vector populations could be suppressed to a level where continued transmission of malaria will no longer be possible. METHODS/DESIGN: A stepped wedge cluster-randomised trial design was used for the implementation of mass mosquito trapping on Rusinga Island, western Kenya (the SolarMal project). Over the course of 2 years (2013-2015) all households on the island were provided with a solar-powered mosquito trapping system. A continuous health and demographic surveillance system combined with parasitological surveys three times a year, successive rounds of mosquito monitoring and regular sociological studies allowed measurement of intervention outcomes before, during and at completion of the rollout of traps. Data collection continued after achieving mass coverage with traps in order to estimate the longer term effectiveness of this novel intervention. Solar energy was exploited to provide electric light and mobile phone charging for each household, and the impacts of these immediate tangible benefits upon acceptability of and adherence to the use of the intervention are being measured. DISCUSSION: This study will be the first to evaluate whether the principle of solar-powered mass mosquito trapping could be an effective tool for elimination of malaria. If proven to be effective, this novel approach to malaria control would be a valuable addition to the existing strategies of long-lasting insecticide-treated nets and case management. Sociological studies provide a knowledge base for understanding the usage of this novel tool. TRIAL REGISTRATION: Trialregister.nl: NTR3496 - SolarMal. Registered on 20 June 2012.

Tracking the mutual shaping of the technical and social dimensions of solar-powered mosquito trapping systems (SMoTS) for malaria control on Rusinga Island, western Kenya.

BACKGROUND: There has been increasing effort in recent years to incorporate user needs in technology design and re-design. This project employed a bottom-up approach that engaged end users from the outset. Bottom-up approaches have the potential to bolster novel interventions and move them towards adaptive and evidence-based strategies. The present study concerns an innovative use of solar-powered mosquito trapping systems (SMoTS) to control malaria in western Kenya. Our paper highlights the co-dependence of research associated with the development of the SMoTS technology on one hand and research for enhancing the sustainable uptake of that very same intervention within the community on the other. METHODS: During the pre-intervention year, we examined the design, re-design and piloting of a novel technology to generate lessons for malaria elimination on Rusinga Island. Initial ideas about many technological necessities were evaluated and re-designed following feedback from various sources, including technical and social research as well as broader interactions with the social environment. We documented the interlocking of the multiple processes and activities that took place through process observation and document reviews. We analysed the data within the conceptual framework of system innovation by identifying mutual shaping between technical and social factors. RESULTS: Our findings illustrate how various project stakeholders including project staff, collaborators, donor, and community members simultaneously pursued interdependent technological transformations and social interests. In the ongoing process, we observed how partial outcomes in the technological domain influenced social events at a later phase and vice versa. CONCLUSIONS: Looking at malaria intervention projects employing novel technologies as niches that may evolve towards system innovation, helps to reveal interrelations between the various technical and social aspects. Revealing these interrelations requires a different role for research and different perspective on innovation where innovation is more than the technical aspects. This approach therefore requires that research is designed in a way that enables obtaining feedback from both aspects.