133 research outputs found

    Violence Increases Psychological Distress Among Women Trafficking Survivors in Ghana

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    Human trafficking is a crime that is often shaped by violence, particularly for women who are trafficked. Additionally, trafficking survivors often report severe psychological distress, though research on the causes of this psychological distress is lacking, as there is little longitudinal data available on trafficking survivors. Informed by past literature on the links between violence and mental health among other traumatized groups of women, we investigate how experiences of violence influence posttraumatic stress, depression, and suicide ideation among a unique longitudinal sample of 116 labor-trafficked women in Ghana. We find that experiencing sexual violence while being trafficked is associated with higher levels of both depression and posttraumatic stress years after the trafficking period ended. This indicates both the long-term effects of stress and the enduring nature of psychological distress among the women in this study. Our analytic account of how violent experiences while trafficked impact mental health over the period of reintegration contributes to the general literature on violence and mental health among women, as well as to literature on the health implications of human traffickin

    New Directions for African Security

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    African security, particularly conflict-related political violence, is a key concern in international relations. This forum seeks to advance existing research agendas by addressing four key themes: domestic politics and peacekeeping; security sector reform programs; peace enforcement; and the protection of civilians. Each of the articles in this forum makes a case for analyzing African agency when it comes to African security. As a way of introduction, this short article sets out the main debates and concludes by providing further directions for future researc

    Thermal behaviour of Anopheles stephensi in response to infection with malaria and fungal entomopathogens

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    <p>Abstract</p> <p>Background</p> <p>Temperature is a critical determinant of the development of malaria parasites in mosquitoes, and hence the geographic distribution of malaria risk, but little is known about the thermal preferences of <it>Anopheles</it>. A number of other insects modify their thermal behaviour in response to infection. These alterations can be beneficial for the insect or for the infectious agent. Given current interest in developing fungal biopesticides for control of mosquitoes, <it>Anopheles stephensi </it>were examined to test whether mosquitoes showed thermally-mediated behaviour in response to infection with fungal entomopathogens and the rodent malaria, <it>Plasmodium yoelii</it>.</p> <p>Methods</p> <p>Over two experiments, groups of <it>An. stephensi </it>were infected with one of three entomopathogenic fungi, and/or <it>P. yoelii</it>. Infected and uninfected mosquitoes were released on to a thermal gradient (14 – 38°C) for "snapshot" assessments of thermal preference during the first five days post-infection. Mosquito survival was monitored for eight days and, where appropriate, oocyst prevalence and intensity was assessed.</p> <p>Results and conclusion</p> <p>Both infected and uninfected <it>An. stephensi </it>showed a non-random distribution on the gradient, indicating some capacity to behaviourally thermoregulate. However, chosen resting temperatures were not altered by any of the infections. There is thus no evidence that thermally-mediated behaviours play a role in determining malaria prevalence or that they will influence the performance of fungal biopesticides against adult <it>Anopheles</it>.</p

    Effect of discriminative plant-sugar feeding on the survival and fecundity of Anopheles gambiae

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    <p>Abstract</p> <p>Background</p> <p>A previous study showed for <it>Anopheles gambiae s.s</it>. a gradation of feeding preference on common plant species growing in a malaria holoendemic area in western Kenya. The present follow-up study determines whether there is a relationship between the mosquito's preferences and its survival and fecundity.</p> <p>Methods</p> <p>Groups of mosquitoes were separately given <it>ad libitum </it>opportunity to feed on five of the more preferred plant species (<it>Hamelia patens</it>, <it>Parthenium hysterophorus</it>, <it>Ricinus communis</it>, <it>Senna didymobotrya</it>, and <it>Tecoma stans</it>) and one of the less preferred species (<it>Lantana camara</it>). The mosquitoes were monitored daily for survival. Sugar solution (glucose 6%) and water were used as controls. In addition, the fecundity of mosquitoes on each plant after (i) only one blood meal (number of eggs oviposited), and (ii) after three consecutive blood meals (proportion of females ovipositing, number of eggs oviposited and hatchability of eggs), was determined. The composition and concentration of sugar in the fed-on parts of each plant species were determined using gas chromatography. Using SAS statistical package, tests for significant difference of the fitness values between mosquitoes exposed to different plant species were conducted.</p> <p>Results and Conclusion</p> <p><it>Anopheles gambiae </it>that had fed on four of the five more preferred plant species (<it>T. stans</it>, <it>S. didymobotrya</it>, <it>R. communis </it>and <it>H. patens</it>, but not <it>P. hysterophorus</it>) lived longer and laid more eggs after one blood meal, when compared with <it>An. gambiae </it>that had fed on the least preferred plant species <it>L. camara</it>. When given three consecutive blood-meals, the percentage of females that oviposited, but not the number of eggs laid, was significantly higher for mosquitoes that had previously fed on the four more preferred plant species. Total sugar concentration in the preferred plant parts was significantly correlated with survival and with the proportion of females that laid eggs. This effect was associated mainly with three sugar types, namely glucose, fructose, and gulose. Except for <it>P. hysterophorus</it>, the results suggest that feeding by mosquitoes on preferred plant species under natural conditions results in higher fitness-related benefits, and that the sugar content in preferred plant parts is largely responsible for these effects.</p

    Declining Burden of Malaria Over two Decades in a Rural Community of Muheza District, North-Eastern Tanzania.

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    The recently reported declining burden of malaria in some African countries has been attributed to scaling-up of different interventions although in some areas, these changes started before implementation of major interventions. This study assessed the long-term trends of malaria burden for 20 years (1992--2012) in Magoda and for 15 years in Mpapayu village of Muheza district, north-eastern Tanzania, in relation to different interventions as well as changing national malaria control policies.\ud Repeated cross-sectional surveys recruited individuals aged 0 -- 19 years from the two villages whereby blood smears were collected for detection of malaria parasites by microscopy. Prevalence of Plasmodium falciparum infections and other indices of malaria burden (prevalence of anaemia, splenomegaly and gametocytes) were compared across the years and between the study villages. Major interventions deployed including mobile clinic, bed nets and other research activities, and changes in national malaria control policies were also marked. In Magoda, the prevalence of P. falciparum infections initially decreased between 1992 and 1996 (from 83.5 to 62.0%), stabilized between 1996 and 1997, and further declined to 34.4% in 2004. A temporary increase between 2004 and 2008 was followed by a progressive decline to 7.2% in 2012, which is more than 10-fold decrease since 1992. In Mpapayu (from 1998), the highest prevalence was 81.5% in 1999 and it decreased to 25% in 2004. After a slight increase in 2008, a steady decline followed, reaching <5% from 2011 onwards. Bed net usage was high in both villages from 1999 to 2004 (>=88%) but it decreased between 2008 and 2012 (range, 28% - 68%). After adjusting for the effects of bed nets, age, fever and year of study, the risk of P. falciparum infections decreased significantly by >=97% in both villages between 1999 and 2012 (p < 0.001). The prevalence of splenomegaly (>40% to <1%) and gametocytes (23% to <1%) also decreased in both villages.Discussion and conclusionsA remarkable decline in the burden of malaria occurred between 1992 and 2012 and the initial decline (1992 -- 2004) was most likely due to deployment of interventions, such as bed nets, and better services through research activities. Apart from changes of drug policies, the steady decline observed from 2008 occurred when bed net coverage was low suggesting that other factors contributed to the most recent pattern. These results suggest that continued monitoring is required to determine causes of the changing malaria epidemiology and also to monitor the progress towards maintaining low malaria transmission and reaching related millennium development goals

    Using the entomological inoculation rate to assess the impact of vector control on malaria parasite transmission and elimination

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    Prior studies have shown that annual entomological inoculation rates (EIRs) must be reduced to less than one to substantially reduce the prevalence of malaria infection. In this study, EIR values were used to quantify the impact of insecticide-treated bed nets (ITNs), indoor residual spraying (IRS), and source reduction (SR) on malaria transmission. The analysis of EIR was extended through determining whether available vector control tools can ultimately eradicate malaria. The analysis is based primarily on a review of all controlled studies that used ITN, IRS, and/or SR and reported their effects on the EIR. To compare EIRs between studies, the percent difference in EIR between the intervention and control groups was calculated. Eight vector control intervention studies that measured EIR were found: four ITN studies, one IRS study, one SR study, and two studies with separate ITN and IRS intervention groups. In both the Tanzania study and the Solomon Islands study, one community received ITNs and one received IRS. In the second year of the Tanzania study, EIR was 90% lower in the ITN community and 93% lower in the IRS community, relative to the community without intervention; the ITN and IRS effects were not significantly different. In contrast, in the Solomon Islands study, EIR was 94% lower in the ITN community and 56% lower in the IRS community. The one SR study, in Dar es Salaam, reported a lower EIR reduction (47%) than the ITN and IRS studies. All of these vector control interventions reduced EIR, but none reduced it to zero. These studies indicate that current vector control methods alone cannot ultimately eradicate malaria because no intervention sustained an annual EIR less than one. While researchers develop new tools, integrated vector management may make the greatest impact on malaria transmission. There are many gaps in the entomological malaria literature and recommendations for future research are provided

    The influence of mosquito resting behaviour and associated microclimate for malaria risk

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    <p>Abstract</p> <p>Background</p> <p>The majority of the mosquito and parasite life-history traits that combine to determine malaria transmission intensity are temperature sensitive. In most cases, the process-based models used to estimate malaria risk and inform control and prevention strategies utilize measures of mean outdoor temperature. Evidence suggests, however, that certain malaria vectors can spend large parts of their adult life resting indoors.</p> <p>Presentation of hypothesis</p> <p>If significant proportions of mosquitoes are resting indoors and indoor conditions differ markedly from ambient conditions, simple use of outdoor temperatures will not provide reliable estimates of malaria transmission intensity. To date, few studies have quantified the differential effects of indoor <it>vs </it>outdoor temperatures explicitly, reflecting a lack of proper understanding of mosquito resting behaviour and associated microclimate.</p> <p>Testing the hypothesis</p> <p>Published records from 8 village sites in East Africa revealed temperatures to be warmer indoors than outdoors and to generally show less daily variation. Exploring the effects of these temperatures on malaria parasite development rate suggested indoor-resting mosquitoes could transmit malaria between 0.3 and 22.5 days earlier than outdoor-resting mosquitoes. These differences translate to increases in transmission risk ranging from 5 to approaching 3,000%, relative to predictions based on outdoor temperatures. The pattern appears robust for low- and highland areas, with differences increasing with altitude.</p> <p>Implications of the hypothesis</p> <p>Differences in indoor <it>vs </it>outdoor environments lead to large differences in the limits and the intensity of malaria transmission. This finding highlights a need to better understand mosquito resting behaviour and the associated microclimate, and to broaden assessments of transmission ecology and risk to consider the potentially important role of endophily.</p

    A Randomized Controlled Phase Ib Trial of the Malaria Vaccine Candidate GMZ2 in African Children

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    BACKGROUND: GMZ2 is a fusion protein of Plasmodium falciparum merozoite surface protein 3 (MSP3) and glutamate rich protein (GLURP) that mediates an immune response against the blood stage of the parasite. Two previous phase I clinical trials, one in naïve European adults and one in malaria-exposed Gabonese adults showed that GMZ2 was well tolerated and immunogenic. Here, we present data on safety and immunogenicity of GMZ2 in one to five year old Gabonese children, a target population for future malaria vaccine efficacy trials. METHODOLOGY/PRINCIPAL FINDINGS: Thirty children one to five years of age were randomized to receive three doses of either 30 µg or 100 µg of GMZ2, or rabies vaccine. GMZ2, adjuvanted in aluminum hydroxide, was administered on Days 0, 28 and 56. All participants received a full course of their respective vaccination and were followed up for one year. Both 30 µg and 100 µg GMZ2 vaccine doses were well tolerated and induced antibodies and memory B-cells against GMZ2 as well as its antigenic constituents MSP3 and GLURP. After three doses of vaccine, the geometric mean concentration of antibodies to GMZ2 was 19-fold (95%CI: 11,34) higher in the 30 µg GMZ2 group than in the rabies vaccine controls, and 16-fold (7,36) higher in the 100 µg GMZ2 group than the rabies group. Geometric mean concentration of antibodies to MSP3 was 2.7-fold (1.6,4.6) higher in the 30 µg group than in the rabies group and 3.8-fold (1.5,9.6) higher in the 100 µg group. Memory B-cells against GMZ2 developed in both GMZ2 vaccinated groups. CONCLUSIONS/SIGNIFICANCE: Both 30 µg as well as 100 µg intramuscular GMZ2 are immunogenic, well tolerated, and safe in young, malaria-exposed Gabonese children. This result confirms previous findings in naïve and malaria-exposed adults and supports further clinical development of GMZ2. TRIAL REGISTRATION: ClinicalTrials.gov NCT00703066
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