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Search Results: 1 - 10 of 257 matches for " Natacha Protopopoff "
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Evidence for a useful life of more than three years for a polyester-based long-lasting insecticidal mosquito net in Western Uganda
Albert Kilian, Wilson Byamukama, Olivier Pigeon, John Gimnig, Francis Atieli, Lizette Koekemoer, Natacha Protopopoff
Malaria Journal , 2011, DOI: 10.1186/1475-2875-10-299
Abstract: In five villages, 190 LLIN and 90 nets conventionally treated with the insecticide alpha-cypermethrin at 25 mg/m2 were distributed randomly and used by the families. Following a baseline household survey a net survey was carried out every six months to capture use, washing habits and physical condition of the nets. Randomly selected nets were collected after 6, 12, 24, 36 and 42 months and tested for remaining insecticide content and ability to knock-down and kill malaria transmitting mosquitoes.During the three and a half years of observation only 16 nets were lost to follow-up resulting in an estimated attrition rate of 12% after three and 20/% after 3.5 years. Nets were used regularly and washed on average 1.5 times per year. After three and a half years 29% of the nets were still in good condition while 13% were seriously torn with no difference between the LLIN and control nets. The conventionally treated nets quickly lost insecticide and after 24 months only 7% of the original dose remained (1.6 mg/m2). Baseline median concentration of alpha-cypermethrin for LLIN was 194.5 mg/m2 or 97% of the target dose with between and within net variation of 11% and 4% respectively (relative standard deviation). On the LLIN 73.8 mg/m2 alpha-cypermethrin remained after three years of use and 56.2 mg/m2 after three and a half and 94% and 81% of the LLIN still had > 15 mg/m2 left respectively. Optimal effectiveness in bio-assays (≥95% 60 minute knock-down or ≥ 80% 24 hour mortality) was found in 83% of the sampled LLIN after three and 71% after three and a half years.Under conditions in Western Uganda the tested long-lasting insecticidal net Interceptor? fulfilled the criteria for phase III of WHO evaluations and, based on preliminary criteria of the useful life, this product is estimated to last on average between three and four years.The technology of long-lasting insecticidal nets (LLIN) was developed in the late 1990'ties as a response to the poor re-treatment practices fo
Evaluation of a national universal coverage campaign of long-lasting insecticidal nets in a rural district in north-west Tanzania
West Philippa A,Protopopoff Natacha,Rowland Mark W,Kirby Matthew J
Malaria Journal , 2012, DOI: 10.1186/1475-2875-11-273
Abstract: Background Insecticide-treated nets (ITN) are one of the most effective measures for preventing malaria. Mass distribution campaigns are being used to rapidly increase net coverage in at-risk populations. This study had two purposes: to evaluate the impact of a universal coverage campaign (UCC) of long-lasting insecticidal nets (LLINs) on LLIN ownership and usage, and to identify factors that may be associated with inadequate coverage. Methods In 2011 two cross-sectional household surveys were conducted in 50 clusters in Muleba district, north-west Tanzania. Prior to the UCC 3,246 households were surveyed and 2,499 afterwards. Data on bed net ownership and usage, demographics of household members and household characteristics including factors related to socio-economic status were gathered, using an adapted version of the standard Malaria Indicator Survey. Specific questions relating to the UCC process were asked. Results The proportion of households with at least one ITN increased from 62.6% (95% Confidence Interval (CI) = 60.9-64.2) before the UCC to 90.8% (95% CI = 89.0-92.3) afterwards. ITN usage in all residents rose from 40.8% to 55.7%. After the UCC 58.4% (95% CI = 54.7-62.1) of households had sufficient ITNs to cover all their sleeping places. Households with children under five years (OR = 2.4, 95% CI = 1.9-2.9) and small households (OR = 1.9, 95% CI = 1.5-2.4) were most likely to reach universal coverage. Poverty was not associated with net coverage. Eighty percent of households surveyed received LLINs from the campaign. Conclusions The UCC in Muleba district of Tanzania was equitable, greatly improving LLIN ownership and, more moderately, usage. However, the goal of universal coverage in terms of the adequate provision of nets was not achieved. Multiple, continuous delivery systems and education activities are required to maintain and improve bed net ownership and usage.
The effect of the spatial repellent metofluthrin on landing rates of outdoor biting anophelines in Cambodia, S.E. Asia
Jacques Derek D Charlwood,Nep Nenhep,Natacha Protopopoff,Sovannaroth Siv,John C Morgan,Janet Hemingway
PeerJ , 2015, DOI: 10.7287/peerj.preprints.751v1
Abstract: Without controlling outdoor transmission, the goal of elimination of malaria is unlikely to be reached. This is particularly the case in places like Cambodia where people spend considerable amounts of time away from houses at night. Metofluthrin is a synthetic pyrethroid insecticide with a high vapor action at ambient temperatures and has been developed as a long lasting insect repellent device that works without the need to apply heat. Emanators of 10% of metofluthrin were therefore tested in landing collections against potential malaria vectors from three areas of the country (Pailin, Pursat and Koh Kong). One to four emanators were hung on wire 1m off the ground on one or four sides of a square 1.5m from collectors. Collections were also undertaken with Furvela tent-traps. 2086 hrs of landing collection were undertaken in Pailin, 528hrs in Veal Veng and 320 in Kroh Salau. Rate ratios were used to determine the significance of the difference between collections. The principal anophelines collected varied between locations. Anopheles minimus s.l. was the most common mosquito in Pailin, An. maculatus s.l in Veal Veng and An. sinensis in Kroh Salau. Among all species collected in Pailin landing rates were reduced by 50% (95% CI 55-44%) when a single emanator was used and by 58% (95% CI 63- 52%) when four were used. The effect was greater in An.minimus s.l 51% ( 95% CI 54-47%) and 70% (72%-66%) respectively. A similar result was obtained in Pursat, where 67% (95% CI 66- 42%) reductions were observed when four emanators were in use, but no significant reduction was observed in Koh Kong. Although the results show promise it is argued that the product needs further development.
Ranking Malaria Risk Factors to Guide Malaria Control Efforts in African Highlands
Natacha Protopopoff,Wim Van Bortel,Niko Speybroeck,Jean-Pierre Van Geertruyden,Dismas Baza,Umberto D'Alessandro,Marc Coosemans
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0008022
Abstract: Malaria is re-emerging in most of the African highlands exposing the non immune population to deadly epidemics. A better understanding of the factors impacting transmission in the highlands is crucial to improve well targeted malaria control strategies.
Vector control in a malaria epidemic occurring within a complex emergency situation in Burundi: a case study
Natacha Protopopoff, Michel Van Herp, Peter Maes, Tony Reid, Dismas Baza, Umberto D'Alessandro, Wim Van Bortel, Marc Coosemans
Malaria Journal , 2007, DOI: 10.1186/1475-2875-6-93
Abstract: Twenty nine hills (administrative areas) were selected in collaboration with the provincial health authorities for the vector control interventions combining indoor residual spraying with deltamethrin and insecticide-treated nets. Impact was evaluated by entomological and parasitological surveys. Almost all houses (99%) were sprayed and nets use varied between 48% and 63%. Anopheles indoor resting density was significantly lower in treated as compared to untreated hills, the latter taken as controls. Despite this impact on the vector, malaria prevalence was not significantly lower in treated hills except for people sleeping under a net.Indoor spraying was feasible and resulted in high coverage despite being a logistically complex intervention in the Burundian context (scattered houses and emergency situation). However, it had little impact on the prevalence of malaria infection, possibly because it was implemented after the epidemic's peak. Nevertheless, after this outbreak the Ministry of Health improved the surveillance system, changed its policy with introduction of effective drugs and implementation of vector control to prevent new malaria epidemics.In the absence of effective drugs and sufficient preparedness, present study failed to demonstrate any impact of vector control activities upon the course of a short-duration malaria epidemic. However, the experience gained lead to increased preparedness and demonstrated the feasibility of vector control measures in this specific context.Malaria epidemics are a growing problem in the African highlands with devastating effects on their immunologically naive population [1,2]. When occurring during complex emergency situations their control is even more difficult. According to WHO [3] "a complex emergency is a situation that affects large civilian populations with war or civil strife, food shortages and population displacement, resulting in excess mortality and morbidity". The approach to malaria control in the acute ph
Spatial targeted vector control in the highlands of Burundi and its impact on malaria transmission
Natacha Protopopoff, Wim Van Bortel, Tanguy Marcotty, Michel Van Herp, Peter Maes, Dismas Baza, Umberto D'Alessandro, Marc Coosemans
Malaria Journal , 2007, DOI: 10.1186/1475-2875-6-158
Abstract: In Karuzi, in 2002–2005, vector control activities combining indoor residual spraying and long-lasting insecticidal nets were implemented. The interventions were done before the expected malaria transmission period and targeted the valleys between hills, with the expectation that this would also protect the populations living at higher altitudes. The impact on the Anopheles population and on malaria transmission was determined by nine cross-sectional surveys carried out at regular intervals throughout the study period.Anopheles gambiae s.l. and Anopheles funestus represented 95% of the collected anopheline species. In the valleys, where the vector control activities were implemented, Anopheles density was reduced by 82% (95% CI: 69–90). Similarly, transmission was decreased by 90% (95% CI: 63%–97%, p = 0.001). In the sprayed valleys, Anopheles density was further reduced by 79.5% (95% CI: 51.7–91.3, p < 0.001) in the houses with nets as compared to houses without them. No significant impact on vector density and malaria transmission was observed in the hill tops. However, the intervention focused on the high risk areas near the valley floor, where 93% of the vectors are found and 90% of the transmission occurs.Spatial targeted vector control effectively reduced Anopheles density and transmission in this highland district. Bed nets have an additional effect on Anopheles density though this did not translate in an additional impact on transmission. Though no impact was observed in the hilltops, the programme successfully covered the areas most at risk. Such a targeted strategy could prevent the emergence and spread of an epidemic from these high risk foci.Malaria epidemics occur frequently in the African highlands [1-3]. Their control is a priority and a specific plan of action was adopted by the African leaders during the 2000 Abuja summit [4]. An early warning system to increase malaria epidemic preparedness and prevention has been promoted, based on climate data, p
Indoor Residual Spraying in Combination with Insecticide-Treated Nets Compared to Insecticide-Treated Nets Alone for Protection against Malaria: A Cluster Randomised Trial in Tanzania
Philippa A. West ,Natacha Protopopoff,Alexandra Wright,Zuhura Kivaju,Robinson Tigererwa,Franklin W. Mosha,William Kisinza,Mark Rowland,Immo Kleinschmidt
PLOS Medicine , 2014, DOI: 10.1371/journal.pmed.1001630
Abstract: Background Insecticide-treated nets (ITNs) and indoor residual spraying (IRS) of houses provide effective malaria transmission control. There is conflicting evidence about whether it is more beneficial to provide both interventions in combination. A cluster randomised controlled trial was conducted to investigate whether the combination provides added protection compared to ITNs alone. Methods and Findings In northwest Tanzania, 50 clusters (village areas) were randomly allocated to ITNs only or ITNs and IRS. Dwellings in the ITN+IRS arm were sprayed with two rounds of bendiocarb in 2012. Plasmodium falciparum prevalence rate (PfPR) in children 0.5–14 y old (primary outcome) and anaemia in children <5 y old (secondary outcome) were compared between study arms using three cross-sectional household surveys in 2012. Entomological inoculation rate (secondary outcome) was compared between study arms. IRS coverage was approximately 90%. ITN use ranged from 36% to 50%. In intention-to-treat analysis, mean PfPR was 13% in the ITN+IRS arm and 26% in the ITN only arm, odds ratio = 0.43 (95% CI 0.19–0.97, n = 13,146). The strongest effect was observed in the peak transmission season, 6 mo after the first IRS. Subgroup analysis showed that ITN users were additionally protected if their houses were sprayed. Mean monthly entomological inoculation rate was non-significantly lower in the ITN+IRS arm than in the ITN only arm, rate ratio = 0.17 (95% CI 0.03–1.08). Conclusions This is the first randomised trial to our knowledge that reports significant added protection from combining IRS and ITNs compared to ITNs alone. The effect is likely to be attributable to IRS providing added protection to ITN users as well as compensating for inadequate ITN use. Policy makers should consider deploying IRS in combination with ITNs to control transmission if local ITN strategies on their own are insufficiently effective. Given the uncertain generalisability of these findings, it would be prudent for malaria control programmes to evaluate the cost-effectiveness of deploying the combination. Trial registration www.ClinicalTrials.gov NCT01697852 Please see later in the article for the Editors' Summary
Malaria Risk Factors in North West Tanzania: The Effect of Spraying, Nets and Wealth
Philippa A. West, Natacha Protopopoff, Mark Rowland, Emma Cumming, Alison Rand, Chris Drakeley, Alexandra Wright, Zuhura Kivaju, Matthew J. Kirby, Franklin W. Mosha, William Kisinza, Immo Kleinschmidt
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0065787
Abstract: Malaria prevalence remains high in many African countries despite massive scaling-up of insecticide treated nets (ITN) and indoor residual spraying (IRS). This paper evaluates the protective effect of pyrethroid IRS and ITNs in relation to risk factors for malaria based on a study conducted in North-West Tanzania, where IRS has been conducted since 2007 and universal coverage of ITNs has been carried out recently. In 2011 community-based cross-sectional surveys were conducted in the two main malaria transmission periods that occur after the short and long rainy seasons. These included 5,152 and 4,325 children aged 0.5–14 years, respectively. Data on IRS and ITN coverage, household demographics and socio-economic status were collected using an adapted version of the Malaria Indicator Survey. Children were screened for malaria by rapid diagnostic test. In the second survey, haemoglobin density was measured and filter paper blood spots were collected to determine age-specific sero-prevalence in each community surveyed. Plasmodium falciparum infection prevalence in children 0.5–14 years old was 9.3% (95%CI:5.9–14.5) and 22.8% (95%CI:17.3–29.4) in the two surveys. Risk factors for infection after the short rains included households not being sprayed (OR = 0.39; 95%CI:0.20–0.75); low community net ownership (OR = 0.45; 95%CI:0.21–0.95); and low community SES (least poor vs. poorest tertile: OR = 0.13, 95%CI:0.05–0.34). Risk factors after the long rains included household poverty (per quintile increase: OR = 0.89; 95%CI:0.82–0.97) and community poverty (least poor vs. poorest tertile: OR = 0.26, 95%CI:0.15–0.44); household IRS or high community ITN ownership were not protective. Despite high IRS coverage and equitable LLIN distribution, poverty was an important risk factor for malaria suggesting it could be beneficial to target additional malaria control activities to poor households and communities. High malaria prevalence in some clusters and the limited protection given by pyrethroid IRS and LLINs suggest that it may be necessary to enhance established vector control activities and consider additional interventions.
Gnoseología y determinismo en la Estoa antigua: ?en qué sentido el sabio es capaz de controlar sus asentimientos?
Argos , 2012,
Abstract: the present paper proposes to notice the cognitive process' moment in which the sage's ability to control his assents would become apparent; this objective presents some difficulties given the context of a radical determinism that characterizes stoic thought. therefore, and with the aim of solving such problems, we will conjugate the existence of a determinations' chain (which constitutes fate) with the possibility that a man has a faculty which 'might be in his power'.
La race comme catégorie pratique: le noir et la coopération européenne au développement
Nicaise, Natacha;
Vibrant: Virtual Brazilian Anthropology , 2012, DOI: 10.1590/S1809-43412012000100016
Abstract: setting out from an analysis of the narrative that turned black people into the archetypical recipients of european development aid, this article examines the production of an ontological, racial and cultural difference between aid donors and recipients. it shows the interconnection between two sociohistorical processes: the reconfigurations of european bureaucracy responsible for relations with 'underdeveloped' countries, and the social and professional trajectories of some of the first civil servants responsible for informing about these policies within the context of european unification. the text examines the definition of the populations and regions receiving development aid in four parts: the racialization of poverty and policies of compassion, the european community and the development of africa, bureaucracy and world organization, and the passions and vocations of development workers.
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