18 research outputs found
Numbers, densities, and colocalization of AMPA- and NMDA-type glutamate receptors at individual synapses in the superficial spinal dorsal horn of rats
Additional file 1. Form for distribution of repellent bottles and recovery of empty bottles or household data sheet. This sheet was used to collect information from household representative during two-weekly bottle exchange. Each sheet is for each bottle exchange and for a household. Each household had a unique identification code (family code) which was used during the entire project
Sugar-fermenting yeast as an organic source of carbon dioxide to attract the malaria mosquito Anopheles gambiae s.s.
<p>Abstract</p> <p>Background</p> <p>Carbon dioxide (CO<sub>2</sub>) plays an important role in the host-seeking process of opportunistic, zoophilic and anthropophilic mosquito species and is, therefore, commonly added to mosquito sampling tools. The African malaria vector <it>Anopheles gambiae sensu stricto </it>is attracted to human volatiles augmented by CO<sub>2</sub>. This study investigated whether CO<sub>2</sub>, usually supplied from gas cylinders acquired from commercial industry, could be replaced by CO<sub>2 </sub>derived from fermenting yeast (yeast-produced CO<sub>2</sub>).</p> <p>Methods</p> <p>Trapping experiments were conducted in the laboratory, semi-field and field, with <it>An. gambiae s.s</it>. as the target species. MM-X traps were baited with volatiles produced by mixtures of yeast, sugar and water, prepared in 1.5, 5 or 25 L bottles. Catches were compared with traps baited with industrial CO<sub>2</sub>. The additional effect of human odours was also examined. In the laboratory and semi-field facility dual-choice experiments were conducted. The effect of traps baited with yeast-produced CO<sub>2 </sub>on the number of mosquitoes entering an African house was studied in the MalariaSphere. Carbon dioxide baited traps, placed outside human dwellings, were also tested in an African village setting. The laboratory and semi-field data were analysed by a χ<sup>2</sup>-test, the field data by GLM. In addition, CO<sub>2 </sub>concentrations produced by yeast-sugar solutions were measured over time.</p> <p>Results</p> <p>Traps baited with yeast-produced CO<sub>2 </sub>caught significantly more mosquitoes than unbaited traps (up to 34 h post mixing the ingredients) and also significantly more than traps baited with industrial CO<sub>2</sub>, both in the laboratory and semi-field. Adding yeast-produced CO<sub>2 </sub>to traps baited with human odour significantly increased trap catches. In the MalariaSphere, outdoor traps baited with yeast-produced or industrial CO<sub>2 </sub>+ human odour reduced house entry of mosquitoes with a human host sleeping under a bed net indoors. <it>Anopheles gambiae s.s</it>. was not caught during the field trials. However, traps baited with yeast-produced CO<sub>2 </sub>caught similar numbers of <it>Anopheles arabiensis </it>as traps baited with industrial CO<sub>2</sub>. Addition of human odour increased trap catches.</p> <p>Conclusions</p> <p>Yeast-produced CO<sub>2 </sub>can effectively replace industrial CO<sub>2 </sub>for sampling of <it>An. gambiae s.s</it>.. This will significantly reduce costs and allow sustainable mass-application of odour-baited devices for mosquito sampling in remote areas.</p
Spatial clustering and risk factors of malaria infections in Ratanakiri Province, Cambodia
Background: Malaria incidence worldwide has steadily declined over the past decades. Consequently, increasingly more countries will proceed from control to elimination. The malaria distribution in low incidence settings appears patchy, and local transmission hotspots are a continuous source of infection. In this study, species-specific clusters and associated risk factors were identified based on malaria prevalence data collected in the north-east of Cambodia. In addition, Plasmodium falciparum genetic diversity, population structure and gene flows were studied.Method: In 2012, blood samples from 5793 randomly selected individuals living in 117 villages were collected from Ratanakiri province, Cambodia. Malariometric data of each participant were simultaneously accumulated using a standard questionnaire. A two-step PCR allowed for species-specific detection of malaria parasites, and SNPgenotyping of P. falciparum was performed. SaTScan was used to determine species-specific areas of elevated risk to infection, and univariate and multivariate risk analyses were carried out.Result: PCR diagnosis found 368 positive individuals (6.4%) for malaria parasites, of which 22% contained mixed species infections. The occurrence of these co-infections was more frequent than expected. Specific areas with elevated risk of infection were detected for all Plasmodium species. The clusters for Falciparum, Vivax and Ovale malaria appeared in the north of the province along the main river, while the cluster for Malariae malaria was situated elsewhere. The relative risk to be a malaria parasite carrier within clusters along the river was twice that outside the area. The main risk factor associated with three out of four malaria species was overnight stay in the plot hut, a human behaviour associated with indigenous farming. Haplotypes did not show clear geographical population structure, but pairwise Fst value comparison indicated higher parasite flow along the river.Discussion: Spatial aggregation of malaria parasite carriers, and the identification of malaria species-specific risk factors provide key insights in malaria epidemiology in low transmission settings, which can guide targeted supplementary interventions. Consequently, future malaria programmes in the province should implement additional specific policies targeting households staying overnight at their farms outside the village, in addition to migrants and forest workers
A phase III trial to evaluate the efficacy, fabric integrity and community acceptance of Netprotect (R) using a recommended long-lasting insecticidal net as positive control
A phase III trial to evaluate the efficacy, fabric integrity and community acceptance of Netprotect (R) using a recommended long-lasting insecticidal net as positive control
Field evaluation of picaridin repellents reveals differences in repellent sensitivity between Southeast Asian vectors of malaria and arboviruses
Scaling up of insecticide treated nets has contributed to a substantial malaria decline. However, some malaria vectors, and most arbovirus vectors, bite outdoors and in the early evening. Therefore, topically applied insect repellents may provide crucial additional protection against mosquito-borne pathogens. Among topical repellents, DEET is the most commonly used, followed by others such as picaridin. The protective efficacy of two formulated picaridin repellents against mosquito bites, including arbovirus and malaria vectors, was evaluated in a field study in Cambodia. Over a period of two years, human landing collections were performed on repellent treated persons, with rotation to account for the effect of collection place, time and individual collector. Based on a total of 4996 mosquitoes collected on negative control persons, the overall five hour protection rate was 97.4% [95%CI: 97.1-97.8%], not decreasing over time. Picaridin 20% performed equally well as DEET 20% and better than picaridin 10%. Repellents performed better against Mansonia and Culex spp. as compared to aedines and anophelines. A lower performance was observed against Aedes albopictus as compared to Aedes aegypti, and against Anopheles barbirostris as compared to several vector species. Parity rates were higher in vectors collected on repellent treated person as compared to control persons. As such, field evaluation shows that repellents can provide additional personal protection against early and outdoor biting malaria and arbovirus vectors, with excellent protection up to five hours after application. The heterogeneity in repellent sensitivity between mosquito genera and vector species could however impact the efficacy of repellents in public health programs. Considering its excellent performance and potential to protect against early and outdoor biting vectors, as well as its higher acceptability as compared to DEET, picaridin is an appropriate product to evaluate the epidemiological impact of large scale use of topical repellents on arthropod borne diseases
Percent repellency with 95% confidence interval between square brackets for repellents, mosquito genera and mosquito species separately and for all mosquitoes and all repellents combined.
<p>Percent repellency with 95% confidence interval between square brackets for repellents, mosquito genera and mosquito species separately and for all mosquitoes and all repellents combined.</p
Logistic regression analysis of the effect of repellent treatment (including Ethanol as negative control) on the parity rate of the vector species.
<p>Odds ratio's (OR) with 95% confidence intervals and p-values are reported.</p><p>* The Odds Ratio (OR) gives the odds of collecting a parous mosquito in Group 1 as compared to the odds of collecting a parous mosquito in Group 2 on persons treated with repellents. If OR<1 less mosquitoes were parous in Group1, if OR>1 more mosquitoes were parous in Group 1.</p><p>**No nulliparous mosquitoes were collected on DEET 20% treated persons, as such influencing the analysis to such an extent that NAs were generated in confidence limits of ORs.</p><p>Logistic regression analysis of the effect of repellent treatment (including Ethanol as negative control) on the parity rate of the vector species.</p
Hourly biting rate calculated as the number of bites per man per hour on negative control persons for the mosquito genera (A) and selected vector species (B).
<p>Hourly biting rate calculated as the number of bites per man per hour on negative control persons for the mosquito genera (A) and selected vector species (B).</p