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Bionomics of Malaria Vectors in Mutare and Mutasa Districts of Manicaland Province, Zimbabwe
No full textBionomics of malaria vectors including species composition, resting and biting behaviour and insecticide resistance are important for insecticide-based malaria control and interventions. The lack of data on malaria vector species composition and relative abundance, resting and biting behaviour, as well as insecticide resistance, make the development of target control measures problematic in Mutare and Mutasa Districts. It is imperative to elucidate, characterize, and identify all members of the An. funestus group and the An. gambiae complex to determine their resting and biting behaviour, host-seeking activities, disease relationships, and resistance to insecticides. A longitudinal study was carried out to investigate the bionomics of malaria vector mosquitoes in Mutare and Mutasa Districts. Anopheline larval and adult sampling was conducted from May 2013 to December 2014 using scooping, pyrethrum spray catch, prokopac aspirator, exit window trap, pit shelter, and Centers for Disease Control (CDC) light trap methods. Indoor and outdoor resting mosquitoes were collected in randomly selected houses and pit shelters, respectively. Mosquitoes sampled by light traps were divided into two cohorts. In one cohort, traps were left overnight and mosquitoes collected the following morning, while in the other set, mosquitoes were collected hourly throughout the night. Mosquito samples for insecticide resistance testing were divided into two subsamples. One subsample was used immediately for WHO susceptibility assays and the other batch was allowed to oviposit in the insectary at the National Institute of Health Research, and females from the F1 progeny were used in further susceptibility assays. Mosquitoes were identified using morphological keys and polymerase chain reaction (PCR) techniques. The PCR-based assays showed the presence of four sibling species: Anopheles funestus sensu stricto (90.8%, 267/294) and An. leesoni (5.1%, 15/294) of the An. funestus group and An. arabiensis (41.9%, 13/31) and An. quadriannulatus (48.4%, 15/31) of the An. gambiae complex. Of the two malaria vectors, An. funestus sensu stricto was more abundant (95.4%, 267/280) than An. arabiensis (4.6%, 13/280). Endophilic collections of the An. funestus group and the An. gambiae complex were five times greater than exophilic catches. Nearly 90% endophilic An. funestus populations were collected on sprayable surfaces and the remainder was caught on unsprayable surfaces. Of the sprayable surfaces catches, 56% were collected on the roofs; with 44% on the walls. Of the gravid An. funestus caught, nearly two-thirds (218/330) were collected exiting recently pyrethroid-treated structures, with a 24-hour mortality of less than 10%. The CDC light trap catches were more abundant indoors (68%) than outdoors (32%). Anopheles funestus showed variable indoor and outdoor flight activity rhythms, with two peaks during the night; between 22:00-23:00 hours and 02:00-04:00 hours. Human blood index was 64.3%, with Plasmodium falciparum infection rate of 1.8%. Wild caught females showed resistance to lambda-cyhalothrin (3.3% mortality), deltamethrin (12.9% mortality), etofenprox (9.2% mortality), and bendiocarb (11.7% mortality). F1 An. funestus females showed resistance to deltamethrin (14.5% mortality), lambda-cyhalothrin (6.9 % mortality), etofenprox (8.3% mortality), and bendiocarb (16.8% mortality), but were susceptible to DDT and pirimiphos-methyl (100% mortality). Intensity resistance assay to bendiocarb had 100% mortality, while deltamethrin, lambda-cyhalothrin, and etofenprox had increased knockdown times with mortalities ranging between 66.7 and 92.7% after 24-hour exposures. The present work revealed important information on the behaviour of malaria vector mosquitoes in Mutare and Mutasa Districts, which if not addressed might threaten gains made in malaria control in the study area. It is imperative to change house-spraying insecticide from pyrethroids to organophosphates or DDT (organochlorine), develop an insecticide resistance management plan, provide extension lances to the house-spraying programme, complement mosquito nets with the use of mosquito repellents and long clothes, and establish a monitoring programme to determine the occurrence and distribution of An. funestus populations in Manicaland Province
Bionomics of malaria vectors in Mutare and Mutasa districts of Manicaland province, Zimbabwe
No full textBionomics of malaria vectors including species composition, resting and biting behaviour and insecticide resistance are important for insecticide-based malaria control and interventions. The lack of data on malaria vector species composition and relative abundance, resting and biting behaviour, as well as insecticide resistance, make the development of target control measures problematic in Mutare and Mutasa Districts. It is imperative to elucidate, characterize, and identify all members of the An. funestus group and the An. gambiae complex to determine their resting and biting behaviour, host-seeking activities, disease relationships, and resistance to insecticides. A longitudinal study was carried out to investigate the bionomics of malaria vector mosquitoes in Mutare and Mutasa Districts. Anopheline larval and adult sampling was conducted from May 2013 to December 2014 using scooping, pyrethrum spray catch, prokopac aspirator, exit window trap, pit shelter, and Centers for Disease Control (CDC) light trap methods. Indoor and outdoor resting mosquitoes were collected in randomly selected houses and pit shelters, respectively. Mosquitoes sampled by light traps were divided into two cohorts. In one cohort, traps were left overnight and mosquitoes collected the following morning, while in the other set, mosquitoes were collected hourly throughout the night. Mosquito samples for insecticide resistance testing were divided into two subsamples. One subsample was used immediately for WHO susceptibility assays and the other batch was allowed to oviposit in the insectary at the National Institute of Health Research, and females from the F1 progeny were used in further susceptibility assays. Mosquitoes were identified using morphological keys and polymerase chain reaction (PCR) techniques. The PCR-based assays showed the presence of four sibling species: Anopheles funestus sensu stricto (90.8%, 267/294) and An. leesoni (5.1%, 15/294) of the An. funestus group and An. arabiensis (41.9%, 13/31) and An. quadriannulatus (48.4%, 15/31) of the An. gambiae complex. Of the two malaria vectors, An. funestus sensu stricto was more abundant (95.4%, 267/280) than An. arabiensis (4.6%, 13/280). Endophilic collections of the An. funestus group and the An. gambiae complex were five times greater than exophilic catches. Nearly 90% endophilic An. funestus populations were collected on sprayable surfaces and the remainder was caught on unsprayable surfaces. Of the sprayable surfaces catches, 56% were collected on the roofs; with 44% on the walls. Of the gravid An. funestus caught, nearly two-thirds (218/330) were collected exiting recently pyrethroid-treated structures, with a 24-hour mortality of less than 10%. The CDC light trap catches were more abundant indoors (68%) than outdoors (32%). Anopheles funestus showed variable indoor and outdoor flight activity rhythms, with two peaks during the night; between 22:00-23:00 hours and 02:00-04:00 hours. Human blood index was 64.3%, with Plasmodium falciparum infection rate of 1.8%. Wild caught females showed resistance to lambda-cyhalothrin (3.3% mortality), deltamethrin (12.9% mortality), etofenprox (9.2% mortality), and bendiocarb (11.7% mortality).F1 An. funestus females showed resistance to deltamethrin (14.5% mortality), lambda-cyhalothrin (6.9 % mortality), etofenprox (8.3% mortality), and bendiocarb (16.8% mortality), but were susceptible to DDT and pirimiphos-methyl (100% mortality). Intensity resistance assay to bendiocarb had 100% mortality, while deltamethrin, lambda-cyhalothrin, and etofenprox had increased knockdown times with mortalities ranging between 66.7 and 92.7% after 24-hour exposures. The present work revealed important information on the behaviour of malaria vector mosquitoes in Mutare and Mutasa Districts, which if not addressed might threaten gains made in malaria control in the study area. It is imperative to change house-spraying insecticide from pyrethroids to organophosphates or DDT (organochlorine), develop an insecticide resistance management plan, provide extension lances to the house-spraying programme, complement mosquito nets with the use of mosquito repellents and long clothes, and establish a monitoring programme to determine the occurrence and distribution of An. funestus populations in Manicaland Province
Bionomics of malaria vectors in Mutare and Mutasa districts of Manicaland province, Zimbabwe
No full textBionomics of malaria vectors including species composition, resting and biting behaviour and insecticide resistance are important for insecticide-based malaria control and interventions. The lack of data on malaria vector species composition and relative abundance, resting and biting behaviour, as well as insecticide resistance, make the development of target control measures problematic in Mutare and Mutasa Districts. It is imperative to elucidate, characterize, and identify all members of the An. funestus group and the An. gambiae complex to determine their resting and biting behaviour, host-seeking activities, disease relationships, and resistance to insecticides. A longitudinal study was carried out to investigate the bionomics of malaria vector mosquitoes in Mutare and Mutasa Districts. Anopheline larval and adult sampling was conducted from May 2013 to December 2014 using scooping, pyrethrum spray catch, prokopac aspirator, exit window trap, pit shelter, and Centers for Disease Control (CDC) light trap methods. Indoor and outdoor resting mosquitoes were collected in randomly selected houses and pit shelters, respectively. Mosquitoes sampled by light traps were divided into two cohorts. In one cohort, traps were left overnight and mosquitoes collected the following morning, while in the other set, mosquitoes were collected hourly throughout the night. Mosquito samples for insecticide resistance testing were divided into two subsamples. One subsample was used immediately for WHO susceptibility assays and the other batch was allowed to oviposit in the insectary at the National Institute of Health Research, and females from the F1 progeny were used in further susceptibility assays. Mosquitoes were identified using morphological keys and polymerase chain reaction (PCR) techniques. The PCR-based assays showed the presence of four sibling species: Anopheles funestus sensu stricto (90.8%, 267/294) and An. leesoni (5.1%, 15/294) of the An. funestus group and An. arabiensis (41.9%, 13/31) and An. quadriannulatus (48.4%, 15/31) of the An. gambiae complex. Of the two malaria vectors, An. funestus sensu stricto was more abundant (95.4%, 267/280) than An. arabiensis (4.6%, 13/280). Endophilic collections of the An. funestus group and the An. gambiae complex were five times greater than exophilic catches. Nearly 90% endophilic An. funestus populations were collected on sprayable surfaces and the remainder was caught on unsprayable surfaces. Of the sprayable surfaces catches, 56% were collected on the roofs; with 44% on the walls. Of the gravid An. funestus caught, nearly two-thirds (218/330) were collected exiting recently pyrethroid-treated structures, with a 24-hour mortality of less than 10%. The CDC light trap catches were more abundant indoors (68%) than outdoors (32%). Anopheles funestus showed variable indoor and outdoor flight activity rhythms, with two peaks during the night; between 22:00-23:00 hours and 02:00-04:00 hours. Human blood index was 64.3%, with Plasmodium falciparum infection rate of 1.8%. Wild caught females showed resistance to lambda-cyhalothrin (3.3% mortality), deltamethrin (12.9% mortality), etofenprox (9.2% mortality), and bendiocarb (11.7% mortality).F1 An. funestus females showed resistance to deltamethrin (14.5% mortality), lambda-cyhalothrin (6.9 % mortality), etofenprox (8.3% mortality), and bendiocarb (16.8% mortality), but were susceptible to DDT and pirimiphos-methyl (100% mortality). Intensity resistance assay to bendiocarb had 100% mortality, while deltamethrin, lambda-cyhalothrin, and etofenprox had increased knockdown times with mortalities ranging between 66.7 and 92.7% after 24-hour exposures. The present work revealed important information on the behaviour of malaria vector mosquitoes in Mutare and Mutasa Districts, which if not addressed might threaten gains made in malaria control in the study area. It is imperative to change house-spraying insecticide from pyrethroids to organophosphates or DDT (organochlorine), develop an insecticide resistance management plan, provide extension lances to the house-spraying programme, complement mosquito nets with the use of mosquito repellents and long clothes, and establish a monitoring programme to determine the occurrence and distribution of An. funestus populations in Manicaland Province
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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