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R. M. Oxborough - One of the best experts on this subject based on the ideXlab platform.

  • evaluating the sterilizing effect of pyriproxyfen treated Mosquito Nets against anopheles gambiae at different blood feeding intervals
    Acta Tropica, 2015
    Co-Authors: Aneesa Jaffer, R. M. Oxborough, Natacha Protopopoff, Franklin W Mosha, David Malone, Mark Rowland
    Abstract:

    Pyrethroid resistant malaria vectors are widespread throughout sub-Saharan Africa and new insecticides with different modes of action are urgently needed. Pyriproxyfen is a juvenile hormone mimic that reduces fecundity and fertility of adult Anopheles Mosquitoes when used as a contact insecticide. A long-lasting insecticidal net incorporating pyriproxyfen is under development. As wild, host-seeking females may succeed in blood-feeding at different intervals after initial contact with Mosquito Nets the aim of this study was to determine the effect that age and gonotrophic status (nulliparous or parous) and the interval between initial pyriproxyfen exposure and blood-feeding has in terms of subsequent reduced fecundity and fertility. Anopheles gambiae s.s. were exposed to pyriproxyfen LLIN for three minutes in WHO cone bioassays. Four regimens were tested with different blood-feeding intervals A-1 hour (nulliparous), B-1 hour (parous), C-24 h (nulliparous), or D-120 h (nulliparous) after pyriproxyfen exposure. Mosquito oviposition rate, fecundity and fertility of eggs were recorded for several days. All four treatment regimens produced levels of mortality similar to unexposed females. The overall reduction in reproductive rate of 99.9% for regimen A relative to the untreated net was primarily due to oviposition inhibition in exposed females (97%). Pyriproxyfen was equally effective against older parous Mosquitoes and when blood-feeding was 24 h after exposure. Regimen D produced a reduction in reproductive rate of 60.1% but this was of lesser magnitude than other regimens and was the only regimen that failed to reduce fertility of laid eggs, indicating the effects of pyriproxyfen exposure on reproduction are to some extent reversible as Mosquitoes age. In an area of moderate to high Mosquito net coverage a host-seeking Mosquito is likely to contact a treated Mosquito net before: (a) penetrating a holed net and blood-feeding shortly after exposure or, (b) be frustrated by intact Nets before succeeding in blood-feeding on an unprotected individual the following night. Mosquito Nets are an appropriate delivery system for pyriproxyfen, based on the large reductions in reproductive rate when blood-feeding between 1 h and 24 h after exposure. Combining with a pyrethroid should be an effective approach if susceptible Mosquitoes are killed and resistant Mosquitoes sterilized.

  • a new class of insecticide for malaria vector control evaluation of Mosquito Nets treated singly with indoxacarb oxadiazine or with a pyrethroid mixture against anopheles gambiae and culex quinquefasciatus
    Malaria Journal, 2015
    Co-Authors: R. M. Oxborough, Franklin W Mosha, David Malone, Patrick K Tungu, Raphael Nguessan, Jovin Kitau, Mark Rowland
    Abstract:

    Background Universal coverage with long-lasting insecticidal Mosquito Nets (LLIN) or indoor residual spraying (IRS) of houses remain the primary strategies for the control of Mosquito vectors of malaria. Pyrethroid resistant malaria vectors are widespread throughout sub-Saharan Africa and new insecticides with different modes of action are urgently needed if malaria vector control is to remain effective. Indoxacarb is an oxadiazine insecticide that is effective as an oral and contact insecticide against a broad spectrum of agricultural pests and, due to its unique site of action, no cross-resistance has been detected through mechanisms associated with resistance to insecticides currently used in public health.

  • indoor application of attractive toxic sugar bait atsb in combination with Mosquito Nets for control of pyrethroid resistant Mosquitoes
    PLOS ONE, 2013
    Co-Authors: R. M. Oxborough, Mark Rowland, Zachary P Stewart, Patrick K Tungu, Matthew J Kirby, S. Irish
    Abstract:

    Background Attractive toxic sugar bait (ATSB) sprayed onto vegetation has been successful in controlling Anopheles Mosquitoes outdoors. Indoor application of ATSB has yet to be explored. The purpose of this study was to determine whether ATSB stations positioned indoors have the potential to kill host-seeking Mosquitoes and constitute a new approach to control of Mosquito-borne diseases. Methods Insecticides were mixed with dyed sugar solution and tested as toxic baits against Anopheles arabiensis, An. Gambiae s.s. and Culex quinquefasciatus in feeding bioassay tests to identify suitable attractant-insecticide combinations. The most promising ATSB candidates were then trialed in experimental huts in Moshi, Tanzania. ATSB stations were hung in huts next to untreated Mosquito Nets occupied by human volunteers. The proportions of Mosquitoes killed in huts with ATSB treatments relative to huts with non-insecticide control treatments huts were recorded, noting evidence of dye in Mosquito abdomens. Results In feeding bioassays, chlorfenapyr 0.5% v/v, boric acid 2% w/v, and tolfenpyrad 1% v/v, mixed in a guava juice-based bait, each killed more than 90% of pyrethroid-susceptible An. Gambiae s.s. and pyrethroid-resistant An. arabiensis and Cx. quinquefasciatus. In the hut trial, mortality rates of the three ATSB treatments ranged from 41-48% against An. arabiensis and 36-43% against Cx. quinquefasciatus and all were significantly greater than the control mortalities: 18% for An. arabiensis, 7% for Cx. quinquefasciatus (p<0.05). Mortality rates with ATSB were comparable to those with long lasting insecticidal Nets previously tested against the same species in this area. Conclusions Indoor ATSB shows promise as a supplement to Mosquito Nets for controlling Mosquitoes. Indoor ATSB constitute a novel application method for insecticide classes that act as stomach poisons and have not hitherto been exploited for Mosquito control. Combined with LLIN, indoor use of ATSB has the potential to serve as a strategy for managing insecticide resistance.

  • Indoor application of attractive toxic sugar bait (ATSB) in combination with Mosquito Nets for control of pyrethroid-resistant Mosquitoes.
    PLOS ONE, 2013
    Co-Authors: Zachary P Stewart, R. M. Oxborough, Mark Rowland, Patrick K Tungu, Matthew J Kirby, S. Irish
    Abstract:

    Background Attractive toxic sugar bait (ATSB) sprayed onto vegetation has been successful in controlling Anopheles Mosquitoes outdoors. Indoor application of ATSB has yet to be explored. The purpose of this study was to determine whether ATSB stations positioned indoors have the potential to kill host-seeking Mosquitoes and constitute a new approach to control of Mosquito-borne diseases. Methods Insecticides were mixed with dyed sugar solution and tested as toxic baits against Anopheles arabiensis, An. Gambiae s.s. and Culex quinquefasciatus in feeding bioassay tests to identify suitable attractant-insecticide combinations. The most promising ATSB candidates were then trialed in experimental huts in Moshi, Tanzania. ATSB stations were hung in huts next to untreated Mosquito Nets occupied by human volunteers. The proportions of Mosquitoes killed in huts with ATSB treatments relative to huts with non-insecticide control treatments huts were recorded, noting evidence of dye in Mosquito abdomens. Results In feeding bioassays, chlorfenapyr 0.5% v/v, boric acid 2% w/v, and tolfenpyrad 1% v/v, mixed in a guava juice-based bait, each killed more than 90% of pyrethroid-susceptible An. Gambiae s.s. and pyrethroid-resistant An. arabiensis and Cx. quinquefasciatus. In the hut trial, mortality rates of the three ATSB treatments ranged from 41-48% against An. arabiensis and 36-43% against Cx. quinquefasciatus and all were significantly greater than the control mortalities: 18% for An. arabiensis, 7% for Cx. quinquefasciatus (p

  • behavioural and insecticidal effects of organophosphate carbamate and pyrethroid treated Mosquito Nets against african malaria vectors
    Medical and Veterinary Entomology, 2009
    Co-Authors: Robert Malima, R. M. Oxborough, Franklin W Mosha, Patrick K Tungu, C A Maxwell, Issa N Lyimo, Victor Mwingira, Johnson Matowo, Stephen M Magesa
    Abstract:

    . Three insecticides – the pyrethroid deltamethrin, the carbamate carbosulfan and the organophosphate chlorpyrifos-methyl – were tested on Mosquito Nets in experimental huts to determine their potential for introduction as malaria control measures. Their behavioural effects and efficacy were examined in Anopheles gambiae Giles s.s. (Diptera: Culicidae) and Anopheles funestus Giles s.s. in Muheza, Tanzania, and in Anopheles arabiensis Patton and Culex quinquefasciatus Say in Moshi, Tanzania. A standardized dosage of 25 mg/m2 plus high dosages of carbosulfan (50 mg/m2, 100 mg/m2 and 200 mg/m2) and chlorpyrifos-methyl (100 mg/m2) were used to compare the three types of insecticide. At 25 mg/m2, the rank order of the insecticides for insecticide-induced mortality in wild An. gambiae and An. funestus was, respectively, carbosulfan (88%, 86%) > deltamethrin (79%, 78%) > chlorpyrifos-methyl (35%, 53%). The rank order of the insecticides for blood-feeding inhibition (reduction in the number of blood-fed Mosquitoes compared with control) in wild An. gambiae and An. funestus was deltamethrin > chlorpyrifos-methyl > carbosulfan. Carbosulfan was particularly toxic to endophilic anophelines at 200 mg/m2, killing 100% of An. gambiae and 98% of An. funestus that entered the huts. It was less effective against the more exophilic An. arabiensis (67% mortality) and carbamate-resistant Cx quinquefasciatus (36% mortality). Carbosulfan deterred anophelines from entering huts, but did not deter carbamate-resistant Cx quinquefasciatus. Deltamethrin reduced the proportion of insects engaged in blood-feeding, probably as a consequence of contact irritancy, whereas carbosulfan seemed to provide personal protection through deterred entry or perhaps a spatial repellent action. Any deployment of carbosulfan as an individual treatment on Nets should be carried out on a large scale to reduce the risk of diverting Mosquitoes to unprotected individuals. Chlorpyrifos-methyl was inferior to deltamethrin in terms of mortality and blood-feeding inhibition and would be better deployed on a net in combination with a pyrethroid to control insecticide-resistant Mosquitoes.

Mark Rowland - One of the best experts on this subject based on the ideXlab platform.

  • evaluating the sterilizing effect of pyriproxyfen treated Mosquito Nets against anopheles gambiae at different blood feeding intervals
    Acta Tropica, 2015
    Co-Authors: Aneesa Jaffer, R. M. Oxborough, Natacha Protopopoff, Franklin W Mosha, David Malone, Mark Rowland
    Abstract:

    Pyrethroid resistant malaria vectors are widespread throughout sub-Saharan Africa and new insecticides with different modes of action are urgently needed. Pyriproxyfen is a juvenile hormone mimic that reduces fecundity and fertility of adult Anopheles Mosquitoes when used as a contact insecticide. A long-lasting insecticidal net incorporating pyriproxyfen is under development. As wild, host-seeking females may succeed in blood-feeding at different intervals after initial contact with Mosquito Nets the aim of this study was to determine the effect that age and gonotrophic status (nulliparous or parous) and the interval between initial pyriproxyfen exposure and blood-feeding has in terms of subsequent reduced fecundity and fertility. Anopheles gambiae s.s. were exposed to pyriproxyfen LLIN for three minutes in WHO cone bioassays. Four regimens were tested with different blood-feeding intervals A-1 hour (nulliparous), B-1 hour (parous), C-24 h (nulliparous), or D-120 h (nulliparous) after pyriproxyfen exposure. Mosquito oviposition rate, fecundity and fertility of eggs were recorded for several days. All four treatment regimens produced levels of mortality similar to unexposed females. The overall reduction in reproductive rate of 99.9% for regimen A relative to the untreated net was primarily due to oviposition inhibition in exposed females (97%). Pyriproxyfen was equally effective against older parous Mosquitoes and when blood-feeding was 24 h after exposure. Regimen D produced a reduction in reproductive rate of 60.1% but this was of lesser magnitude than other regimens and was the only regimen that failed to reduce fertility of laid eggs, indicating the effects of pyriproxyfen exposure on reproduction are to some extent reversible as Mosquitoes age. In an area of moderate to high Mosquito net coverage a host-seeking Mosquito is likely to contact a treated Mosquito net before: (a) penetrating a holed net and blood-feeding shortly after exposure or, (b) be frustrated by intact Nets before succeeding in blood-feeding on an unprotected individual the following night. Mosquito Nets are an appropriate delivery system for pyriproxyfen, based on the large reductions in reproductive rate when blood-feeding between 1 h and 24 h after exposure. Combining with a pyrethroid should be an effective approach if susceptible Mosquitoes are killed and resistant Mosquitoes sterilized.

  • a new class of insecticide for malaria vector control evaluation of Mosquito Nets treated singly with indoxacarb oxadiazine or with a pyrethroid mixture against anopheles gambiae and culex quinquefasciatus
    Malaria Journal, 2015
    Co-Authors: R. M. Oxborough, Franklin W Mosha, David Malone, Patrick K Tungu, Raphael Nguessan, Jovin Kitau, Mark Rowland
    Abstract:

    Background Universal coverage with long-lasting insecticidal Mosquito Nets (LLIN) or indoor residual spraying (IRS) of houses remain the primary strategies for the control of Mosquito vectors of malaria. Pyrethroid resistant malaria vectors are widespread throughout sub-Saharan Africa and new insecticides with different modes of action are urgently needed if malaria vector control is to remain effective. Indoxacarb is an oxadiazine insecticide that is effective as an oral and contact insecticide against a broad spectrum of agricultural pests and, due to its unique site of action, no cross-resistance has been detected through mechanisms associated with resistance to insecticides currently used in public health.

  • Mosquito Nets treated with a mixture of chlorfenapyr and alphacypermethrin control pyrethroid resistant anopheles gambiae and culex quinquefasciatus Mosquitoes in west africa
    PLOS ONE, 2014
    Co-Authors: Raphael Nguessan, Abibatou Odjo, David Malone, Corine Ngufor, Andreas A Kudom, Pelagie Boko, Mark Rowland
    Abstract:

    Background The effectiveness of insecticide treated Nets is under threat across Africa south of the Sahara from the selection of pyrethroid resistance in Anopheles gambiae Mosquitoes. To maintain progress against malaria it is necessary to identify alternative residual insecticides for Mosquito Nets. Mixtures of pyrethroid and insecticides with novel mode of action provide scope for both improved control and management of resistance through concurrent exposure to unrelated insecticides. Methods The pyrrole chlorfenapyr and the pyrethroid alphacypermethrin were tested individually and as a mixture on Mosquito Nets in an experimental hut trial in southern Benin against pyrethroid resistant An gambiae and Culex quinquefasciatus Mosquitoes. The Nets were deliberately holed to simulate the effect of wear and tear. Results The Nets treated with the mixture of chlorfenapyr 200 mg/m2 and alphacypermethrin 25 mg/m2 killed a proportion of An gambiae (77%, 95%CI: 66–86%) significantly greater than Nets treated with alphacypermethrin 25 mg/m2 (30%, 95%CI: 21–41%) but not significantly different from Nets treated with chlorfenapyr 200 mg/m2 (69%, 95%CI: 57–78%). The Nets treated with the mixtures procured personal protection against An gambiae biting(58–62%) by a greater margin than the alphacypermethrin treated net (39%), whereas the chlorfenapyr treated net was not protective. A similar trend in mortality and blood feeding inhibition between treatments was observed in Cx quinquefasciatus to that seen in An. gambiae, although the effects were lower. A mixture of alphacypermethrin with chlorfenapyr applied at 100 mg/m2 had an effect similar to the mixture with chlorfenapyr at 200 mg/m2. Conclusion The effectiveness of ITNs against pyrethroid resistant Mosquitoes was restored by the mixture: the alphacypermethrin component reduced human-vector contact while the chlorfenapyr controlled pyrethroid-resistant Mosquitoes. The complementary action of these unrelated insecticides demonstrates that the combination on Nets has potential for preventing malaria transmission in areas compromised by the spread of pyrethroid resistance.

  • indoor application of attractive toxic sugar bait atsb in combination with Mosquito Nets for control of pyrethroid resistant Mosquitoes
    PLOS ONE, 2013
    Co-Authors: R. M. Oxborough, Mark Rowland, Zachary P Stewart, Patrick K Tungu, Matthew J Kirby, S. Irish
    Abstract:

    Background Attractive toxic sugar bait (ATSB) sprayed onto vegetation has been successful in controlling Anopheles Mosquitoes outdoors. Indoor application of ATSB has yet to be explored. The purpose of this study was to determine whether ATSB stations positioned indoors have the potential to kill host-seeking Mosquitoes and constitute a new approach to control of Mosquito-borne diseases. Methods Insecticides were mixed with dyed sugar solution and tested as toxic baits against Anopheles arabiensis, An. Gambiae s.s. and Culex quinquefasciatus in feeding bioassay tests to identify suitable attractant-insecticide combinations. The most promising ATSB candidates were then trialed in experimental huts in Moshi, Tanzania. ATSB stations were hung in huts next to untreated Mosquito Nets occupied by human volunteers. The proportions of Mosquitoes killed in huts with ATSB treatments relative to huts with non-insecticide control treatments huts were recorded, noting evidence of dye in Mosquito abdomens. Results In feeding bioassays, chlorfenapyr 0.5% v/v, boric acid 2% w/v, and tolfenpyrad 1% v/v, mixed in a guava juice-based bait, each killed more than 90% of pyrethroid-susceptible An. Gambiae s.s. and pyrethroid-resistant An. arabiensis and Cx. quinquefasciatus. In the hut trial, mortality rates of the three ATSB treatments ranged from 41-48% against An. arabiensis and 36-43% against Cx. quinquefasciatus and all were significantly greater than the control mortalities: 18% for An. arabiensis, 7% for Cx. quinquefasciatus (p<0.05). Mortality rates with ATSB were comparable to those with long lasting insecticidal Nets previously tested against the same species in this area. Conclusions Indoor ATSB shows promise as a supplement to Mosquito Nets for controlling Mosquitoes. Indoor ATSB constitute a novel application method for insecticide classes that act as stomach poisons and have not hitherto been exploited for Mosquito control. Combined with LLIN, indoor use of ATSB has the potential to serve as a strategy for managing insecticide resistance.

  • Indoor application of attractive toxic sugar bait (ATSB) in combination with Mosquito Nets for control of pyrethroid-resistant Mosquitoes.
    PLOS ONE, 2013
    Co-Authors: Zachary P Stewart, R. M. Oxborough, Mark Rowland, Patrick K Tungu, Matthew J Kirby, S. Irish
    Abstract:

    Background Attractive toxic sugar bait (ATSB) sprayed onto vegetation has been successful in controlling Anopheles Mosquitoes outdoors. Indoor application of ATSB has yet to be explored. The purpose of this study was to determine whether ATSB stations positioned indoors have the potential to kill host-seeking Mosquitoes and constitute a new approach to control of Mosquito-borne diseases. Methods Insecticides were mixed with dyed sugar solution and tested as toxic baits against Anopheles arabiensis, An. Gambiae s.s. and Culex quinquefasciatus in feeding bioassay tests to identify suitable attractant-insecticide combinations. The most promising ATSB candidates were then trialed in experimental huts in Moshi, Tanzania. ATSB stations were hung in huts next to untreated Mosquito Nets occupied by human volunteers. The proportions of Mosquitoes killed in huts with ATSB treatments relative to huts with non-insecticide control treatments huts were recorded, noting evidence of dye in Mosquito abdomens. Results In feeding bioassays, chlorfenapyr 0.5% v/v, boric acid 2% w/v, and tolfenpyrad 1% v/v, mixed in a guava juice-based bait, each killed more than 90% of pyrethroid-susceptible An. Gambiae s.s. and pyrethroid-resistant An. arabiensis and Cx. quinquefasciatus. In the hut trial, mortality rates of the three ATSB treatments ranged from 41-48% against An. arabiensis and 36-43% against Cx. quinquefasciatus and all were significantly greater than the control mortalities: 18% for An. arabiensis, 7% for Cx. quinquefasciatus (p

Pieter Spanoghe - One of the best experts on this subject based on the ideXlab platform.

  • Validation of a multi-residue method to determine deltamethrin and alpha-cypermethrin in Mosquito Nets by gas chromatography with electron capture detection (GC-μECD)
    Parasites & Vectors, 2013
    Co-Authors: Jean Pierre Nabléni Ouattara, Olivier Pigeon, Pieter Spanoghe
    Abstract:

    BackgroundNowadays long-lasting insecticidal Mosquito Nets (LNs) are frequently used around the world to protect people against malaria vectors. As they contain insecticide, laboratory control is needed to check whether the content of the active ingredient follows the conditions of the manufacturer and also if the active ingredient is still present after some time of use. For this purpose, an analytical method had to be developed. The fact that LNs include a range of polymers for the yarn and use coated or incorporated technologies for the active ingredient, it is a challenge to find only one analytical method determining the active ingredient in LNs, which takes into account both impregnation technologies. Some methods are provided by international organizations but are limited by the determination of only one pesticide per method. The aim of this study was to optimize a short time extraction method for deltamethrin and alpha-cypermethrin from coated and incorporated Mosquito Nets and also to detect both insecticides in one analytical run, using gas chromatography with electron capture detection (GC-μECD).MethodsBased on the literature, the most suitable solvent and the adequate extraction process for the insecticides used for net making were identified and adapted for the new multi-residue method.ResultsThe validation data of the multi-residue method to determine deltamethrin and alpha-cypermethrin in Mosquito Nets by GC-μECD are given. Depending on the concentration of the active ingredient spiked on the Nets, the mean recovery for alpha-cypermethrin ranged between 86% and 107% with a relative standard deviation below 3.5%. For deltamethrin it ranged between 90% and 108% with a relative standard deviation also below 3.5%. The limit of detection is 0.009 g.a.i/kg of net (0.3 mg a.i./m^2 of net) both for alpha-cypermethrin and deltamethrin.ConclusionsData obtained are excellent. A 30 minutes reflux extraction method with xylene was developed to determine alpha-cypermethrin and deltamethrin in long-lasting insecticidal Mosquito Nets (LNs) by gas chromatography with electron capture detection (GC-μECD). The method can be easily extended to others pyrethroid used for Mosquito net treatment. This paper also presents an overview of the studies dealing with pesticide determination in Mosquito Nets.

  • validation of a multi residue method to determine deltamethrin and alpha cypermethrin in Mosquito Nets by gas chromatography with electron capture detection gc μecd
    Parasites & Vectors, 2013
    Co-Authors: Jean Pierre Nabléni Ouattara, Olivier Pigeon, Pieter Spanoghe
    Abstract:

    Background Nowadays long-lasting insecticidal Mosquito Nets (LNs) are frequently used around the world to protect people against malaria vectors. As they contain insecticide, laboratory control is needed to check whether the content of the active ingredient follows the conditions of the manufacturer and also if the active ingredient is still present after some time of use. For this purpose, an analytical method had to be developed. The fact that LNs include a range of polymers for the yarn and use coated or incorporated technologies for the active ingredient, it is a challenge to find only one analytical method determining the active ingredient in LNs, which takes into account both impregnation technologies. Some methods are provided by international organizations but are limited by the determination of only one pesticide per method. The aim of this study was to optimize a short time extraction method for deltamethrin and alpha-cypermethrin from coated and incorporated Mosquito Nets and also to detect both insecticides in one analytical run, using gas chromatography with electron capture detection (GC-μECD).

S. Irish - One of the best experts on this subject based on the ideXlab platform.

  • indoor application of attractive toxic sugar bait atsb in combination with Mosquito Nets for control of pyrethroid resistant Mosquitoes
    PLOS ONE, 2013
    Co-Authors: R. M. Oxborough, Mark Rowland, Zachary P Stewart, Patrick K Tungu, Matthew J Kirby, S. Irish
    Abstract:

    Background Attractive toxic sugar bait (ATSB) sprayed onto vegetation has been successful in controlling Anopheles Mosquitoes outdoors. Indoor application of ATSB has yet to be explored. The purpose of this study was to determine whether ATSB stations positioned indoors have the potential to kill host-seeking Mosquitoes and constitute a new approach to control of Mosquito-borne diseases. Methods Insecticides were mixed with dyed sugar solution and tested as toxic baits against Anopheles arabiensis, An. Gambiae s.s. and Culex quinquefasciatus in feeding bioassay tests to identify suitable attractant-insecticide combinations. The most promising ATSB candidates were then trialed in experimental huts in Moshi, Tanzania. ATSB stations were hung in huts next to untreated Mosquito Nets occupied by human volunteers. The proportions of Mosquitoes killed in huts with ATSB treatments relative to huts with non-insecticide control treatments huts were recorded, noting evidence of dye in Mosquito abdomens. Results In feeding bioassays, chlorfenapyr 0.5% v/v, boric acid 2% w/v, and tolfenpyrad 1% v/v, mixed in a guava juice-based bait, each killed more than 90% of pyrethroid-susceptible An. Gambiae s.s. and pyrethroid-resistant An. arabiensis and Cx. quinquefasciatus. In the hut trial, mortality rates of the three ATSB treatments ranged from 41-48% against An. arabiensis and 36-43% against Cx. quinquefasciatus and all were significantly greater than the control mortalities: 18% for An. arabiensis, 7% for Cx. quinquefasciatus (p<0.05). Mortality rates with ATSB were comparable to those with long lasting insecticidal Nets previously tested against the same species in this area. Conclusions Indoor ATSB shows promise as a supplement to Mosquito Nets for controlling Mosquitoes. Indoor ATSB constitute a novel application method for insecticide classes that act as stomach poisons and have not hitherto been exploited for Mosquito control. Combined with LLIN, indoor use of ATSB has the potential to serve as a strategy for managing insecticide resistance.

  • Indoor application of attractive toxic sugar bait (ATSB) in combination with Mosquito Nets for control of pyrethroid-resistant Mosquitoes.
    PLOS ONE, 2013
    Co-Authors: Zachary P Stewart, R. M. Oxborough, Mark Rowland, Patrick K Tungu, Matthew J Kirby, S. Irish
    Abstract:

    Background Attractive toxic sugar bait (ATSB) sprayed onto vegetation has been successful in controlling Anopheles Mosquitoes outdoors. Indoor application of ATSB has yet to be explored. The purpose of this study was to determine whether ATSB stations positioned indoors have the potential to kill host-seeking Mosquitoes and constitute a new approach to control of Mosquito-borne diseases. Methods Insecticides were mixed with dyed sugar solution and tested as toxic baits against Anopheles arabiensis, An. Gambiae s.s. and Culex quinquefasciatus in feeding bioassay tests to identify suitable attractant-insecticide combinations. The most promising ATSB candidates were then trialed in experimental huts in Moshi, Tanzania. ATSB stations were hung in huts next to untreated Mosquito Nets occupied by human volunteers. The proportions of Mosquitoes killed in huts with ATSB treatments relative to huts with non-insecticide control treatments huts were recorded, noting evidence of dye in Mosquito abdomens. Results In feeding bioassays, chlorfenapyr 0.5% v/v, boric acid 2% w/v, and tolfenpyrad 1% v/v, mixed in a guava juice-based bait, each killed more than 90% of pyrethroid-susceptible An. Gambiae s.s. and pyrethroid-resistant An. arabiensis and Cx. quinquefasciatus. In the hut trial, mortality rates of the three ATSB treatments ranged from 41-48% against An. arabiensis and 36-43% against Cx. quinquefasciatus and all were significantly greater than the control mortalities: 18% for An. arabiensis, 7% for Cx. quinquefasciatus (p

  • Is K-O Tab 1-2-3® long lasting on non-polyester Mosquito Nets?
    Acta Tropica, 2009
    Co-Authors: R. M. Oxborough, V. Weir, S. Irish, C. Metonnou, A Yates, H. Kaur, Abibatou Odjo, Raphael N’guessan, Pelagie Boko, Martin Akogbeto
    Abstract:

    Abstract Many societies use locally sourced Mosquito Nets made from a variety of materials. For protecting against malaria these require regular re-treatment with insecticide. K-O Tab 1-2-3 is a ‘dip-it-yourself’ long-lasting formulation with time-limited interim recommendation from WHO for treatment of washed white and coloured polyester Nets for up to 15 washes. To determine wash-resistance on different fabrics, Nets made of polyester, polyethylene, cotton or nylon were treated with K-O Tab 1-2-3 and washed up to 20 times using standard WHO washing procedures. Efficacy was assessed using cone and cylinder bioassays and tunnel tests, and deltamethrin content using high-pressure liquid chromatography. Polyethylene and cotton Nets treated with K-O Tab 1-2-3 and washed 20 times achieved the WHO threshold of >80% mortality in tunnel tests. Polyethylene matched the performance of polyester in all bioassays in contrast to cotton and nylon which produced low mortality and knock-down in cone and cylinder bioassays. After 20 washes 16.5% of the loading dose of deltamethrin remained on the polyester Nets compared with 28.7% on polyethylene, 38.9% on cotton and 2.2% on nylon. Cotton Nets retained a high concentration of insecticide but the relatively poor performance in terms of knock-down and mortality suggest most insecticide is bound within the cotton fibres rather than on the surface. K-O Tab 1-2-3 renders insecticide wash fast on polyethylene Nets, less so on cotton and nylon. Nets made from polyethylene can be treated in the home to render the insecticide long lasting.

  • Is K-O Tab 1-2-3®long lasting on non-polyester Mosquito Nets?
    Acta Tropica, 2009
    Co-Authors: R. M. Oxborough, V. Weir, S. Irish, P. Boko, C. Metonnou, A Yates, H. Kaur, R. N'guessan, Abibatou Odjo, Martin Akogbeto
    Abstract:

    Many societies use locally sourced Mosquito Nets made from a variety of materials. For protecting against malaria these require regular re-treatment with insecticide. K-O Tab 1-2-3 is a 'dip-it-yourself' long-lasting formulation with time-limited interim recommendation from WHO for treatment of washed white and coloured polyester Nets for up to 15 washes. To determine wash-resistance on different fabrics, Nets made of polyester, polyethylene, cotton or nylon were treated with K-O Tab 1-2-3 and washed up to 20 times using standard WHO washing procedures. Efficacy was assessed using cone and cylinder bioassays and tunnel tests, and deltamethrin content using high-pressure liquid chromatography. Polyethylene and cotton Nets treated with K-O Tab 1-2-3 and washed 20 times achieved the WHO threshold of >80% mortality in tunnel tests. Polyethylene matched the performance of polyester in all bioassays in contrast to cotton and nylon which produced low mortality and knock-down in cone and cylinder bioassays. After 20 washes 16.5% of the loading dose of deltamethrin remained on the polyester Nets compared with 28.7% on polyethylene, 38.9% on cotton and 2.2% on nylon. Cotton Nets retained a high concentration of insecticide but the relatively poor performance in terms of knock-down and mortality suggest most insecticide is bound within the cotton fibres rather than on the surface. K-O Tab 1-2-3 renders insecticide wash fast on polyethylene Nets, less so on cotton and nylon. Nets made from polyethylene can be treated in the home to render the insecticide long lasting. © 2009 Elsevier B.V. All rights reserved.

Martin Akogbeto - One of the best experts on this subject based on the ideXlab platform.

  • Is K-O Tab 1-2-3® long lasting on non-polyester Mosquito Nets?
    Acta Tropica, 2009
    Co-Authors: R. M. Oxborough, V. Weir, S. Irish, C. Metonnou, A Yates, H. Kaur, Abibatou Odjo, Raphael N’guessan, Pelagie Boko, Martin Akogbeto
    Abstract:

    Abstract Many societies use locally sourced Mosquito Nets made from a variety of materials. For protecting against malaria these require regular re-treatment with insecticide. K-O Tab 1-2-3 is a ‘dip-it-yourself’ long-lasting formulation with time-limited interim recommendation from WHO for treatment of washed white and coloured polyester Nets for up to 15 washes. To determine wash-resistance on different fabrics, Nets made of polyester, polyethylene, cotton or nylon were treated with K-O Tab 1-2-3 and washed up to 20 times using standard WHO washing procedures. Efficacy was assessed using cone and cylinder bioassays and tunnel tests, and deltamethrin content using high-pressure liquid chromatography. Polyethylene and cotton Nets treated with K-O Tab 1-2-3 and washed 20 times achieved the WHO threshold of >80% mortality in tunnel tests. Polyethylene matched the performance of polyester in all bioassays in contrast to cotton and nylon which produced low mortality and knock-down in cone and cylinder bioassays. After 20 washes 16.5% of the loading dose of deltamethrin remained on the polyester Nets compared with 28.7% on polyethylene, 38.9% on cotton and 2.2% on nylon. Cotton Nets retained a high concentration of insecticide but the relatively poor performance in terms of knock-down and mortality suggest most insecticide is bound within the cotton fibres rather than on the surface. K-O Tab 1-2-3 renders insecticide wash fast on polyethylene Nets, less so on cotton and nylon. Nets made from polyethylene can be treated in the home to render the insecticide long lasting.

  • Is K-O Tab 1-2-3®long lasting on non-polyester Mosquito Nets?
    Acta Tropica, 2009
    Co-Authors: R. M. Oxborough, V. Weir, S. Irish, P. Boko, C. Metonnou, A Yates, H. Kaur, R. N'guessan, Abibatou Odjo, Martin Akogbeto
    Abstract:

    Many societies use locally sourced Mosquito Nets made from a variety of materials. For protecting against malaria these require regular re-treatment with insecticide. K-O Tab 1-2-3 is a 'dip-it-yourself' long-lasting formulation with time-limited interim recommendation from WHO for treatment of washed white and coloured polyester Nets for up to 15 washes. To determine wash-resistance on different fabrics, Nets made of polyester, polyethylene, cotton or nylon were treated with K-O Tab 1-2-3 and washed up to 20 times using standard WHO washing procedures. Efficacy was assessed using cone and cylinder bioassays and tunnel tests, and deltamethrin content using high-pressure liquid chromatography. Polyethylene and cotton Nets treated with K-O Tab 1-2-3 and washed 20 times achieved the WHO threshold of >80% mortality in tunnel tests. Polyethylene matched the performance of polyester in all bioassays in contrast to cotton and nylon which produced low mortality and knock-down in cone and cylinder bioassays. After 20 washes 16.5% of the loading dose of deltamethrin remained on the polyester Nets compared with 28.7% on polyethylene, 38.9% on cotton and 2.2% on nylon. Cotton Nets retained a high concentration of insecticide but the relatively poor performance in terms of knock-down and mortality suggest most insecticide is bound within the cotton fibres rather than on the surface. K-O Tab 1-2-3 renders insecticide wash fast on polyethylene Nets, less so on cotton and nylon. Nets made from polyethylene can be treated in the home to render the insecticide long lasting. © 2009 Elsevier B.V. All rights reserved.