Single blinded semi-field evaluation of MAÏA® topical repellent ointment compared to unformulated 20% DEET against Anopheles gambiae, Anopheles arabiensis and Aedes aegypti in Tanzania

Abstract Background N,N-Diethyl-3-methylbenzamide (DEET) topical mosquito repellents are effective personal protection tools. However, DEET-based repellents tend to have low consumer acceptability because they are cosmetically unappealing. More attractive formulations are needed to encourage regular user compliance. This study evaluated the protective efficacy and protection duration of a new topical repellent ointment containing 15% DEET, MAÏA® compared to 20% DEET in ethanol using malaria and dengue mosquito vectors in Bagamoyo Tanzania. Methods Fully balanced 3 × 3 Latin square design studies were conducted in large semi-field chambers using laboratory strains of Anopheles gambiae sensu stricto, Anopheles arabiensis and Aedes aegypti. Human volunteers applied either MAÏA® ointment, 20% DEET or ethanol to their lower limbs 6 h before the start of tests. Approximately 100 mosquitoes per strain per replicate were released inside each chamber, with 25 mosquitoes released at regular intervals during the collection period to maintain adequate biting pressure throughout the test. Volunteers recaptured mosquitoes landing on their lower limbs for 6 h over a period of 6 to 12-h post-application of repellents. Data analysis was conducted using mixed-effects logistic regression. Results The protective efficacy of MAÏA® and 20% DEET was not statistically different for each of the mosquito strains: 95.9% vs. 97.4% against An. gambiae (OR = 1.53 [95% CI 0.93–2.51] p = 0.091); 96.8% vs 97.2% against An. arabiensis (OR = 1.08 [95% CI 0.66–1.77] p = 0.757); 93.1% vs 94.6% against Ae. aegypti (OR = 0.76 [95% CI 0.20–2.80] p = 0.675). Average complete protection time (CPT) in minutes of MAÏA® and that of DEET was similar for each of the mosquito strains: 571.6 min (95% CI 558.3–584.8) vs 575.0 min (95% CI 562.1–587.9) against An. gambiae; 585.6 min (95% CI 571.4–599.8) vs 580.9 min (95% CI 571.1–590.7) against An. arabiensis; 444.1 min (95% CI 401.8–486.5) vs 436.9 min (95% CI 405.2–468.5) against Ae. aegypti. Conclusions MAÏA® repellent ointment provides complete protection for 9 h against both An. gambiae and An. arabiensis, and 7 h against Ae. aegypti similar to 20% DEET (in ethanol). MAÏA® repellent ointment can be recommended as a tool for prevention against outdoor biting mosquitoes in tropical locations where the majority of the people spend an ample time outdoor before going to bed.

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Single blinded semi-field evaluation of MAÏA® topical repellent ointment compared to unformulated 20% DEET against Anopheles gambiae, Anopheles arabiensis and Aedes aegypti in Tanzania

10.21203/rs.3.rs-56100/v3 ◽

2020 ◽

Author(s):

Emmanuel Mbuba ◽

Olukayode Odufuwa ◽

Frank Tenywa ◽

Rose Philipo ◽

Mgeni Tambwe ◽

...

Keyword(s):

Aedes Aegypti ◽

Anopheles Gambiae ◽

Protective Efficacy ◽

Latin Square ◽

Field Evaluation ◽

Sensu Stricto ◽

Lower Limbs ◽

Complete Protection ◽

Regular User ◽

Outdoor Biting

Abstract Background N, N-Diethyl-3-methylbenzamide (DEET) topical mosquito repellents are effective personal protection tools. However, DEET-based repellents tend to have low consumer acceptability because they are cosmetically unappealing. More attractive formulations are needed to encourage regular user compliance. This study evaluated the protective efficacy and protection duration of a new topical repellent ointment containing 15% DEET, MAÏA® compared to 20% DEET in ethanol using malaria and dengue mosquito vectors in Bagamoyo Tanzania.Methods Fully balanced 3x3 Latin square design studies were conducted in large semi-field chambers using laboratory strains of Anopheles gambiae sensu stricto, Anopheles arabiensis and Aedes aegypti. Human volunteers applied either MAÏA® ointment, 20% DEET or ethanol to their lower limbs six hours before the start of tests. Approximately 100 mosquitoes per strain per replicate were released inside each chamber, with 25 mosquitoes released at regular intervals during the collection period to maintain adequate biting pressure throughout the test. Volunteers recaptured mosquitoes landing on their lower limbs for six hours over a period of six to 12-hours post-application of repellents. Data analysis was conducted using mixed-effects logistic regression.Results The protective efficacy of MAÏA® and 20% DEET was not different for each of the mosquito strains: 95.9% vs 97.4% against An. gambiae (OR=1.53 [95% CI: 0.93–2.51] p=0.091); 96.8% vs 97.2% against An. arabiensis (OR =1.08 [95% CI: 0.66 –1.77] P=0.757); 93.1% vs 94.6% against Ae. aegypti (OR=0.76 [95% CI: 0.20-2.80] p=0.675). Average complete protection time (CPT) of MAÏA® and that of DEET was similar for each of the mosquito strains: 571.6 minutes (95% CI: 558.3-584.8) vs 575.0 minutes (95% CI: 562.1-587.9) against An. gambiae; 585.6 minutes (95% CI: 571.4-599.8) vs 580.9 minutes (95% CI: 571.1-590.7) against An. arabiensis; 444.1 minutes (95% CI: 401.8-486.5) vs 436.9 minutes (95% CI: 405.2-468.5) against Ae. aegypti.Conclusions MAÏA® repellent ointment provides complete protection for 9 hours against both An. gambiae and An. arabiensis, and 7 hours against Ae. aegypti similar to 20% DEET (in ethanol). MAÏA® repellent ointment can be recommended to be used as a tool for prevention of outdoor biting mosquitoes in tropical locations as it protects for more than 6 hours.

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Single blinded semi-field evaluation of MAÏA® topical repellent ointment compared to unformulated 20% DEET against Anopheles gambiae s.s., Anopheles arabiensis and Aedes aegypti in Tanzania

10.21203/rs.3.rs-56100/v2 ◽

2020 ◽

Author(s):

Emmanuel Mbuba ◽

Olukayode Odufuwa ◽

Frank Tenywa ◽

Rose Philipo ◽

Mgeni Tambwe ◽

...

Keyword(s):

Aedes Aegypti ◽

Anopheles Gambiae ◽

Protective Efficacy ◽

Latin Square ◽

Field Evaluation ◽

Lower Limbs ◽

Complete Protection ◽

Anopheles Gambiae S.S ◽

Regular User ◽

Outdoor Biting

Abstract Background: N,N-Diethyl-3-methylbenzamide (DEET) topical mosquito repellents are effective personal protection tools. However, DEET-based repellents tend to have low consumer acceptability because they are cosmetically unappealing. More attractive formulations are needed to encourage regular user compliance. This study evaluated the protective efficacy and protection duration of a new topical repellent ointment containing 15% DEET, MAÏA® compared to 20% DEET in ethanol using malaria and dengue mosquito vectors in Bagamoyo Tanzania.Methods: Fully balanced 3x3 Latin square design studies were conducted in large semi-field chambers using laboratory strains of Anopheles gambiae s.s, An. arabiensis and Aedes aegypti. Human volunteers applied either MAÏA® ointment, 20% DEET or ethanol to their lower limbs six hours before the start of tests. Approximately 100 mosquitoes per strain per replicate were released inside each chamber, with 25 mosquitoes released at regular intervals during the collection period to maintain adequate biting pressure throughout the test. Volunteers recaptured mosquitoes landing on their lower limbs for six hours over a period of six to 12-hours post-application of repellents. Data analysis was conducted using mixed-effects logistic regression.Results: The protective efficacy of MAÏA® and 20% DEET was not different for each of the mosquito strains: 95.9% vs 97.4% against An. gambiae (OR=1.53 [95% CI: 0.93–2.51] p=0.091); 96.8% vs 97.2% against An. arabiensis (OR =1.08 [95% CI: 0.66 –1.77] P=0.757); 93.1% vs 94.6% against Ae. aegypti (OR=0.76 [95% CI: 0.20-2.80] p=0.675). Average complete protection time (CPT) of MAÏA® and that of DEET was similar for each of the mosquito strains: 571.6 minutes (95% CI: 558.3-584.8) vs 575.0 minutes (95% CI: 562.1-587.9) against An. gambiae; 585.6 minutes (95% CI: 571.4-599.8) vs 580.9 minutes (95% CI: 571.1-590.7) against An. arabiensis; 444.1 minutes (95% CI: 401.8-486.5) vs 436.9 minutes (95% CI: 405.2-468.5) against Ae. aegypti.Conclusions: MAÏA® repellent ointment provides complete protection for 9 hours against both An. gambiae and An. arabiensis, and 7 hours against Ae. aegypti similar to 20% DEET (in ethanol). MAÏA® repellent ointment can be recommended to be used as a tool for prevention of outdoor biting mosquitoes in tropical locations as it protects for more than 6 hours.

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MAÏA® Topical Repellent Ointment Provides Long-Lasting Protection Against Anopheles Gambiae s.s., Anopheles Arabiensis and Aedes Aegypti Under Semi-Field Conditions in Tanzania

10.21203/rs.3.rs-56100/v1 ◽

2020 ◽

Author(s):

Emmanuel Mbuba ◽

Olukayode Odufuwa ◽

Frank Tenywa ◽

Rose Philipo ◽

Mgeni Tambwe ◽

...

Keyword(s):

Aedes Aegypti ◽

Anopheles Gambiae ◽

Anopheles Arabiensis ◽

Protective Efficacy ◽

Latin Square ◽

Lower Limbs ◽

Complete Protection ◽

Anopheles Gambiae S.S ◽

Outdoor Biting ◽

Duration Of Protection

Abstract Background: N,N-Diethyl-3-methylbenzamide (DEET) topical mosquito repellents are effective personal protection tools. However, DEET repellents tend to have low consumer acceptability because they are cosmetically unappealing. More attractive formulations are needed to encourage regular compliance. This study evaluated the protective efficacy and duration of protection of a new topical repellent ointment, MAÏA® compared to 20% DEET in ethanol using malaria and dengue mosquito vectors in Tanzania.Methods: Fully balanced 3x3 Latin square design studies were conducted in large semi-field chambers using laboratory strains of Anopheles gambiae s.s, Anopheles arabiensis and Aedes aegypti. Human volunteers applied either MAÏA® ointment, 20% DEET or ethanol to their lower limbs six hours before the start of tests. Approximately 100 mosquitoes per strain per replicate were released inside each chamber, with 25 mosquitoes released at regular intervals during the collection period to maintain adequate biting pressure throughout the test. Volunteers recaptured mosquitoes landing on their lower limbs for six hours over a period of six to 12-hours post-application of repellents. Data analysis was conducted using mixed-effects logistic regression.Results: The protective efficacy of MAÏA® and 20% DEET was not different for each of the mosquito strains: 95.9% vs 97.4% against An. gambiae (OR=1.53 [95% CI: 0.93–2.51] p=0.091); 96.8% vs 97.2% against An. arabiensis (OR =1.08 [95% CI: 0.66 –1.77] P=0.757); 93.1% vs 94.6% against Ae. aegypti (OR=0.76 [95% CI: 0.20-2.80] p=0.675). Average complete protection time (CPT) of MAÏA® and that of DEET was similar for each of the mosquito strains: 571.6 minutes (95% CI: 558.3-584.8) vs 575.0 minutes (95% CI: 562.1-587.9) against An. gambiae; 585.6 minutes (95% CI: 571.4-599.8) vs 580.9 minutes (95% CI: 571.1-590.7) against An. arabiensis; 444.1 minutes (95% CI: 401.8-486.5) vs 436.9 minutes (95% CI: 405.2-468.5) against Ae. aegypti.Conclusions: MAÏA® repellent ointment provides complete protection for 9 hours against both An. gambiae and An. arabiensis, and 7 hours against Ae. aegypti similar to 20% DEET (in ethanol). MAÏA® repellent ointment can be recommended as a tool for prevention of outdoor biting mosquitoes in tropical locations with a suggested reapplication time of 6 hours.

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Repellent Activity of TRIG (N-N Diethyl Benzamide) against Man-Biting Mosquitoes

Journal of Tropical Medicine ◽

10.1155/2018/9037616 ◽

2018 ◽

Vol 2018 ◽

pp. 1-5

Author(s):

Shandala Msangi ◽

Eliningaya Kweka ◽

Aneth Mahande

Keyword(s):

Aedes Aegypti ◽

Anopheles Gambiae ◽

Culex Quinquefasciatus ◽

Laboratory Tests ◽

Field Evaluation ◽

Human Landing Catch ◽

Complete Protection ◽

Protection Time ◽

Human Volunteers ◽

Human Landing

A study was conducted to assess efficacy of a new repellent brand TRIG (15% N-N Diethyl Benzamide) when compared to DEET (20% N-N Methyl Toluamide). The repellents were tested in laboratory and field. In the laboratory, the repellence was tested on human volunteers, by exposing their repellent-treated arms on starved mosquitoes in cages for 3 minutes at hourly intervals, while counting the landing and probing attempts. Anopheles gambiae and Aedes aegypti mosquitoes were used. Field evaluation was conducted by Human Landing Catch technique. During the night, the repellents were applied on arms and legs and mosquitoes landing on these areas were collected. In laboratory tests, TRIG provided complete protection (100%) against Anopheles gambiae when applied at 1.25 g, while DEET provided this at 0.75 g. When tested on Aedes aegypti, TRIG provided complete protection when applied at 1 g, compared to 0.5 g for DEET. In the field, when applied at a recommended dose, both TRIG and DEET achieved above 90% protection against both An. arabiensis and Culex quinquefasciatus and a Complete Protection Time of about 6 hrs against both species of mosquitoes. The performances of the two products were found to be comparable and TRIG was recommended for use as repellent against mosquito bites.

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Anopheles gambiae and Anopheles arabiensis population densities and infectivity in Kopere village, Western Kenya

The Journal of Infection in Developing Countries ◽

10.3855/jidc.1979 ◽

2012 ◽

Vol 6 (08) ◽

pp. 637-643 ◽

Cited By ~ 5

Author(s):

Andrew Ambogo Obala ◽

Helen L Kutima ◽

Henry D.N. Nyamogoba ◽

Anne W Mwangi ◽

Chrispinus J Simiyu ◽

...

Keyword(s):

Anopheles Gambiae ◽

Malaria Vector ◽

Anopheles Arabiensis ◽

Mosquito Species ◽

Sensu Stricto ◽

Malaria Vector Control ◽

Insecticide Treated Nets ◽

Western Kenya ◽

Endemic Malaria ◽

Vector Mosquito

Introduction: This study was conducted in a sugar belt region of western Kenya interfacing epidemic and endemic malaria transmission. We investigated Anopheles gambiae sensu stricto (ss) and Anopheles arabiensis species compositions and densities, human host choice, and infectivity. Methodology: Mosquitoes were captured using pyrethrum spray catch technique and first identified based on morphology; species were confirmed by PCR. Blood meal preference and sporozoite rates were determined by ELISA. Parity rates and entomological inoculation rates (EIR) were determined. Seasonal densities were compared against environmental temperatures, relative humidity and rainfall. Results: In total 2,426 An. gambiae were collected. Out of 1,687 female blood-fed mosquitoes, 272 were randomly selected for entomological tests. An. gambiae ss and An. arabiensis comprised 75% (205/272) and 25% (68/272) of the selection, respectively. An. gambiae ss had higher preference for human blood (97%; n=263/272) compared with An. arabiensis, which mostly fed on bovines (88%; n=239/272). The sporozoite and parity rates were 6% (16/272) and 66% (179/272) for An. gambiae ss and 2% (4/272) and 53% (144/272) for An. arabiensis respectively, while EIR was 0.78 infective bites/person/night. Climate (ANOVA; F=14.2; DF=23) and temperature alone (r=0.626; t=3.75; p=0.001) were significantly correlated with vector densities. Conclusion: An. gambiae ss are the most efficient malaria vector mosquito species in Kopere village. Because An. gambiae ss largely rests and feeds indoors, use of indoor residual spray and insecticide-treated nets is likely the most suitable approach to malaria vector control in Kopere village and other parts of Kenya where this species is abundant.

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Biological Activity of Sumilarv 0.5G against Anopheles gambiae sensu stricto and Anopheles arabiensis in Northern Tanzania

East Africa Science ◽

10.24248/easci.v1i1.17 ◽

2019 ◽

Vol 1 (1) ◽

pp. 35-42

Author(s):

Eliningaya Kweka ◽

Aneth Mahande ◽

Shandala Msangi ◽

Subira Sayumwe ◽

Johnson Ouma ◽

...

Keyword(s):

Biological Activity ◽

Anopheles Gambiae ◽

Anopheles Arabiensis ◽

Sensu Stricto ◽

Anopheles Gambiae Sensu Stricto ◽

Northern Tanzania

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Semi Field Evaluation of Freestanding Transfluthrin Passive Emanators and the BG Sentinel Trap as a “Push-Pull control Strategy” Against Aedes aegypti Mosquitoes

10.21203/rs.3.rs-26088/v1 ◽

2020 ◽

Author(s):

Mgeni Mohamed Tambwe ◽

Sarah Moore ◽

Hassan Chilumba ◽

Johnson Kyeba Swai ◽

Jason Moore ◽

...

Keyword(s):

Aedes Aegypti ◽

Field Experiments ◽

Protective Efficacy ◽

Malaria Vectors ◽

Human Landing Catch ◽

Regular User ◽

Pull System ◽

Significant Difference ◽

Human Landing ◽

Bg Sentinel

Abstract Background The use of volatile pyrethroids and odor-baited traps in a push-pull system has been shown to reduce house entry and outdoor bites for malaria vectors. This technology has the potential to control other outdoor biting mosquitoes such as Aedes aegypti that transmit arboviral diseases. In this study, semi-field experiments were conducted to evaluate whether a push-pull system could be used to reduce bites from Aedes.Methods The push and pull under investigation consisted of two freestanding transfluthrin passive emanators (FTPE), and a BG sentinel trap (BGS) respectively. The FTPE contained hessian strips treated with 5.25 g of transfluthrin active ingredient. The efficacies of FTPE and BGS alone and in combination were evaluated by human landing catch in a large semi-field system in Tanzania. We also investigated the protection of FTPE over six months. The data was analyzed using generalized linear mixed models with binomial distribution.Results Two FTPE have a protective efficacy (PE) of 61% (95% Confidence interval (CI): 52.18–69.91) against human landing rate of Aedes aegypti. The BGS did not significantly reduce mosquito landings; the PE was 2.14% (95% CI: -2.87-7.16). The combination of FTPE and BGS (push-pull) provided the PE of 64.46% (95% CI: 59.06–69.85). However, there was no significant difference in the protective efficacy between the push-pull and the two FTPE against Ae. aegypti (p = 0.286). The FTPE offered significant protection against Ae. aegypti at month three, with a PE of 46.44% (95% CI: 41.12–51.76), but not at six months with a PE of 2.20% (95% CI: -9.00-14.02).Conclusions The protective efficacy of the FTPE and the full push-pull system are similar, indicative that bite prevention is primarily due to the activity of the FTPE. While these results are encouraging for the FTPE, further work is needed for a push-pull system to be recommended for Ae. aegypti control. The three-month protection provided by the FTPE against Ae. aegypti bites suggests it would be a useful additional personal protection tool during dengue outbreaks, that does not require regular user compliance.

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