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Ngufor C, Govoetchan R, Fongnikin A, Hueha C, Ahoga J, Syme T, Agbevo A, Daleb A, Small G, Nimmo D, Bradley J, Aikpon R, Iyikirenga L, Osse R, Tokponnon F, Padonou GG. Community evaluation of VECTRON™ T500, a broflanilide insecticide, for indoor residual spraying for malaria vector control in central Benin; a two arm non-inferiority cluster randomised trial. Sci Rep 2023; 13:17852. [PMID: 37857762 PMCID: PMC10587144 DOI: 10.1038/s41598-023-45047-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Accepted: 10/15/2023] [Indexed: 10/21/2023] Open
Abstract
VECTRON™ T500 is a wettable powder IRS formulation of broflanilide, a newly discovered insecticide. We performed a two-arm non-inferiority community randomised evaluation of VECTRON™ T500, compared to Fludora® Fusion against pyrethroid-resistant Anopheles gambiae s.l. in an area of high coverage with pyrethroid-only nets in the Za-Kpota District of central Benin. One round of IRS was applied in all consenting households in the study area. Sixteen clusters were randomised (1:1) to receive VECTRON™ T500 (100 mg/m2 for broflanilide) or Fludora® Fusion (200 mg/m2 for clothianidin and 25 mg/m2 for deltamethrin). Surveys were performed to assess adverse events and the operational feasibility and acceptability of VECTRON™ T500 among spray operators and household inhabitants. Human landing catches were conducted in 6 households every 1-2 months for up to 18 months post-intervention to assess the impact on vector densities, sporozoite rates and entomological inoculation rates. Bottle bioassays were performed to monitor vector susceptibility to pyrethroids, broflanilide and clothianidin. Monthly wall cone bioassays were conducted for 24 months to assess the residual efficacy of the IRS formulations using susceptible and pyrethroid-resistant An. gambiae s.l. A total of 26,562 female mosquitoes were collected during the study, of which 40% were An. gambiae s.l., the main malaria vector in the study area. The vector population showed high intensity pyrethroid resistance but was susceptible to broflanilide (6 µg/bottle) and clothianidin (90 µg/bottle). Using a non-inferiority margin of 50%, vector density indicated by the human biting rate (bites/person/night) was non-inferior in the VECTRON™ T500 arm compared to the Fludora® Fusion arm both indoors (0.846 bites/p/n in Fludora® Fusion arm vs. 0.741 bites/p/n in VECTRON™ T500 arm, IRR 0.54, 95% CI 0.22-1.35, p = 0.150) and outdoors (0.691 bites/p/n in Fludora® Fusion arm vs. 0.590 bites/p/n in VECTRON™ T500 clusters, IRR 0.75, 95% CI 0.41-1.38, p = 0.297). Sporozoite rates and entomological inoculation rates did not differ significantly between study arms (sporozoite rate: 0.9% vs 1.1%, p = 0. 0.746, EIR: 0.008 vs 0.006 infective bites per person per night, p = 0.589). Cone bioassay mortality with both VECTRON™ T500 and Fludora® Fusion was 100% for 24 months post-IRS application on both cement and mud treated house walls with both susceptible and pyrethroid-resistant strains of An. gambiae s.l. Perceived adverse events reported by spray operators and householders were generally very low (< 6%) in both study arms. VECTRON™ T500 was non-inferior to Fludora® Fusion in reducing the risk of malaria transmission by pyrethroid resistant vectors when applied for IRS in communities in central Benin. The insecticide showed prolonged residual efficacy on house walls, lasting over 24 months and had a high acceptability with homeowners. Community application of VECTRON™ T500 for IRS provides improved and prolonged control of pyrethroid resistant malaria vectors and enhances our capacity to manage insecticide resistance.
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Affiliation(s)
- Corine Ngufor
- London School of Hygiene and Tropical Medicine (LSHTM), London, WC1E 7HT, UK.
- Centre de Recherches Entomologiques de Cotonou (CREC), Cotonou, Benin.
- Panafrican Malaria Vector Research Consortium (PAMVERC), Cotonou, Benin.
| | - Renaud Govoetchan
- London School of Hygiene and Tropical Medicine (LSHTM), London, WC1E 7HT, UK
- Centre de Recherches Entomologiques de Cotonou (CREC), Cotonou, Benin
- Panafrican Malaria Vector Research Consortium (PAMVERC), Cotonou, Benin
| | - Augustin Fongnikin
- Centre de Recherches Entomologiques de Cotonou (CREC), Cotonou, Benin
- Panafrican Malaria Vector Research Consortium (PAMVERC), Cotonou, Benin
| | - Corneille Hueha
- Centre de Recherches Entomologiques de Cotonou (CREC), Cotonou, Benin
- Panafrican Malaria Vector Research Consortium (PAMVERC), Cotonou, Benin
| | - Juniace Ahoga
- Centre de Recherches Entomologiques de Cotonou (CREC), Cotonou, Benin
- Panafrican Malaria Vector Research Consortium (PAMVERC), Cotonou, Benin
| | - Thomas Syme
- London School of Hygiene and Tropical Medicine (LSHTM), London, WC1E 7HT, UK
- Centre de Recherches Entomologiques de Cotonou (CREC), Cotonou, Benin
- Panafrican Malaria Vector Research Consortium (PAMVERC), Cotonou, Benin
| | - Abel Agbevo
- London School of Hygiene and Tropical Medicine (LSHTM), London, WC1E 7HT, UK
- Centre de Recherches Entomologiques de Cotonou (CREC), Cotonou, Benin
- Panafrican Malaria Vector Research Consortium (PAMVERC), Cotonou, Benin
| | - Abdoulaye Daleb
- Centre de Recherches Entomologiques de Cotonou (CREC), Cotonou, Benin
| | - Graham Small
- Innovative Vector Control Consortium, Liverpool, UK
| | - Derric Nimmo
- Innovative Vector Control Consortium, Liverpool, UK
| | - John Bradley
- London School of Hygiene and Tropical Medicine (LSHTM), London, WC1E 7HT, UK
| | - Rock Aikpon
- National Malaria Control Programme, Ministry of Health, Cotonou, Benin
| | | | - Razaki Osse
- Centre de Recherches Entomologiques de Cotonou (CREC), Cotonou, Benin
| | - Filemon Tokponnon
- Centre de Recherches Entomologiques de Cotonou (CREC), Cotonou, Benin
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Balla K, Malm K, Njie O, Hounto Ogouyemi A, Uhomoibhi P, Poku-Awuku A, Tchouatieu AM, Aikpon R, Bah A, Kolley O, Ogbulafor N, Oppong S, Adomako K, Houndjo W, Jah H, Banerji J, Nikau J, Affoukou C, Egwu E, Houtohossou C, Van Hulle S. Introducing field digital data collection systems into seasonal malaria chemoprevention campaigns: opportunities for robust evidence development and national e-health strategies. BMJ Glob Health 2022; 7:bmjgh-2021-007899. [PMID: 35296463 PMCID: PMC8928254 DOI: 10.1136/bmjgh-2021-007899] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 02/01/2022] [Indexed: 11/28/2022] Open
Abstract
Seasonal malaria chemoprevention (SMC) is a World Health Organization-recommended intervention to protect children under the age of 5 in Africa’s Sahel region. While SMC remains highly effective in decreasing malaria cases, implementing countries face several challenges regarding collecting quality data; monitoring coverage and compliance and overcoming delays in campaigns due to late payment to field distributors. To address these challenges, the National Malaria Control Programmes of Benin, The Gambia, Ghana and Nigeria introduced digital data collection (DDC) tools to support their SMC campaigns. To facilitate cross-country learning, this paper investigates the impact of using DDCs in SMC campaigns by comparing country responses. Country experience suggests that in comparison to paper-based data collection systems, using DDC tools help to overcome data quality and operational challenges; cloud-based features also made data more accessible. Thus, scaling up DDC tools and linking them with routine national health management systems could help generate robust evidence for malaria policy development and programming. Of note, evidence from Benin showed that using digital tools reduced the time to pay staff and volunteers by 5 weeks. In Benin’s experience, DDC also offered cost benefits (1.5 times cheaper) versus the use of paper-based tools. The authors note that no application offers greater benefits than the other—countries will select a technology that best suits their needs. Several applications are currently being used and newer ones are also being developed. Another option is to develop in-house applications that can be adjusted to local health programmes. Cost-effectiveness studies to inform on whether DDCs offer cost advantages would be beneficial. More studies on DDC are needed from SMC-implementing countries to identify additional benefits and drawbacks of digital applications. These will similarly help national malaria policy and programming efforts.
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Affiliation(s)
- Kanda Balla
- National Malaria Control Programme of the Gambia, Ministry of Health, Banjul, Gambia
| | - Kezia Malm
- National Malaria Control Programme, Ghana Health Service, Accra, Greater Accra, Ghana
| | - Ousman Njie
- Malaria Programming, Catholic Relief Services, Banjul, Gambia
| | | | | | - Abena Poku-Awuku
- Access and Product Management Department, Medicines for Malaria Venture, Geneva, Switzerland
| | | | - Rock Aikpon
- National Malaria Control Programme, Ghana Health Service, Accra, Ghana
| | - Alieu Bah
- Malaria Programming, Catholic Relief Services, Banjul, Gambia
| | - Olimatou Kolley
- National Malaria Control Programme of the Gambia, Ministry of Health, Banjul, Gambia
| | - Nnenna Ogbulafor
- Federal Ministry of Health, Abuja, Federal Capital Territory, Nigeria
| | | | | | - William Houndjo
- National Malaria Control Programme of Benin, Ministry of Health Benin, Coutonou, Benin
| | - Huja Jah
- Programming, Catholic Relief Services, Baltimore, Maryland, USA
| | - Jaya Banerji
- Medicines for Malaria Venture, Geneva, Switzerland
| | - Jamilu Nikau
- National Malaria Elimination Programme, Federal Ministry of Health, Lagos, Nigeria
| | - Cyriaque Affoukou
- National Malaria Control Programme of Benin, Ministry of Health Benin, Coutonou, Benin
| | - Elijah Egwu
- Malaria Programming, Catholic Relief Services, Coutonou, Benin
| | - Camille Houtohossou
- National Malaria Control Programme of Benin, Ministry of Health Benin, Coutonou, Benin
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Padonou GG, Ossè R, Salako AS, Aikpon R, Sovi A, Kpanou C, Sagbohan H, Akadiri Y, Lamine BM, Akogbeto MC. Entomological assessment of the risk of dengue outbreak in Abomey-Calavi Commune, Benin. Trop Med Health 2020; 48:20. [PMID: 32308531 PMCID: PMC7147049 DOI: 10.1186/s41182-020-00207-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Accepted: 04/01/2020] [Indexed: 11/10/2022] Open
Abstract
Background In May 2019, a confirmed dengue fever case was detected at the local hospital of Abomey-Calavi Commune in southern Benin. In Benin, there remains a dearth of literature concerning the distribution and biology of Aedes aegypti, the principal vector of dengue fever. This study was initiated by the Ministry of Health to partially fill this gap. The findings allowed us to assess the arboviral transmission risk incurred by the population of Abomey-Calavi to support programmatic decision-making. Methods Entomological assessments were conducted in 5% of the houses, meaning 314 houses selected from 11 boroughs in Abomey-Calavi Centre district and 9 villages in Hêvié district. The surveyed breeding sites were water containers located in (domestic) and around (peri-domestic) the dwellings. When a container was positive (housing larvae), a portion of the immature population was sampled with a larval dipper and poured into labeled jars. Immatures were then reared to adulthood at the Centre de Recheche Entomologique de Cotonou (CREC) insectary. Adult mosquitoes were morphologically identified to species level by site and, a subsample of the collected Ae. aegypti mosquitoes were used for WHO susceptibility tube tests. Results Of the 1372 adult Aedes specimens which emerged from the collected larvae and pupae, 1356 Ae. aegypti (98.83%), 10 Ae. luteocephalus, and 4 Ae. vittatus were identified. The Breteau indices were 160.2 in Abomey-Calavi Centre and 150 in Hêvié, whereas the House indices were 58.5% and 61.6% in the respective districts. WHO insecticide susceptibility tube tests showed that the mortality rates were 38.71% in Abomey-Calavi Centre and 85.71% in Hêvié for permethrin, and 72.22% in Abomey-Calavi Centre and 100% in Hêvié for deltamethrin. Conclusion The two districts were highly infested by Ae. aegypti whose breeding sites were mostly man-made. Considering this, human behavioral change to substantially reduce the number of larval habitats is necessary to control the vector populations. As Aedes mosquitoes are day biters, the use of repellents such as ointments and smoke coils can also be useful.
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Affiliation(s)
- Germain Gil Padonou
- 1Centre de Recherche entomologique de Cotonou (CREC), Cotonou, Benin.,7Laboratory of Biology and Molecular Typing in Microbiology, Faculty of Sciences and Technology, University of Abomey-Calavi, Abomey-Calavi, Benin
| | - Razaki Ossè
- 1Centre de Recherche entomologique de Cotonou (CREC), Cotonou, Benin.,Université Nationale d'Agriculture, Porto-Novo, Bénin
| | - Albert Sourou Salako
- 1Centre de Recherche entomologique de Cotonou (CREC), Cotonou, Benin.,3Faculté des Sciences et Techniques de l'Université d'Abomey-Calavi, Cotonou, Benin
| | - Rock Aikpon
- 1Centre de Recherche entomologique de Cotonou (CREC), Cotonou, Benin.,Université Nationale des Sciences, Technologies, Ingénierie et Mathématiques, Abomey, Bénin
| | - Arthur Sovi
- 1Centre de Recherche entomologique de Cotonou (CREC), Cotonou, Benin.,5Faculty of Agronomy, University of Parakou, BP 123 Parakou, Benin.,6Disease Control Department, Faculty of Infectious & Tropical Diseases, The London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT UK
| | - Casimir Kpanou
- 1Centre de Recherche entomologique de Cotonou (CREC), Cotonou, Benin.,3Faculté des Sciences et Techniques de l'Université d'Abomey-Calavi, Cotonou, Benin
| | - Hermann Sagbohan
- 1Centre de Recherche entomologique de Cotonou (CREC), Cotonou, Benin.,3Faculté des Sciences et Techniques de l'Université d'Abomey-Calavi, Cotonou, Benin
| | - Yessoufou Akadiri
- 3Faculté des Sciences et Techniques de l'Université d'Abomey-Calavi, Cotonou, Benin
| | - Baba-Moussa Lamine
- 7Laboratory of Biology and Molecular Typing in Microbiology, Faculty of Sciences and Technology, University of Abomey-Calavi, Abomey-Calavi, Benin
| | - Martin C Akogbeto
- 1Centre de Recherche entomologique de Cotonou (CREC), Cotonou, Benin
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Agossa FR, Aikpon R, Azondekon R, Govoetchan R, Padonou GG, Oussou O, Oke-Agbo F, Akogbeto MC. Efficacy of various insecticides recommended for indoor residual spraying: pirimiphos methyl, potential alternative to bendiocarb for pyrethroid resistance management in Benin, West Africa. Trans R Soc Trop Med Hyg 2014; 108:84-91. [DOI: 10.1093/trstmh/trt117] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Aïzoun N, Ossè R, Azondekon R, Alia R, Oussou O, Gnanguenon V, Aikpon R, Padonou GG, Akogbéto M. Comparison of the standard WHO susceptibility tests and the CDC bottle bioassay for the determination of insecticide susceptibility in malaria vectors and their correlation with biochemical and molecular biology assays in Benin, West Africa. Parasit Vectors 2013; 6:147. [PMID: 23688233 PMCID: PMC3669035 DOI: 10.1186/1756-3305-6-147] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Accepted: 05/15/2013] [Indexed: 11/23/2022] Open
Abstract
Background The detection of insecticide resistance in natural populations of Anopheles vectors is absolutely necessary for malaria control. In the African region, the WHO insecticide susceptibility test is the most common method for assessing resistance status. In order to search for a simple, rapid and more reliable technique in the assessment of insecticide resistance in malaria vectors, we compared the WHO tests with the CDC bottle bioassay in the Ouemé province of southern Benin where insecticide resistance has been widely reported. Methods Larvae and pupae of Anopheles gambiae s.l. mosquitoes were collected from the breeding sites in Ouemé. WHO and CDC susceptibility tests were conducted simultaneously on unfed female mosquitoes aged 2–5 days old. WHO bioassays were performed with impregnated papers of deltamethrin (0.05%) and bendiocarb (0.1%), whereas CDC bioassays were performed with stock solutions of deltamethrin (12.5 μg per bottle) and bendiocarb (12.5 μg per bottle). PCR techniques were used to detect species, Kdr and Ace-1 mutations. CDC biochemical assays using synergists were also conducted to assess the metabolic resistance. Results A slight decrease in mortality rates was observed with 97.95% and 98.33% obtained from CDC and WHO bioassays respectively in populations of mosquitoes from Adjara and Dangbo. PCR revealed that all specimens tested were Anopheles gambiae s.s. The Kdr mutation was found at high frequency in all populations and both the Kdr mutation and mono-oxygenase enzymes were implicated as mechanisms of pyrethroid resistance in An. gambiae from Misserete. Conclusion This study emphasizes that both WHO and CDC bioassays give similar results with regards to the susceptibility of mosquitoes to insecticides in southern Benin. There were complementarities between both methods, however, some specificity was noted for each of the two methods used. Both Kdr and metabolic mechanisms were implicated in the resistance.
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