1
|
da Silva Ferreira Lima AC, Galardo AKR, Müller JN, de Andrade Corrêa APS, Ribeiro KAN, Silveira GA, Hijjar AV, Soares da Roch Bauzer LG, Lima JBP. Evaluation of Long-lasting insecticidal nets (LLINs) for malaria control in an endemic area in Brazil. Parasit Vectors 2023; 16:162. [PMID: 37173754 PMCID: PMC10182611 DOI: 10.1186/s13071-023-05759-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Accepted: 03/29/2023] [Indexed: 05/15/2023] Open
Abstract
BACKGROUND Most cases of malaria in Brazil are concentrated in the Amazon region. One of the vector control alternatives recommended by the WHO is the long-lasting insecticidal net (LLIN). This tool is used in the nine federal states of the Brazilian Legal Amazon, where LLINs are essential for reducing vector density and disease transmission as they prevent contact between the mosquito and the individual. The objective of this study was to evaluate the residuality and use of LLIN insecticides in different health regions in a city located in the Brazilian Amazon. METHODS A total of 17,027 LLINs were installed in the third, fifth and ninth health regions of the municipality of Porto Velho, Rondonia State, Brazil. The LLINs were of two types: Olyset (permethrin), for around the bed, and Interceptor (alphacypermethrin), for around hammocks. The residuality of 172 LLINs was evaluated using cone bioassays to verify the mortality rate of the mosquito Nyssorhynchus darlingi, over a period of 2 years. Structured questionnaires on the acceptance and use of LLINs were distributed to the participating population (n = 391), covering a total sample of 1147 mosquito nets. The mortality rate was evaluated both in terms of days after LLIN installation and the type of insecticide used. Statistical analyses were based on analysis of variance (ANOVA) and Chi-square and were performed using the SPSS statistical program. RESULTS For the Ny. darlingi mosquito, Interceptor-type LLINs showed residual efficacy, with mortality rates ≥ 80% during the 2-year study period, as determined by the WHO. In contrast, Olyset-type LLINs were associated with a reduction in mortality rates, with 76% and 45% mortality rates in the last two assessments, which occurred during the last 6 months of the study period. Based on the structured questionnaires, the acceptance rate, i.e. percentage of individuals accepting the permanence of the 1147 LLINs sampled, in the three health regions of Porto Velho was 93.8% (of 1076 LLINs). CONCLUSION The alphacypermethrin-impregnated LLIN was more effective than the LLIN impregnated with permethrin. The results indicate that the correct use of mosquito nets-and consequently the protection of the population-needs to be supported by health promotion actions. These initiatives are considered to be essential for the success of this vector control strategy. New studies that consider the monitoring of the placement of mosquito nets are necessary to provide effective support in the correct use of this methodology.
Collapse
Affiliation(s)
- Ana Cristina da Silva Ferreira Lima
- Laboratório de Entomologia Médica, Instituto de Pesquisas Científicas e Tecnológicas do Estado do Amapá (IEPA), Macapá, Amapá, Brazil
- Laboratório de Fisiologia e Controle de Artrópodes Vetores, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
- Programa de Pós-Graduação em Medicina Tropical, Instituto Oswaldo Cruz FIOCRUZ, Rio de Janeiro, Brazil
| | - Allan Kardec Ribeiro Galardo
- Laboratório de Entomologia Médica, Instituto de Pesquisas Científicas e Tecnológicas do Estado do Amapá (IEPA), Macapá, Amapá, Brazil
| | - Josiane Nogueira Müller
- Laboratório de Entomologia Médica, Instituto de Pesquisas Científicas e Tecnológicas do Estado do Amapá (IEPA), Macapá, Amapá, Brazil.
- Laboratório de Fisiologia e Controle de Artrópodes Vetores, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil.
- Programa de Pós-Graduação em Medicina Tropical, Instituto Oswaldo Cruz FIOCRUZ, Rio de Janeiro, Brazil.
| | - Ana Paula Sales de Andrade Corrêa
- Laboratório de Entomologia Médica, Instituto de Pesquisas Científicas e Tecnológicas do Estado do Amapá (IEPA), Macapá, Amapá, Brazil
- Laboratório de Fisiologia e Controle de Artrópodes Vetores, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
- Programa de Pós-Graduação em Medicina Tropical, Instituto Oswaldo Cruz FIOCRUZ, Rio de Janeiro, Brazil
| | | | | | | | | | - José Bento Pereira Lima
- Laboratório de Fisiologia e Controle de Artrópodes Vetores, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
- Programa de Pós-Graduação em Medicina Tropical, Instituto Oswaldo Cruz FIOCRUZ, Rio de Janeiro, Brazil
| |
Collapse
|
2
|
Bouraima A, Djènontin A, Dossou Y, Houessou L, Soares C, Anato M, Zinsou BE, Dechavanne C, Clain J, Massougbodji A, Cottrell G. Measuring entomological parameters before implementing a study on asymptomatic carriers of Plasmodium falciparum in the Zè District in southern Benin. Malar J 2023; 22:24. [PMID: 36670482 PMCID: PMC9862539 DOI: 10.1186/s12936-023-04450-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Accepted: 01/10/2023] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND The objective of this study was to estimate malaria transmission and insecticide resistance status in malaria vectors in Adjrako village from Zè District in Southern Benin. The present study was carried out prior to investigations on infectivity of blood from asymptomatic carriers of Plasmodium falciparum to malaria vector mosquitoes. METHODS Human landing collections (HLCs) were performed in Adjrako village during the rainy season (September-November 2021). In this village, host-seeking mosquitoes were collected during three nights per survey from 22:00 to 06:00 in six randomly selected houses. Malaria vectors were dissected in orders to determinate their parity. Plasmodium falciparum infection in malaria vectors was determined by qPCR and the entomological inoculation rate (EIR) was calculated. The World Health Organization (WHO) insecticide susceptibility test-kits were used to evaluate the susceptibility of Anopheles gambiae sensu lato (s.l.) to deltamethrin at 0.05% and bendiocarb at 0.1%. RESULTS A total of 3260 females of mosquitoes belonging to 4 genera (Anopheles, Culex, Aedes and Mansonia) were collected. Most of the mosquitoes collected were An. gambiae sensu lato (s.l.). The entomological inoculation rate (EIR) for the three collection months was 8.7 infective bites per person and the parity rate was 84%. Mortality rates of An. gambiae s.l. exposed to 0.05% deltamethrin and 0.1% bendiocarb were 18% and 96%, respectively, indicating that this vector population was resistant to deltamethrin and possibly resistant to bendiocarb in the study area. CONCLUSION This study showed that malaria transmission is effective in the study area and that An. gambiae s.l. is the main malaria vector. The entomological parameters indicate this study area is potentially favourable for investigations on P. falciparum asymptomatic carriers.
Collapse
Affiliation(s)
- Aziz Bouraima
- grid.412037.30000 0001 0382 0205Centre de Recherche Pour La Lutte Contre Les Maladies Infectieuses Tropicales (CReMIT), Université d’Abomey-Calavi (UAC), BP 526, Cotonou, Bénin ,grid.473220.0Centre de Recherche Entomologique de Cotonou (CREC), 06 BP 2604, Cotonou, Bénin
| | - Armel Djènontin
- grid.412037.30000 0001 0382 0205Centre de Recherche Pour La Lutte Contre Les Maladies Infectieuses Tropicales (CReMIT), Université d’Abomey-Calavi (UAC), BP 526, Cotonou, Bénin ,grid.473220.0Centre de Recherche Entomologique de Cotonou (CREC), 06 BP 2604, Cotonou, Bénin
| | - Yannelle Dossou
- Institut de Recherche Clinique du Bénin (IRCB), 04 BP 1114, Cotonou, Bénin
| | - Lenucthadius Houessou
- grid.412037.30000 0001 0382 0205Centre de Recherche Pour La Lutte Contre Les Maladies Infectieuses Tropicales (CReMIT), Université d’Abomey-Calavi (UAC), BP 526, Cotonou, Bénin ,grid.473220.0Centre de Recherche Entomologique de Cotonou (CREC), 06 BP 2604, Cotonou, Bénin
| | - Christophe Soares
- grid.412037.30000 0001 0382 0205Centre de Recherche Pour La Lutte Contre Les Maladies Infectieuses Tropicales (CReMIT), Université d’Abomey-Calavi (UAC), BP 526, Cotonou, Bénin ,grid.473220.0Centre de Recherche Entomologique de Cotonou (CREC), 06 BP 2604, Cotonou, Bénin
| | - Montchédé Anato
- grid.412037.30000 0001 0382 0205Centre de Recherche Pour La Lutte Contre Les Maladies Infectieuses Tropicales (CReMIT), Université d’Abomey-Calavi (UAC), BP 526, Cotonou, Bénin ,grid.473220.0Centre de Recherche Entomologique de Cotonou (CREC), 06 BP 2604, Cotonou, Bénin
| | - Boris-Enock Zinsou
- Institut de Recherche Clinique du Bénin (IRCB), 04 BP 1114, Cotonou, Bénin
| | - Célia Dechavanne
- grid.464031.40000 0004 0508 7272Université Paris Cité, IRD, MERIT, 75006 Paris, France ,Centre d’Etude Et de Recherche Sur Les Pathologies Associées À La Grossesse Et À L’Enfance (CERPAGE), Cotonou, Bénin
| | - Jerome Clain
- grid.464031.40000 0004 0508 7272Université Paris Cité, IRD, MERIT, 75006 Paris, France ,Centre d’Etude Et de Recherche Sur Les Pathologies Associées À La Grossesse Et À L’Enfance (CERPAGE), Cotonou, Bénin
| | | | - Gilles Cottrell
- grid.464031.40000 0004 0508 7272Université Paris Cité, IRD, MERIT, 75006 Paris, France ,Centre d’Etude Et de Recherche Sur Les Pathologies Associées À La Grossesse Et À L’Enfance (CERPAGE), Cotonou, Bénin
| |
Collapse
|
3
|
Sovi A, Gnanguenon V, Azondekon R, Oké-Agbo F, Houevoessa S, Salako AS, Akinro B, Govoetchan R, Ossé R, Tokponnon F, Padonou GG, Akogbéto MC. Coverage, Usage, Physical Integrity, and Bio-efficacy of Olyset Nets in the Plateau Region, South Benin Following the 2011 Nationwide Distribution. JOURNAL OF MEDICAL ENTOMOLOGY 2022; 59:337-349. [PMID: 34791327 DOI: 10.1093/jme/tjab190] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Indexed: 06/13/2023]
Abstract
The present study investigated in 8 villages of the Plateau region the coverage, usage, physical integrity, and bio-efficacy of the Olyset nets distributed nationwide by the Benin's National Malaria Control Programme in July 2011. The questionnaire administered as well as the observations made in the households allowed estimating the coverage and usage rates of the 2011 Olyset nets. While their physical integrity was assessed through standard WHO methodology, their bio-efficacy was evaluated through gas chromatography, and WHO cone testing performed with the Kisumu susceptible strain. Mosquito collections through human landing catches (HLCs) were also performed in torn nets to assess if a loss of protection of sleepers occurred as the nets fabric integrity got more damaged. Nine months postdistribution, the coverage and usage rates of the 2011 Olyset nets were 67.4% (95% CI: 65.8-68.9) and 73.3% (95% CI: 70.7-75.8) respectively. About 28% of the 2011 Olyset nets were torn. A drastic drop of the insecticide quantity on the fibers of the nets [from 7.08 µg (95% CI: 5.74-8.42) to 0.2 µg (95% CI: 0.01-0.38)] as well as mortality rates <80% were observed with most nets evaluated. Moreover, the biting rates of An. gambiae s.l. (Diptera: Culicidae) inside torn nets increased in line with their fabric integrity loss. These data support the conclusion that future deployment of nets in the field must be strengthened by community sensitization on their correct use in order to postpone as much as possible appearance of holes and loss of insecticidal activity and encourage repairing of torn nets.
Collapse
Affiliation(s)
- Arthur Sovi
- Faculty of Agronomy, University of Parakou, Parakou, Benin
- Center for Research in Entomology of Cotonou, Cotonou, Benin
- Faculty of Infectious and Tropical Diseases, Disease Control Department, London School of Hygiene and Tropical Medicine, London, UK
| | | | | | | | | | - Albert S Salako
- Center for Research in Entomology of Cotonou, Cotonou, Benin
| | - Bruno Akinro
- Center for Research in Entomology of Cotonou, Cotonou, Benin
| | - Renaud Govoetchan
- Faculty of Agronomy, University of Parakou, Parakou, Benin
- Center for Research in Entomology of Cotonou, Cotonou, Benin
- Faculty of Infectious and Tropical Diseases, Disease Control Department, London School of Hygiene and Tropical Medicine, London, UK
| | - Razaki Ossé
- Center for Research in Entomology of Cotonou, Cotonou, Benin
- Ecole de Gestion et d'Exploitation des Systèmes d'Elevage, Université Nationale d'Agriculture, Kétou, Benin
| | | | - Gil G Padonou
- Center for Research in Entomology of Cotonou, Cotonou, Benin
- Faculty of Sciences and Techniques, University of Abomey-Calavi, Abomey-Calavi, Benin
| | | |
Collapse
|
4
|
Yovogan B, Sovi A, Padonou GG, Adoha CJ, Akinro B, Chitou S, Accrombessi M, Dangbénon E, Akpovi H, Messenger LA, Ossè R, Hounto AO, Cook J, Kleinschmidt I, Ngufor C, Rowland M, Protopopoff N, Akogbéto MC. Pre-intervention characteristics of the mosquito species in Benin in preparation for a randomized controlled trial assessing the efficacy of dual active-ingredient long-lasting insecticidal nets for controlling insecticide-resistant malaria vectors. PLoS One 2021; 16:e0251742. [PMID: 34014982 PMCID: PMC8136630 DOI: 10.1371/journal.pone.0251742] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 05/01/2021] [Indexed: 11/18/2022] Open
Abstract
Background This study provides detailed characteristics of vector populations in preparation for a three-arm cluster randomized controlled trial (RCT) aiming to compare the community impact of dual active-ingredient (AI) long-lasting insecticidal nets (LLINs) that combine two novel insecticide classes–chlorfenapyr or pyriproxifen–with alpha-cypermethrin to improve the prevention of malaria transmitted by insecticide-resistant vectors compared to standard pyrethroid LLINs. Methods The study was carried out in 60 villages across Cove, Zangnanando and Ouinhi districts, southern Benin. Mosquito collections were performed using human landing catches (HLCs). After morphological identification, a sub-sample of Anopheles gambiae s.l. were dissected for parity, analyzed by PCR for species and presence of L1014F kdr mutation and by ELISA-CSP to identify Plasmodium falciparum sporozoite infection. WHO susceptibility tube tests were performed by exposing adult An. gambiae s.l., collected as larvae from each district, to 0.05% alphacypermethrin, 0.75% permethrin, 0.1% bendiocarb and 0.25% pirimiphos-methyl. Synergist assays were also conducted with exposure first to 4% PBO followed by alpha-cypermethrin. Results An. gambiae s.l. (n = 10807) was the main malaria vector complex found followed by Anopheles funestus s.l. (n = 397) and Anopheles nili (n = 82). An. gambiae s.l. was comprised of An. coluzzii (53.9%) and An. gambiae s.s. (46.1%), both displaying a frequency of the L1014F kdr mutation >80%. Although more than 80% of people slept under standard LLIN, human biting rate (HBR) in An. gambiae s.l. was higher indoors [26.5 bite/person/night (95% CI: 25.2–27.9)] than outdoors [18.5 b/p/n (95% CI: 17.4–19.6)], as were the trends for sporozoite rate (SR) [2.9% (95% CI: 1.7–4.8) vs 1.8% (95% CI: 0.6–3.8)] and entomological inoculation rate (EIR) [21.6 infected bites/person/month (95% CI: 20.4–22.8) vs 5.4 (95% CI: 4.8–6.0)]. Parous rate was 81.6% (95%CI: 75.4–88.4). An. gambiae s.l. was resistant to alpha-cypermethrin and permethrin but, fully susceptible to bendiocarb and pirimiphos-methyl. PBO pre-exposure followed by alpha-cypermethrin treatment induced a higher 24 hours mortality compared to alphacypermethrin alone but not exceeding 40%. Conclusions Despite a high usage of standard pyrethroid LLINs, the study area is characterized by intense malaria transmission. The main vectors An. coluzzii and An. gambiae s.s. were both highly resistant to pyrethroids and displayed multiple resistance mechanisms, L1014F kdr mutation and mixed function oxidases. These conditions of the study area make it an appropriate site to conduct the trial that aims to assess the effect of novel dual-AI LLINs on malaria transmitted by insecticide-resistant vectors.
Collapse
Affiliation(s)
- Boulais Yovogan
- Faculté des Sciences et Techniques de l’Université d’Abomey-Calavi, Abomey-Calavi, Benin
- Centre de Recherche Entomologique de Cotonou, Cotonou, Benin
| | - Arthur Sovi
- Centre de Recherche Entomologique de Cotonou, Cotonou, Benin
- Faculté d’Agronomie, Université de Parakou, Parakou, Benin
- Faculty of Infectious and Tropical Diseases, Disease Control Department, London School of Hygiene and Tropical Medicine, London, United Kingdom
- * E-mail:
| | - Gil G. Padonou
- Faculté des Sciences et Techniques de l’Université d’Abomey-Calavi, Abomey-Calavi, Benin
- Centre de Recherche Entomologique de Cotonou, Cotonou, Benin
| | - Constantin J. Adoha
- Faculté des Sciences et Techniques de l’Université d’Abomey-Calavi, Abomey-Calavi, Benin
- Centre de Recherche Entomologique de Cotonou, Cotonou, Benin
| | - Bruno Akinro
- Centre de Recherche Entomologique de Cotonou, Cotonou, Benin
| | - Saïd Chitou
- Centre de Recherche Entomologique de Cotonou, Cotonou, Benin
| | - Manfred Accrombessi
- Faculty of Infectious and Tropical Diseases, Disease Control Department, London School of Hygiene and Tropical Medicine, London, United Kingdom
- Institut de Recherche Clinique du Bénin, Abomey-Calavi, Benin
| | | | - Hilaire Akpovi
- Centre de Recherche Entomologique de Cotonou, Cotonou, Benin
| | - Louisa A. Messenger
- Faculty of Infectious and Tropical Diseases, Disease Control Department, London School of Hygiene and Tropical Medicine, London, United Kingdom
- American Society for Microbiology, Washington, DC, United States of America
| | - Razaki Ossè
- Centre de Recherche Entomologique de Cotonou, Cotonou, Benin
- Ecole de Gestion et d’Exploitation des Systèmes d’Elevage, Université Nationale d’Agriculture, Kétou, Benin
| | - Aurore Ogouyemi Hounto
- Programme Nationale de Lutte Contre Le Paludisme (PNLP), Cotonou, Benin
- Faculté des Sciences de la Santé, Université d’Abomey-Calavi, Cotonou, Benin
| | - Jackie Cook
- Medical Research Council (MRC) Tropical International Statistics and Epidemiology Epidemiology Group, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Immo Kleinschmidt
- Medical Research Council (MRC) Tropical International Statistics and Epidemiology Epidemiology Group, London School of Hygiene and Tropical Medicine, London, United Kingdom
- School of Pathology, Faculty of Health Sciences, University of Witwatersrand, Johannesburg, South Africa
- Southern African Development Community Malaria Elimination Eight Secretariat, Windhoek, Namibia
| | - Corine Ngufor
- Centre de Recherche Entomologique de Cotonou, Cotonou, Benin
- Faculty of Infectious and Tropical Diseases, Disease Control Department, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Mark Rowland
- Faculty of Infectious and Tropical Diseases, Disease Control Department, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Natacha Protopopoff
- Faculty of Infectious and Tropical Diseases, Disease Control Department, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | | |
Collapse
|
5
|
Sagbohan HW, Kpanou CD, Osse R, Dagnon F, Padonou GG, Sominahouin AA, Salako AS, Sidick A, Sewade W, Akinro B, Ahmed S, Impoinvil D, Agbangla C, Akogbeto M. Intensity and mechanisms of deltamethrin and permethrin resistance in Anopheles gambiae s.l. populations in southern Benin. Parasit Vectors 2021; 14:202. [PMID: 33853655 PMCID: PMC8048290 DOI: 10.1186/s13071-021-04699-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Accepted: 03/22/2021] [Indexed: 11/24/2022] Open
Abstract
Background Insecticide resistance is threatening the effectiveness of efforts to control malaria vectors in Benin. This study explores the levels and mechanisms of insecticide resistance in An. gambiae s.l. to pyrethroids. Methods Larvae were collected from August 2017 to July 2018 in five communes in southern Benin (Adjohoun, Allada, Bohicon, Cotonou, and Porto-Novo) representing diverse ecological regions, and were reared in Benin’s insectary. Two- to five-day-old female mosquitoes from each district were exposed to multiple doses of deltamethrin and permethrin (1×, 2×, 5×, and 10×) using the WHO insecticide resistance intensity bioassay. The effect of pre-exposure to the synergist, piperonyl butoxide (PBO), was also tested at different pyrethroid doses. Molecular allele frequencies of kdr (1014F) and ace-1R (119S) insecticide resistance mutations and levels of detoxification enzymes were determined for mosquitoes sampled from each study area. Results An. gambiae s.l. were resistant to pyrethroid-only exposure up to 10× the diagnostic doses in all the study sites for both deltamethrin and permethrin. Mortality was significantly higher in An. gambiae s.l. pre-exposed to PBO followed by exposure to deltamethrin or permethrin compared to mosquitoes exposed to deltamethrin or permethrin only (p < 0.001). The difference in mortality between deltamethrin only and PBO plus deltamethrin was the smallest in Cotonou (16–64%) and the greatest in Bohicon (12–93%). The mortality difference between permethrin only and PBO plus permethrin was the smallest in Cotonou (44–75%) and the greatest in Bohicon (22–72%). In all the study sites, the kdr resistance allele (1014F) frequency was high (75–100%), while the ace-1 resistance allele (G119S) frequency was low (0–3%). Analysis of the metabolic enzymatic activity of An. gambiae s.l. showed overexpression of nonspecific esterases and glutathione S-transferases (GST) in all study sites. In contrast to the PBO results, oxidase expression was low and was similar to the susceptible An. gambiae s.s. Kisumu strain in all sites. Conclusion There is high-intensity resistance to pyrethroids in southern Benin. However, pre-exposure to PBO significantly increased susceptibility to the pyrethroids in the different An. gambiae s.l. populations sampled. The use of PBO insecticide-treated bed nets may help maintain the gains in An. gambiae (s.l.) control in southern Benin. Graphical Abstract ![]()
Collapse
Affiliation(s)
- Hermann Watson Sagbohan
- Centre de Recherche Entomologique de Cotonou, Cotonou, Benin. .,Faculty of Science and Technology of the University of Abomey-Calavi, Godomey, Benin.
| | - Casimir D Kpanou
- Centre de Recherche Entomologique de Cotonou, Cotonou, Benin.,Faculty of Science and Technology of the University of Abomey-Calavi, Godomey, Benin
| | - Razaki Osse
- Centre de Recherche Entomologique de Cotonou, Cotonou, Benin.,National University of Agriculture of Porto-Novo, Porto-Novo, Benin
| | | | - Germain G Padonou
- Centre de Recherche Entomologique de Cotonou, Cotonou, Benin.,Faculty of Science and Technology of the University of Abomey-Calavi, Godomey, Benin
| | | | - Albert Sourou Salako
- Centre de Recherche Entomologique de Cotonou, Cotonou, Benin.,Faculty of Science and Technology of the University of Abomey-Calavi, Godomey, Benin
| | | | - Wilfried Sewade
- Centre de Recherche Entomologique de Cotonou, Cotonou, Benin
| | - Bruno Akinro
- Centre de Recherche Entomologique de Cotonou, Cotonou, Benin
| | - Saadani Ahmed
- US President's Malaria Initiative, US Agency for International Development, Cotonou, Benin
| | - Daniel Impoinvil
- US President's Malaria Initiative, Centers for Disease Control and Prevention (CDC), Atlanta, USA
| | - Clément Agbangla
- Faculty of Science and Technology of the University of Abomey-Calavi, Godomey, Benin.,Genetics and Biotechnology Laboratory of the UAC, Godomey, Benin
| | - Martin Akogbeto
- Centre de Recherche Entomologique de Cotonou, Cotonou, Benin
| |
Collapse
|
6
|
Sovi A, Govoétchan R, Ossé R, Koukpo CZ, Salako AS, Syme T, Anagonou R, Fongnikin A, Nwangwu UC, Oké-Agbo F, Tokponnon F, Padonou GG, Akogbeto MC. Resistance status of Anopheles gambiae s.l. to insecticides following the 2011 mass distribution campaign of long-lasting insecticidal nets (LLINs) in the Plateau Department, south-eastern Benin. Malar J 2020; 19:26. [PMID: 31941494 PMCID: PMC6964090 DOI: 10.1186/s12936-020-3116-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 01/10/2020] [Indexed: 11/17/2022] Open
Abstract
Background In 2011, Benin’s National Malaria Control Programme (NMCP) organized a nationwide mass distribution campaign of LLINs throughout the country. Following this intervention, it was important to assess whether the level of susceptibility of malaria vectors to insecticides had remained the same as compared to the pre-intervention period. The current study investigated this. Methods Larval collections were conducted in Ifangni, Sakété, Pobè and Kétou districts located in Plateau department, Southeastern Benin before (2009) and after (2012–2013) LLIN distribution. Anopheles gambiae sensu lato (s.l.) larvae from the 4 study districts were reared to adulthood and WHO susceptibility tests were conducted. The insecticides tested were deltamethrin (0.05%), permethrin (0.75%), bendiocarb (0.1%) and DDT (4%). Molecular species identification as well as, the characterization of the kdr L1014F mutation were also performed in the An. gambiae s.l. complex using PCR method. Results Overall, a significant decrease in mortality rates of An. gambiae s.l. to deltamethrin (0.05%), permethrin (0.75%) and DDT (4%) was observed post-LLIN distribution, respectively: (100% vs 80.9%, p < 0.0001), (77.5% vs 70%, p = 0.01) and, (47.8% vs 4.4%, p < 0.0001). By contrast, susceptibility of vectors to bendiocarb (0.1%) remained the same (100% mortality in the WHO susceptibility tube tests) pre- and post-intervention. An increase in the kdr L1014F frequency was observed post-LLIN distribution [F(kdr) = 0.91)] compared to the pre-intervention period [F(kdr) = 0.56], p < 0.0001. Anopheles coluzzii and An. gambiae were the two molecular species identified in the study area. Conclusion The decrease susceptibility to pyrethroids and DDT as well as, the increase in the frequency of the kdr L1014F mutation after the intervention stressed at the time, the need for the development and implementation of effective insecticide resistance management strategies. At present, an update of the vectors resistance status in the area is also necessary for decision-making.
Collapse
Affiliation(s)
- Arthur Sovi
- Centre de Recherche Entomologique de Cotonou (CREC), Ministère de la Santé, 06BP2604, Cotonou, Bénin. .,Faculté d'Agronomie, Université de Parakou (UP), BP123, Parakou, Bénin. .,Disease Control Department, Faculty of Infectious & Tropical Diseases, The London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK.
| | - Renaud Govoétchan
- Centre de Recherche Entomologique de Cotonou (CREC), Ministère de la Santé, 06BP2604, Cotonou, Bénin.,Faculté d'Agronomie, Université de Parakou (UP), BP123, Parakou, Bénin
| | - Razaki Ossé
- Centre de Recherche Entomologique de Cotonou (CREC), Ministère de la Santé, 06BP2604, Cotonou, Bénin.,Ecole de Gestion et d'Exploitation des Systèmes d'Elevage, Université Nationale d'Agriculture, BP 43, Kétou, Bénin
| | - Come Z Koukpo
- Centre de Recherche Entomologique de Cotonou (CREC), Ministère de la Santé, 06BP2604, Cotonou, Bénin.,Faculté des Sciences et Techniques (FAST), Université d'Abomey-Calavi (UAC), BP 32, Abomey-Calavi, Bénin
| | - Albert S Salako
- Centre de Recherche Entomologique de Cotonou (CREC), Ministère de la Santé, 06BP2604, Cotonou, Bénin.,Faculté des Sciences et Techniques (FAST), Université d'Abomey-Calavi (UAC), BP 32, Abomey-Calavi, Bénin
| | - Thomas Syme
- Centre de Recherche Entomologique de Cotonou (CREC), Ministère de la Santé, 06BP2604, Cotonou, Bénin.,Disease Control Department, Faculty of Infectious & Tropical Diseases, The London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
| | - Rodrigue Anagonou
- Centre de Recherche Entomologique de Cotonou (CREC), Ministère de la Santé, 06BP2604, Cotonou, Bénin
| | - Augustin Fongnikin
- Centre de Recherche Entomologique de Cotonou (CREC), Ministère de la Santé, 06BP2604, Cotonou, Bénin.,Faculté des Sciences et Techniques (FAST), Université d'Abomey-Calavi (UAC), BP 32, Abomey-Calavi, Bénin
| | - Udoka C Nwangwu
- National Arbovirus and Vectors Research Centre (NAVRC), 33 Park Avenue, GRA, PMB 01573, Enugu, Enugu State, Nigeria
| | - Frédéric Oké-Agbo
- Centre de Recherche Entomologique de Cotonou (CREC), Ministère de la Santé, 06BP2604, Cotonou, Bénin.,Statistics and Actuarial Science Department, College of Liberal Arts and Sciences, The University of Iowa, Iowa City, IA, 52240, USA
| | | | - Gil Germain Padonou
- Centre de Recherche Entomologique de Cotonou (CREC), Ministère de la Santé, 06BP2604, Cotonou, Bénin.,Faculté des Sciences et Techniques (FAST), Université d'Abomey-Calavi (UAC), BP 32, Abomey-Calavi, Bénin
| | - Martin Codjo Akogbeto
- Centre de Recherche Entomologique de Cotonou (CREC), Ministère de la Santé, 06BP2604, Cotonou, Bénin
| |
Collapse
|
7
|
Aïkpon RY, Padonou G, Dagnon F, Ossè R, Ogouyemi Hounto A, Tokponon F, Aïkpon G, Lyikirenga L, Akogbéto M. Upsurge of malaria transmission after indoor residual spraying withdrawal in Atacora region in Benin, West Africa. Malar J 2020; 19:3. [PMID: 31900182 PMCID: PMC6942255 DOI: 10.1186/s12936-019-3086-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Accepted: 12/21/2019] [Indexed: 11/23/2022] Open
Abstract
Background In Benin, malaria vector control mostly relies on long-lasting, insecticidal-treated bed nets (LLINs) and indoor residual spraying (IRS) operations. From 2011 to 2016, an IRS programme has been implemented in Atacora region. However, in 2017 the programme was withdrawn from two other regions in the northern part of the country, with hopes that gains would be relatively sustained because of the seasonality of malaria transmission. What would be the vulnerability of populations to malaria after the withdrawal of IRS? Methods Monthly mosquito collections were performed through human landing captures (HLCs) for 24 months (from January to December 2016 during the last IRS campaign, and from January to December 2018, 2 years after the withdrawal of IRS). Vector mosquitoes biting density was sampled by HLC and was tested for presence of Plasmodium falciparum sporozoites. The carcass of these mosquitoes (abdomens, wing, legs) were subjected to molecular species identification using polymerase chain reaction (PCR) assays. Results It is noticed a drastic increase (~ 3 times higher) of vector abundance after the withdrawal of IRS. Mosquito biting rates in the 3 survey districts increased significantly after IRS was withdrawn. In 2018, after IRS cessation a significant increase of entomological inoculation rate was recorded, where each inhabitant received an average of 94.9 infected bites/year to 129.21 infected bites/year against an average of 17.15 infected bites/year to 24.82 infected bites/year in 2016. Conclusion It is obvious that the withdrawal of IRS confers a vulnerability of the population with regard to the malaria transmission. Robust monitoring is needed to better understand when and where IRS should be most adequate, or can be safely withdrawn. In case of withdrawal, adapted accompanying measures should be proposed according to the context not only to maintain the gains capitalized with IRS, but also to avoid any rebound of transmission.
Collapse
Affiliation(s)
- Rock Yves Aïkpon
- Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Benin. .,Ecole Normale Supérieure de Natitingou (ENS), Natitingou, Benin. .,Université Nationale des Sciences, Technologies, Ingénierie et Mathématiques (UNSTIM), Abomey, Benin.
| | - Gil Padonou
- Ecole Normale Supérieure de Natitingou (ENS), Natitingou, Benin.,Université d'Abomey-Calavi, Cotonou, Benin
| | - Fortuné Dagnon
- US President's Malaria Initiative, US Agency for International Development, Cotonou, Benin
| | - Razaki Ossè
- Ecole Normale Supérieure de Natitingou (ENS), Natitingou, Benin.,Université Nationale d'Agriculture (UNA), Ketou, Benin
| | - Aurore Ogouyemi Hounto
- Faculté des Sciences de la Santé (FSS), Cotonou, Benin.,Programme National de Lutte Contre le Paludisme, Cotonou, Benin
| | | | | | | | - Martin Akogbéto
- Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Benin
| |
Collapse
|
8
|
Tokponnon FT, Sissinto Y, Ogouyémi AH, Adéothy AA, Adechoubou A, Houansou T, Oke M, Kinde-Gazard D, Massougbodji A, Akogbeto MC, Cornelie S, Corbel V, Knox TB, Mnzava AP, Donnelly MJ, Kleinschmidt I, Bradley J. Implications of insecticide resistance for malaria vector control with long-lasting insecticidal nets: evidence from health facility data from Benin. Malar J 2019; 18:37. [PMID: 30744666 PMCID: PMC6371432 DOI: 10.1186/s12936-019-2656-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Accepted: 01/16/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Insecticide-based interventions have averted more than 500 million malaria cases since 2000, but insecticide resistance in mosquitoes could bring about a rebound in disease and mortality. This study investigated whether insecticide resistance was associated with increased incidence of clinical malaria. METHODS In an area of southern Benin with insecticide resistance and high use of insecticide-treated nets (ITNs), malaria morbidity and insecticide resistance were measured simultaneously in 30 clusters (villages or collections of villages) multiple times over the course of 2 years. Insecticide resistance frequencies were measured using the standard World Health Organization bioassay test. Malaria morbidity was measured by cases recorded at health facilities both in the whole population using routinely collected data and in a passively followed cohort of children under 5 years old. RESULTS There was no evidence that incidence of malaria from routinely collected data was higher in clusters with resistance frequencies above the median, either in children aged under 5 (RR = 1.27 (95% CI 0.81-2.00) p = 0.276) or in individuals aged 5 or over (RR = 1.74 (95% CI 0.91-3.34) p = 0.093). There was also no evidence that incidence was higher in clusters with resistance frequencies above the median in the passively followed cohort (RR = 1.11 (0.52-2.35) p = 0.777). CONCLUSIONS This study found no association between frequency of resistance and incidence of clinical malaria in an area where ITNs are the principal form of vector control. This may be because, as other studies have shown, ITNs continue to offer some protection from malaria even in the presence of insecticide resistance. Irrespective of resistance, nets provide only partial protection so the development of improved or supplementary vector control tools is required to reduce Africa's unacceptably high malaria burden.
Collapse
Affiliation(s)
- Filémon T Tokponnon
- National Malaria Control Programme, Cotonou, Benin.,Ministry of Health, Cotonou, Benin
| | - Yolande Sissinto
- Faculté des Sciences de la Santé de l'Université d'Abomey Calavi, Cotonou, Benin
| | | | - Adicath Adéola Adéothy
- National Malaria Control Programme, Cotonou, Benin.,Faculté des Sciences de la Santé de l'Université d'Abomey Calavi, Cotonou, Benin
| | - Alioun Adechoubou
- National Malaria Control Programme, Cotonou, Benin.,Ministry of Health, Cotonou, Benin
| | | | - Mariam Oke
- National Malaria Control Programme, Cotonou, Benin.,Ministry of Health, Cotonou, Benin
| | | | - Achille Massougbodji
- Faculté des Sciences de la Santé de l'Université d'Abomey Calavi, Cotonou, Benin
| | | | - Sylvie Cornelie
- Maladies Infectieuses et Vecteurs, Ecologie, Génétique, Evolution et Contrôle (MIVEGEC), Institut de Recherche pour le Développement (IRD), CNRS, University of Montpellier, Montpellier, France
| | - Vincent Corbel
- Maladies Infectieuses et Vecteurs, Ecologie, Génétique, Evolution et Contrôle (MIVEGEC), Institut de Recherche pour le Développement (IRD), CNRS, University of Montpellier, Montpellier, France
| | - Tessa B Knox
- Global Malaria Programme, WHO, Geneva, Switzerland
| | | | - Martin J Donnelly
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Immo Kleinschmidt
- MRC Tropical Epidemiology Group, London School of Hygiene and Tropical Medicine, London, UK
| | - John Bradley
- MRC Tropical Epidemiology Group, London School of Hygiene and Tropical Medicine, London, UK.
| |
Collapse
|
9
|
Salako AS, Ahogni I, Aïkpon R, Sidick A, Dagnon F, Sovi A, Sominahouin AA, Agossa F, Iyikirenga L, Akogbeto MC. Insecticide resistance status, frequency of L1014F Kdr and G119S Ace-1 mutations, and expression of detoxification enzymes in Anopheles gambiae (s.l.) in two regions of northern Benin in preparation for indoor residual spraying. Parasit Vectors 2018; 11:618. [PMID: 30509288 PMCID: PMC6278060 DOI: 10.1186/s13071-018-3180-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Accepted: 10/30/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND This study aims to provide baseline data on the resistance status to insecticides, the frequency of mechanisms involved and the impact of the association with the synergist piperonyl butoxide (PBO) on resistant Anopheles gambiae (s.l.) populations in two regions of northern Benin, prior to an indoor residual spraying campaign and introduction of next generation long-lasting insecticidal nets (LLINs) incorporating PBO. METHODS Adult Anopheles gambiae (s.l.) originating from larvae collected in two study regions (Alibori within the Kandi-Gogounou-Segbana districts and Donga within the Djougou-Copargo-Ouake districts) were tested with impregnated papers (bendiocarb 0.1%, pirimiphos-methyl 0.25%, permethrin 0.75% and deltamethrin 0.05%). The synergist PBO was used to check for the involvement of detoxification enzymes in pyrethroid resistant populations. Molecular analyses were performed for the identification of species within the Anopheles gambiae (s.l.) complex and kdr L1014F and G119S Ace-1 mutations. Biochemical assays assessed the activity of detoxification enzymes. RESULTS Anopheles gambiae (s.l.) was resistant to pyrethroids, with a mortality range of 25-83% with deltamethrin and 6-55% with permethrin. A significant increase in mortality was observed after pre-exposure to PBO for both deltamethrin (63-99%) and permethrin (56-99%). With bendiocarb, An. gambiae (s.l.) were susceptible in Kandi (99% mortality), with possible resistance (92-95%) recorded in Djougou, Copargo, Gogounou, Ouake and Segbana. All study populations were fully susceptible to pirimiphos-methyl. The frequencies of resistant mutations varied according to species and sites: 0.67-0.88 for L1014F kdr and 0-0.06 for G119S Ace-1. Three study locations (Djougou, Gogounou and Kandi) showed high oxidase activity and four sites (Djougou, Ouake, Copargo and Kandi) showed elevated esterase activity. CONCLUSIONS This study confirms resistance to pyrethroids and suggests emerging bendiocarb resistance in An. gambiae (s.l.) populations in northern Benin. However, recovery of susceptibility to pyrethroids after PBO exposure, and susceptibility to organophosphates in the An. gambiae (s.l.) populations indicate that next generation LLINs incorporating PBO synergist combined with an indoor residual spraying (IRS) campaign with organophosphate insecticides may be regarded as alternative control tools.
Collapse
Affiliation(s)
- Albert Sourou Salako
- Centre de Recherche entomologique de Cotonou (CREC), Cotonou, Benin. .,Faculté des Sciences et Techniques de l'Université d'Abomey-Calavi, Abomey-Calavi, Benin.
| | - Idelphonse Ahogni
- Centre de Recherche entomologique de Cotonou (CREC), Cotonou, Benin.,Faculté des Sciences et Techniques de l'Université d'Abomey-Calavi, Abomey-Calavi, Benin
| | - Rock Aïkpon
- Centre de Recherche entomologique de Cotonou (CREC), Cotonou, Benin.,Technologies, Ingénierie et Mathématiques, Université Nationale des Sciences, Abomey, Bénin
| | - Aboubakar Sidick
- Centre de Recherche entomologique de Cotonou (CREC), Cotonou, Benin
| | - Fortune Dagnon
- US Agency for International Development, US President's Malaria Initiative, Cotonou, Benin
| | - Arthur Sovi
- PMI VectorLink project, Abt associates, Bamako, Mali
| | - André Aimé Sominahouin
- Centre de Recherche entomologique de Cotonou (CREC), Cotonou, Benin.,Faculté des Sciences Humaines et Sociales de l'Université d'Abomey-Calavi, Abomey-Calavi, Benin
| | - Fiacre Agossa
- Centre de Recherche entomologique de Cotonou (CREC), Cotonou, Benin
| | | | | |
Collapse
|
10
|
Salako AS, Ahogni I, Kpanou C, Sovi A, Azondekon R, Sominahouin AA, Tokponnon F, Gnanguenon V, Dagnon F, Iyikirenga L, Akogbeto MC. Baseline entomologic data on malaria transmission in prelude to an indoor residual spraying intervention in the regions of Alibori and Donga, Northern Benin, West Africa. Malar J 2018; 17:392. [PMID: 30373576 PMCID: PMC6206707 DOI: 10.1186/s12936-018-2507-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2018] [Accepted: 10/06/2018] [Indexed: 11/16/2022] Open
Abstract
Background Despite the success of indoor residual insecticide spraying (IRS) in Africa, particularly in Benin, some gaps of information need to be filled to optimize the effectiveness of this intervention in the perspective of the country’s effort to eliminate malaria. In anticipation to the 2018 IRS campaign in two targeted regions of northern Benin, this study aimed, to collect baseline information on vector composition, spatio-temporal variation and peak malaria transmission in the Alibori and Donga, two targeted regions of northern Benin. Information collected will help to better plan the implementation and later on the impact assessment of this IRS campaign. Methods The study was carried out in four districts of the two IRS targeted regions of northern Benin. Human landing catches and pyrethrum spray catches protocols were used to assess the biting rate (HBR) and, biting/resting behaviour of malaria vector populations. After morphological identification of collected Anopheles, the heads and thoraxes of Anopheles gambiae sensu lato (s.l.) were analysed by the ELISA CSP tests to estimate the sporozoite index (SI). The entomological inoculation rate was calculated as the product of mosquito biting rate (HBR) and the SI. Results The biting rates of An. gambiae s.l., the major vector in this study sites, varied significantly from region to region. It was higher: in rural than in urban areas, in rainy season than in dry season, indoors than outdoors. Overall, SI was comparable between sites. The highest EIRs were observed in the Donga region (16.84 infectious bites/man/month in Djougou district and 17.64 infectious bites/man/month in Copargo district) and the lowest in the Alibori region (10.74 infectious bites/man/month at Kandi district and 11.04 infectious bites/man/month at Gogounou district). Conclusion This study showed the heterogeneous and various nature of malaria epidemiology in Northern Benin. Indeed, the epidemiological profile of malaria transmission in the Alibori and Donga regions is made of a single season of transmission interrupted by a dry season. This period of transmission is relatively longer in Donga region than in Alibori. This information can be used to guide the extension of IRS in the Alibori and in the Donga, by primarily targeting areas with short periods of transmission, and easy to cover.
Collapse
Affiliation(s)
- Albert S Salako
- Centre de Recherche entomologique de Cotonou (CREC), Cotonou, Benin. .,Faculté des Sciences et Techniques de l'Université d'Abomey-Calavi, Abomey-Calavi, Benin.
| | - Idelphonse Ahogni
- Centre de Recherche entomologique de Cotonou (CREC), Cotonou, Benin.,Faculté des Sciences et Techniques de l'Université d'Abomey-Calavi, Abomey-Calavi, Benin
| | - Casimir Kpanou
- Centre de Recherche entomologique de Cotonou (CREC), Cotonou, Benin.,Faculté des Sciences et Techniques de l'Université d'Abomey-Calavi, Abomey-Calavi, Benin
| | - Arthur Sovi
- PMI VectorLink Project, Abt Associates, Bamako, Mali
| | - Roseric Azondekon
- Centre de Recherche entomologique de Cotonou (CREC), Cotonou, Benin.,University of Wisconsin Milwaukee, Milwaukee, WI, USA
| | - André A Sominahouin
- Centre de Recherche entomologique de Cotonou (CREC), Cotonou, Benin.,Faculté des Sciences Humaines et Sociales de l'Université d'Abomey-Calavi, Abomey-Calavi, Benin
| | | | | | - Fortuné Dagnon
- US President's Malaria Initiative, US Agency for International Development, Cotonou, Benin
| | | | | |
Collapse
|
11
|
Bradley J, Ogouyèmi-Hounto A, Cornélie S, Fassinou J, de Tove YSS, Adéothy AA, Tokponnon FT, Makoutode P, Adechoubou A, Legba T, Houansou T, Kinde-Gazard D, Akogbeto MC, Massougbodji A, Knox TB, Donnelly M, Kleinschmidt I. Insecticide-treated nets provide protection against malaria to children in an area of insecticide resistance in Southern Benin. Malar J 2017; 16:225. [PMID: 28549431 PMCID: PMC5446701 DOI: 10.1186/s12936-017-1873-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Accepted: 05/23/2017] [Indexed: 11/22/2022] Open
Abstract
Background Malaria control is heavily reliant on insecticides, especially pyrethroids. Resistance of mosquitoes to insecticides may threaten the effectiveness of insecticide-based vector control and lead to a resurgence of malaria in Africa. Methods In 21 villages in Southern Benin with high levels of insecticide resistance, the resistance status of local vectors was measured at the same time as the prevalence of malaria infection in resident children. Results Children who used LLINs had lower levels of malaria infection [odds ratio = 0.76 (95% CI 0.59, 0.98, p = 0.033)]. There was no evidence that the effectiveness of nets was different in high and low resistance locations (p = 0.513). There was no association between village level resistance and village level malaria prevalence (p = 0.999). Conclusions LLINs continue to offer individual protection against malaria infection in an area of high resistance. Insecticide resistance is not a reason to stop efforts to increase coverage of LLINs in Africa.
Collapse
Affiliation(s)
- John Bradley
- MRC Tropical Epidemiology Group, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK.
| | - Aurore Ogouyèmi-Hounto
- Unité d'Enseignement et de Recherche en Parasitologie-Mycologie de la Faculté des Sciences de la Santé de Cotonou, Cotonou, Benin
| | - Sylvie Cornélie
- Institut Régional de développement/Centre de Recherche Entomologique de Cotonou, Cotonou, Benin
| | - Jacob Fassinou
- Unité d'Enseignement et de Recherche en Parasitologie-Mycologie de la Faculté des Sciences de la Santé de Cotonou, Cotonou, Benin
| | - Yolande Sissinto Savi de Tove
- Unité d'Enseignement et de Recherche en Parasitologie-Mycologie de la Faculté des Sciences de la Santé de Cotonou, Cotonou, Benin
| | - Adicath Adéola Adéothy
- Unité d'Enseignement et de Recherche en Parasitologie-Mycologie de la Faculté des Sciences de la Santé de Cotonou, Cotonou, Benin
| | | | - Patrick Makoutode
- Programme National de Lutte contre le paludisme Cotonou, Cotonou, Benin
| | - Alioun Adechoubou
- Programme National de Lutte contre le paludisme Cotonou, Cotonou, Benin
| | - Thibaut Legba
- Programme National de Lutte contre le paludisme Cotonou, Cotonou, Benin
| | | | - Dorothée Kinde-Gazard
- Unité d'Enseignement et de Recherche en Parasitologie-Mycologie de la Faculté des Sciences de la Santé de Cotonou, Cotonou, Benin
| | - Martin C Akogbeto
- Institut Régional de développement/Centre de Recherche Entomologique de Cotonou, Cotonou, Benin
| | - Achille Massougbodji
- Unité d'Enseignement et de Recherche en Parasitologie-Mycologie de la Faculté des Sciences de la Santé de Cotonou, Cotonou, Benin
| | | | | | - Immo Kleinschmidt
- MRC Tropical Epidemiology Group, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
| |
Collapse
|
12
|
Yahouédo GA, Cornelie S, Djègbè I, Ahlonsou J, Aboubakar S, Soares C, Akogbéto M, Corbel V. Dynamics of pyrethroid resistance in malaria vectors in southern Benin following a large scale implementation of vector control interventions. Parasit Vectors 2016; 9:385. [PMID: 27378358 PMCID: PMC4932690 DOI: 10.1186/s13071-016-1661-8] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2016] [Accepted: 06/22/2016] [Indexed: 01/13/2023] Open
Abstract
Background Large-scale implementation of Indoor Residual Spraying and Insecticide Treated Nets has been implemented in Plateau Department, Benin between 2011 and 2014. The purpose of this study was to monitor the frequency and mechanisms of pyrethroid resistance in malaria vectors following the implementation of vector control tools for malaria prevention. Methods Anopheles larvae were collected in 13 villages twice a year from 2012 to 2014. WHO tube tests were used to assess the phenotypic resistance of each population to 0.05 % deltamethrin. Sibling species within Anopheles gambiae complex were identified by PCR techniques. Taqman and biochemical assays were performed to identify the presence of kdr mutations in individual mosquitoes and to detect any increase in the activity of enzymes putatively involved in insecticide metabolism (oxidases, esterase and glutathione-S-transferases). Quantitative real time PCR was used to measure the expression of three metabolic genes involved in pyrethroid resistance (CYP6P3, CYP6M2 and GSTD3). Results Anopheles populations showed < 90 % mortality to deltamethrin in all villages and at all time points. The 1014 F kdr allele frequency was close to fixation (> 0.9) over the sampling periods in both An. gambiae and An. coluzzii. Biochemical assays showed higher activities of alpha esterase and GST in field malaria vector populations compared to susceptible mosquitoes. qPCR assays showed a significant increase of CYP6P3, CYP6M2 GSTD3 expression in An. gambiae after a three-year implementation of LLINs. Conclusion The study confirmed that deltamethrin resistance is widespread in malaria vectors in Southern Benin. We suspect that the increase in deltamethrin resistance between 2012 and 2014 resulted from an increased expression of metabolic detoxification genes (CYP6M2 and CYP6P3) rather than from kdr mutations. It is urgent to evaluate further the impact of metabolic resistance on the efficacy of vector control interventions using pyrethroid insecticides.
Collapse
Affiliation(s)
- Gildas A Yahouédo
- Institut de Recherche pour le Développement (IRD), Maladies Infectieuses et Vecteurs: Ecologie, Génétique, Evolution et Contrôle (MIVEGEC), UMR UM1-UM2 - CNRS 5290 - IRD 224, Montpellier, France. .,Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Bénin.
| | - Sylvie Cornelie
- Institut de Recherche pour le Développement (IRD), Maladies Infectieuses et Vecteurs: Ecologie, Génétique, Evolution et Contrôle (MIVEGEC), UMR UM1-UM2 - CNRS 5290 - IRD 224, Montpellier, France.,Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Bénin
| | - Innocent Djègbè
- Institut de Recherche pour le Développement (IRD), Maladies Infectieuses et Vecteurs: Ecologie, Génétique, Evolution et Contrôle (MIVEGEC), UMR UM1-UM2 - CNRS 5290 - IRD 224, Montpellier, France.,Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Bénin
| | - Justine Ahlonsou
- Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Bénin
| | - Sidick Aboubakar
- Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Bénin
| | | | - Martin Akogbéto
- Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Bénin
| | - Vincent Corbel
- Institut de Recherche pour le Développement (IRD), Maladies Infectieuses et Vecteurs: Ecologie, Génétique, Evolution et Contrôle (MIVEGEC), UMR UM1-UM2 - CNRS 5290 - IRD 224, Montpellier, France.,Department of Entomology, Faculty of Agriculture, Kasetsart University, 50 Ngam Wong Wan Rd, Lat Yao Chatuchak, Bangkok, 10900, Thailand
| |
Collapse
|
13
|
Gnanguenon V, Agossa FR, Badirou K, Govoetchan R, Anagonou R, Oke-Agbo F, Azondekon R, AgbanrinYoussouf R, Attolou R, Tokponnon FT, Aïkpon R, Ossè R, Akogbeto MC. Malaria vectors resistance to insecticides in Benin: current trends and mechanisms involved. Parasit Vectors 2015; 8:223. [PMID: 25886599 PMCID: PMC4395909 DOI: 10.1186/s13071-015-0833-2] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Accepted: 03/29/2015] [Indexed: 11/29/2022] Open
Abstract
Background Insecticides are widely used to control malaria vectors and have significantly contributed to the reduction of malaria-caused mortality. In addition, the same classes of insecticides were widely introduced and used in agriculture in Benin since 1980s. These factors probably contributed to the selection of insecticide resistance in malaria vector populations reported in several localities in Benin. This insecticide resistance represents a threat to vector control tool and should be monitored. The present study reveals observed insecticide resistance trends in Benin to help for a better management of insecticide resistance. Methods Mosquito larvae were collected in eight sites and reared in laboratory. Bioassays were conducted on the adult mosquitoes upon the four types of insecticide currently used in public health in Benin. Knock-down resistance, insensitive acetylcholinesterase-1 resistance, and metabolic resistance analysis were performed in the mosquito populations based on molecular and biochemical analysis. The data were mapped using Geographical Information Systems (GIS) with Arcgis software. Results Mortalities observed with Deltamethrin (pyrethroid class) were less than 90% in 5 locations, between 90-97% in 2 locations, and over 98% in one location. Bendiocarb (carbamate class) showed mortalities ranged 90-97% in 2 locations and were over 98% in the others locations. A complete susceptibility to Pirimiphos methyl and Fenitrothion (organophosphate class) was observed in all locations with 98-100% mortalities. Knock-down resistance frequencies were high (0.78-0.96) and similar between Anopheles coluzzii, Anopheles gambiae, Anopheles arabiensis, and Anopheles melas. Insensitive acetylcholinesterase-1 was rare (0.002-0.1) and only detected in Anopheles gambiae in concomitance with Knock-down resistance mutation. The maps showed a large distribution of Deltamethrin resistance, Knock-down mutation and metabolic resistance throughout the country, a suspected resistance to Bendiocarb and detection of insensitive acetylcholinesterase-1 from northern Benin, and a wide distribution of susceptible vectors to Pirimiphos methyl and Fenitrothion. Conclusion This study showed a widespread resistance of malaria vectors to pyrethroid previously located in southern Benin, an early emergence of carbamates resistance from northern Benin and a full susceptibility to organophosphates. Several resistance mechanisms were detected in vectors with a potential cross resistance to pyrethroids through Knock-down and metabolic resistance mechanisms.
Collapse
Affiliation(s)
- Virgile Gnanguenon
- Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Benin. .,Faculté des Sciences et Techniques de l'Université d'Abomey-Calavi, Abomey-Calavi, Benin.
| | - Fiacre R Agossa
- Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Benin. .,Faculté des Sciences et Techniques de l'Université d'Abomey-Calavi, Abomey-Calavi, Benin.
| | - Kefilath Badirou
- Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Benin. .,Faculté des Sciences et Techniques de l'Université d'Abomey-Calavi, Abomey-Calavi, Benin.
| | - Renaud Govoetchan
- Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Benin. .,Faculté des Sciences et Techniques de l'Université d'Abomey-Calavi, Abomey-Calavi, Benin.
| | - Rodrigue Anagonou
- Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Benin. .,Faculté des Sciences et Techniques de l'Université d'Abomey-Calavi, Abomey-Calavi, Benin.
| | - Fredéric Oke-Agbo
- Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Benin.
| | - Roseric Azondekon
- Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Benin.
| | - Ramziath AgbanrinYoussouf
- Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Benin. .,Faculté des Sciences et Techniques de l'Université d'Abomey-Calavi, Abomey-Calavi, Benin.
| | - Roseline Attolou
- Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Benin. .,Faculté des Sciences et Techniques de l'Université d'Abomey-Calavi, Abomey-Calavi, Benin.
| | | | - Rock Aïkpon
- Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Benin. .,Faculté des Sciences et Techniques de l'Université d'Abomey-Calavi, Abomey-Calavi, Benin.
| | - Razaki Ossè
- Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Benin. .,Université d'Agriculture de Kétou, Kétou, Benin.
| | - Martin C Akogbeto
- Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Benin. .,Faculté des Sciences et Techniques de l'Université d'Abomey-Calavi, Abomey-Calavi, Benin.
| |
Collapse
|