scholarly journals Biting and resting preferences of malaria vectors in The Gambia

2020 ◽  
Author(s):  
Majidah Hamid-Adiamoh ◽  
Davis Nwakanma ◽  
Benoit Sessinou Assogba ◽  
Mamadou Ousmane Ndiath ◽  
Umberto D’Alessandro ◽  
...  
Keyword(s):  
Scale Up ◽  
Indoor Residual Spraying ◽  
The Gambia ◽  
Malaria Vectors ◽  
Resistance Mutations ◽  
Animal Blood ◽  
Malaria Burden ◽  
Polymerase Chain ◽  
Host Blood ◽  
Outdoor Resting

AbstractBackgroundThe scale-up of indoor residual spraying and long-lasting insecticidal nets, together with other interventions have considerably reduced the malaria burden in The Gambia. This study examined the biting and resting preferences of the local insecticide-resistant vector populations few years following scale-up of anti-vector interventions.MethodIndoor and outdoor-resting Anopheles gambiae mosquitoes were collected between July and October 2019 from ten villages in five regions in The Gambia using pyrethrum spray collection (indoor) and prokopack aspirator from pit traps (outdoor). Polymerase chain reaction assays were performed to identify molecular species, insecticide resistance mutations, Plasmodium infection rate and host blood meal. ResultsA total of 844 mosquitoes were collected both indoors (421, 49.9%) and outdoors (423, 50.1%). Four main vector species were identified, including An. arabiensis (indoor: 15%, outdoor: 26%); An. coluzzii (indoor: 19%, outdoor: 6%), An. gambiae s.s. (indoor: 11%, outdoor: 16%), An. melas (indoor: 2%, outdoor: 0.1%) and hybrids of An. coluzzii-An. gambiae (indoors: 3%, outdoors: 2%). A significant preference for outdoor resting was observed in An. arabiensis (Pearson X2=22.7, df=4, P<0.001) and for indoor resting in An. coluzzii (Pearson X2=55.0, df=4, P<0.001). Prevalence of the voltage-gated sodium channel (Vgsc)-1014S was higher in the indoor-resting (allele freq. = 0.96, 95%CI: 0.78–1) than outdoor-resting (allele freq. = 0.82, 95%CI: 0.76–0.87) An. arabiensis population. For An. coluzzii, the prevalence of most mutation markers were higher in the outdoor (allele freq. = 0.92, 95%CI: 0.81–0.98) than indoor-resting (allele freq. = 0.78, 95%CI: 0.56–0.86) mosquitoes. Sporozoite positivity rate was 1.3% (95% CI: 0.5–2%). Indoor-resting An. coluzzii had mainly fed on human blood while indoor-resting An. arabiensis, animal blood.ConclusionThe indoor-resting behavior of An. arabiensis that preferred animal blood and had low sporozoite rates, may be determined by the Vgsc-1014S mutation. Control interventions may include complementary vector control approaches such as zooprophylaxis.

scholarly journals Influence of insecticide resistance on the biting and resting preferences of malaria vectors in the Gambia

PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0241023
Author(s):  
Majidah Hamid-Adiamoh ◽  
Davis Nwakanma ◽  
Benoit Sessinou Assogba ◽  
Mamadou Ousmane Ndiath ◽  
Umberto D’Alessandro ◽  
...  
Keyword(s):  
Insecticide Resistance ◽  
Scale Up ◽  
Indoor Residual Spraying ◽  
The Gambia ◽  
Malaria Vectors ◽  
Resistance Mutations ◽  
Animal Blood ◽  
Malaria Burden ◽  
Host Blood ◽  
Outdoor Resting

Background The scale-up of indoor residual spraying and long-lasting insecticidal nets, together with other interventions have considerably reduced the malaria burden in The Gambia. This study examined the biting and resting preferences of the local insecticide-resistant vector populations few years following scale-up of anti-vector interventions. Method Indoor and outdoor-resting Anopheles gambiae mosquitoes were collected between July and October 2019 from ten villages in five regions in The Gambia using pyrethrum spray collection (indoor) and prokopack aspirator from pit traps (outdoor). Polymerase chain reaction assays were performed to identify molecular species, insecticide resistance mutations, Plasmodium infection rate and host blood meal. Results A total of 844 mosquitoes were collected both indoors (421, 49.9%) and outdoors (423, 50.1%). Four main vector species were identified, including An. arabiensis (indoor: 15%, outdoor: 26%); An. coluzzii (indoor: 19%, outdoor: 6%), An. gambiae s.s. (indoor: 11%, outdoor: 16%), An. melas (indoor: 2%, outdoor: 0.1%) and hybrids of An. coluzzii-An. gambiae s.s (indoors: 3%, outdoors: 2%). A significant preference for outdoor resting was observed in An. arabiensis (Pearson X2 = 22.7, df = 4, P<0.001) and for indoor resting in An. coluzzii (Pearson X2 = 55.0, df = 4, P<0.001). Prevalence of the voltage-gated sodium channel (Vgsc)-1014S was significantly higher in the indoor-resting (allele freq. = 0.96, 95%CI: 0.78–1, P = 0.03) than outdoor-resting (allele freq. = 0.82, 95%CI: 0.76–0.87) An. arabiensis population. For An. coluzzii, the prevalence of most mutation markers was higher in the outdoor (allele freq. = 0.92, 95%CI: 0.81–0.98) than indoor-resting (allele freq. = 0.78, 95%CI: 0.56–0.86) mosquitoes. However, in An. gambiae s.s., the prevalence of Vgsc-1014F, Vgsc-1575Y and GSTe2-114T was high (allele freq. = 0.96–1), but did not vary by resting location. The overall sporozoite positivity rate was 1.3% (95% CI: 0.5–2%) in mosquito populations. Indoor-resting An. coluzzii had mainly fed on human blood while indoor-resting An. arabiensis fed on animal blood. Conclusion In this study, high levels of resistance mutations were observed that could be influencing the mosquito populations to rest indoors or outdoors. The prevalent animal-biting behaviour demonstrated in the mosquito populations suggest that larval source management could be an intervention to complement vector control in this setting.

scholarly journals Resting Behavior of Malaria Vectors in Ghana and Its Implication on Vector Control.

2022 ◽  
Author(s):  
Akua Obeng Forson ◽  
Isaac A. Hinne ◽  
Shittu B. Dhikrullahi ◽  
Isaac Kwame Sr ◽  
Abdul Rahim Mohammed ◽  
...  
Keyword(s):  
Vector Control ◽  
Anopheles Gambiae ◽  
Blood Meal ◽  
Indoor Residual Spraying ◽  
Sub Saharan Africa ◽  
Malaria Vectors ◽  
Resistance Mutations ◽  
Sub Saharan ◽  
Outdoor Resting ◽  
Resting Behavior

Abstract Background: In Sub-Saharan Africa, there is widespread use of long-lasting insecticidal nets (LLINs) and Indoor residual spraying (IRS) to help control the density of malaria vectors and decrease the incidence of malaria in communities. An understanding of the interactions between increased insecticide use and resting behaviour patterns of malaria mosquitoes is important for an effective vector control programme. This study was carried out to investigate the resting behavior, host preference and infection with Plasmodium falciparum of malaria vectors in Ghana in the context of increasing insecticide resistance in malaria vectors in sub-saharan Africa.Methods: Indoor and outdoor resting Anopheline mosquitoes were sampled during the dry and rainy seasons in five sites that were in 3 ecological landscapes [Sahel savannah (Kpalsogou, Pagaza, Libga), Coastal savannah (Anyakpor) and Forest (Konongo) zones] using pyrethrum spray catches (PSC), mechanical aspiration (Prokopack) for indoor collections, pit shelter and Prokopack for outdoor collections. PCR based molecular diagnostics were used to determine mosquito speciation, genotype for knockdown resistance mutations (L1014S and L1014F), G119S Ace-1 mutation, specific host blood meal origins and sporozoite infection in field collected mosquitoes.Results: Anopheles gambiae s. l. was the predominant species (89.95%, n = 1,718), followed by An. rufipes (8.48%, n=162), and An. funestus s. l. (1.57%, n = 30). Sibling species of the Anopheles gambiae revealed An. coluzzii accounted for 63% (95% CI: 57.10 – 68.91), followed by An. gambiae s. s [27% (95% CI: 21.66 – 32.55)], and An. arabiensis [9% (95% CI: 6.22 – 13.57)]. The mean resting density of An. gambiae s. l. was higher outdoors (79.63%; 1,368/1,718) than indoors (20.37%; 350/1,718) (z = -4.815, p< 0.0001). The kdr west L1014F and the Ace-1 mutations were highest in indoor resting An. coluzzii and An. gambiae in the sahel-savannah sites compared to the forest and coastal savannah sites. Overall, the blood meal analyses revealed a large proportion of the malaria vectors preferred feeding on humans (70.2 %) than animals (29.8%) in all sites. The sporozoite rates was only detected in indoor resting An. coluzzii from the sahel savannah (5.0%) and forest (2.5%) zones.Conclusion: The study reports high outdoor resting densities of An. gambiae and An. coluzzii with high kdr west mutation frequencies, and persistence of malaria transmission indoors despite the use of LLINs and IRS. Continuous monitoring of changes in resting behavior of mosquitoes and implementation of complementary malaria control interventions are needed to target outdoor resting Anopheles mosquitoes in Ghana.

scholarly journals Insecticide Susceptibility Profile of Malaria Vector Populations from the Coastal and Mainland Areas of Akwa Ibom State, Nigeria

2019 ◽  
pp. 1-11
Author(s):  
I. A. Atting ◽  
N. D. Ekpo ◽  
M. E. Akpan ◽  
B. E. Bassey ◽  
M. J. Asuquo ◽  
...  
Keyword(s):  
Malaria Vector ◽  
Scale Up ◽  
Resistance Mechanism ◽  
Indoor Residual Spraying ◽  
Probit Model ◽  
World Health ◽  
Malaria Vectors ◽  
Morphological Identification ◽  
Insecticide Treated Nets ◽  
Study Sites

Development of resistance by different malaria vector populations to insecticides has become a big threat to malaria vector elimination. This study evaluated the susceptibility of Anopheles mosquito populations in Akwa Ibom State, Nigeria to permethrin (0.75%), deltamethrin (0.5%), lambdacyhalothrin (0.5%), alphacypermethrin (0.75%), Dichlorodiphenyltrichloethane (DDT), propoxur, bendiocarb and pirimiphosmethylin in World Health Organization (WHO) test tubes following standard protocols. The mosquitoes were obtained as aquatic forms and reared under laboratory conditions to adults. The adults were subjected to WHO susceptibility bioassays following standard procedures. Malaria vectors across the study sites were resistant to permethrin, deltamethrin, lambdacyhalothrin and alphacypermethrin insecticides. Full susceptibility to propoxur and bendiocarb was recorded across the sites. Full susceptibility to pirimiphosmethyl was recorded in populations from three sites. Nevertheless, population of the malaria vectors collected from Oron was resistant to pirimiphosmethyl. KDT50 and KDT95 estimated for each insecticide using a log-time probit model revealed that knockdown was more rapid for deltamethrin, lambdacyhalothrin, alphacypermethrin, propoxur, bendiocarb and pirimiphosmethyl than for DDT and permethrin  across the study sites. Morphological identification of all the mosquito samples used revealed that they were female Anopheles gambiae s.l. Sustained susceptibility of malaria vectors to pyrethriod is necessary for successful malaria control with insecticide treated nets and Indoor Residual Spraying (IRS). Emergence of focal points with insecticide resistance gives serious concern especially with the scale-up in distribution of pyrethriod treated nets to these areas. This may increase selection pressures due to overexposure. Further study to identify the exact resistance mechanism(s) of malaria vectors from these sites is recommended.

The impact of stopping and starting indoor residual spraying on malaria burden in 14 districts of Uganda

2020 ◽  
Author(s):  
Jane Namuganga ◽  
Adrienne Epstein ◽  
Joaniter Nankabirwa ◽  
Arthur Mpimbaza ◽  
Moses Kiggundu ◽  
...  
Keyword(s):  
Malaria Incidence ◽  
Critical Role ◽  
Scale Up ◽  
Indoor Residual Spraying ◽  
Fold Increase ◽  
Bed Nets ◽  
Malaria Burden ◽  
Vector Control Intervention ◽  
Using Data ◽  
The Impact

Abstract The scale-up of malaria control efforts has led to marked reductions in malaria burden over the past twenty years, but progress has slowed. Implementation of indoor residual spraying (IRS) of insecticide, a proven vector control intervention, has been limited and difficult to sustain partly because questions remain on its added impact over widely accepted interventions such as bed nets. Using data from 14 enhanced surveillance health facilities in Uganda, a country with high bet net coverage yet high malaria burden, we estimate the impact of starting and stopping IRS. We show that stopping IRS resulted in a 5-fold increase in malaria incidence within 10 months, but reinstating IRS led to an over 5-fold decrease within 8 months. In areas where IRS was initiated and sustained, malaria incidence dropped by 85% after year 4. IRS could play a critical role in achieving global malaria targets, particularly in areas where progress has stalled.

scholarly journals Is outdoor-resting behaviour in malaria vectors consistent? Short report from northern Ghana.

2021 ◽  
Author(s):  
Majidah Hamid-Adiamoh ◽  
Davis Nwakanma ◽  
Isaac Sr ◽  
Alfred Amambua-Ngwa ◽  
Yaw A. Afrane
Keyword(s):  
Fluorescent Dyes ◽  
Indoor Residual Spraying ◽  
Blood Feeding ◽  
Northern Ghana ◽  
Malaria Vectors ◽  
Short Report ◽  
Insecticide Treated Nets ◽  
Resting Behaviour ◽  
Vector Population ◽  
Outdoor Resting

Abstract Background Recent reports of a change in the resting behaviour of malaria vectors, from predominantly indoor resting to outdoor resting following blood feeding, have been attributed to selection pressure from use of vector control tools such as indoor residual spraying and long-lasting insecticide-treated nets. Recent studies have observed vectors resting predominantly outdoors in settings where anti-vector tools are extensively deployed. This present study examined if the outdoor resting behaviour in the vector population, is random or indicative of a consistent preference of one resting site over the other. Methods Mark-release-recapture (MRR) experiments were conducted with outdoor-resting Anopheles gambiae and An. funestus mosquitoes collected from pit shelters, animal houses and granaries in two villages in Northern Ghana during rainy and dry seasons. Mosquitoes were marked with fluorescent dyes and released indoors. The experiments were controlled with indoor-resting mosquitoes, which were marked and released outdoors. Species of all recaptured mosquitoes were identified and assessed for consistency in their resting behaviour. Results A total of 4,460 outdoor-resting mosquitoes comprising An. gambiae sensu lato (s.l.) (2,630, 59%) and An. funestus complex (1,830, 41%) were marked and released. Overall, 31 (0.7%) mosquitoes were recaptured mostly from outdoor location comprising 25 (81%) An. gambiae s.l. and 6 (19%) An. funestus complex. Only 3 (10%) of the recaptured mosquitoes were found resting indoors where they were released. The majority of the outdoor-recaptured mosquitoes were An. arabiensis (11, 39%), followed by An. coluzzii (7, 25%); whereas all indoor-recaptured mosquitoes were An. coluzzii. For the control experiment, 324 indoor-resting mosquitoes constituting 313 (97%) An. gambiae s.l. and 11 (3%) An. funestus complex were marked and released. However, none of these was recaptured neither indoors nor outdoors. More mosquitoes were significantly captured and recaptured during rainy season ( Z = 6.579, P < 0.0001). Conclusions The results obtained suggested the tendency for the mosquitoes to retain their outdoor-resting behaviour. Further investigations are required to ascertain if emerging preference for outdoor resting behaviour in malaria vector populations is consistent or a random occurrence.

scholarly journals The impact of stopping and starting indoor residual spraying on malaria burden in Uganda

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jane F. Namuganga ◽  
Adrienne Epstein ◽  
Joaniter I. Nankabirwa ◽  
Arthur Mpimbaza ◽  
Moses Kiggundu ◽  
...  
Keyword(s):  
Malaria Incidence ◽  
Critical Role ◽  
Scale Up ◽  
Indoor Residual Spraying ◽  
Fold Increase ◽  
Bed Nets ◽  
Malaria Burden ◽  
Vector Control Intervention ◽  
Using Data ◽  
The Impact

AbstractThe scale-up of malaria control efforts has led to marked reductions in malaria burden over the past twenty years, but progress has slowed. Implementation of indoor residual spraying (IRS) of insecticide, a proven vector control intervention, has been limited and difficult to sustain partly because questions remain on its added impact over widely accepted interventions such as bed nets. Using data from 14 enhanced surveillance health facilities in Uganda, a country with high bed net coverage yet high malaria burden, we estimate the impact of starting and stopping IRS on changes in malaria incidence. We show that stopping IRS was associated with a 5-fold increase in malaria incidence within 10 months, but reinstating IRS was associated with an over 5-fold decrease within 8 months. In areas where IRS was initiated and sustained, malaria incidence dropped by 85% after year 4. IRS could play a critical role in achieving global malaria targets, particularly in areas where progress has stalled.

scholarly journals Bionomics and ecology of Anopheles merus along the East and Southern Africa coast

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Brian Bartilol ◽  
Irene Omedo ◽  
Charles Mbogo ◽  
Joseph Mwangangi ◽  
Martin K. Rono
Keyword(s):  
Malaria Transmission ◽  
Mosquito Species ◽  
Scale Up ◽  
Indoor Residual Spraying ◽  
Temporal Distribution ◽  
Malaria Vectors ◽  
Behavioural Plasticity ◽  
Insecticide Treated Nets ◽  
Resting Behaviour ◽  
Residual Malaria Transmission

AbstractMalaria transmission persists despite the scale-up of interventions such as long-lasting insecticide-treated nets (LLINs) and indoor residual spraying (IRS). Understanding the entomological drivers of transmission is key for the design of effective and sustainable tools to address the challenge. Recent research findings indicate a shift in vector populations from the notorious Anopheles gambiae (s.s.) as a dominant vector to other species as one of the factors contributing to the persistence of malaria transmission. However, there are gaps in the literature regarding the minor vector species which are increasingly taking a lead role in malaria transmission. Currently, minor malaria vectors have behavioural plasticity, which allows their evasion of vector control tools currently in use. To address this, we have reviewed the role of Anopheles merus, a saltwater mosquito species that is becoming an important vector of malaria transmission along the East and Southern African coast. We performed a literature review from PubMed and Google Scholar and reviewed over 50 publications relating to An. merus's bionomics, taxonomy, spatial-temporal distribution and role in malaria transmission. We found that An. merus is an important vector of malaria and that it contributes to residual malaria transmission because of its exophilic tendencies, insecticide resistance and densities that peak during the dry seasons as the freshwater mosquitoes decline. Spatial and temporal studies have also shown that this species has increased its geographical range, densities and vectorial capacity over time. In this review, we highlight the resting behaviour and breeding habitats of this mosquito, which could be targeted for surveillance studies and control interventions.

scholarly journals Is Outdoor-Resting Behaviour in Malaria Vectors Consistent? Short Report From Northern Ghana.

2021 ◽  
Author(s):  
Majidah Hamid-Adiamoh ◽  
Davis Nwakanma ◽  
Isaac Sr ◽  
Alfred Amambua-Ngwa ◽  
Yaw A Afrane
Keyword(s):  
Fluorescent Dyes ◽  
Indoor Residual Spraying ◽  
Blood Feeding ◽  
Northern Ghana ◽  
Malaria Vectors ◽  
Short Report ◽  
Insecticide Treated Nets ◽  
Resting Behaviour ◽  
Vector Population ◽  
Outdoor Resting

Abstract BackgroundRecent reports of a change in the resting behaviour of malaria vectors, from predominantly indoor resting to outdoor resting following blood feeding, have been attributed to selection pressure from use of vector control tools such as indoor residual spraying and long-lasting insecticide-treated nets. Recent studies have observed vectors resting predominantly outdoors in settings where anti-vector tools are extensively deployed. This present study examined if the outdoor resting behaviour in the vector population, is random or indicative of a consistent preference of one resting site over the other. MethodsMark-release-recapture (MRR) experiments were conducted with outdoor-resting Anopheles gambiae and An. funestus mosquitoes collected from pit shelters, animal houses and granaries in two villages in Northern Ghana. Mosquitoes were marked with fluorescent dyes and released indoors. The experiments were controlled with indoor-resting mosquitoes, which were marked and released outdoors. Species of all recaptured mosquitoes were identified and assessed for consistency in their resting behaviour. ResultsA total of 4,460 outdoor-resting mosquitoes comprising An. gambiae sensu lato (s.l.) (59%) and An. funestus complex (41%) were marked and released. Overall, 31 (0.7%) mosquitoes (25 An. gambiae s.l. and 6 An. funestus complex) were recaptured mostly from outdoor location. Only 3 of the recaptured mosquitoes were found resting indoors where they were released. The majority of the outdoor-recaptured mosquitoes were An. arabiensis (11, 39%), followed by An. coluzzii (7, 25%); whereas the indoor-recaptured mosquitoes were mainly (3) An. coluzzii. For the control experiment, 324 indoor-resting mosquitoes constituting 313 An. gambiae s.l. and 11 An. funestus complex were marked and released. However, none of these was recaptured neither indoors nor outdoors.ConclusionsThe mosquitoes demonstrated the tendency to retain their outdoor-resting behaviour. Further investigations are required to ascertain if emerging preference for outdoor resting behaviour in malaria vector populations is consistent or a random occurrence.

scholarly journals Molecular Detection of Insecticide Resistance Mutations in Anopheles gambiae from Sierra Leone Using Multiplex SNaPshot and Sequencing

2021 ◽  
Vol 11 ◽  
Author(s):  
Jianhai Yin ◽  
Frederick Yamba ◽  
Canjun Zheng ◽  
Shuisen Zhou ◽  
Samuel Juana Smith ◽  
...  
Keyword(s):  
Insecticide Resistance ◽  
Vector Control ◽  
Anopheles Gambiae ◽  
Sierra Leone ◽  
Statistical Significance ◽  
Indoor Residual Spraying ◽  
Malaria Vectors ◽  
Mosquito Vector ◽  
Resistance Mutations ◽  
African Countries

Vector control interventions including long-lasting insecticidal nets and indoor residual spraying are important for malaria control and elimination. And effectiveness of these interventions depends entirely on the high level of susceptibility of malaria vectors to insecticides. However, the insecticide resistance in majority of mosquito vector species across African countries is a serious threat to the success of vector control efforts with the extensive use of insecticides, while no data on insecticide resistance was reported from Sierra Leone in the past decade. In the present study, the polymerase chain reaction was applied for the identification of species of 757 dry adult female Anopheles gambiae mosquitoes reared from larvae collected from four districts in Sierra Leone during May and June 2018. And the mutations of kdr, rdl, ace-1 genes in An. gambiae were detected using SNaPshot and sequencing. As a result, one sample from Western Area Rural district belonged to Anopheles melas, and 748 An. gambiae were identified. Furthermore, the rdl mutations, kdr west mutations and ace-1 mutation were found. The overall frequency was 35.7%, 0.3%, 97.6% and 4.5% in A296G rdl, A296S rdl, kdrW and ace-1, respectively. The frequencies of A296G rdl mutation (P &lt; 0.001), kdrW mutation (P = 0.001) and ace-1 mutation (P &lt; 0.001) were unevenly distributed in four districts, respectively, while no statistical significance was found in A296S rdl mutation (P = 0.868). In addition, multiple resistance patterns were also found. In conclusion, multiple mutations involved in insecticide resistance in An. gambiae populations in Sierra Leone were detected in the kdrW, A296G rdl and ace-1 alleles in the present study. It is necessary to monitor vector susceptibility levels to insecticides used in this country, and update the insecticide resistance monitoring and management strategy.

scholarly journals Insecticide resistance status of malaria vectors Anopheles gambiae (s.l.) of southwest Burkina Faso and residual efficacy of indoor residual spraying with microencapsulated pirimiphos-methyl insecticide

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Dieudonné Diloma Soma ◽  
Barnabas Zogo ◽  
Domonbabele François de Sales Hien ◽  
Aristide Sawdetuo Hien ◽  
Didier Alexandre Kaboré ◽  
...  
Keyword(s):  
Insecticide Resistance ◽  
Burkina Faso ◽  
Anopheles Gambiae ◽  
Local Population ◽  
Residual Activity ◽  
Indoor Residual Spraying ◽  
Susceptible Strain ◽  
Malaria Vectors ◽  
Pirimiphos Methyl ◽  
Residual Efficacy

Abstract Background The rapid spread of insecticide resistance in malaria vectors and the rebound in malaria cases observed recently in some endemic areas underscore the urgent need to evaluate and deploy new effective control interventions. A randomized control trial (RCT) was conducted with the aim to investigate the benefit of deploying complementary strategies, including indoor residual spraying (IRS) with pirimiphos-methyl in addition to long-lasting insecticidal nets (LLINs) in Diébougou, southwest Burkina Faso. Methods We measured the susceptibility of the Anopheles gambiae (s.l.) population from Diébougou to conventional insecticides. We further monitored the efficacy and residual activity of pirimiphos-methyl on both cement and mud walls using a laboratory susceptible strain (Kisumu) and the local An. gambiae (s.l.) population. Results An. gambiae (s.l.) from Diébougou was resistant to DDT, pyrethroids (deltamethrin, permethrin and alphacypermethrin) and bendiocarb but showed susceptibility to organophosphates (pirimiphos-methyl and chlorpyrimiphos-methyl). A mixed-effect generalized linear model predicted that pirimiphos-methyl applied on cement or mud walls was effective for 210 days against the laboratory susceptible strain and 247 days against the local population. The residual efficacy of pirimiphos-methyl against the local population on walls made of mud was similar to that of cement (OR = 0.792, [0.55–1.12], Tukey’s test p-value = 0.19). Conclusions If data on malaria transmission and malaria cases (as measured trough the RCT) are consistent with data on residual activity of pirimiphos-methyl regardless of the type of wall, one round of IRS with pirimiphos-methyl would have the potential to control malaria in a context of multi-resistant An. gambiae (s.l.) for at least 7 months.

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