New distribution record of Anopheles rivulorum-like from Sadiola, Mali, with notes on malaria vector insecticide resistance

Author(s):  
Sue-Ellen Wragge ◽  
Nelius Venter ◽  
Dramane Touré ◽  
Richard H Hunt ◽  
Maureen Coetzee

Abstract Background The SEMOS gold mine in Sadiola, southwestern Mali, has been implementing a malaria vector control programme for 15 y using indoor residual house spraying and sporadic larval control. Periodic screening of the vector populations have been carried out over the years to provide information to the control programme, mainly on vector species present and their insecticide resistance status. The data from five entomological surveys, carried out in 2006, 2011, 2014, 2016 and 2018, are presented. Methods Adult mosquitoes were collected resting on walls inside houses and on verandas. Insecticide susceptibility assays were carried out and mosquitoes subsequently identified by species using molecular assays. Results The major malaria vector mosquitoes, Anopheles gambiae and Anopheles arabiensis were abundant at each sampling period with Anopheles coluzzii and Anopheles funestus being rare or absent. Anopheles rivulorum was identified in 2006 and Anopheles leesoni in 2016. The presence of Anopheles rivulorum-like, identified for the first time in 2018, was not screened for in previous surveys. Insecticide susceptibility bioassays showed resistance in both A. gambiae and A. arabiensis to pyrethroids, carbamates and dichlorodiphenyltrichloroethane over the 12 y. Conclusions This is the first record of A. rivulorum-like west of Côte d'Ivoire. Resistance levels to the three classes of insecticides were variable but appeared to decrease after pyrethroids were discontinued for house spraying.

2015 ◽  
Vol 14 (1) ◽  
Author(s):  
Jacob M. Riveron ◽  
Martin Chiumia ◽  
Benjamin D. Menze ◽  
Kayla G. Barnes ◽  
Helen Irving ◽  
...  

2016 ◽  
Vol 15 (1) ◽  
Author(s):  
Rousseau J. Djouaka ◽  
Seun M. Atoyebi ◽  
Genevieve M. Tchigossou ◽  
Jacob M. Riveron ◽  
Helen Irving ◽  
...  

2020 ◽  
Vol 19 (1) ◽  
Author(s):  
Jeanine A. C. M. Loonen ◽  
Dominic B. Dery ◽  
Bertin Z. Musaka ◽  
Janvier B. Bandibabone ◽  
Teun Bousema ◽  
...  

Abstract Background Malaria remains a major public health concern in the Democratic Republic of the Congo (DRC) and its control is affected by recurrent conflicts. Médecins Sans Frontières (MSF) initiated several studies to better understand the unprecedented incidence of malaria to effectively target and implement interventions in emergency settings. The current study evaluated the main vector species involved in malaria transmission and their resistance to insecticides, with the aim to propose the most effective tools and strategies for control of local malaria vectors. Methods This study was performed in 52 households in Shamwana (Katanga, 2014), 168 households in Baraka (South Kivu, 2015) and 269 households in Kashuga (North Kivu, 2017). Anopheles vectors were collected and subjected to standardized Word Health Organization (WHO) and Center for Disease Control (CDC) insecticide susceptibility bioassays. Mosquito species determination was done using PCR and Plasmodium falciparum infection in mosquitoes was assessed by ELISA targeting circumsporozoite protein. Results Of 3517 Anopheles spp. mosquitoes collected, Anopheles gambiae sensu lato (s.l.) (29.6%) and Anopheles funestus (69.1%) were the main malaria vectors. Plasmodium falciparum infection rates for An. gambiae s.l. were 1.0, 2.1 and 13.9% for Shamwana, Baraka and Kashuga, respectively. Anopheles funestus showed positivity rates of 1.6% in Shamwana and 4.4% in Baraka. No An. funestus were collected in Kashuga. Insecticide susceptibility tests showed resistance development towards pyrethroids in all locations. Exposure to bendiocarb, malathion and pirimiphos-methyl still resulted in high mosquito mortality. Conclusions This is one of only few studies from these conflict areas in DRC to report insecticide resistance in local malaria vectors. The data suggest that current malaria prevention methods in these populations are only partially effective, and require additional tools and strategies. Importantly, the results triggered MSF to consider the selection of a new insecticide for indoor residual spraying (IRS) and a new long-lasting insecticide-treated net (LLIN). The reinforcement of correct usage of LLINs and the introduction of targeted larviciding were also included as additional vector control tools as a result of the studies.


2020 ◽  
Vol 13 (1) ◽  
Author(s):  
El hadji Diouf ◽  
El hadji Amadou Niang ◽  
Badara Samb ◽  
Cheikh Tidiane Diagne ◽  
Mbaye Diouf ◽  
...  

Abstract Background High coverage of long-lasting insecticidal nets (LLINs) and indoor residual spraying (IRS) are the cornerstones of vector control strategy in Senegal where insecticide resistance by the target vectors species is a great of concern. This study explores insecticide susceptibility profile and target-site mutations mechanisms within the Anophelesgambiae complex in southeastern Senegal. Methods Larvae of Anopheles spp. were collected in two sites from southeastern Senegal Kedougou and Wassadou/Badi in October and November 2014, and reared until adult emergence. Wild F0 adult mosquitoes were morphologically identified to species. Susceptibility of 3–5-day-old An. gambiae (s.l.) samples to 11 insecticides belonging to the four insecticide classes was assessed using the WHO insecticide susceptibility bioassays. Tested samples were identified using molecular techniques and insecticide resistance target-site mutations (kdr, ace-1 and rdl) were determined. Results A total of 3742 An.gambiae (s.l.) were exposed to insecticides (2439 from Kedougou and 1303 from Wassadou-Badi). Tests with pyrethroid insecticides and DDT showed high level of resistance in both Kedougou and Wassadou/Badi. Resistance to pirimiphos-methyl and malathion was not detected while resistance to bendoicarb and fenitrothion was confirmed in Kedougou. Of the 745 specimens of An.gambiae (s.l.) genotyped, An.gambiae (s.s.) (71.6%) was the predominant species, followed by An.arabiensis (21.7%), An.coluzzii (6.3%) and hybrids (An. gambiae (s.s.)/An.coluzzii; 0.4%). All target site mutations investigated (Vgsc-1014F, Vgsc-1014S, Ace-1 and Rdl) were found at different frequencies in the species of the Anophelesgambiae complex. Vgsc-1014F mutation was more frequent in An.gambiae (s.s.) and An.coluzzii than An.arabiensis. Vgsc-1014S was present in An.gambiae (s.l.) populations in Wassadou but not in Kedougou. Ace-1 and rdl mutations were more frequent in An.gambiae (s.s.) in comparison to An.arabiensis and An.coluzzii. Conclusions Resistance to all the four insecticide classes tested was detected in southeastern Senegal as well as all target site mutations investigated were found. Data will be used by the national Malaria Control Programme.


PLoS ONE ◽  
2011 ◽  
Vol 6 (1) ◽  
pp. e16066 ◽  
Author(s):  
Delenasaw Yewhalaw ◽  
Fantahun Wassie ◽  
Walter Steurbaut ◽  
Pieter Spanoghe ◽  
Wim Van Bortel ◽  
...  

2022 ◽  
Vol 2022 ◽  
pp. 1-8
Author(s):  
Ashok K. Mishra ◽  
Praveen K Bharti ◽  
Gyan Chand ◽  
Aparup Das ◽  
Himanshu Jayswar ◽  
...  

Background. Indoor residual spraying (IRS) and long-lasting insecticidal nets (LLINs) are malaria vector control measures used in India, but the development of insecticide resistance poses major impediments for effective vector control strategies. As per the guidelines of the National Vector Borne Disease Control Programme (NVBDCP), the study was conducted in 12 districts of Madhya Pradesh to generate data on insecticide resistance in malaria vectors. Methods. The susceptibility tests were conducted on adult An. culicifacies as per the WHO standard technique with wild-caught mosquitoes. The blood-fed female mosquitoes were exposed in 3 to 4 replicates on each occasion to the impregnated papers with specified discriminating dosages of the insecticides (DDT: 4%, malathion: 5%, deltamethrin: 0.05%, and alphacypermethrin: 0.05%), for one hour, and mortality was recorded after 24-hour holding. Results. An. culicifacies was found resistant to DDT 4% in all the 12 districts and malathion in 11 districts. The resistance to alphacypermethrin was also observed in two districts, and possible resistance was found to alphacypermethrin in seven districts and to deltamethrin in eight districts, while the vector was found susceptible to both deltamethrin and alphacypermethrin in only 3 districts. Conclusion. An. culicifacies is resistant to DDT and malathion and has emerging resistance to pyrethroids, alphacypermethrin, and deltamethrin. Therefore, regular monitoring of insecticide susceptibility in malaria vectors is needed for implementing effective vector management strategies. However, studies to verify the impact of IRS with good coverage on the transmission of disease are required before deciding on the change of insecticide in conjunction with epidemiological data.


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