BackgroundThe success of current control tools in combatting malaria vectors is well established. However, sustained residual transmission of Plasmodium parasites persists. Mass drug administration (MDA) to humans of the endectocide ivermectin for vector control is receiving increasing attention. However, vectors feeding upon animals escape this promising approach. Zoophagy of mosquitoes sustains both the vector population and endemic population of vector-borne pathogens. Therefore, only a strategy that will combine ivermectin MDAs targeted at humans and their peridomestic animals could be successful at controlling residual malaria transmission.MethodsBurkinabé cattle have been treated with injectable therapeutic dose of ivermectin (0.2 mg/kg of body weight) to render blood meals toxic to field representative populations of Anopheles coluzzii carrying the kdr mutation. Direct skin-feeding assays were performed from 2 to 28 days after injection (DAI) and mosquitoes were followed for their survival, ability to become gravid and fecundity. Membrane feeding assays were further performed to test if an ivermectin blood meal taken at 28 DAI impacts gametocyte establishment and development in females fed with infectious blood.ResultsThe mosquitocidal effect of ivermectin is complete for 2 weeks after injection, whether 12 days cumulative mortalities were of 75 and 45 % the third and fourth weeks, respectively. The third week, a second ivermectin blood meal at sub-lethal concentrations further increased mortality to 100 %. Sub-lethal concentrations of ivermectin also significantly decreased egg production by surviving females, increasing further the detrimental effect of the drug on vector densities. Although females fitness was impaired by sub-lethal ivermectin blood meals, these did not diminish nor increase their susceptibility to infection.ConclusionThis study demonstrates the potential of integrated MDA of ivermectin to both human and peridomestic cattle to target vector reservoirs of residual malaria transmission. Such integration lies in ‘One-Health’ efforts being implemented around the globe, and would be especially relevant in rural communities in Africa where humans are also at risk of common zoonotic diseases.Electronic supplementary materialThe online version of this article (doi:10.1186/s12936-015-1001-z) contains supplementary material, which is available to authorized users.

Background Twenty-seven villages were selected in southwest Burkina Faso to implement new vector control strategies in addition to long lasting insecticidal nets (LLINs) through a Randomized Controlled Trial (RCT). We conducted entomological surveys in the villages during the dry cold season (January 2017), dry hot season (March 2017) and rainy season (June 2017) to describe malaria vectors bionomics, insecticide resistance and transmission prior to this trial. Methods We carried out hourly catches (from 17:00 to 09:00) inside and outside 4 houses in each village using the Human Landing Catch technique. Mosquitoes were identified using morphological taxonomic keys. Specimens belonging to the Anopheles gambiae complex and Anopheles funestus group were identified using molecular techniques as well as detection of Plasmodium falciparum infection and insecticide resistance target-site mutations. Results Eight Anopheles species were detected in the area. Anopheles funestus s . s was the main vector during the dry cold season. It was replaced by Anopheles coluzzii during the dry hot season whereas An . coluzzii and An . gambiae s . s . were the dominant species during the rainy season. Species composition of the Anopheles population varied significantly among seasons. All insecticide resistance mechanisms ( kdr-w , kdr-e and ace-1 target site mutations) investigated were found in each members of the An . gambiae complex but at different frequencies. We observed early and late biting phenotypes in the main malaria vector species. Entomological inoculation rates were 2.61, 2.67 and 11.25 infected bites per human per month during dry cold season, dry hot season and rainy season, respectively. Conclusion The entomological indicators of malaria transmission were high despite the universal coverage with LLINs. We detected early and late biting phenotypes in the main malaria vector species as well as physiological insecticide resistance mechanisms. These data will be used to evaluate the impact of complementary tools to LLINs in an upcoming RCT.

22Background: The present study presents results of entomological surveys conducted to 23 address the malaria vectors bionomic, insecticide resistance and transmission prior to the 24 implementation of new strategies complement long-lasting insecticidal nets (LLINs) in the 25 framework of a randomized control trial in southwest Burkina Faso. 26 Methods: We conducted entomological surveys in 27 villages during the dry cold season 27 (January 2017), dry hot season (March 2017) and rainy season (June 2017). We carried out 28 hourly catches (from 17:00 to 09:00) inside and outside 4 houses in each village using the 29 Human Landing Catch technique. Mosquitoes were identified using morphological taxonomic 30 keys. Specimens belonging to the Anopheles gambiae complex and Funestus Group were 31 identified using molecular techniques as well as detection of Plasmodium falciparum 32 infection and insecticide resistance target-site mutations. 33 Results: Eight Anopheles species were detected in the area. Anopheles funestus s.s was the 34 main vector during the dry cold season. It was replaced by Anopheles coluzzii during the dry 35 hot season whereas An. coluzzii and An. gambiae s.s. were the dominant species during the 36 rainy season. Species composition of the Anopheles population varied significantly among 37 surveys. All researched target site mutation of insecticide resistance (kdr-w, kdr-e and ace-1) 38 were detected in all members of the An. gambiae complex of the area but at different 39 frequencies. We observed early and late biting phenotypes in the main malaria vector species. 40 Entomological inoculation rates were 0.087, 0.089 and 0.375 infected bites per human per 41 night during dry cold season, dry hot season and rainy season, respectively. 42 Conclusion: The intensity of malaria transmission was high despite the universal coverage 43 with LLINs. We detected early and late biting phenotypes in the main malaria vector species 44 as well as physiological insecticide resistance mechanisms. These vectors might mediate 45 residual transmission. These data highlight the need to develop complementary tools in 46 3 addition to LLINs in order to better control resistant malaria vectors and to monitor 47 insecticide resistance. 48