Malaria transmission pattern was studied in 3 villages (Toubanding, Daga Ndoup, and Keur Samba Guèye) situated within an area selected for clinical trials. The study was conducted in the rainy season from July to December 2011. The main objective of this work was to gather baseline data on malaria transmission intensity and other entomological parameters before the advent of clinical trials. Mosquitoes were collected by Human-Landing Collections (HLCs) and by pyrethrum spray catches (PSCs). Five anopheline species were collected, namely, An. arabiensis, An. gambiae, An. funestus, An. pharoensis, and An. rufipes, giving a heterogeneous distribution within the study area. The populations dynamics of the vectors varied temporarily in each village depending on the pattern of the rainy season. Transmission intensity estimated by the entomological inoculation rate (EIR) was measured in each of the three villages with the variations linked to the microecological differences between the villages. Measurements were calculated for August, September, and October and were found to vary between 4 and 30 infected bites per person over the study period with a peak intensity observed in September. These results indicate that epidemiological field trials on malaria could be conducted in this area on the basis of the differences observed with transmission intensity, micro-ecological variations, and the objectives of the trials. 1. Background Malaria continues to be a major public health problem throughout the world despite more than a century of study, especially in Africa where 90% of the global cases are recorded. The situation is worsening due to the spread of drug resistant parasites strains, spread of insecticide resistance in the vector populations, and poor economic status of endemic populations [1]. To alleviate the problem, an integrated approach against both the parasites and vectors for an effective control is necessary. Over the last five years, considerable efforts have been made to control malaria in many countries around the world (especially in Sub-Saharan Africa) using strategic measures with available tools. This has led to the decline in malaria transmission in many parts of Africa [2, 3]. These changes are as a result of an extensive use of long-lasting insecticidal nets (LLINs) and improved malaria diagnosis and treatment. However, despite these significant progresses, malaria remains an acute problem killing 800000 people each year, mostly children under five years living in Sub-Saharan Africa [1]. The situation is particularly worrying with the
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