Victor Asoala
University
Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.
PhD Title
Malaria Transmission Dynamics and Insecticide Resistance of Malaria Vectors in the Kasena Nankana Districts of Ghana
Abstract
Malaria is the most important parasitic disease in humans accounting for about one million deaths a year (Greenwood et al., 2005). Current interventions used for the control of malaria vectors are mainly targeted at the adults through the use of insecticide treated bed nets (ITNs). Pyrethroids are currently the insecticides that are used because of their low toxicity and rapid action. ITNs have been used successfully in the Kassena-Nankana district (KND) of Ghana for over a decade; first as the earliest experimental intervention trial. This led to the adoption of ITNs as a national malaria control policy. Due to all year round irrigated agricultural activity and ITN use in KND, it is logical that these activities are imposing a selection pressure on the vectors and hence resistance to commonly used insecticides. This will ultimately affect efforts aimed at reducing malaria transmission in the district. The general Objective of this study is to assess the resistance status of vector populations in the district as a first step towards developing a resistance management strategy and to estimate the intensity of malaria transmission. The Vector Population Monitoring Tool (VPMT), which consists of a suite of assays used to screen mosquito vectors for traits like, An. gambiae s.l. species identification, the detection of sporozoite infectivity, and detection of insecticide resistance mechanisms will be used in the analysis of mosquito samples. This study will generate comprehensive data on the insecticide resistance status of malaria vectors and its relationship to the factors that influence the level of transmission in the KND.
Background
Malaria is the most important parasitic disease in humans accounting for about one million deaths a year. The most recent measurement of Malaria transmission in KND dates close to six years ago. Many activities and interventions like Artesunate combination treatment (ACT), Intermittent Preventive Treatment in infants (IPTi), Intermittent Preventive Treatment during pregnancy (IPTp), focused antenatal care and ITN use have taken place in the districts which could have influenced the dynamics of malaria transmission. This study therefore aims to estimate the intensity of malaria transmission in an area with long use and high ITN coverage and to relate these data to historical patterns of transmission intensity. It will also assess the resistance status of vector populations in the area as a first step towards developing a resistance management strategy for the area. The determination of the various parameters for the measurement of malaria transmission and insecticide resistance will be done by the analysis of mosquito samples using the Vector Population Monitoring Tool (VPMT). It is hoped that the study will generate comprehensive data on vectors of malaria transmission characteristics and factors that influence the level of transmission and the status of insecticide resistance of malaria vectors in the KND.