Knockdown Resistance (KDR) Genotype Frequencies and Distribution of Molecular Forms of Anopheles Gambiae in some areas of Accra Metropolis and Okyereko

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Malaria is one of the most contending diseases of the world with sub-Saharan Africa being the greatest sufferer. There have been several combating procedures; some focus on the causative parasite – plasmodium species, whilst others look into areas like vaccine technology, feasibility of large scale sterilization of the male Anopheles gambiae and vector control of the mosquito. A major constraint to vector control, based on indoor residual spraying and insecticide-treated materials, is the development of resistance by the mosquito vector to insecticides used for their control. This study reports on the distribution of the molecular forms of An. gambiae and insecticide resistance (the kdr mutation) carried out by sampling mosquito larvae from five locations in the Accra metropolis, and one out-group – Okyereko. Polymerase chain reaction (PCR) was used for the several analyses, and amplified nucleotide sequences were obtained when reaction products were analyzed by gel electrophoresis. The molecular M and S forms of An. gambiae were found to occur in sympatry in all locations. The M form predominated throughout locations where rice and vegetable fields existed and were undergoing irrigation, with Korle Bu having the highest frequency of 96.7 %. Labadi Wireless had the highest frequency of the S form of 66.7 %. M/S hybrids were detected in three locations, with Madina scoring 70 %. The kdr mutation was observed at very high frequencies within the S form (80-100 %), M form (73.9-100 %), and M/S form (85.7-100 %). A comprehensive study of the mosquito on a large scale would ensure a properly-structured vector control programme in order to curtail the spread of insecticide resistant An. gambiae and also to eradicate the parasite.
A thesis submitted to the Department of Biochemistry and Biotechnology of Kwame Nkrumah University of Science and Technology, Kumasi, in partial fulfilment of the requirement for the degree of Master of Science, 2009