Erlank, Erica2022-12-082022-12-082021https://hdl.handle.net/10539/33673A dissertation submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Master of Science in Medicine, 2021Plasmodium falciparum makes its human host more attractive for its vector companion, the Anopheles mosquito. Once in the host, the malaria parasite synthesizes isoprenoids via the 2-C-methyl-D-erythritol 4-phosphate pathway. The precursor for isoprenoids in this pathway is known as (E)-4-hydroxy-3-methyl-but-2- enyl pyrophosphate (HMBPP). HMBPP activates red blood cells to release volatile organic compounds that acts as an attractant to the mosquito to stimulate blood feeding. Only a few anopheline mosquito species are known to transmit the human malaria parasite. These mosquitoes can be classified as either major or minor vectors, depending on their impact on malaria transmission. The main African malaria vectors are responsible for 95% of malaria cases while minor vectors contribute to the remaining 5%. During this study, the aim was to evaluate if HMBPP influences P. falciparum susceptibility, feeding rate and attraction in major, minor and non-vector mosquito species. The standard membrane feeding assay was used to artificially infect mosquitoes and evaluate feeding rate, whereas attraction assays was conducted with a dual choice chamber. Results revealed that both the major vector, An. gambiae s.s., and the minor vector, An. merus, had an increase in both prevalence and intensity of parasite oocysts. An increase in feeding rate and attraction was also observed for some vectors, in the presence of HMBPP. These findings could play an important role in understanding the role of parasite volatiles in malaria transmission.enThesis