Malaria is by far the worlds most important parasitic disease and is responsible for 8.2% of disability-adjusted life years (DALYs). It exacts an enormous toll on lives in medical costs and in days of labour lost. The estimated costs of malaria in terms of strain on health systems and economic activity lost are enormous amounting to about US $10 billion to $12 billion every year in lost Gross Domestic Product (GDP). It is still a public health problem today in more than 90 countries with an estimated worldwide incidence of about 300-500 million cases each year and a mortality of over 1million deaths per annum, significant proportion of which occurs in children under five years of age and pregnant women. Malaria control has gone round a full cycle from control to eradication and back to control. Attempts at eradication via the use of insecticide spray began shortly after the discovery of dichloro diphenyl trichloroethane (DDT). This chemical vector control which was combined with chemotherapy and surveillance have not largely met with the desired objectives due to toxicity from persistence in the environment, resistance of vectors and resistance of parasites to drugs This approach has since run out of favour and its use is now restricted to specific high risk and epidemic prone areas. However, newer methods based on the usefulness of pyrethoids from naturally occurring plants (Crysanthemum spp) and its synthetic products as residual insecticides has brought renewed hope.
Last date updated on July, 2020