D3350: Threats of agrochemical usage to malaria control in Ghana

The use of insecticides remains principal for controlling malaria vectors in Ghana however, resistance to pyrethroids and other classes of insecticides by the main malaria vector, Anopheles gambiae s.l., threatens the success of control tools. Uncontrolled pesticide use in agriculture could contribute to insecticide resistance development, especially in malaria vectors. This study sought to investigate which pesticides are commonly used by local farmers and most sold by agrochemical vendors and their implications on malaria control. A total of 1343 farmers participated in the survey between 2021 and 2023. 73% (n= 979/1343) use herbicides, while 25.3% (n= 340/1343) were recorded to use Insecticides, and 1.3% (n= 18/1343) use fungicides. The most common herbicide, 70.9% (n= 687/969), is used has an active ingredient, glyphosate, an Organophosphate. Bifenthrin (pyrethroid) 18% (n= 61/340) was also recorded as the most used insecticide.Out of the 165agrochemical sellers surveyed, the majority of them, 49.7% (n= 82/165), have had education up to the senior high school/technical level. 22.4% (n= 37/165) were university graduates, and 19.4% (n= 32/165) with JHS/MSLC certificates. The vendors sell more units of herbicides a week, 41.2% (n= 68/165), than insecticides, 40% (n= 66/165). This study showed that the use of agrochemicals might contribute to the insecticide-resistance development of malaria vectors, with most used and purchased pesticides having the same insecticide class as that used in malaria control in Ghana. This study offers the opportunity for further studies of agrochemicals that are adding to the development of insecticide resistance.