Inhibition of malaria infection and repellent effect against mosquitoes by chlorine dioxide

Abstract

We examined whether chlorine dioxide (ClO2) could inhibit malaria infections when applied to the skin. Anesthetized mice were divided into two groups: one group was sprayed with ClO2 solution and the other with distilled water. Each mouse was then placed on a vessel housing malaria-infected mosquitoes. The proportion of mosquitoes that fed on mice sprayed with distilled water was 47.7% (42/88) and the proportion of malaria-infected mice was 54.5% (6/11). These values were 5.9% (6/101) (p<0.01) and 7.7% (1/13) (p<0.05) in ClO2-sprayed mice. In a separate experiment, mosquitoes (Anopheles stephensi, Culex pipiens pallens and Aedes albopictus) were placed in a mesh-covered tube with an air-containing box at one end and a ClO2-containing box at the other. Mosquitoes were more likely to stay at the side facing the air-containing box, which indicated that they avoided ClO2 gas at concentrations as low as 0.03 ppm. ClO2 spray and gas could be used as a mosquito-repellent and may also reduce the transmission of malaria.