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.