Studies by Australian scientists suggest that platelets have a protective function in the early stages of malaria infection and that aspirin can interfere with this protective effect (McMorran BJ et al. Science. 2009;323:797-800).
Platelet-deficient mice infected with a rodent version of the malaria parasite were significantly more likely than control mice to die from the infection. Mice without platelet deficiency that were treated with aspirin, which decreases platelet activation, also were significantly more susceptible than animals treated with placebo.
Stephenson J. Platelets and Malaria. JAMA. 2009;301(13):1329. doi:10.1001/jama.2009.429