Both P-ter of Gene Expression and John Hawks have covered the new publication on blood type O and malaria resistance. This is a very well studied marker and very important to human evolution because it has been a major selective force on the human population. I even isolated my own blood type alleles recently and I’m happy to confirm that I’m O for both alleles because this new paper says how blood type O is more resistant to malaria.
Here’s the link to the paper, which is currently open access, “Blood group O protects against severe Plasmodium falciparum malaria through the mechanism of reduced rosetting.”
Anthropology.net 
can malaria cause discrepancies in ABO and Rhesus Typing
I will stick with my type A blood that more resistant to Cholera than type O blood. Especially since i live at too high a latitude to worry about malaria.