RE: Does breastfeeding confers immunity on nursing mothers?

Good that you came into that conclusion! I was a little bit worried! I think the answer isn't associated to immunity, at least has less probability in that. The Plasmodium protist is carried by Anopheles mosquitoes, even if you guys sleep under the same bed, it is difficult that the same mosquito that transmitted you the protozoa. Even with a high incidence of malaria in your incidence being attacked by a bunch of Anopheles carrying the parasite is possible, but it is rare I guess. In addition to that, you don't stay only at home right? Maybe you were bitten somewhere else? Moreover, you have multiple other mosquitoes that carry other diseases or even no diseases, and of course, you will find other species in your house.
I am from Rio de Janeiro, we faced bad outbreaks of Dengue virus. When I had it, neither my parents or my brother had it, even though we had tons of mosquitos entering and exiting our home. My brother had the disease I guess a couple of years after in another outbreak, and neither of the rest of us had it at that time.
Again, is it possible that there is something unknown by science happening in the breastfeeding mother? Yes , but I think that there are more chances of happening than I cited! There is something else that you don't mention that it can also play to the resistance, maybe your wife is heterozygous for the sickle cell anemia? This also confers resistance to the protozoa.
!1UP