malaria cannot be spread by kissing or by any other sexual activity. I would not rule out blood transfusions but I would think they would be a very rare way to spread malaria because the malaria virus does not live in cold temperatures and most donated blood is cooled until used. I would think that it would have to be a direct transfusion, such as is sometimes done in crisis situations in remote locations in order to spread the malaria virus. Other than that it would most likely only be spread via mosquito bite.
What I can think of is getting bit by a mosquito then spreading it to someone else ex: ur girlfriend or boyfriend gets bit u kiss them BOOM u might have a chance at getting it or also by sexual activity and also just simply your friend at school sneezing or vouching in there hand or at you and u shake their hand or u have your mouth open and u might get it