I would like to know the mechanism that the parasite penetrate into the urine and saliva. Some research papers detect the plasmodium parasite in urine and saliva.
Since Plasmodium parasite dwells in the blood cells, It is not possible for malaria parasite to survive in the saliva and urine or faecal matter. However, the dead malaria parasite or its remains could be detected in saliva and urine using molecular methods.
As you know, malaria parasites belong to Apicomplexa. All member of this phylum able to penetrate and pass the cell membrane due to their interacellular part of life cycle. So they can inter the urine and/or saliva similar to T.gondii. As you know we observe the congenital malaria indicates that malaria parasites can exit from the circulation and pass through some biologic barrier as placenta. So it possible that the malaria parasites have seen in saliva or urine rarely. But almost of assessment were done on parasites' DNA using molecular biologic methods like PCR. Hope it be useful.