The causative agent of malaria fever in man is

The causative agent of malaria fever in man is Plasmodium sp.
Malaria is caused by a single-celled parasite of the genus Plasmodium. The parasite is transmitted to humans most commonly through mosquito bites.
It is caused by Plasmodium parasites. Four Plasmodium species (Plasmodium falciparum, Plasmodium vivax, Plasmodium ovale and Plasmodium malariae) give disease in humans, and humans are their only relevant reservoir. Transmission requires an intermediate mosquito (anopheles) host.