Are Malaria Protozoa Free Living Organisms?

Malaria is caused by infection with a type of one-celled organism known as a protozoon. The protozoa that cause malaria are not free-living organisms, meaning that they cannot live in environments other than their vectors, which transmit the disease, and hosts.

Identification

• The protozoa that cause malaria belong to the genus Plasmodia, and there are four species: P. falciparum, P. vivax, P. malariae and P. ovale, according to the Mayo Clinic.

Features

• Plasmodia belong to a group of protozoa known as sporozoans. According to the Albany School of Public Health, sporozoans cannot move on their own.

Vector

• Malaria protozoa enter the human body through a bite from a female anopheles mosquito. The mosquito, according to the Mayo Clinic, is the disease vector. It carries the protozoa, but is not made sick by them.

Effects

• Plasmodia enter the human from the mosquito in a form called gametocytes. According to the Mayo Clinic, some of the plasmodia return to this form throughout the infection, so that they can be picked up again by another mosquito.

Considerations

• P. vivax, P. malariae and P. ovale can stay in host liver cells for a number of years and cause disease later, according to the Mayo Clinic.