Protozoan diseases include amoebiasis, African sleeping sickness and toxoplasmosis among many more. These diseases vary in intensity, source and duration and may affect the health of humans, plants and other living organisms. Some diseases caused by protozoa are relatively benign, while others are malignant and may be life threatening.
Amoebiasis is caused by a group of protozoa called sarcodina. These organisms secrete enzymes that are absorbed by tissues within the bodies of hosts. Amoebiasis is transmittable from one organism to the next and moves between them through contact with infected feces. Food and water containing contaminated feces are the most common methods of transmission, but oral contact with infected fecal matter may cause the disease to spread too.
Symptoms of infection include loose stools, inflamed colon and potentially blood in the stool. According to Med Health Net, giardiasis is another disease caused by protozoa and is also transmitted by contaminated feces. African sleeping sickness is another protozoa disease and is carried by the tsetse fly. This illness affects humans and animals and is transmitted to organisms by the bite of infected flies. This disease causes severe symptoms in humans, including excessive fatigue and neurological symptoms such as confusion, disorientation, seizures, insomnia, weight loss and slurred speech.