Protists are mostly single-celled organisms that can cause many serious illnesses that can become life threatening if not treated properly. However, most of these illnesses can be treated and the cause of infection can be established.
Protists are eukaryotes, meaning they have a nucleus, and are classified in the Kingdom Protista, which also includes algae, protozoans and some types of fungus. These organisms are neither plant nor animal, which is why they are classified in their own kingdom. The term “protist” was coined in 1886 by Ernst Haeckel, a German zoologist and evolutionist. Protists can be parasitic, which means they cause damage while living in hosts. These parasitic protists are carried by “vectors,” organisms that transmit the parasite and infect the human population.
Malaria is an infectious disease that kills up to 2.7 million people a year, mostly in tropical and subtropical climates such as areas below the Sahara Desert in Africa. Although it isn’t seen much in the United States, travelers coming from countries such as Africa or South America can transmit the disease when they return home. Malaria is caused by a parasitic protist that is carried by the mosquito, a blood-sucking insect that is also known to spread the West Nile Virus. The protist takes up residence in the bloodstream, causing capillaries to clog and red blood cells to die. Symptoms include fever, excessive sweating, severe chills, malaise, vomiting and diarrhea.
African Sleeping Sickness
African sleeping sickness, also known as trypanosomiasis, is found mostly in areas below the Sahara Desert in Africa. The parasitic protist that causes this disease, trypanosoma, is carried by the tsetse fly, which is found only in Africa. Upon initial infection, symptoms may include headache, fever and severe joint pain. Once the protist moves on to the central nervous system, the host will experience coordination problems, fatigue and general confusion. Trypanosomiasis is deadly without medical treatment.
This disease is caused by the protist giardia, which is one of the most frequently found waterborne parasites in the United States. Infection typically occurs after drinking contaminated water, usually from a lake, stream or well. The parasite can also contaminate water through infected animal feces. These protists can be ingested directly or as cysts, which will break open inside the human body, releasing the parasite. Giardia will attach itself to the intestinal wall, causing watery diarrhea or oily feces, nausea, stomach pains and fatigue.
Amoebic dysentery is most commonly referred to as “Montezuma’s Revenge.” This affliction is caused by the amoeba Entamoeba histolytica and is transmitted similarly to giardiasis, infecting the host through ingestion of contaminated water or food. The parasite can be ingested as either free amoebae, which usually die in the acidic environment of the stomach, or infective cysts, which can burst open and release the parasite into the intestines. This disease typically affects travelers visiting foreign countries where water could be contaminated. Symptoms include bloody diarrhea, pain during bowel movements or peritonitis, which is an infection of the intestinal lining.