Protists are eukaryotic microorganisms lacking tissue specialization, thus setting them apart from other eukaryotes such as plants, animals and fungi. The majority live in water and can be found anywhere in the world. Many protists are pathogens that can cause serious illness in plants and animals, including humans.
Malaria
Malaria is a serious protist disease that claims the lives of approximately 1 million individuals each year, according to Mayo Clinic. The disease is most commonly spread by mosquitoes carrying the protist Plasmodium. When bitten by a mosquito, the Plasmodium parasite is transmitted into an individual where it travels to the liver. From the liver, the Plasmodium may remain dormant or enters the bloodstream, at which point the symptoms of malaria develop. Common symptoms include recurrent attacks of chills, high fever and severe sweating. High-risk zones for malaria include tropical and subtropical countries, with the majority of cases occurring in sub-Saharan Africa. Several antimalarial medications exist, but drug resistance is a constant battle, rendering some medications useless, according to Mayo Clinic.
African Sleeping Sickness
Also referred to as African trypanosomiasis, African sleeping sickness is a serious infection that is common in parts of Africa. Infection is caused by two protists of the Trypanosoma family that are spread by the African tsetse fly. The organism can infect the central nervous system and heart, leading to possible swelling of the brain and death. The disease commonly causes drowsiness during the day and insomnia at night, gradually getting worse as the disease progresses. Other symptoms include anxiety, fever, mood changes, and swollen and painful nodules at the site of the bite. Without treatment, death may occur within six months, but several drugs can be prescribed to treat the infection, according to MedlinePlus.
Giardiasis
Giardiasis is an intestinal infection by Giardia parasites, a type of protist, found all across the globe, primarily in areas with unclean water or poor sanitation. It is the leading cause of waterborne illness in the United States, and infection can occur through contaminated food or person-to-person contact, according to Mayo Clinic. Generally an infection will clear within six weeks, but intestinal problems may remain long after the infection. Symptoms include watery, foul-smelling diarrhea; abdominal cramping and bloating; nausea; weight loss; and fatigue. However, some individuals may never display symptoms while carrying the parasitic infection. Infected individuals often recover on their own without treatment, but medication is needed for more serious cases. Taking preventive actions can help prevent the disease. These include frequent hand washing and abstaining from drinking untreated or unpurified water, such as that in lakes and streams.
