Name two diseases caused by protozoa.

Malaria and amoebic dysentery are two significant diseases caused by protozoa that affect millions of people globally. Malaria is caused by Plasmodium species (particularly P. falciparum and P. vivax), parasitic protozoa transmitted to humans through the bite of infected female Anopheles mosquitoes. The parasites invade red blood cells, causing recurring cycles of high fever, chills, sweating, fatigue, and anemia. Malaria remains one of the deadliest infectious diseases worldwide, particularly affecting tropical and subtropical regions, with children under five and pregnant women being most vulnerable.

Amoebic dysentery, also called amoebiasis, is caused by Entamoeba histolytica, a protozoan parasite that infects the intestines and sometimes spreads to the liver. Transmission occurs through contaminated food and water containing protozoan cysts, making it common in areas with poor sanitation. Symptoms include severe diarrhea with blood and mucus, abdominal pain, cramping, and fever. Both diseases are preventable through vector control (mosquito nets and insecticides for malaria) and improved sanitation, safe drinking water, and food hygiene (for dysentery). Effective medications exist for treatment—antimalarial drugs for malaria and antiprotozoal drugs for dysentery—but prevention remains the most cost-effective approach.