Plasmodium falciparum
Plasmodium falciparum is a unicellular protozoan parasite of humans, and the deadliest species of "Plasmodium" that cause malaria in humans. It is transmitted through the bite of a female "Anopheles" mosquito. It is responsible for roughly 50% of all malaria cases. It causes the disease's most dangerous form called falciparum malaria. It is therefore regarded as the deadliest parasite in humans, causing 435,000 deaths in 2017. It is also associated with the development of blood cancer (Burkitt's lymphoma) and is classified as Group 2A carcinogen.
Soil-transmitted helminthiasis
It has become the most common parasitic disease of humans worldwide. Approximately two billion people (about a third of global population) are infected as of the latest estimate, and four billion at risk, surpassing even the all-time most prevalent parasitic disease, malaria. The largest numbers of cases occur in impoverished rural areas of Sub-Saharan Africa, Latin America, Southeast Asia, and China. Its main cause, like for many types of helminth infections, is lack of sanitation, such as the practice of open defecation and lack of hygiene such as hand washing. It is regarded as one of the world's most important causes of intellectual and physical retardation.