According to Welcome-trust, an organization involved in the study and research of malaria, there are over 120 known species of the parasite genus Plasmodium, but only four of these 120 species infect humans causing malaria. Humans can be infected with four species of Plasmodium parasites: Plasmodium vivax, Plasmodium malariae, Plasmodium falciparum, and Plasmodium ovale. The main difference between the different species is that Plasmodium falciparum can cause severe and life-threatening malaria, while the other “Malaria life cycle - mosquito stages | Wellcome Trust") In most cases of malaria the patient feels well and the infection is detected only by a blood test which detects parasites in the blood. This is the most common case of malaria among people who have experienced several attacks of malaria and have some established degree of immunity to the disease; this is also the case for older children and adults in most of Africa south of the Sahara. Since immunity is obtained primarily from exposure to malaria (Fagan , 2000) without infection severe symptoms are very rare among people without immune defenses, such as travelers from a malaria-free area who become infected with (P. falciparum) Plasmodium falciparum causes simple malaria which, although very unpleasant, does not pose an immediate threat to life. Patient usually suffers from persistent fever with characterized by vomiting, vomiting with anemia (low hemoglobin in the blood) and excessively enlarged spleen. The victim also experiences persistent diarrhea. Symptoms in children may be a little more severe because as in addition to the symptoms mentioned above, children may also suffer from rapid breathing and may experience a...... middle of paper ......a diary | Full text | Increased detection of Plasmodium knowlesi in Sandakan Division, Sabah as revealed by PlasmoNex¿", 2013,) Although all forms of malaria are taken seriously. Plasmodium vivax, Plasmodium malariae and Plasmodium ovale are not usually considered fatal. However, the victims still need to be treated Treatment The parasite remains in the liver stage (dormant) in the body for years without causing disease because if left untreated, the parasites are dormant could reactivate and cause a multitude of health problems if the parasite reactivates from the liver stage , weakens the victim's immune system, making it easy for infection by opportunistic diseases such as tuberculosis (TB) (Crutcher & Hoffman, 1996) Plasmodium falciparum (P. falciparum) is considered the most dangerous species as it causes the most deaths ( Crutcher & Hoffman, 1996)