Malaria

What it is

Malaria is the most important parasitic disease of human beings. It affected an estimated 216 million people and caused 445,000 deaths in 2016, and 40% of the world is at risk, children and pregnant women above all. The organism is plasmodium, and there are 5 species: 1. Falciparum, 2. Vivax, 3. Ovale, 4. Malariae, 5. Knowlesi. Plasmodium simium and Plasmodium cynomolgi are named alongside them. The route is a bite by the mosquito anopheles, the vector is the female Anopheles mosquito, the definitive host is the mosquito because sexual multiplication occurs there, and man is both the reservoir and the intermediate host. The transmission cycle runs from the first infected person to the first infected mosquito, then to infected liver cells and infected red blood cells. The five species differ, and the table is worth holding row by row. 1. P. vivax: tertian fever cycle, 51% of world cases, has a liver stage, infects retics, low parasite level, chloroquine resistance uncommon. 2. P. ovale: tertian, 1%, has a liver stage, retics, low parasite level, resistance rare. 3. P. falciparum: tertian, 48%, no liver stage, infects all red cells, high parasite level, chloroquine resistance yes. 4. P. malariae: quartan, 1%, no liver stage, old red cells, low parasite level, no resistance. 5. P. knowlesi: irregular, under 1%, no liver stage, all red cells, parasite level may be high, no resistance. In Oman, malaria cases are counted year by year from 1988 to 2015 in the Manual on Communicable Diseases MOH 2017, and the epidemiological classification of malaria cases started from 1994. Severe malaria is set out by clinical criteria and by laboratory criteria, and the criteria are given for three: 1. falciparum malaria, 2. knowlesi malaria, 3. vivax malaria. Knowlesi malaria takes the criteria as per falciparum malaria, with inability to tolerate oral therapy added on the clinical side and with modified parasitemia cutoffs on the laboratory side: jaundice and parasitemia >20,000/uL, or parasitemia >100,000/uL. Vivax malaria takes the criteria as per falciparum malaria excluding parasite density thresholds.