QUESTION:
What causes malaria?
ANSWER:
Malaria is a disease caused by a parasitic single-celled animal known as Plasmodium. There are different species of Plasmodium, which cause different kinds of malaria. The main types which infect humans are P. falciparum, P. vivax, P. ovale and P. malariae. The parasite is transmitted by certain species of mosquito; the parasite lives in the human blood stream and so goes in to the mosquito when the insect feeds. When the same individual mosquito then feeds on another person, it transmits parasites into a new host.
The symptoms of malaria are caused by the actions that the parasite undertakes while in the human host. For example, part of its reproductive cycle involves invading and then multiplying inside red blood cells. Once several cycles of reproduction have occurred, the new parasites burst out of the red blood cell, destroying it. The cycles are times so that all the new parasites burst out of the red blood cells at the same time; this coordinated destruction of the red blood cells, either every 24, 48 or 72 hours, depending on the malaria species, causes the one day, two day or three day cycles of fevers and chills that characterise malaria infection episodes.
Malaria is an vector (arthropod) borne disease caused by any of the four species of Plasmodium (falciparum, vivax, ovale and malariae) which is a single celled unicellular organism. The vector or the vehicle in this case is mosquito which is an arthropod. so malaria also comes under the category of arthropodborne diseases. The mosquito in this case is from the genus Anopheles and interestingly only the female mosquitoes transmit the disease as they need a blood meal to provide proteins for the development of their eggs. During such a blood meal the female Anopheles transmits the parasites into a healthy human.