It is a disease caused by a protozoan parasite named Plasmodium. The various species are
P falciparum, P vivax, P malariae, P ovale and P knowlesi.
First 2 are common in India. P ovale is found only in Africa. P malariae is also rare while it is not certain whether P knowlesi transmission occurs through monkeys.
The disease is spread from one human being to another by the bite of female Anopheles mosquito. This bites during the night (after sunset) till day break.
Transmission is influenced by no of mosquitoes, no of bites, the no of parasites in the blood which is ingested by mosquitoes and the no of parasites in the saliva of mosquitoes injected in man.
Falciparum is usually more dangerous than vivax. However, more and more cases of complicated vivax malaria are being seen now.
After a bite of infected man by mosquitoes, it takes 8 to 30 days before the mosquito can transmit malaria.
Coming up Clinical manifestations and diagnosis.