Question

Which species are found in the region of South America and West Africa and is the least harmful?
a) P. ovale
b) P. vivax
c) P. falciparum
d) P. malariae

Answer 1

The Plasmodium sp. usually causes malaria in human beings. These different species cause different types of malarial fever. Malaria is caused by the biting of the mosquitoes. It is caused due to unhygienic surroundings where the mosquitoes can survive easily.

Complete step by step answer:
The species found in the region of South America and West Africa and is least harmful is the P. vivax. It causes benign tertian malaria and is least harmful to other species of plasmodium. The fever caused by them reappears after every third day and these recurrent attacks of the fever are also known as paroxysms. The symptoms include mild recurring fever.

So, the answer is ‘P. vivax’.

Additional information: To cause the infection of the malaria two hosts are required by the parasite to complete its life cycle and reach the infective stage. The first or the primary host is the Anopheles mosquitoes and the secondary host is the human or other vertebrates. The parasites are transported into the humans when the mosquito feeds on them in the form of sporozoites. These then travel to the liver through the bloodstream and form the schizonts. These schizonts formed then mature and rupture to release the merozoites which cause the symptoms to be visible in the infected host. The parasites complete their whole life cycle inside the secondary host. The infection is spread if the mosquitoes take the blood of the infected human and then bites the non-infected person.

Note:
The incubation period of the malaria is usually up to 12 to 15 days but a relapse may occur 2 years later also when the hypnozoites are in dormant stages. The most common symptoms of malaria include fever, headache, nausea, vomiting, and body aches.