Question

Shivering in malaria is due to
A. Toxin released during the merozoite release from lysed RBC
B. Signet ring
C. Both A and B
D. None of the above

Answer 1

Members of the genus Plasmodium are collectively known as malaria parasites because they cause a febrile disease by the bite of female Anopheles mosquitoes. When an infected female anopheles mosquitoes' bites and feeds a healthy person and sucks its blood, it injects the spores (infectious stage) into the person's blood along with saliva.

Complete answer:
• Malaria has been known as a disease for centuries. The night air was once thought to be poisonous and cause a fever similar to malaria. Actually, malaria means bad air. Malaria is caused by four types of Plasmodium species, although the shape and life cycle are almost identical, but with some characteristics.
• Life cycle -Plasmodium falciparum, the primary causative organism, requires Anopheles mosquitoes and humans to complete their life cycle.
• The sexual cycle of protozoa occurs in mosquitoes. When mosquitoes bite the skin to feed on human blood, the immature spores of the mosquito's saliva are passed on to humans. Inside the human body, parasites reach the liver, multiply, enter the bloodstream, attack red blood cells, and absorb haemoglobin.
• The red blood cells break down, releasing merozoites and attacking more red blood cells. When the red blood cells are destroyed, Hemozoin venom is released. This causes high fever, chill and shivering.
• Some merozoites develop into sexually mature gamete cells called gametocytes and are transferred to the bites of other mosquitoes. In mosquitoes, the sexual cycle begins with gamete cells.

Hence, the correct answer is option (A).

Note: Charles Laveran (1880) discovered plasmodium in the blood of patients with malaria. In 1895, Indian Army doctor Ronald Ross discovered Plasmodium eggs in the belly of a female anopheles mosquito.
The life cycle of Plasmodium is completed in the bodies of both host man and female anopheles mosquitoes, hence the heterogeneous life cycle. The male is the primary and the female Anopheles mosquito is the secondary or intermediate host or vector.