Question

Maximum chances of relapse of malaria occur by which two species?
A. Plasmodium ovale and falciparum
B. Falciparum and malariae
C. Ovale and falciparum
D. Vivax and ovale

Answer 1

Hint: Malaria is a common vector-borne disease caused by the species Plasmodium. Its main symptoms include fever, chills, fatigue, and gastrointestinal distress. Not all species of Plasmodium are dangerous but some are if not treated properly.

Complete answer: Malaria is a vector-borne protozoan disease caused primarily by the species Plasmodium. It is usually transmitted by an infected mosquito, which acts as the vector in this case. This species has a dual life cycle, where one half occurs inside the mosquito and the other half occurs in human RBCs. It is one of the most chronic diseases where 40% of the entire world population is at risk. The most potent form of Plasmodium is P. falciparum. It is known as one of the deadliest strains of the five Plasmodium species capable of infecting humans. P. vivax and P. ovale are other less virulent forms of Plasmodium, which also contribute to several malarial infections and are more widely known to cause recurrent malarial infections. They do so by the aid of hypnozoites. Hypnozoites are dormant forms of the parasitic protozoa which can become activated by P. vivax or P. ovale. This triggers delayed parasitic growth in liver cells and causes a relapse of malaria.
Thus, the correct answer is option D.

Note: The Plasmodium protozoa have two stages of the life cycle, where one occurs in the mosquito and the other occurs in the hepatocytes of humans. During the life cycle, dormant forms of the parasite reside within the liver which mostly occurs if the infection is by P. vivax and or P. ovale. P. falciparum is the most potent form of malaria parasite but does not cause a relapse of the infection. P. malariae is more commonly associated with kidney dysfunction and thickening of the glomerular membrane.