Question

Which one has the highest incubation period.
A. Plasmodium malariae
B. Plasmodium falciparum
C. Plasmodium vivax
D. Plasmodium ovale

Answer 1

Hint: Incubation period is the time from the second of vulnerability to an infectious agent up to indication and symptoms of the disease appear. This mosquito has an incubation period of about 27 to 30 days.

Complete answer:
Plasmodium malariae causes quadrant malaria, in which fever comes after every 72 hours, and relapses occur. The incubation period varies from 27 to 30 days, which has the longest incubation period. Erythrocytes are not enlarged. It is found in both tropical and temperate zones but is not very widespread. It has dark brown hemozoin granules, and its gametophytes are round but smaller than the blood corpuscles. Plasmodium falciparum is very common in tropics and it causes malignant deadly cerebral malaria fever. Cerebral malaria is quite common in north-eastern states of India. If not treated, it causes death in three days. Its schizogony cycle is irregular, taking 24 to 48 hours. The incubation period is 12 days. Plasmodium vivax causes benign terrain malaria in which fever comes every 48 hours due to the formation of new generations of merozoites. It is the most widespread in both tropical and temperate zones and relapses occur in it. The incubation period is 14 days. Schizonts and gametophytes make erythrocytes very large. It’s harmonium granules are light brown and the gametocytes are round in shape and larger than the blood corpuscles. Plasmodium ovale is found in humans in West Africa and South America; in it, new generations of merozoites are formed every 48 hours; it causes mild tertian malaria. Its incubation period is 14 days. Schizonts and gametophytes enlarge the infected erythrocytes. The other three species are common and have a wide distribution.
So, the correct answer is option A.

Note: The causative agent of malaria, was discovered by Charles Laveran in 1880. Lancisi first suspected a relationship between mosquito and malaria. Plasmodium is found in man, birds, reptiles and rats. Some of the symptoms of malaria include fever, headache, muscle ache, joints ache, etc.