Malaria is communicable disease caused by a parasitic proto­zoa belonging to the genus Plasmodium. Malaria is characterised by periodic chills and fever, enlargement of spleen and secondary anemia.


It is transmitted by the bite of female Anopheles mosquito which acts as a vector.

Life cycle of malarial parasite


The life cycle of malarial parasite can be classified into: 1. An asexual cycle which occurs in the infected host. 2. A sexual cycle which occurs in the mosquito.

Asexual cycle

When a female Anopheles mosquito bile’s a normal individual, it introduces sporozoites into circulation. The sporozoites are car­ried to liver. There they are converted into merozoites. The mero- zoites are then released in circulation. They enter red blood cells and multiply. The rupture of red blood cells releases more and more merozoites which coincides with the fever of malaria. Some of the merozoites differentiate into male (mocrogametocytes) and female (microgametocytes) sexual forms. These sexual forms are sucked when the mosquito bites an infected individual.

Sexual cycle


In the mosquito, the microgametocytes and microgametocytes unite to form a zygote. The zygote develops into oocyte, oocyte and then into sporozoite. The sporozoite is introduced into circula­tion, when the mosquito bites a normal individual.

Prevention and control

1. Early diagnosis through examination of blood smears.

2. Immediate notification to health authorities.


3. Hygienic measures like good drainage. This will prevent stagnation of water where mosquitoes bread.

4. Destruction of mosquitoes by spraying DDT or kerosene.

5. Prevention of mosquito bite by rubbing mosquito repellents or using mosquito nets.

6. Treatment with antimalarial drugs like quinine and chloroquine.


7. Health education about proper drainage and related sanitary measures.