Question

Why do the symptoms of malaria not appear immediately after the entry of sporozoites into the human body when bitten by female anopheles ? explain.

Answer 1

Malaria is caused by the plasmodium parasite and transmitted by the female anopheles mosquito. These mosquitoes breed in drainages and stagnant water.

Complete answer:
When the female mosquito bites a person, it injects the sporozoites inside it. The sporozoites move into the liver cells called hepatocytes. These multiply then enter the bloodstream and convert into trophozoite stage. It affects the red blood cells, as the RBC’s are affected they burst and release hemozoin.

This hemozoin is responsible for the chills and fever caused during malaria. Malaria pathogenesis is the process in which malaria parasites cause illness, abnormal function, or damage in human hosts.

The symptoms do not appear immediately after the entry of sporozoites because hemozoin is not released. Only after the release of hemozoin the malarial symptoms are released.

The life cycle of malaria is completed in two different hosts: humans and female anopheles. In female mosquitoes, the reproduction and fertilization occurs in their gut. The parasite's multiplication in mosquitoes is known as sporogonic cycle. The zygotes produced, turn motile.

There are different types of malarial parasites that belong to genus plasmodium: P. falciparum, P. vivax, P. ovale, P. malariae, P. knowlesi. The mosquitoes go through four stages: egg, larva, pupa and adult. Adult females lay approximately 50-200 eggs.

Note: Mosquitoes are only vectors. Most female mosquitoes are nocturnal or diurnal. They are found in places with poor sanitization. They are generally short lived. A diverse group of anopheles ( 30 to 40 species).