- 1 HOW IS MALARIA TRANSMITTED
HOW IS MALARIA TRANSMITTED
How can I become infected with malaria?
– Through a female Anopheles mosquito bite, in case this mosquito is infected by malaria parasite. Mosquitoes can be transported on aircraft traveling from malaria endemic areas, so they can transmit this disease elsewhere. People living near airports, are more likely to be bitten by a mosquito that has traveled in a plane.
– By direct infection of a pregnant infected woman to her child through the placenta.
– By direct infection with infected blood which gets in contact with a wound.
– By transfusion with infected blood.
How can I not become infected with malaria?
– It is not spread from humans to animals and vice versa.
– It is not spread from human to human, but in the ways mentioned above.
In parts of Africa, where the infection rate is the highest in the world, some people have developed a kind of “acquired immunity”. They do not manifest the disease but they are carriers or have milder chronic symptoms .
This can happen after they have suffered massive and constant infected mosquito bites or as a result of taking some drugs to prevent this infection, such as some prophylactic antibiotics.
How do anopheles mosquitoes act and infect?
This infectious disease is transmitted by the bite of an Anopheles mosquito. The mosquito that has infected a healthy person must have previously bitten another person infected with the parasite.
Only the females bite and transmit malaria. They need people’s blood in order to feed themselves to mature their eggs. Males, on the other hand, do not bite because they feed on nectar and, therefore, they do not transmit malaria.
Breeding cycle of Plasmodium parasites
The infection and replication cycle of the malaria parasites consists of two essential factors. One is the guest that the parasite chooses (may be people and / or animals). The guest is is the place, environment or body where the parasite will multiply and reproduce.
The other essential part to perform this cycle is the transmitter of infection, That’s to say, the responsible member to perform and spread the infection to different hosts. In the case of Plasmodium parasites, the transmitter of the infection is the Anopheles mosquito.
In the host, the parasite reproduces asexually, while, in the mosquito, the parasite reproduces sexually.
Sexual reproduction cycle in mosquitoes
The female Anopheles mosquitoes bite humans to feed on blood. If the human is previously infected with the malaria parasite, the mosquito gets infected absorbing the male and female parasite cells,called gametocytes, that are found in the infected human blood.
Once in the intestinal system of the mosquito, parasite male cells are transformed, resulting in other cells, called gametes. At this time, the male gametes are cells that will join female gametocytes, will perform a sexual fertilization and will create an egg, called ookinete.
The fertilized cell, that’s to say, the ookinete egg, penetrates into the mosquito’s gut mucosa and it is deposited between the epithelium of the intestinal mucosa and the peritoneum. They split into smaller cells called sporozoites, which reside in the mosquito’s saliva. The sporozoites are cells capable of infecting people with malaria. The disease is transmitted by mosquito bites to humans when, in order to feed itself, a mosquito produces infected saliva.
Asexual reproduction cycle in humans
These parasites in form of sporozoites are introduced into the body through the bite of a previously infected Anopheles mosquito.
Once inside the body, they go to the liver where they multiply in the hepatocytes, (The liver cells). These sporozoites change shape when they mature, becoming merozoites.
The merozoites break the liver cells and enter the bloodstream where they affect and destroy the red blood cells in our body, reason why they produce chronic anemia.
The method of reproduction of these parasites consists of performing both replication within the liver cells and in the interior of blood cells. In both cases causing the cells to rupture, by increasing their content. When broken, the merozoites are spread to be multiplied, and, thereby, they contaminate and infect other red blood cells from the blood stream still prevailing healthy.
This replication cycle, consisting on the destruction of red blood cells and the infection of other healthy red blood cells, covers a time interval (usually between two and three days) that is usually the time between infection and reinfection. Each of them coincides with the so-called fever crisis.
* Related information: Malaria prevention
More information on malaria.
19 March, 2019