MALARIA

Malaria

Malaria

Malaria

Malaria is a group of vector-borne infectious diseases transmitted to humans through the bites of mosquitoes of the genus Anopheles (mosquitoes) and accompanied by fever, chills, splenomegaly (spleen size increased), hepatomegaly (enlarged liver), anemia. It is characterized by a chronic relapsing course and is caused by parasitic protists kind Plasmodium (80-90% of cases - Plasmodium falciparum).

Malaria causes annually about 350-500 million infections and about 1.3-3 million deaths in humans. In sub-Saharan Africa deaths account for 85-90% in such these cases. The vast majority of infected children lie under the age of 5 years. Mortality is expected to double over the next 20 years.

The History of the Study of Malaria

There is an assumption that people suffer from malaria for the past 50,000 years. It is believed that the birthplace is West Africa Malaria and Central Africa. Molecular genetic data suggest that the ancestor of Plasmodium was the simplest free-living, capable of photosynthesis, which is adapted to live in the intestines of aquatic invertebrates (Sherman, 1998, pp. 19). Also, it could live in mosquito larvae first detachment Diptera, where there are 150-200 million years ago, quickly acquired the ability to have two masters. With the advent of human malaria parasites have developed that are capable of changing the master between man and the mosquito genus Anopheles. The oldest fossils of mosquitoes found with the remains of malaria parasites are age 30 million years.

What Causes Malaria

Malaria is the simplest kind of Plasmodium (Plasmodium). For human pathogens are four species of this genus: P.vivax, P.ovale, P.malariae and P.falciparum and in the recent years it was found that malaria in humans in Southeast Asia is caused by a fifth species known as Plasmodium knowlesi (who.int). A person becomes infected by them at the time of inoculation (injection), a female mosquito of one of the stages of the life cycle of the pathogen (called sporozoites) into the bloodstream or lymphatic system, which occurs when the bloodsucking.

For infections caused by P.falciparum and P.malariae, liver stage of parasite development starts in this part. For infections caused by other types of malaria parasite, "dormant" stage of liver (so-called gipnozoity) remain long-term persist in the liver, they can cause months or years after infection with new relapses and new episodes of exit of parasites in the blood (parasitemia).

Erythrocyte, or clinical, the stage of malaria begins with attachment of merozoites into the blood fallen to specific receptors on the surface of erythrocyte membranes. These receptors are targets for infection of employees, appears to be different for different species of malaria parasites.

Epidemiology of malaria

The source of infection is diseased or parasite in the blood which has gametocytes. More effective is the source of the patient, usually with a higher parasitemia and low intensity of immunity (Oaks, Et. al, 1991, pp. 15). Parasites are less important, since they have generated more than anti-parasite immunity and circulating antibodies in the blood blocking the development of gametocytes in the body vector.

The most effective source of infection are ...