Malaria
Plasmodium vivax or malaria parasites is an intercellular blood parasites of man which causes malaria in human being.
Discovery
Charles laveran(1880) discovered plasmodium in the blood of a malaria patients.In the year 1895 Ronald Ross,an Indian army doctor discovered the oocyst of plasmodium in the stomach of the female anopheles mosquito.
Life cycle The life cycle of plasmodium is completed the body of two host such as male and female anopheles mosquito. hence, the life cycle is digenetic.
Mode of infection
When an infected female anopheles mosquito bites a healthy person to suck blood, it injects the sporozoites(infective stage)into the human blood along with its saliva. Sporozoites are inoculated in thousands into the human blood. A sporozoite is microscopic, slender and sickle shaped animalcule.Two secretary gland are present at the anterior end which are believed to help in penetrations into the cell.
Life style
The asexual life cycle in man is called schizogony. It is divided into 3 phases (a)pre-erythrocytic schizogony,(b)exo-erythrocytic schizogony,(c)erythro-cytic schizogony. The sporozoite is the infective stage . while sucking blood an infected mosquito injects the sporozoites into the body of man.
The sporozoite enter the liver to carry on pre and exo -erthrocytic schizogony.for this two cycle large number of merozite are produced.
They enter R.B.C to carry on erythrocytic schizogony. This erythrocytic cycle is repeated in every 48 hours which coincides with the appearance of symptoms of malaria. Some of the merozites produced by erythrocytic cycle never attack fresh R.B.C. They wait for the mosquito to be sucked. They are of two types: male and female gametocytes. They carry on sexual reproduction inside the stomach of mosquito.
The sexual part of the life cycle occurs in the body of mosquito in low temperature.
After entering into the stomach of mosquito, the male or microgametocyte produces 4-8microgametes. This process occurs through exflagellation. The female or macrogametocyte produces only one macrogamete. A microgamete fuss with a macrogamete to form zygote. and finally occyst divided to form sporoblast.Each sporoblast produce large number of sporozoites. This process is known as sporogony.
When the inflected mosquito bites a healthy man the sporozoites are injected along with the saliva.
Types of malaria
Types of malaria.four species of plasmodium causes malaria in human beings. Each species has specific incubation period.
1-Benign Tertian malaria: It is also simple called Tertian malaria. As it is caused by p.vivax, it can be called vivax malaria.in this incubation period is 14 days and the recurrence of fever is after every 48 hours. This types of malaria death rate is low.
2-Quartan Malaria: It is also called subclinical malaria and caused by p.malariae. incubation period is 28 days.
3-Mild Tertian Malaria: it is also known as ovale malaria as it is caused by p.ovale. this types of malaria resembles to Tertian malaria. Incubation period is 14 days and the fever recurs every 48 hours or third day.
4- Malignant Tertian Malaria: it is also called pernicious malaria and it's caused by p.falciparum. the incubation period is 12 days . And the re recurrence of fever occurs every 48 hours.date rate is highest in this case.
Treatment
The treatment of malaria by inoculation or vaccination is not possible because the paracite does not produce antibody in human body.
So that quinine was is the effective antimalaria drug used for malaria.
Prevention
Malaria can be prevented by following below steps.
- Use of drugs.
- To control malaria adult Anopheles mosquito are destroyed by spraying insecticide like D.D.T.,Grammaxene.
- The mosquito larvae and pupae grow in stagnant water.
- The helpful thing is that use Grmbusia affinis in water where mosquito larvae developed.
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