6. plasmodium

plasmodium features

1. Sporozoa Malarial Parasite- Plasmodium

2. Plasmodium Plasmodium is an unicellular blood parasite and it causes malaria disease in humans. The word malaria means bad air (Italian words malo means bad and aria means air). Earlier it was believed that people inhaled bad air during night and became ill with malaria but it is not so. It is the mosquitoes which are likely to be out in the night air and spread malaria.

3. Plasmodium Four species of malaria parasites infect humans, Plasmodium vivax P. ovale P. malariae P. falciparum . All are transmitted by female Anopheles mosquitoes Geographical distribution - malaria is present worldwide in tropical and subtropical areas.

4. Habitat It is found in parenchymal cells of liver Erythrocytes and other organs

5. Transmission the bite of infected female Anopheles mosquitoes Malaria is also transmitted via blood transfusion sharing of contaminated needles among IV drug abusers Congenital transmission also has been documented.

6. Life Cycle Of Malaria Plasmodium has two hosts: mosquitoes and humans . Sexual reproduction ( Sporogony ) takes place in the mosquito and the parasite is transmitted to humans when the mosquito takes a blood meal . The asexual reproduction (Schizigony) takes place in humans.

7. Life Cycle of Plasmodium

8. Life Cycle Of Malaria: Humans The mosquito injects Plasmodium into a human in the form of sporozoites . The sporozoites first invade liver cells and asexually reproduce to produce huge numbers of merozoites which spread to red blood cells where more merozoites are produced through more asexual reproduction. Some parasites transform into sexually reproducing gametocytes and these if ingested by a mosquito continue the cycle.

9. Life Cycle Of Malaria: Mosquitoes Gametocytes ingested by a mosquito combine in the mosquito’s stomach to produce zygotes. These zygotes develop into motile elongated ookinites . The ookinites invade the mosquito’s midgut wall where they ultimately produce sporozoites , which make their way to the salivary glands where they can be injected into a new human host.

10. Pathogenesis Plasmodia invades red blood cells grow at host cells . Which rupture when schizogony is complete. Debris of ruptured cells, released merozoites and their metabolic products stimulates chemoreceptor of the temperature regulating mechanism of host. Number of invaded red cells increases and the sexual cycle of parasite increases. Pyrogen released produces characteristic chills and fever of malaria attack

11. Contd…….. P. vivax prefers to invade young erythrocytes whereas P. malariae prefers older erythrocytes. With each schizogony the parasitized cells are destroyed and also a considerable destruction of unparasitized cells due to lysis and phagocytosis in liver and spleen. Blockade of small vessels by sticky parasitized erythrocytes.

12. Features Fever : Three stages Cold stage Hot stage Sweating stage Febrile paroxysms Anemia S plenomegaly These three stages are not always observed due to maturation of generations of parasite at different times

13. Laboratory Diagnosis P eripheral blood smear examination Thick blood smears are useful for examining larger quantity of blood quickly when the parasites are few in the peripheral blood. Thin blood smears are useful for examining the peripheral blood when the parasites are numerous. It is only in the thin blood smears that the species of malarial parasites and the morphological stages of the organisms such as ring stage , schizont stage, male and female gametocytes can be diagnosed . Serological studies- Indirect haemagglutination test(IHA), ELISA etc

14. Treatment Chloroquine Quinine Primaquin Pyrimethamine + Sulfadoxine

15. Control & Prevention Treatment of patient by the use of anti-malarial drugs. Prevention of infection by using protective measures such as mosquito nets, odomos cream, mosquito oil, mosquito repellants etc. Control of vector by filling ditches; killing larvae by spraying insecticides, kerosene oil , DDT and by introducing natural enemies like larvicidal fish into pond.