p vivax ppt.

Maleria causes treatment, control and its life cycle

1. By Dr. Priti D.Diwan Assistant Professor Department of Zoology J.D.Patil Sangludkar Mahavidyalay Daryapur . Plasmodium vivax ( MALARIAL PARASITE)

2. The most interesting sporozoan genus is plasmodium B e cause o f t heir m ala r ia caus i ng a b il iti e s , t hese spec i es c o m m o n l y referred as malarial parasites All resides in the RBC Mosquitoes are the vectors The Malarial parasite

3. 4 species are known to cause different types of malaria P. vivax, P. ovale, P. malariae and P. falciparium Geographically distributed in tropical and temperate countries P . v i v ax i s m ost c o m m o n l y d i s tri b ut e d and p r e vai l s i n the temperate regions of the world.

4. Life Cycle of P. vivax P. Vivax is the most common of the human infecting malaria fever parasites. Causes benign tertian or vivax malaria, characterized by a 48 h cycle b/w first fever and subsequent chills and fever. Hosts: diagenetic Man: asexual cycle in two phases First in liver – liver schizogony Second in RBC – erythrocytic schizogony and forms gametes Mosquito: Sexual cycle is completed in female anopheles It involves gametogony and sporogony

5. Asexual cycle of P. vivax in man [1]. Infection Anopheles bite resulting in the inoculation of thousands of sporozoites along with saliva into the persons body (victim) [2]. Sporozoites Infective form of parasite Small, spindle shaped measuring about 11-12 µ in length and 0.5-1 µ in width

6. [3]. Liver Schizogony After 30m of infection, sporozoites invades hepatic tissues and multiply by schizogony in two phases (pre and exo-erythrocytic) a). Pre-erythrocytic phase Sporozoite becomes cryptozoite in hepatic cells and becomes spherical and non-pigmented schizont. Undergo multiple fission (schizogony) and forms numeros uninucleate cryptomerozoites At the end of phase, hepatic cell bursts and cryptomerozoites are liberated. b). Exo-erythrocytic phase Cryptomerozoites enter new liver cells and becomes metacryptozoites Undergo similar schizogony and produces metacryptomerozoites.

7. [4]. Erythrocytic schizogony Micro metacryptomerozoites invades RBC and starts erythrocytic schizogony and includes following stages: a). Tropozoite stage Inside RBC, micro metacryptomerozoites becomes rounded and modified into trophozoite. b). Signet ring stage T r o p h o z o i te g r ows, d eve l ops vac u ole and c l in i c al l y r efer r ed as signet ring stage. c). Amoeboid stage Meanwhile signet stage develops into active amoeboid trophozoite A t t his s t a g e , s a m le r e d eos i nophi l ic granul e s a p p ear i n th e cytoplasm –schuffners granules d). Schizont Amo e bo i d t r op h o z o i te aft er feed i n g b e com e s r o u n d ed, g r ows in size and becomes schizont It undergoes schizogony and forms merozoites One erythrocytic cycle takes 48h

8. [5]. Post-erythrocytic schizogony Sometimes merozoites reach the liver and undergoes schizogonic development in the liver cells –post-erythrocytic schizogony. [6]. Formation of gametes Merozoites increases in size to become rounded gametocytes. Male – microgametocyte and female- magagametocyte Gametocytes donot devide but remain as intracellular parasite until they either die or ingested by vector

9. Sexual cycle of P. vivax in man [1]. Ingestion by mosquito Female anopheles gets the infection by sucking the blood of infected person RBC are digested and gametocytes are liberated and lodged into the cavity of the gut. [2]. Gametogony Development of gametes (Haploids) from gametocyte – gametogony/ gametogenesis. Gamtes are of two types a). Microgametes Male or microgamete undergoes exflagellation in the midgut of mosquito Each nucleus divides by mitosis and produce 6-8 haploid daughter and assemble at periphery Cytoplasm outgrows into long thin flagella like projection and later these projections break away as mature male gamete b). Megagametes Female megagametocyte undergo some reorganisationa nd becomes a female gamete, which is ready for fertilization.

10. [3]. Fertilization Megagamete gives out a cytoplasmic projection – fertilization cone. Microgamete attached to this cone and transfer its nucleus to megagamete Fertilization or syngamy takes place Diploid zygote forms [4]. Ookinete After sometime zygote becomes active and shows gliding moment and is k/as ookinete It measures about 15-22 micron in length and 3 micron in width. It attaches itself to peritrophic membrane of gut. [5]. Encystment Ookinete penetrates through walls of midgut, becomes spherical and begins enyst. The encysted zygote – oocyst / sporont

11. [6]. Sporogony Oocyst enters into a phase of asexual multiplication- sporogony Firstly divides by meosis and then by mitosis and forms enormous haploid nuclei surrounded by cytoplasmic masses The daughter nuclei arrange themselves along the margin of cytoplasmic masses and later forms slender finger like processes having single nuclei in each In this way about 10,000 minute slender and sickle bodies are formed-sporozoites . When sporozoite matures oocyst ruptures and liberated into haeomocoel later penetrates into salivary glands Whole sexual cycle completes into 0-12 days Now mosquito becomes infective

12. Pathogenesis of malarial parasite S y m p toms o f m a l aria fi rs t appear se v eral days after the infection of the parasite. This time – incubation period Each attack of fever shows three stages: 1. Cold Stage A t the ons e t o f m a l ar i a pate n t s u ffe r s from severe shaking chill. Cold stage lasts for 20 min 2. Hot stage As the chill subsides, the body temp rises as high as 106°F. and lasts for 1-4 h. 3. Sweating stage As the temp lowers down, patent sweats profusely. Fever c o mes d o w n and te m per a tu r e becomes normal

13. Malaria fever occurs when schizont in RBC bursts and set free their merozoites and malarial pigment haemozoin in the plasma. Anemia is inevitable due to: Destruction of RBC Infected RBC become more fragile and rupture easily Parasite produce haemolysin- brings haemolysis In chronic case- spleen becomes enlarged Control of Malaria Control Measures falls into three categories: Elimination or destruction of vector Prophylaxis (prevention of infection) Treatment of infected patents

14. [A]. Destruction of anopheles Most effective and surest way of controlling malaria and can be done through Destruction of adult mosquitoes: method used are killing of hands, traps, fumigation, spraying and sterilization . Elimination of breeding places: swampy, marshy and water logging areas are cleared out, bushes and shrubs are cleared off etc. Destruction of larvae and pupae of mosquito through proper drainage (Flowing water), oil screens, chemical larvicides and biological methods. [B]. Prevention of infection Through the use of insect repellent, nets, gloves and by screening bedroom windows. [C]. Treatment Chlorquine and quinine: anti-erythrocytic stage drugs. Primaquine and pyrimethamine: anti-exoerythrocytic stage drugs.