Pathogenesis of malaria

MALARIAL MICROBIOLOGY AND PATHOLOGY

1. CARDIOVASCULAR AND HAEMOPOETIC SYSTEM CORRELATION SEMINAR TOPIC : MALARIA 1 1 KOUSTAV MUKHOPADHYAY MBBS

2. OBJECTIVE: Describe pathogenesis of malaria. 2 2

3. INTRODUCTION: WHY MALARIA ? MAL=foul ; ARIA=air One of the most common infectious disease and enormous health problem. It causes disease in approximately 219 million cases of malaria in 87 countries. 4,35,000 Malarial deaths worldwide in 2017. 3 3

4. WHO ARE AT RISK? Younger children, Pregnant women, Immunocompromised patient and traveler. 4 4

5. WHERE ? 5 5

6. MALARIAL PATHOGENESIS 6 6 Paniker’s Textbook of Medical Parasitology

7. HEPATIC PHASE Sporozoites attach to and invade liver cells by binding to the hepatocyte receptor for the serum proteins: T hrombospondin and Properdin . Malaria parasites multiply, releasing as many as 30,000 merozoites ( asexual, haploid forms) infected hepatocyte ruptures. 7 7 Robbins and Cotran Pathologic Basis of diseases SAE

8. HEPATIC PHASE P. falciparum infection, rupture usually occurs w ithin 8 to 12 weeks. P. vivax and P. ovale form latent hypnozoites in hepatocytes , which cause relapses of weeks to months. 8 8 A colour atlas of tropical medicine and Parasitology 2 nd E

9. ERYTHOCYTIC PHASE Plasmodium merozoites use a lectin -like molecule to bind to sialic acid residues on glycophorin molecules on the surface of RBCs and invade by active membrane penetration. Schizogony in RBCs Release of merozoites by lysis of RBCs Robbins and Cotran Pathologic Basis of diseases SAE 9 9

10. ERYTHOCYTIC PHASE Release of toxic waste products-RBC membrane products, hemozoin pigment Activate macrophages and endothelium Release tumor necrosis factor alpha(TNF alpha) & other cytokines(IL-1 , IL-6, IL-8, etc .). Fever , Chills and Rigors characteristic of malaria 10 10

11. HEPATIC & SPLENIC 11 1 1 Paniker’s Textbook of Medical Parasitology

12. 12 12 Atlas of Medical Helminthology and Protozoology

13. 13 13 • • Destruction of large number of RBCs by complement mediated and autoimmune hemolysis • • Suppression of erythropoesis in the bone marrow • • Increased clearance of both parasitied and non parasitized RBCs by the spleen. • • Failure of the host to recycle the iron bound in hemozoin pigment. CAUSES OF ANAEMIA IN MALARIA A colour atlas of tropical medicine and Parasitology 2 nd E

14. Plasmodium vivax , P malariae , and P ovale parasitemias are relatively low grade, primarily because the parasites favor e ither young or old red cells but not both. 14 14 Source:Internet

15. PATHOGENESIS OF SEVERE MALARIA P. Falciparum infects all ages of RBCs P. falciparum erythrocyte membrane protein1 ( PfEMP1), associate and form knobs on the surface of infected red cells PfEMP1 binds to ligands on endothelial cells, including CD36, thrombospondin,VCAM-1 , ICAM-1 , and E- selectin 15 15

16. PATHOGENESIS OF SEVERE MALARIA Infected RBCs to clump together(ROSETTE) Stick to endothelial cell lining of small blood vessels ( SEQUESTRATION) Blood flow blocks which decreases tissue perfusion and leads to Ischemia [Manifestation of cerebral malaria ] Robbins and Cotran Pathologic Basis of diseases SAE 16

17. 17 10 Atlas of Medical Helminthology and Protozoology Robbins and Cotran Pathologic Basis of diseases SAE

18. 18 18 Davidson’s Medicine 23 rd E

19. SUMMARY 19 19 Markell and Voge’s Medical Parasitology 9E

20. CORRELATION: 20 Malaria is vector borne infectious disease caused by protozoan parasites of genus Plasmodium. It can be transmitted to people of all ages, bitten by the vector female Anopheles mosquitoes. It reflect multifactorial pathogenic process affecting many different organs. 20

21. BIBILOGRAPHY: Atlas of Medical Helminthology and Protozoology Robbins and Cotran Pathologic Basis of diseases SAE Markell and Voge’s Medical Parasitology 9E Paniker’s Textbook of Medical Parasitology Davidson’s Medicine 23 rd E Kayser Medical Microbiology © 2005 Thieme A colour atlas of tropical medicine and Parasitology 2 nd E 21 21

22. THANK YOU ! 22 22