Malaria Parasite: Life Cycle, Transmission, and Control

This presentation delves into the world of malaria parasites, shedding light on one of the most persistent and deadly pathogens affecting millions worldwide. It explores the biology of Plasmodium species, the complex life cycle involving humans and mosquitoes, and the mechanisms behind transmission and infection.

The slides also cover the clinical manifestations of malaria, diagnostic methods, and current treatment strategies. Additionally, the presentation highlights the ongoing challenges in malaria control, including drug resistance and vaccine development.

Rich with informative charts, maps illustrating global prevalence, and compelling images, this presentation is designed to educate healthcare professionals, students, and anyone interested in understanding this global health menace.

1. TOPIC : MALARIA PARASITES (PLASMODIUM SPP.) GROUP 3 (THREE) PRESENTATION

2. OUTLINES: INTRODUCTION MALARIA VECTOR EPIDEMIOLOGY PLASMODIUM HABITATS THE LIFE CYCLE THE MORPHOLOGY DISEASE/CLINICAL MANIFESTATION LABORATORY DIAGNOSIS TREATMENTS PREVENTION AND CONTROL

3. INTRODUCTION Malaria is a mosquito-borne infectious disease of humans and other animals caused by protists of the genus Plasmodium . It begins with a bite from an infected female mosquito, which introduces the protists via its saliva into the circulatory system, and ultimately to the liver where they mature and reproduce .

4. There are approximately 156 named species of plasmodium which infect various species of vertebrates. Five are known to infect humans; Plasmodium falciparum Plasmodium vivax Plasmodium malariae Plasmodium ovale Plasmodium knowlesi INTRO CONT’D.

5. Malaria is transmitted by female mosquitoes of the family culicidae with about 3300 species The genus anapholes consist of about 400 known species of which 17% are capable of transmitting the malaria parasite, Plasmodium spp. The common anopheles species found in Afrotropical region is Anopheles gambiae and Anopheles funestus They undergoes complete metamorphosis Gonotrophic cycle take four days MALARIA VECTOR

6. It is the most important of all the tropical disease in terms of morbidity and mortality. World wide, about two billion individual are at the risk of malaria 100 million develop over clinical disease and 1.5-2.7 million die every year. Nearly 85% of the cases are found in tropical Africa. EPIDEMIOLOGY

7. Did you know?

8. The incidence of malaria is increasing due to resistance of vectors to insecticides and drug resistant parasites. EPIDEMIOLOGY CONT’D...

9. Of the five species that infect human, P. vivax and P. falciparum account 95% of infection. Plasmodium falciparum (P. faliparum ) - The most serious form of the disease. It is most common in Africa, especially sub-Saharan Africa . Plasmodium vivax (P. vivax ) -This type has the widest geographic distribution globally. About 60% of infections in India are due to P. vivax . This parasite has a liver stage and can remain in the body for years without causing sickness. EPIDEMIOLOGY CONT’D...

10. Plasmodium species lives as an intracellular parasite in the red blood cell (RBC) of man in the form of its mature adult called trophozoite The asexual stage is found in the reticulo -endothelial system of man and sexual stage spends in the digestive system in the female anopheles mosquito. HABITAT

11. LIFE CYCLE Malaria parasite exhibit a complex life cycle involving alternating cycles of asexual division ( schizogony ) occurring in man (intermediate host) and sexual development ( sporogony ) occurring in female anopheles mosquito (definitive host).

12. LIFE CYCLE OF PLASMODIUM IN HUMAN Life cycle of plasmodium in human involves; Exo-erythrocytic schizogony Erythrocytic schizogony Gametogony

13. The sporozoite are the infective form of the parasite. They are present in the salivary gland of female anopheles mosquito. It usually bite at night or during twilight hours. During the act of biting, the proboscis of mosquito pierces the skin and the saliva containing sporozoites is injected directly into the blood stream. LIFE CYCLE…

14. Within one hour all the sporozoite leave the blood stream and enter into liver parenchyma cells. They undergoes binary fission to develop into exoerythrocytic schizont , hence exoerythrocytic schizogony ) The liver cell ruptures and schizont also rupture and release merozoites into the blood stream ( merogony ) . The merozoites released enter the blood stream and invade red blood cells where they multiply at the expense of the host cells. LIFE CYCLE…

15. The merozoites develop to form trophozoite in the RBC, The trophozoites develop to form schizont , hence erythrocytic schizogony the schizont rupture to release another set of merozoites which invade another RBC, the erythrocytic cycle is repeated in the course of malaria infection. LIFE CYCLE…

16. The trophozoite can also give rise to male and female gametocyte known as microgametocytes and macrogametocytes respectively hence gametogony . They develop in the RBC of the capillaries of internal organs like spleen and bone marrow. Only mature gametocytes are found in the peripheral blood. LIFE CYCLE…

17. LIFE CYCLE OF PLASMODIUM IN MOSQUITOES Sexual cycle actually start in the human host by formation of gametocyte which are present in the peripheral blood. Both asexual and sexual forms of the parasite are ingested by female anopheles mosquito during its blood meal from the patient. In the stomach of the mosquito the microgametocyte transform to microgamete by the process known as ex-flagellation

18. While the macrogametocyte form macrogamete, the fertilization occur when microgamete penetrate this projection to form zygote, this process is known as syngamy . Within 24hrs the zygote lengthen and mature to ookinete a motile vermiculate stage. It penetrate the epithelial lining of the stomach of the mosquito and become oocyst. On about 10 th day the oocyst is fully mature, rupture and release sporozoites in the body cavity of the mosquito. LIFE CYCLE…

19. The sporozoites migrate to the salivary gland and stay. When the mosquito goes for its blood meal again it ingest the sporozoites into human through its saliva and the cycle continue… LIFE CYCLE…

20. The complex life cycle of m alaria parasite ( Plasmodium spp )

21. MORPHOLOGY

22. DISEASE/CLINICAL MANIFESTATION Febrile paroxysm (cold stage, hot stage, and sweating stage Anaemia Splenomegaly Pernicious malaria Cerebral malaria,

23. LABORATORY DIAGNOSIS OF MALARIA PARASITE Microscopy (thin and thick blood film) Rapid diagnostic test Quantitative Buffy C oat (QBC) test Polymerase Chain Reaction (PCR)

24. TREATMENT OF MALARIA The preferred antimalarial for interim oral treatment is artemether-lumefantrine ( Coartem ) because of its fast onset of action. Other oral options include atovaquone-proguanil ( Malarone ), quinine, and mefloquine , chloroquin

25. PREVENTION/CONTROL