Introduction to medical parasitology

educational material

1. Tutorials Medical parasitology Mosab Nouraldein

2. Medical parasitology Branch of medical sciences dealing with organisms( =parasites) which live temporarily or permanently , on or within the human body

3. Medical parasitology classes A ) Medical Protozoology B) Medical Helminthology C ) Medical Entomology

4. Parasite An organism that lives in or on another organism and benefits by deriving nutrients at the host’s expense.

5. Types of parasites Endoparasite (endozoa): Parasite lives inside the host Ectoparasite (ectozoa): Parasite lives outside (body surface) the host Epiparasite: Parasite feed on other parasite in a relation known as hyperparasitism.

6. Temporary parasite: Stay in its host for short period. Permanent parasite: Leads parasitic life throughout the whole period of its life. Obligatory parasite: Can not exist without the parasitic life.

7. Accidental parasite: Attacks an unusual host Wandering or aberrant parasite: Happens to reach a place where it cannot live

8. Host An organism that harbors a parasitic stage, providing nourishment and/or shelter to the parasite.

9. Types of host a)Primary (definitive) host: An organism that supports the adult stages or sexually mature reproductive form of a parasite. b)Intermediate host: An organism that hosts the asexual form of the parasite .

10. Intermediate hosts are divided into: Passive intermediate host (e.g. snails) Active intermediate host (e.g. Tse tse fly)

11. c) Reservoir host: A primary host that harbors the pathogen but shows no ill effects and serves as a source of infection.

12. Paratenic host: An intermediate host whose presence may be required for the completion of a parasite’s life cycle but in which no development of the parasite occurs.

13. Life cycle Life cycle is the cycle of development begins from the definitive and back to the definitive host. Definitive host Definitive host

14. Types of life cycle a)Direct life cycle: A parasite life cycle in which the parasite is transmitted directly from host to host without an intermediate

15. b)Indirect life cycle: A parasite life cycle in which the parasite is transmitted directly from host to host with an intermediate

16. Host parasite relationship(symbiosis) Symbiosis: An association in which both organisms are so dependent upon each other that one can not live without the help of the other. ( the living together of two organisms or more)

17. Types of symbiosis(HPR) A) Commensalism: An association in which the parasite only is deriving benefit without causing injury to its host. (+/0).

18. B) Parasitism: An association in which the parasite derives benefits and host suffers some injury (+/-)

19. c) Mutualism : An association in which both organisms benefit (+/+)

20. Classification Parasites are classified into: Protozoa ( unicellular parasites) Metazoa (multicellular parasites)

21. Classes of protozoa a)Sarcomastigophora: Sarcodina : move by pseudopodium (e.g. amoeba). Mastigophora: move by flagella (e.g. Giardia lamblia) b)Ciliophora: (ciliate) : move by cilia c)Sporozoa : (coccidia)

22. Metazoan parasites are divided into: A) arthropods B) helminthes (worms)

23. Helminthes are classified into: Platyhelminthes Nematodes

24. Platyhelminthes Cestodes Trematodes (flukes)

25. Trematodes( flukes) are divided according to their residing's (habitat) into: Blood flukes: S chistosoma species Liver flukes: F asciola species Intestinal flukes: e.g. F asciolopsis buski Lung flukes: Paragonimus westermani

26. General features of flukes (trematodes) Dorso-ventrally flattened No body cavity Leaf like , except schistosoma species Hermaphrodite , except schistosoma species