Lecturer: Fedonyuk L.Ya.

1. Medical and biological basics of parasitism. Medical Protozoology. Medical Helmintology. Medical arachnoentomology Lecturer: Fedonyuk L.Ya.

2. Parasitology is the study of parasites and as such that does not include bacterial, fungal or viral parasites. Human parasites are separated into intestinal and blood borne parasites. For a parasite to be defined as intestinal it must have an intestinal life cycle stage, though it may have life-cycle stages in the heart, blood vessels, and lungs in the humans, other animals or the environment. The association between two organisms may be one of the following: SYMBIOSIS MUTUALISM COMMENSALISM PARASITISM

3. MUTUALISM: mutual benefit is derived from the association. SYMBIOSIS: mutual benefit, but the two organisms cannot live independently. COMMENSALISM: one partner benefits (commensal) while the other (host) is unaffected. It may be called a non-pathogenic parasite. When an animal lives on another organism from which it receives food and shelter without any compensation to it, and then this association is called parasitism. The animal, which enjoys advantages, is the parasite. All animals have parasites; hence there are more parasites than free-living animals. The habitat occupied by a parasite is very different from the environment of its free-living ancestors, hence it has either to adapt itself to this new habitat or perish.

4. Parasitism Parasitism (in Greek: παρασσυτισμός) is an interaction between two organisms, in which one organism (the parasite) attains all the benefits of the close relationship. Parasitism can be considered a special case of predation since their effects on the host are similarly, though not equivalently, detrimental. Parasitism is the form of mutual relations between organisms of various kinds, from which one (parasite) uses another (host) as environment for living, and from which it obtains food causing him damage (disease). PARASITOLOGY is a complex biological science studying the phenomena of parasitism. There are mutual relations between the parasite and host, their dependence on the factors of external environment, and also diseases, caused by the parasites, and methods of fighting with them in man, animals and plants. MEDICAL PARASITOLOGY consists of 3 parts: medical protozoology, medical helminthology and medical entomology.

5. Different types of parasite (I) Parasites can be divided into different classes of parasite : Obligatory parasites. These parasites can only survive in a host and therefore go directly from one host to another. This may involve complex life cycles. Temporary parasites. These parasites spend only part of their lives as a parasite and another part as free-living organism. Facultative parasites. These organisms are normally free living and infect a host only by accident.

6. Different types of parasite (II) Acording to localisation of life, parasites can be divided into next classes: Ectoparasites that remain outside of the host's body Endoparasites that enter the host's body Microparasites that reproduce in the host and are usually single-celled Macroparasites that release juvenile stages to the world outside of the host

7. Types of host Like the parasites, the hosts can be divided in to several classes as well. These are: Definitive host (DH). A definitive host is an organism that hosts the adult (sexual) form of the parasite Intermediate host (IH). An intermediate host is an organism that hosts the asexual form of the parasite (only when there is an obligatory passage through the host). Intermediate hosts can be divided into two groups: Passive IH (molluscs in the case of Schistosoma) Active IH (tsetse fly in the case of trypanosomes) Also the vectors can be divided into two different types: Biological vectors. Examples: haematophagous athropodes such as mosquitoes and other biting insects Mechanical vectors. Examples: flies for transport of amoebal cysts.

8. Life Cycle of E. histolytica Amebiasis Transmission • Humans acquire E. histolytica by: • Ingestingcysts in fecally contaminated food or drink • Rarely by directly inoculatingtrophozoites into colon or other sites (anal sex?) • Fecal-Oral transmission (hand to mouth) • Infective cysts and trophozoites pass in feces

9. Pathogenesis of Amebiasis Trophozoites ... Attach to mucosal epithelial cells (MEC) Lyse MEC Ulcerate and invade mucosa Cause dysentery (diarrhea + blood) Metastasize via blood &/or lymph to form abscesses in extraintestinal sites

10. Patology Intestinal ulcers are due to enzymatic degradation of tissue. The infection may result in appendicitis, perforation, stricture granuloma, pseudo-polyps, liver abscess Sometimes brain, lung and spleen abscesses can also occur. Stricturesand pseudo-polyps result from the host inflammatory response.

11. Gross pathology of liver containing amebic abscess Gross pathology of amebic abscess of liver. Amebic abscess of liver

12. Entamoebasis injuries of lungs perforation of diaphragm abscess in liver injury of ascending colon injury of descendingcolon

13. Diagnosis of Intestinal Amebiasis Techniques: Direct Fecal Smear (trophs and cysts) Fecal concentration techniques - (cysts) ZnSO4 or formalin-ether Permanent Stained Fecal Smear PVA/Schaudinn’s fixation + Trichrome stain Sigmoidoscopy Serologic Tests (for chronic disease)

14. Entamoeba histolytica trophozoites in section of intestine. Entamoeba histolytica cyst and trophozoite, haematoxylin stained E. histolytica: Microscopy 1 2

15. Prevention/Control of Amebiasis Individual measures Diagnosis and treatment of E. histolytica patients no animal reservoirs (other than humans) are known Safe drinking water (boiling or 0.22 µm filtration) Cleaning of uncooked fruits and vegetables Prevention of contamination of foods

16. Prevention/Control of Amebiasis Community measures Public services and utilities Adequate disposal of human stools Safe and adequate water supply Primary health care systems Health education (washing hands, cleaning and protecting food, controlling insects) Specific surveillance programs and Control programs integrated into ongoing sanitation & diarrhea control Health Regulations Control of food vendors and food handlers Control of flies and cockroaches

17. Giardia

21. Life Cycle Transmission occurs through: drinking contaminated water; ingesting contaminated food; person-to-person contact

22. Trichomonas

23. Life Cycle Trichomonads have the simplest kind of protozoan life cycle, in which the organism occurs only as a trophozoite. Division is by binary fission. Because there is no resistant cyst, transmission from host to host must be relatively direct

26. Leishmania

27. Leishmania

28. Leishmania

29. Leishmania

31. Trypanosomabrucei U N деление F K периферическая кровеносная система

32. эпимастиготная форма в триатомовом клопе Trypanosomacruzi K N U 10 mm

35. Trypanosomacruzi 1 mm Triatoma gerstaeckeri 5 mm

38. Structure andd Life Cycle

40. Malaria 200 mm Anopheles sp.

41. Malaria 10 mm GametocytesPlasmodium falciparum

42. Malaria 10 mm TrophozoitesPlasmodium malariae

43. Malaria 10 mm Erythrocytic stage schizontPlasmodium malariae

44. Malaria 10 mm Erythrocytic stage schizontPlasmodium ovale

45. Malaria 10 mm TrophozoitesPlasmodium ovale

46. CILIATES • Balantidium coli only ciliate infecting humans • large and diverse group • majority are free-living • covered with rows of cilia • defining characteristic is nuclear dimorphism • micronucleus (genetic) • macronucleus (somatic) • sexual reproduction involving conjugation

47. Life Cycle Balantidium coli world-wide distribution especially prevalent in tropics rarely exceeds 1% common in pigs and monkeys unlikely to be reservoirs usually non-pathogenic commensal in large intestine can invade intestinal epithelium and cause ulceration with dysentery-like symptoms BALANTIDIASIS • aka, balantidiasis, balantidial dysentery • symptoms: acute diarrhea with mucus and blood, cramps • diagnosis: identify cyst or trophozoite in feces • treatment: tetracycline or iodoquinol • prevention: same as other fecal-oral diseases

48. Balantidiumcoli Balantidosis • world-wide distribution • especially prevalent in tropics • rarely exceeds 1% • common in pigs and monkeys • unlikely to be reservoirs • usually non-pathogenic commensal in l. intestine • can invade intestinal epithelium and cause ulceration with dysentery-like symptoms • aka, balantidiasis, balantidial dysentery • symptoms: acute diarrhea with mucus and blood, cramps • diagnosis: identify cyst or trophozoite in feces • treatment: tetracycline or iodoquinol • prevention: same as other fecal-oral diseases

49. Balantidiumcoli

50. unstained trichrome eosin