1. Parasitology
Parasitology – science about parasitic animals and relationships with their hosts.
Para + situ + logos = conversation about those living nearby us
= parasitology.

2. History infections come from a period of
The first written records of what
are almost certainly parasitic
infections come from a period of
Egyptian medicine from 3000 to
400 BC, particularly the Ebers
papyrus of 1500 BC discovered
at Thebes.

3. A.lumbricoides eggs have been found in human coprolites from Peru dating from 2277 BC.
* human coprolites – fossilized feces
Larval nematodes,possibly hook worms, have been found in fecal samples dated to about 200 BC from the Colorado Plateau
In 1910, Marc Armand Ruffer found
S.haematobium eggs in two Egyptian mummies dating from the 1250 to 1000 BC

4. A parasite, is an organism that lives on or inside another organism to the detriment of the host organism.
The parasite grows, feeds, or uses shelter of the host organism (including the host itself) contributing negatively to the relationship.

5. Parasitism:
A symbiotic relationship in which the symbiont (parasite) benefits at the expense of the host by living either within the host (endoparasite) or outside the host (ectoparasite).

6. Types of parasitism
Obligate parasites:All or most of their life cycle are parasitic.
Temporary parasites:parasitic for limited period for either feeding or reproduction.

7. Facultative parasites:organisms are not parasitic but can live parasitic for a limited period.
Accidental parasites:normally free living organisms can survive within a host when they are accidentally taken.

8. What is a Parasite Host?
The host is the organism that the parasite lives in.
*A definitive host
* An intermediate host
*A paratenic host
*A reservoir host

9. Ex: When a human has an adult beef tapeworm in the intestine producing
A definitive host is an organism that the adult, or sexually reproductive stage of the parasite lives in.
Ex: When a human has an adult beef
tapeworm in the intestine producing
eggs,he or she is a “definitive host”

10. Ex:Human are “intermediate hosts” to malariae parasites which multiply
An intermediate host is an organism that hosts an immature parasitic stage, or a stage that reproduces asexually
Ex:Human are “intermediate hosts” to
malariae parasites which multiply
in human liver and blood cells.

11. Reservoir hosts, with respect to human parasites, are hosts that are infected with a parasite and keep it alive even if the parasite is wiped out in humans.
“Reservoir hosts can spread the parasite and reintroduce it to human populations”.

12. ●A paratenic host is an organism that is infected with a parasite and can pass it on to another host, but in which the parasite does not develop further.

13. SYMBIOSIS
A biological relationship in which (usually) two species live in close proximity to each other and interact regularly in such a way as to benefit one or both of the organisms.
*Symbiosis may exist between two or more individuals of the same species as well as between two or more individuals representing two different species

14. The three principal varieties
of symbiosis are
*mutualism,
*commensalism,
* parasitism.

15. parasite,benefit at the expense of the other
MUTUALISM
Mutualism is any relationship between two species of
organisms that benefits both species
COMMENSALISM
A symbiotic relationship in which one organism, the
commensal,benefits without causing any detriment to
the other organism which is the host.
PARASITISM
parasite,benefit at the expense of the other
organism,which is the host.

16. Other Parasitology Definitions
*A cyst is a stage of many protozoan parasites that survives well in the environment. Cysts of human parasites are infective to humans. *A trophozoite is a moving, feeding, and multiplying stage of protozoan life cycles. There are no male and female trophozoites: they multiply asexually.

17. Other Parasitology Definitions
Infective (=invasive) stage The stage of the parasite that invades the host .
Vector:An Arthropod which is carrying and transferring parasites from one host to an other
(Egg-larval stages-adult parasite-eggs)

18. Other Parasitology Definitions
Reservoir= Non-human “host” where the parasite can live.This term is only applied when the parasite can infect humans .
Life Cycle= Stages of development of a parasite

19. Essential features of the parasitism
*Parasite is smaller then the host
*Parasite has a shorter life span than it’s host
*Parasite has a greater reproductive potential than it’s host

20. Classification of parasites
Zoological Classification
Living organisms
Without cell With cellular
construction construction
(VIRUS)
Procaryotic cell Eucaryotic cell
(= monera) (=protista /single cell)
RICKETSIA PROTOZOA
BACTERIA (=metazoa)
HELMINTHS
ARTHROPODS

21. Ecological Classification
Endoparasite:a parasite that inhabits the
internal organs or tissues of an animal
or plant
Ectoparasite:any parasite that lives on
the outer surface of an animal.

22. Different location of parasites into the host body
Living in digestive system - coelozoic
parasites (tapeworms)
Living in tissues – histozoic parasites
(trichinelliosis)
●Living in blood – hemoparasites (Malaria etc.).

23. Methods of invasion and escape
- Via vectors
- Oral
Penetration from the skin
ESCAPE
Sputum
Via vectors
Feces or urine

24. Pathologic effects of parasites
Physical trauma (skin,mucosa)
Migration
Nutrition
Toxins
Immunosupression

25. Diagnosis of Parasitic Infections:
1. Clinical diagnosis
2. Laboratory diagnosis

26. Methods for study and clinical analysis
Parasitological analysis:
tissue samples, excrements, surgical methods (biopsy)…
Serodiagnosis (Immunodiagnostics. ELISA test etc)

27. Major Groups of Parasites
PROTOZOANS
-- Single-celled eukaryotes
– Malaria, Giardia, Trichomonas vaginalis
HELMINTHS (The Worms)
– Multicellular animals
– Flukes, Tapeworms, Roundworms
ECTOPARASITES
– Live outside the host
– Ticks, Lice, Fleas

28. Treatment of Parasitic Infections:
1. Medical and surgical
2. Chemotherapy
3. Adequate nutrition

29. Prevention and Control:
1. Reduction in sources
2. Education
3. Destruction and/or control of
reservoir hosts and vector

30. PROTOZOA Microscopic, one-celled animals Ciliophora (Ciliates)
Mastigophora
Sarcodina

31. Ciliophora (Ciliates)
Protozoa that move by means of many short, hair-like projections
Balantidium coli is the only ciliate parasite harmful to humans
Causes dysentery
Transmitted by feces, fingers, food, fomites, flies

32. Mastigophora Also known as flagellates
Move by one or more long, whip-like flagella
Giardia lamblia – most common intestinal parasite in the US
Traveller’s diarrhea
Transmitted by drinking contaminated water

33. Mastigophora Trypanosoma rhodesiense African sleeping sickness
Fever, headaches, joint pains
Most common in Uganda, and Congo
Confusion, disruption of sleep cycle
Fatal if not treated
Mother to Child
Blood transfusion
Sexual Contact
Tsetse fly (large brown biting fly)

34. Mastigophora Trypanosoma cruzi Chagas’ disease
Fever, fatigue, body aches, headache, rash, diarrhea, vomiting
Swelling of eyelids on the side of the face near the bite wound
60 -80% will never develop symptoms
20-40% will develop life-threatening heart and/or digestive disorders

36. Mastigophora Trichomonas vaginalis
Most common pathogenic protozoan infection of humans in industrialized countries
Infection rates between men and women are the same with women showing symptoms while men are usually asymptomatic
WHO estimates 180 million cases annually
North America = 5-8 million infections each year

37. Trichomonas vaginalis
Sexually transmitted in the urogential tract
Most common site of infection is the urethra and the vagina in women
Complications include pregnancy complications (preterm delivery, low birth weight, increased mortality) cervical cancer, pneumonia, bronchitis, and increased secretions, and itching

38. Sarcodina Also known as amoebas
Move by extending cytoplasmic projections
Reproduces by fission

39. Sarcodina Entamoeba histolytica Causes dysentery in humans
Can invade the liver and cause hepatitis

40. Helminths Parasitic worms that include Cestodes (flatworms)
Nematodes (roundworms)
Trematodes (flukes)

41. Nematodes Roundworms Distributed worldwide, found mostly in children
Hookworms
Pinworms
Whipworms
Distributed worldwide, found mostly in children

43. 28 foot tapeworm taken from person (transmitted by sushi)
Cestodes
Flatworms
Taenia saginata (beef) tapeworm
Taenia solium (pork) tapeworm
Cause intestinal disorders and severe weight loss
Can grow up to 20 meters
28 foot tapeworm taken from person (transmitted by sushi)

44. Trematodes Flukes, flat leaf-shaped helminths
Can inhabit the intestine, the liver, the lung, and the blood vessels
Chronic diarrhea
Abdominal pain
Ulcers
Hemorrhage of the intestinal wall
Liver damage
Transmitted
Drinking infected water
Eating infected raw meat or shellfish