1. Lec.(1) ألأستاذ الدكتورعبدالسلام المختار MEDICAL PARASITOLOGY Aims :
TARGET  : Third Year Students
Aims :
1.To provide core knowledge of pathogenic parasites relevant to the diagnosis and management of tropical and infectious diseases.

2. OBJECTIVES:
1.To provide the student with knowledge of parasites of medical importance and the diseases they cause, with emphasis on endemic diseases in our country.

3. 2. To provide the student with knowledge and technical skills to be able to use laboratory methods for detection of parasitic infection and for confirmation of clinical diagnosis of parasitic diseases.

4. MEDICAL PARASITOLOGY
STUDENT LEARNING OBJECTIVE
For each of the parasite of major importance to human health and public health which will be presented in the course, the student should be able to:

5. 1.Identify important morphologic and structure characteristics of the parasite.
2.Describe transmisshon and geographic distribution (Epidemiology) of the parasite.

6. 3.Describe the typical life cycle of the parasite.
4.Identify the risk factors of parasitic infection to human being.
5.Identify the most common pathology seen with each of these parasites and their effect on public health.
       

7. 6.Identify a reasonable diagnostic methods to determine if a patient is infected by these parasites or not.
7.Recommend appropriate control measures to reduce and prevent incidence of disease in the population.

8. 8.As the lectures are organized by parasites, each lecture will address each objective for the specific parasite.

9. Parasitology
Is a science, study all the relationship between two organisms one called parasite & the other is called the host .
OBJECTIVES:
1.Simple classification of human parasites.
2.To explain the different names of parasites,hosts and vector of transmitting diseases to human. .

10. CLASSIFICATION OF PARASITES:
1- Protozoa.
2- Helmenths.
3- Arthropods. .

11. 1- Class sarcodina: Parasites that move by means of
I- Protozoa :
It is unicellular parasites, divided into 4 classes according to the organ of locomotion:
1- Class sarcodina: Parasites that move by means of
pseudopodia example Amoeba .
2-Class mastigophora : Parasites that move by
means of flagella example Giardia lamblia

12. 3- Class ciliates : parasites that move by means of cilia example balantidium coli .
4- Class Sporozoa : parasites have both sexual and asexual reproductive organs. all these parasites are intracellular and they have no organ of locomotion example Plasmodium parasites causing malaria.

13. 1.Class Nematoda ( Roundworms ) :
II- Helminths :
They are metazoa ( Multicellular parasite ) wormlike parasite, divided into 3 classes :
1.Class Nematoda ( Roundworms ) :
a- Intestinal nematodes, e.g, Ascaris lumbricoides .
b- Tissue nematodes, e.g, Wuchereria bancrofti .

14. 2- Class Cestoda ( Tapeworms) :
They are flattened and segmente worms, e.g.
Taenia saginata .
3- Class Trematoda (Flukes):
They are flattened leaf- shaped worms. e.g.
Schistosoma heamatobium.

15. III- Arthropods :
These parasites having exoskeleton and jointed legs, divided into 2 classes:
1- Class Insecta :e.g. Flies, mosquitoes, bugs , lice and fleas .
2- Class Arachnida :e.g. Ticks and mites . .

16. GENERAL TERMINOLOGY:
* pathogenic parasite: A parasite infect the host and cause tissue changes or a disease.
* Commensal paasite (Commensalism): The association of two different species of parasites in which one of them is benefited and the other neither benefited nor injured . .

17. * Ectoparasite: A parasite present on or in the exterior surface of a host.
* Endoparasite: A parasite present within the body of its host .

18. Facultative parasite: A parasite capable of living an independent or a parasitic existence .
Obligatory parasite: A parasite is capable of living as parasitic on host, but it can not exist as independet living.

19. * Parasitism. The association of two different species of parasites in which the smaller species live upon within the other, and has a metabolic dependence on the larger host species example Ascaris lumbricoides.

20. * Definitive host: The animal in which a parasite passes its adult existence and or sexual reproductive phase .

21. * Carrier. A host carring a parasite but not showing any clinical sings or symptoms.
* Accidental ( or incidental ) host : Infection of a host other than the normal host species.

22. Serology. The study of antibody – antigen reactions in vitro
*Serology. The study of antibody – antigen reactions in vitro. Using host serum for study .
* Symbiosis. The association of two different species of parasites exhibiting metabolic dependence by their relationship .

23. Vector:
Any arthropod or other living carrier which transport a pathogenic micro-organism from an infected to a non infected host. A vector may transmit disease :
(1)passively called (mechanical vector) e.g.housefly or
(2) The vector is essential in the life cycle of the pathogenic parasites called (biologic vector) e.g.mosqutoes.

24. * In vivo: Experiment done within the living body .
* In vitro : Experiment done in a test tube ,or other nonliving system (out side the living body).

25. PROTOZOA :
Is a phylum of the animal kingdom consisting of unicellular parasites .
* Atria (or atrium):Refers to the mouth, vagina,and urethra .
* Chromatin: Basophilic nuclear DNA .

26. * Chromatoidal body (or bar): A rod-shaped structure of condensed RNA material within the cytoplasm of some protozoa cysts .

27. * Ectoplasm: The gelatinous material beneath the cell membrane .
*Endoplasm: The fluid & inner material of a protozoal parasite . .

28. Trophozoite: The motile stage of a protozoal parasite which feeds and multiplies.
Cyst: The immotile stage protected by a cyst wall .In this stage the protozoa is readily transmitted to a new host . .

29. Excystation:
Transformation from a cyst to a trophozoite after the cystic form has been swallowed by the host . .

30. Reservoir host:
An animal e.g. (dogs,cats or rodents) which carry a species of parasite e.g. (Leishmania species) from which man may become infected.

31. Epidemiology
A field of science dealing with the relationships of the various factors which determine the frequency ,distribution and tansmission of infection to human being..

32. *Flagellum(flagella) :
An extension of ectoplasim which provides locomotion similar to a tail which move with a whiplike motion .

33. Pseudopod:A protoplasmic extension on the trophozoites of amoeba allowing them to move and engulf food .
Cilia: Hairlike processes attached to a free surface of a cell; function for motility of fluids at the surface of the cell, e.g. Balantidium coli .

34. * Karyosome ( Endosome ) : The dot or mass of chromatin within the nucleus.
* Dysentery: It mean a bloody diarrhea and mucus in feces .

35. ألأستاذ الدكتورعبدالسلام المختار Lec.(2) Amoebas:
Many amoeba in the genus Entamoeba infect humans, but not all of them are associated with disease,like E. histolytica which is a pathogenic amoeba causing intestinal and extraintestinal Infections.

36. OBJECTIVES
1.Medical importance of Entamoeba histolytica.
2.None pathogenic amoaeba.

37. None pathogenic amoaeba :
These parasites are commensal none pathogenic but they are important because they may be confused with E.
histolytica in diagnostic investigations These amoebas include many free-living and parasitic amebas.The most important species :amoebas affecting human being are

38. 1- E.coli.
2- E.gingivalis .
3- Dientamoeba fraglis Endolimax nana .
5- Iodoamoeba butschlii .
6- Other amoebas infecting human are morphologically very simillar to E.histolytica, e.g, E.hartmanni and E.dispar.

39. 7- Free living amoebas are Negleria & Acanthameba are accidental parasites of human being .The majority of these amoeba are non-pathogenic commensal parasites or only cause mild infection.

40. E.histolytica:
can cause sever infection & can become a highly virulent and invasive parasite that cause a lethal systemic disease .
So the identification of E.histolytica requires differentiation from other none pathogenic amoebas which are mentioned above:

41. Entamoeba coli :
It is a parasite of the large intestine .Its life cycle is similar to that of E.histolytica.It is of medical importance only because it may be mistaken for E.histolytica .The important different characters are :
Trophozoite:
1- It has more granular endoplasm containing ingested bacteria and debris (no RBCs) .

42. Amoebas species which parasites human being are :
Amebas include many free-living and parasitic amebas.The most important
species which parasites human being are :
1- Entamoeba histolytica E.coli E.gingivalis .
4- Dientamoeba fraglis Endolimax nana Iodoamoeba butschlii .
7- Other amoebas infecting human are morphologically very simillar to
E.histolytica, e.g, E.hartmanni , E.dispar. & E.polecki .
8- Free living amoebas are Negleria & Acanthameba are accidental parasites
of human being .
The majority of these amoeba are non-pathogenic commensal parasites, or only cause mild disease.
E.histolytica can cause sever infection & can become a highly virulent and
invasive parasite that causes a lethal systemic disease .
So the identification of E.histolytica requires differentiation from other parasites wich are mentioned above.

43. 2. The ectoplasm is not clear. and it has small pseudopodia.
3. It has one nucleous contain large eccentric kariosome, and large chromatin granules arrenged irregularly beneath nuclear membrane.
The cyst is large oval in shape and it has 8 nucleous, the characters just like that of trophozoite.

44. Entamoeba gingivalis :
Is a nonpathogenic amoeba present in the mouth, it is usually found in the tartar of the teeth and gingival pockets. It has only trophozoite, with one nucleus which contain small karysome and small peripheral and irregular chromatin .

45. Dientamoeba fragilis :
It is small amoeba of the instentinal tract is found only as a trophozoite . It differs from the other amoebas in that it has two nuclei each one with four karyosomes .

46. Iodamoeba butschlii :
This amoeba can be identified by the characteristic nucleus which contain large central karyosome and clear space between the nuclear membrane and the karyosome ( no chromatin granules ) .

47. Free Living Amoebas :
Naegleria fowleri and Acanthamoeba spp., commonly found in lakes, swimming pools, and tap water.
These amebas are important causes of disease in humans and animals e.g.:

48.   Naegleria fowleri
produce an acute, and usually sever and leathal infection in central nervous system (CNS) , called primary amoebic meingoencephalitis (PAM). 

49. Acanthamoeba spp Causes mostly subacute or chronic granulomatous amoebic encephalitis (GAE), with a clinical picture of headaches, altered mental status, and focal neurologic deficit, which lead after several weeks to death. 

50. ألأستاذ الدكتورعبدالسلام المختار Lec.(3).
ENTAMOEBA HISTOLYTICA
OBJECTIVES:
1.Morphology and Life cycle.
2.Amoebiasis. 50

51. Morphology ( Trophozoite ):
1- Clear ectoplasm Large finger – like pseudopdia
3- The endoplasm is granular and may contain RBCs.
4- It has one nucleous, contain small central keryosome and fine chromatin granules arrenged regularly beneath nuclear membrane.

52. Trohozoites of E.histolytica,one show very clear pseudopodia and the other show very clear central kariosome and periferal chromatin granules.

53. Morphology ( mature cyst) :
1- Small, spherical in shape, containing nuclei is usually found in feces . Each nucleous contain similar nuclear morphology like the trophozoite.

54. Life cycle of E. histolytica:
Cysts are passed in feces .  Infection by E. histolytica occurs by ingestion of mature cysts in fecally contaminated food, water, or hands.  Excystation occurs in the small intestine and trophozoites are released which migrate to the large intestine.  The trophozoites multiply by binary fission and produce cysts , which are passed in the feces .

55. cyst
trophozoite

56. Life cycle of E.histolytica.
Flagellates:
Giardia lamblia
Dientamoeba fragilis
Chilomastix mesnili
Trichomonas hominis
Enteromonas hominis
Retortamonas intestinalis
Ameba:
Entamoeba histolytica
Entamoeba dispar
Entamoeba coli
Entamoeba hartmanni
Endolimax nana
Iodamoeba bütschlii
Apicomplexa:
Cryptosporidium hominis
Cryptosporidium parvum
Cyclospora cayetanensis
Isospora belli
Other:
Blastocystis hominis
Balantidium coli
INTESTINAL PROTOZOA
Life cycle of E.histolytica.

57. Extraintestinal Amebiasis
metastasis via blood stream
primarily liver (portal vein)
other sites less frequent
ameba-free stools common
high antibody titers

58. Because of the protection conferred by their walls, the cysts can survive days to-weeks in the external environment and are responsible for ttransmission. Trophozoites can also be passed in diarrheal stools, but are rapidly destroyed once outside the body, and if ingested rapidly destroyed by gastric juice.   In many cases, the trophozoites remain in intestinal lumen as noninvasive infection of individuals who

59. are asymptomatic carriers, passing cysts in their stool only
are asymptomatic carriers, passing cysts in their stool only.  In some patients the trophozoites invade the intestinal mucosa and cause intestinal disease or developed perforated ulcer and the trophozoites migrate through the blood stream to invade the extraintestinal organs such as the liver, brain, and lungs and it will cause amoebic infection in these organs.

60. Epidemiology : .
* The incidence of Amebiasis is common & high in tropical & subtropical especially in areas of lower socioeconomic status due to:
(1) poor sanitation(2) overcrowding & (3)malntrition It is estimated that up to 10% of the world`s population may infected with E.hist.
Transmision of amoebiasis occure through:

61. 1. Mature cyst is the main sourse of the infection which passing with the feces of chronic patients or asymptomatic carrier .
2. Human being acquire the infection via contamination of food, drings, vegetables or hands with infective cysts especially in restorants .
3. Flise (House fly) play an important roles in trasnmission of these cysts to the food of human .

62. Pathogenesis of E.histolytica:
The Pathogenic activity of E. histolytica depend upon :

63. 1- The resistant of the host .
2- The number of the amebas.
3- Presence of pathogenic bacteria.
4.Presence of physical & chemical injury of the mucosa .

64. The lesions produced by E. histolytica are
primarily in large intestine andseconderily extraintestinal especially the liver or may be
the brain or every organ of the body may be affected .

65. Pathogenisis of Intestinal lesion :
1.The lesion vary from small ulcer to a large typical flask shape ulcer.
2.The ulcer charecterised with large area of tissue necrosis, cell infiltration & rapid lysis of inflamatory cells.
3.The ulcer has a wide base and narrow opening with irregular elevated edges .
4.The amoebas usually found on the floor of the base of ulcer.

66. E. histolytica in the large intestine
( Flask shape ulser )

67. 1- The incubation period range from 2 – 4 weeks .
Clinical features of intestinal lesion :
1- The incubation period range from 2 – weeks .
2- The majority of infections with E.histolytica show no symptoms (Asymptomatic cyst) or show symptoms which varies from mild to intense and long lasting .

68. The typical symptoms include :
1- Diarrohea, The diarrohea frequently alternates with constipation or soft stools may contain mucous but no visible blood .
2-Abdominal cramps.
3-Nausia.
4-Anoroxia.

69. 5- Dysentery : Which is usually starts slowly with abdominal cramps and associated with loose stools and diarrohea with blood و mucus and necrotic tissues.
6- Few patients especially children may show fever, vomiting, abdominal tender ness .

70. The complications of intestinal amoebiasis:
1- Appendicitis .
2- Intestinal perforation .
3- Hemorrhage .
4- Liver abscess.
5- Ameboma (Granulomas) : a. Are a painful abdominal mass which occur most frequently in the caecum and assending colon .

71. b. This lesion may be confused with carcinomas or tumour .
c.Obstructive symptoms or dysentery may also be associated with ameboma.

72. Extraintestinal Amoebiasis :
1.The metastasis of amoeba usually via blood streem or by direct extension after intestinal perforation to the peritonium the amoeba may cause local abcsess or peritonitis or migrate to
the liver is the most commonly affected than other organs e.g, lungs, perianal skin or brain.

73. Extraintestinal AmebiasiS

74. 2.Amoebic liver abscesses: Are the most common extraintestinal amebiasis and characterised By:
a.Hepatomegaly, Liver tenderness, fever and anorexia .
b. Liver function tests are usually normal or slightly abnormal .
c. Liver abscesses will occasionally rupture into the peritoneum causing peritonits

75. 3.Pulmonery amoebiasis :
a. This infection due to the direct extension of the liver abscess through the diaphragm, or via blood b.The clinical symptoms are: cough, chest pain, dysnea and fever .
c.The sputum may be purulent or contain blood and trophozoites of E. histolytica.

76. 4. Cutaneous amoebiasis :
It is caused by contact of the skin with amoebic abscess which lead to fistula in the skin.

77. الدكتورعبدالسلام المختار Lec.(4).
ENTAMOEBA HISTOLYTICA:
OBJECTIVES:
1.Diagnosis,Pathogenesis,Treatment.
2.Prevention and control. 77

78. Diagnosis of Amoebiasis :
1- Stool of patient should be examined by :
a- Direct method with saline for motile trophozoite .
b- Stool specimens should be stained usually with ioden and microscopically examined for cysts opf E.histolytica .

79. 2- Culture of stool.
3- Sigmoidoscopy may reveal the charecteristic flask-shaped ulcers especially in sever cases .

80. 4- Biopsy & fluid from large intestine aspirates also be examined microscopically for trophozoites .
5- Serology, is very important for the diagnosis of extraintestinal amoebiasis
e,g, Indirect haemagglutination (IHA) & Polymirase Chain Reaction (PCR test) .

81. 6- Ultrasound, CTscan, MRI can be used to detect hepatic abscesses .
7- The typical amoebic stool is contain blood, mucous , few WBC & Bacteria .

82. Treatment :
1. A symptomatic patients can be treated with Diiodohydroxyquine with tetracycline.

83. Treatment :
2. Symptomatic patients with diarrhoea or dysentary or extraintesinal amebiasis should be treated as follows :
a- Patients should remain in bed and receive a high protein and high vitamin with adequate fluids .

84. b. Chemotherapy for sever amoebiasis:
1.Metronidazol (Flagel) is the drug of choice :
750 mg three times a day, orally for 5 – 10 day.
2.Tetracycline & diiodohydroxyquine are recommended to be given to the patient since metronidzal may not always cure the intestinal infection .

85. The side effects of Mitronidazole are :
Nausea ,haedach, diarrohea and may be carcinogenic in experimental animal .

86. 3. Alternative drugs of amoebic dysentery are Emetine hydrochloride, it is effective but it is toxic.Dehydroemtin Dihydrochloride is less toxic than emetine and is equally effective.

87. Prevention & Control :
1- All human infections should be treated because human being is the only chief source of infection .
2- A symptomatic carriers should be treated especially those working in restorants .

88. 3- Effective enviromental sanitation is necessary to prevent water ,food , and vegitable contamination, e.g. Sewage disposal should be treated with chemical before used as fertiliser in gardens.
4- Chlorination & filtered water supply are important to kill the cyst of E.histolytica.

89. 5- Insects should be controlled by insecticides.
6- Uncooked vegetables should be washed with running water. .

90. Lec.(5) الدكتور عبد السلام المختار
Intestinal and Luminal Flagilates of Human Being.
Giardia lambilia (intestinalis) :
OBJECTIVES:
1.Medical importance of Giardia lambilia .
2.Morphology and Life cycle.
3.Epidemiology.

91. Giardia lambilia (intestinalis) :
Disease : Giardiasis or lambiliasis.

92. Morphology : of trophozoite :
1- Bilaterally symetrical,12–15 Mm.in length.
2- Pear shaped flagellate with rounded anterior end and tapering posterior end .
3- The dorsal surface is convex & it has a concave sucking disc ventraly .

93. 4- It has two nuclei with large central karyosome
5- There are two axostyle & and two deeply staining parabasal bodies .
6-It has four pair of flagella .

94. Giardia lamblia CYST TROPHOZOITE infective stage passed in feces
replicative stage
small intestine

96. Morphology of the cyst:
1- Small, 9 – 12 Mm. in size .
2-Rround or oval in shape & contain four nuclei .
3- It contain remaining parts of the trophozoites.

99. Life cycle :
Human being is the natural host of Giardia lamblia inhabit the upper part of small intestine especially duodenum . Multiplication occurs by mitotic division during cyst formation, which pass with feces into soil outside the host and can remain viable for months under moist conditions .

100. Man especially children acquired the infection through the ingestion of cysts via contamineted food, these cysts passes through the stomach into duodenum where excystation takes place & within 30 minutes after emerging from the cyst resulting in two binucleated trophozoites .

101. Epidemiology: Worldwide in its distribution especially in chilidren
Epidemiology: Worldwide in its distribution especially in chilidren.It is present in Iraq.
The disease transmitted by contamination of food and drinks with infected cysts of G,lambilia.
House flys and insects can transmit the infected cysts to the human being by mechanical way.
101

102. Lec.(6). ألدكتورعبدالسلام المختار OBJECTIVE:
OBJECTIVE:
1.Pathogenesis, Clinicai picture of the disease. 3.Diagnosis andTreatment prevention and control.
102

103. Pathogenesis: 1.The specific mechanisum of Giardia leading to fatty diarrohea (steatorea).
2.Intestinal malabsorption due to attachment of trophozoites to cover large areas of the intestinal epithelium to produce a mechanical irritation & prevent absorption of food especially fat .
103

104. 3.Giardia infection can also lead to Lactase deficiencies as well as other enyzme deficiencies and this may explain the malabsorption syndromes in giardiasis.
104

105. Giardia lamblia CYST TROPHOZOITE infective stage passed in feces
replicative stage
small intestine

106. Adhesive Disk and Attachment

107. Pathogenesis Possible Mechanisms mechanical irritation
epithelial damage
villus blunting
crypt cell hypertrophy
cellular infiltration
malabsorbtion
enzyme deficiencies
lactase (lactose intolerance)
Possible Mechanisms
mechanical irritation
obstruction of absorption

108. Clinical picture of Giardiasis:
The incubation periods is about 1 – 2 weeks . The clinical features associated with Giardia infection are range from Asymptomatic, to acute diarrhea,or may lead to chronic syndromes.

109. Acute Giardiasis :
1.The first signs include : Nausea, loss of appetite and an upper gastro – intestinal pain .
2.Watery or loose fatty diarrhea with absence blood or mucus which may help to distinguish giardiasis from other acute diarrheas.

110. 3. Abdominal cramps, malabsorption, steatorrhea (excessive loss of fat in the feces), loss of weight, and bad smelling of the feces .

111. Acute infection may also lead to:
Chronic infection : which characterised with :
1- Recurrent loose of stools .
2- Abdominal distention .
3- Normal stools or constipation ulternate with watery stools diarrhea .

112. 4- Anorexia, nausea and epigastric pain .
5- Nutritional disorder .
6- Weight loss .

113. Diagnosis :
1- By direct examination with Saline & ioden : Is usually made by finding cysts of Giardia in soft stools and trophozoites & cysts in diarroheaic feces

114. 2- Examination of duodenal content by aspiration given higher percentage of positive finding of trophozoites than that of the feces .

115. Treatment: Several drugs are available to treat giardiasis but metronidazole and tinidazole are the drugs of choice.

116. Prevention and control :
Is just like that of E.histolytica.
1- All human infections should be treated because human being is the only chief source of infection .
2- A symptomatic carriers should be treated especially those working in restorants .

117. 3- Effective enviromental sanitation is necessary to prevent water ,food , and vegitable contamination, e.g. Sewage disposal should be treated with chemical before used as fertiliser in gardens.

118. 4- Chlorination & filtered water supply are important to kill the cyst of G.lamblia.
5-Flies and Insects should be controlled by insecticides because they transmit the infective stage by mechanical methods.
6- Uncooked vegetables should be washed with running water. .