Learning Objectives. 3. Epidemiology distribution; endemic; 4. Basic Morphology 5. Name of diesease 6. Prevention and Control

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1 Learning Objectives At the end of the class student will able to state 1. Life cycle Environment, Human, Animals 2. Name of parasite: (Genus), (Species) 3. Epidemiology distribution; endemic; 4. Basic Morphology 5. Name of diesease 6. Prevention and Control

2 Parasitology: (Protozoa and Helminthes) Protozoa: 1. PARASITOLOGY- science that deals with organisms that seek shelter and nourishment on or within other living organisms. 2. Protozoa are unicellular (eukaryotic) or acellular organisms which are capable of performing all the vital functions of life. 3. Protozoan is measured in microns (size vary from µ). 4. Cytoplasmic extension in form of pseudopodia, flagellae or cilia are responsible for locomotion. 5. Nucleus may be compact with diffuse chromatin or vesicular with central or eccentric karyosome (DNA) and peripheral chromatin (RNA). 6. Respiration is mostly anaerobic. 7. Secretion: Protozoa secrete digestive enzymes, toxins, cytolysin and antigenic substances. 8. Reproduction: may be asexual or sexual.

CYCLE OF PROTOZOA Infective stage Cysts, Oocysts, Sporozoites, Sporesdormant stages and resistant;

3 Module: Medical Parasitology & Entomology Helmintology helminths/worms - Metazoa ENTOMOLOGY science that deals with arthropods of medical importance Protozoology PROTOZOA unicellular STAGES IN LIFE CYCLE OF PROTOZOA Infective stage Cysts, Oocysts, Sporozoites, Sporesdormant stages and resistant; Vegetative stage Trophozoites take nourishment from the hosts; invasive causing pathology; most are motile.

4 Parasitology: (Protozoa) Entamoeba histolytica: A world wide in distribution More often in tropical countries with poor sanitary conditions A commensal protozoa when human has a normal immune function. Invading host tissues and causing amoebiasis when human has a lower immune function

5 Protozoa: Entamoeba histolytica Morphology:- Trophozoite No regular in shape, 20~60μm in size. An active-moving trophozoite produce pseudopods (organelle) A spherical nucleus. Nucleolus in the center. peripheral chromatin Erythrophagocytosis RBCs

Immature cyst (1 or 2 nuclei) has the glycogen vacuole & chromatoid

6 Protozoa: Entamoeba histolytica Cyst Spherical in shape & 10~20μm in diameter. 1~4 nuclei (similar to that of the trophozoite). Immature cyst (1 or 2 nuclei) has the glycogen vacuole & chromatoid body. No inclusions disappear In mature cyst (4 nuclei) ---infective stage

7 Protozoa: Entamoeba histolytica Microscopic characteristics of Entamoeba histolytica:

8 Protozoa: Entamoeba histolytica Characteristic of life cycle Basic model : cyst trophozoite cyst Parasitic location : large intestine (common) ; intestinal tissue or other tissues (occasional) Infective stage : mature cyst Trophozoite in diarrhea or pus ; Cyst in formed feces Infection : by ingestion of mature cyst Pathologic changes Colonic tissues : flask-shaped ulcers The destruction of trophozoites on mucosa may be shallow and small. While they enter the submucosa, they multiply and spread laterally give rise to extensive destruction. Extraintestinal tissues (liver) : abscess --- Anchovy-sauce type pus.

9 Ulcer of large intestine Amoebic ulceration Amebic liver abscess

10 Protozoa: Giardia intestinalis/lambia Giardia intestinalis:- Worldwide distribution higher prevalence in tropical or developing countries (20%) 1-6% in temperate countries Most common protozoa in stools: ~200 million cases/yr Giardiasis: -often asymptomatic OR -acute or chronic diarrhea Morphology Giardia have two nuclei, each with four associated flagella, and lack both mitochondria and a Golgi apparatus. Fecal-Oral Transmission Factors Poor personal hygiene: -children (eg, day care centers) - food handlers Developing countries: -poor sanitation - endemic -travelers diarrhea Water-borne epidemics Male homosexuality: oral-anal contact

11 Protozoa: Giardia intestinalis Pathogenesis: Trophozoite stage induces malabsorption of fats. Clinical Disease: Diarrhea (steatorrhea) Weight loss Constipation Fatigue Histopathological correlate: Flattened villi

12 Protozoa: Giardia intestinalis Diagnosis: Identify trophozoites and cysts by microscopic examination of stool Giardia intestinalis trophozoite: Iron hematoxylin stain. Cyst

Protozoa: Trichomonas vaginalis Trichomonas vaginalis Worldwide in distribution The most common pathogenic protozoan of human in industrialized countries Transmission is by contact (by sexual

13 Protozoa: Trichomonas vaginalis Trichomonas vaginalis Worldwide in distribution The most common pathogenic protozoan of human in industrialized countries Transmission is by contact (by sexual intercourse). Sometimes, by indirect contact, such as sharing damp washclothes / swimming clothes. Morphology (trophozoite) Pear-like (teardrop), 7~32 X 5~12μm One nucleus and a axostyle projected posterior out of the body. Undulating membrane on one side (one-third the length of the body). Basal body on anterior to nucleus and produce 4 anterior flagella and 1 posterior flagellum.

14 TRICHOMONAS VAGINALIS

Causing persistent vaginitis, complain of itching and burning sensation; vaginal wall is injected, tender,

15 Pathology and Symptoms: Bacterial flora, physiological status of the vagina eg ph are some of the determining factors. Causing persistent vaginitis, complain of itching and burning sensation; vaginal wall is injected, tender, hyperemia, petechial haemorrhage and some areas become granular strawberry vagina. The surface is covered with frothy, seropurulent, creamy or yellowish discharge leucorrhoea. In males, there may be urethritis and protato vesiculitis.

16 CRYPTOSPORIDIUM PARVUM Cryptosporidiasis is often the cause of profuse watery diarrhoea in AIDS patients. Produce disease in immunocompetent hosts as well- outbreaks of diarrhoea in veterinary workers dealing with calves; common cause of diarrhoea among travelers and day care centers. Sexual and asexual multiplication in the enterocytes. Oocysts are excreted in patients stool. Clinical symptoms: Diarrhoea, nausea, vomitting, abdominal cramps and fever. Severe fluid loss (dehydration) from diarrhoea and vomitting can lead to a fatal outcome in children.

17 Protozoa: Plasmodium:- Plasmodium:- Four species of Plasmodium can infect humans: P. falciparum P. vivax P. ovale P. malariae Plasmodium: Vector: Fatal malaria Hypnozoites in liver cells Relapse Anopheles mosquitoes 430 Anopheles species, only transmit malaria (i.e., are "vectors") Human malaria is transmitted only by females of the genus Need blood for the development of eggs

18 Protozoa: Plasmodium:- Malaria: Symptoms:- Fever Chills Malaria quartana 3-day cycle P. malariae Malaria tertiana 2-day cycle P. ovale/vivax (P. falciparum) Headache Flu-like symptoms Muscle aches Fatigue Anemia Jaundice Enlarged spleen Enlarged liver

19 Protozoa: Plasmodium:- Malaria: Diagnosis:- Microscopy Ring Trophozoite Schizont Gametocyte Molecular PCR Patient antibodies

CONTROL AND PREVENTION OF INTESTINAL INFECTIONS WITH PROTOZOA In general, the prevention of intestinal protozoal

Infections can be reduced or even eliminated in a community by: (1) sanitary disposal of fecal wastes; (2) the

Screened toilets and latrines from flies, cockroaches mechanical vectors Cryptosporidium for vet., med.

20 CONTROL AND PREVENTION OF INTESTINAL INFECTIONS WITH PROTOZOA In general, the prevention of intestinal protozoal infectionsis largely a problem of sanitation and hygiene. Infections can be reduced or even eliminated in a community by: (1) sanitary disposal of fecal wastes; (2) the protection of susceptible individuals, (3) treatment of infected individuals; (4) wash hands and vegetables; (5) Screened toilets and latrines from flies, cockroaches mechanical vectors Cryptosporidium for vet., med. and lab personnel, contact with infected material must be avoided by use of gloves, gowns and hand-washings. Instruments and equipments should be autoclaved. Disinfect with common bleach (chlorox)

21 Toxoplasmosis Toxoplasmosis is one of the zoonotic diseases. Etiologic agent = Toxoplasma gondii.

22 Host Intermediate host Mainly domestic and wild cats. Human, birds, pigs, rodents, and sheep.

23 Toxoplasma gondii, Life-cycle

24 Toxoplasma gondii ACUTE PHASE CHRONIC PHASE Immunity + Tachyzoites: rapidly dividing forms Immunity - Bradyzoites: slowly dividing forms

25 Tachyzoite stage Toxoplasmosis oocyst

26 Transmission of infection: 1: Congenital. 2: Acquired : 3: Reactivation of infection Immunocompromised e.g. AIDS Immunosuppression e.g. drugs Transmission

27 Congenital Toxoplasmosis

28 Symptoms Infection is usually asymptomatic in healthy individuals. In acute infection: Lymphadenitis is the most common in humans. Flu-like symptoms (Headache, fever, muscle pain) the infection is generally self limited & symptom usually resolve in few months.

29 Symptoms Causes Encephalitis, hepatitis, for immunosuppressed patients and people infected with (AIDS). Congenital neurological defects in infants. Abortion. In chronic infections: visual problems or blindness may occur over time.

30 Prevention & Control Hands should be washed after contact with raw meat or in contact with soil. Vegetables should be washed well. Avoid undercooked meats. If you are owned by a cat Keep it inside if possible. Don t feed it raw meat. Avoid cat for pregnant women.

31 Geographic Distribution Worldwide Infection is more common in warm climates and lower altitudes than cold climates and mountainous regions. 750 human deaths per year make it the 3rd most common lethal food poisoning.

Flagellates I Genito-urinary & Intestinal flagellates

Flagellates I Genito-urinary & Intestinal flagellates Dr. Anuluck Junkum PARA 317221 Objective Can describe the morphology, life cycle, pathology, diagnosis and prevention of pathogenic flagellate Classification