HUMAN PARASITOLOGY. lumbricoides, Trichuris trichiura, hookworm. Human Parasitology (Code: ) Guideline

Transcription

1 HUMAN PARASITOLOGY Human Parasitology (Code: ) Guideline I. Course Introduction 128 classes comprise 72 for lecturing, 54 for lab practice, and 2 for self-study. 6.0 credits; 5 th semester II. Lecturing section Lecturing and Research Section, Department of Parasitology III. Attribution IV. Requirements V. Compulsory subject Contents Lecturing Class Discussion Self-study Lab Chapter 1 Introduction 2 Chapter 2 Nematodes I: introduction to nematodes, Ascaris lumbricoides, Trichuris trichiura, hookworm Chapter 3 Nematodes II: Enterobius vermicularis, Trichinella spiralis, filaria Chapter 4 Cestodes I: introduction to cestodes, Taenia solium, Spirometra mansoni 2 Chapter 5 Cestodes Echinococcus Hymenolepis II: granulosus,

2 Chapter 6 Trematodes I: introduction to trematodes, Clonorchis sinensis, Fasciolopsis buski, Lung fluke Chapter 7 Trematodes II: Schistosoma japonicum Review of helminth 3 Chapter 8 Protozoa I: Entamoeba histolytica, Giardia lamblia, Trichomonas vaginalis Chapter 9 Protozoa II: Plasmodium 2 Chapter 10 Protozoa III: Toxoplasma gondii, Leishmania donovani Chapter 11 Arthropod I: mosquito, fly 2 Chapter 12 Arthropod II: flea, louse, tick and mite Total 24 0 VI. References 1. Textbook Gerald D. Schmidt & Larry S. Roberts, Foundations of Parasitology, 8th ed. Higher Education. 2. Journal Journal of Parasitology Trends in Parasitology

3 3. Website VII. Course organization 50% attendance and laboratory exam (specimen exam); 50% final exam Chapter 1 Introduction To master the definition of parasitism, parasites and hosts, different types of life cycle; To master the relationship between parasites and hosts, host immunity to different parasites To master the characters of parasitic infection and parasitic disease, the key links in prevalence of parasitic disease; To know the classification of parasites, the prevalence and prevention of parasitic disease. II.key points The definition of parasitism, the relationship between parasites and hosts; The life cycle of parasites, the characters of parasitic infection and parasitic disease; The principles of prevention of parasitic disease III. 1. To introduce the harms of parasitic disease in the world. 2. To introduce the definitions of parasitism, parasites, hosts and life cycle, the types of parasites, hosts and life cycle. 3. To introduce the relationship between hosts and parasites, including the harms of parasites to hosts and immunity of host to parasites. 4. To introduce the characters of parasitic infection and parasitic disease. 5. To introduce the key points in prevalence of parasitic disease. Definitions Emerging parasitic diseases; parasitic zoonosis; commensalism; mutualism; parasitism; parasite; host; obligatory parasite; facultative parasite; endoparasite; ectoparasite; definitive host; intermediate host; reservoir host; paratenic host; larva migrans; Cutaneous larva migrans; ectopic parasitism; opportunistic parasite; suppressive infection 1. What is the harms of parasites to humans? 2. What are the characters of prevalence of parasitic disease? Chapter 2 Nematodes I: introduction to nematodes, Ascaris lumbricoides, Trichuris trichiura, hookworm To master the morphology, life cycle, pathogenesis and diagnosis of Ascaris lumbricoides, Trichuris trichiura, hookworm;

4 To understand the prevalence and prevention of Ascaris lumbricoides, Trichuris trichiura, hookworm. The life cycle and pathogenesis of Ascaris lumbricoides, Trichuris trichiura, hookworm. 1. Introduce the common character of nematodes; 2. Introduce the morphology, life cycle, pathogenesis, clinical manifestation, diagnosis, prevalence and prevention of Ascaris lumbricoides, Trichuris trichiura, hookworm. Soil-transmitted nematodes, bio-nematodes 1. What is the difference in life cycle of Ascaris lumbricoides, Trichuris trichiura, and hookworm? Chapter 3 filaria Nematodes II: Enterobius vermicularis, Trichinella spiralis, To master the morphology, life cycle, pathogenesis and diagnosis of Enterobius vermicularis, Trichinella spiralis, filaria; To understand the prevalence and prevention of Enterobius vermicularis, Trichinella spiralis, filaria. The life cycle and pathogenesis of Enterobius vermicularis, Trichinella spiralis, filaria 1. Introduce the morphology, life cycle, pathogenesis, clinical manifestation, diagnosis, prevalence and prevention of Enterobius vermicularis, Trichinella spiralis, filarial. 2. Introduce two species of filarial and the difference in life cycle and pathogenesis. Nocturnal periodicity 1. What are the differences in pathogenesis, diagnosis and prevalence of two species of filaria? Chapter 4 Cestodes I: introduction to cestodes, Taenia solium, Spirometra mansoni To master the morphology, life cycle, pathogenesis and diagnosis of Taenia solium, Spirometra mansoni; To understand the prevalence and prevention of Taenia solium, Spirometra mansoni. The life cycle and pathogenesis of Taenia solium, Spirometra mansoni;

5 1. Introduce the common character of cestodes; 2. Introduce the morphology, life cycle, pathogenesis, clinical manifestation, diagnosis, prevalence and prevention of Taenia solium, Spirometra mansoni. Metacestode 1. How can we be infected by Taenia solium and Spirometra mansoni? 2. What are the differences between Taenia solium and Taenia saginata? Chapter 5 Cestodes II: Echinococcus granulosus, Hymenolepis To master the morphology and life cycle of Echinococcus granulosus, Hymenolepis. To master the pathogenesis of Echinococcus granulosus To understand the prevalence and prevention of Echinococcus granulosus, Hymenolepis The life cycle of Echinococcus granulosus, Hymenolepis. 1. Introduce the morphology, life cycle, pathogenesis, clinical manifestation, diagnosis, prevalence and prevention of Echinococcus granulosus, Hymenolepis. Self-infection 1. What is the difference in life cycle between Hymenolepis nana and other cestodes? Chapter 6 Trematodes I: introduction to trematodes, Clonorchis sinensis, Fasciolopsis buski, lung fluke To master the morphology, life cycle, pathogenesis and diagnosis of Clonorchis sinensis, Fasciolopsis buski, lung fluke; To understand the prevalence and prevention of Clonorchis sinensis, Fasciolopsis buski, lung fluke. The life cycle, pathogenesis and diagnosis of Clonorchis sinensis, Fasciolopsis buski, lung fluke 1. Introduce the common character of trematodes; 2. Introduce the morphology, life cycle, pathogenesis and diagnosis of Clonorchis sinensis, Fasciolopsis buski, Lung fluke; 3. Introduce the prevalence and prevention of Clonorchis sinensis, Fasciolopsis buski, lung fluke 4. Introduce two species of lung fluke.

6 1. What is the difference in life cycle of Clonorchis sinensis, Fasciolopsis buski, lung fluke? Chapter 7 Trematodes II: Schistosoma japonicum To master the morphology and life cycle of Schistosoma japonicum; To master the pathogenesis, clinical manifestation, diagnosis, prevalence and prevention of schistosomiasis japonica. The life cycle and pathogenesis of Schistosoma japonicum 1. Introduce species of schistosomes; 2. Introduce the morphology, life cycle, pathogenesis, clinical manifestation, diagnosis, prevalence and prevention of Schistosoma japonicum. Concomitant immunity 1. What is the pathogenic stages of Schistosoma japonicum? Chapter 8 Protozoa I: Entamoeba histolytica, Giardia lamblia, Trichomonas vaginalis To master the morphological characters of Entamoeba histolytica, Giardia lamblia, Trichomonas vaginalis; To master the life cycle of Entamoeba histolytica, Giardia lamblia, Trichomonas vaginalis; To master the pathogenesis of Entamoeba histolytica, Giardia lamblia, Trichomonas vaginalis; To understand the prevalence and prevention of Giardia lamblia, Trichomonas vaginalis; To know the prevalence and prevention of Entamoeba histolytica. The morphology, life cycle, pathogenesis of Entamoeba histolytica, Giardia lamblia, Trichomonas vaginalis. 1. Introduce the morphology, classification, and common characters of protozoa; 2. Introduce the morphology of trophozoite and cyst of Entamoeba histolytica; the life cycle, pathogenesis, clinical manifestation and pathogenic diagnosis of Entamoeba histolytica; 3. Introduce the morphology of trophozoite and cyst of Giardia lamblia; the life cycle, pathogenesis, clinical manifestation and pathogenic diagnosis of Giardia lamblia; 4. Introduce the morphology, life cycle, pathogenesis, clinical manifestation and pathogenic diagnosis of Trichomonas vaginalis.

7 Trophozoite; cyst; amebic granuloma; amebic liver abscess; ameboma 1. What is the difference in life cycle of Entamoeba histolytica, Giardia lamblia and Trichomonas vaginalis? Chapter 9 Protozoa II: Plasmodium To master the morphology and life cycle of four species of plasmodium; To master the pathogenesis, clinical manifestation, diagnosis, prevalence and prevention of malaria. II Key points The morphology, life cycle, pathogenesis, clinical manifestation, diagnosis, and prevalence of plasmodium. III Lecturing contents and important points 1. Introduce four species of plasmodium in human; 2. Introduce the morphology and development of plasmodium; 3. Introduce the pathogenesis and clinical manifestation of plasmodium; 4. Introduce the diagnosis and prevalence of malaria; 5. Introduce the prevention and control of malaria. Premonition 1. What is the difference in life cycle of four species of plasmodium? Chapter 10 Protozoa III: Toxoplasma gondii, Leishmania donovani To master the morphology of trophozoite of Toxoplasma gondii; To understand the life cycle, pathogenesis and diagnosis of Toxoplasma gondii and Leishmania donovani; To know the prevalence of Toxoplasma gondii and Leishmania donovani. II Key points The life cycle, pathogenesis and clinical manifestation of Toxoplasma gondii and Leishmania donovani. III Lecturing contents and important points 1. Introduce the morphology, life cycle, pathogenesis, clinical manifestation and diagnosis of Toxoplasma gondii and Leishmania donovani. Opportunistic protozoa V Study questions 1. what is opportunistic protozoa? Chapter 11 Arthropod I: introduction to arthropod, mosquito, fly

8 To master the morphology, life cycle and harms of medical arthropods; To master the morphology, habitat and harms of important species of mosquito and fly. II Key points The harms of medical arthropod; the criteria to judge medical arthropod. III Lecturing contents and important points 1. Introduce the morphology and classification of medical arthropods; 2. Introduce the medical importance of arthropods; 3. Introduce the judgment of medical arthropods; 4. Introduce the morphology, habitat and harms of important species of mosquito and fly; 5. Introduce the prevention of mosquito and fly; IV Definitions Arbo disease, Metamorphosis V Study questions 1. What is the relationship between mosquito and disease? 2. How many types in harms of medical arthropods? Chapter 12 Arthropod II: flea, louse, tick and mite To master the morphology, habitat and harms of important species of flea, louse, tick and mite. II Key points The harms of flea, louse, tick and mite. III Lecturing contents and important points 1. Introduce the morphology, habitat and harms of important species of flea, louse, tick and mite; 2. Introduce the prevention of flea, louse, tick and mite. IV Study questions 1. What is the difference between hard tick and soft tick? Experiments For Human Parasitology Chapter I Nematodes I 1. Mastery of morphological character of the ovum of Ascaris lumbricoides, Trichuris trichiura and hookworm 2. Knowing morphological character of the adults of Ascaris lumbricoides, Trichuris trichiura and hookworm 3. Knowing well the principle and methods of simple smear, saturated brine method and larval cultivation in a tube. Slides, tubes, microscope

9 Saline, saturated brine, clean water Detection of eggs by direct smear. 1. Direct smear: obtain a microscope slide and the stool specimen. Add 1~2 drop of physiological saline on the center of a clean slide and smearing well distributed the stool specimen in size of a rice with the saline. The area of the wet mount should be 1~2 cm in diameter and do not reach the edges of the slide. The thickness of the wet mount should be as the image and the words under the wet mount can be identified. It is necessary to make 3 smear slides for one stool specimen and each smear should be take the stool from different points of the specimen. 2. Saturated brine method: The specific gravity of hookworm egg ( ) is lower than that of saturated brine (1.200), the eggs in a container with saturated brine will be floated on water. (1) Prepare saturated brine using 37.5g saline and 100 ml of water. Take 1 g of stool and mix it with saturated brine in a tube, pick out the large debris in the tube and then dropping more saturated brine until the top of the tub, keeping the tube for 15 min. (2) Take a clean slide and contacting with the top of the tube and then turning over the slide, check the slide under a microscope. 3. Larval cultivation in a tube: Larvae of hookworm can be hatched from the eggs under suitable conditions (25~35 o C, relative humidity 60%~80% and sufficient air), the larvae trend to moisture and will be concentrated in water of bottom of a tube if they are cultured in a tube. (1) Cut a filter paper as T shape,put 0.2g of stool in the middle area of the paper and then insert the paper into a tube with water in its bottom, keeping the edge of the paper in contact with water and place it in a cultivator with 25~35 o C for 3 days. (2) Check the larvae in water with naked eye or a lens, the larvae are white and move as a snake. If nothing to be discovered, replacing the tube in the cultivator for 2 days and check it again. Observe the morphological characters of eggs and adults of Ascaris lumbricoides, Trichuris trichiura and hookworm. Notes Eggs of Ascaris lumbricoides may continue to develop and are infectious even when preserved in formalin. Chapter II Nematodes II 1. Mastery of morphological character of the ovum of Enterobius vermicularis, larva of Trichinella spiralis 2. Knowing morphological character of the adults of Enterobius vermicularis and filaria 3. Understanding the principle and method to collect the eggs from the skin of the buttocks.

10 Slides, cellulose tape, cotton swab, microscope Saline Detection of eggs of Enterobius vermicularis by following methods. 1. Collect the eggs from the skin of the buttocks by adhesive cellulose tape: (1) Cut an adhesive cellulose tape in size of 3cm x2 cm and sticking it on a clean slide; (2) Expose the sticky face of the tape and contact with the perianal skin and then replace the tape on the slide, do not leave the air bubble between the tape and slide. (3) Detection of the eggs under a microscope. 2. Collect the eggs from the skin of the buttocks by cotton swab: (1) Wet a cotton swab with physiological saline and wiping the perianal skin; (2) Put the swab into a test tube with physiological saline and shaking it; (3) Take out the swab and centrifuge the tube, check the eggs from the sediments. Observe the morphological characters of eggs and adults of Enterobius vermicularis, larva of Trichinella spiralis, Wuchereia bancrofit and Brugia malayi. Chapter III Cestodes 1. Mastery of morphological character of the ovum of Taenia solium and Hymenolepis 2. Knowing morphological character of the adults of Taenia solium and Hymenolepis, the larva of Taenia solium, Echinococcus granulosus, and Spirometra mansoni. Slides, microscope Saline Detection of eggs of Taenia solium and Hymenolepis by direct smear. Observe the morphological characters of eggs, larva and adults of Taenia solium, Echinococcus granulosus, and Spirometra mansoni. Chapter IV Trematodes I 1. Mastery of morphological character of the ovum and adults of Clonorchis sinensis, Fasciolopsis buski, Lung fluke 2. Knowing morphological character of the larva and intermediate hosts of Clonorchis sinensis, Fasciolopsis buski, Lung fluke. Slides, microscope

11 Saline Detection of eggs of Clonorchis sinensis, Fasciolopsis buski, Lung fluke by direct smear. Observe the morphological characters of eggs, larva and adults of Clonorchis sinensis, Fasciolopsis buski, Lung fluke. Chapter V Trematodes II 1. Mastery of morphological character of the ovum, larva and adults of S. japonicum 2. Mastery of common methods to diagnose schistosomiasis 3. Knowing parasitic position of adult worm, distribution of eggs in final host and pathogenicity. Slides, scissors, forceps, needles, culture plate, dish Saline 1. Detection of eggs of S. japonicum by direct smear. 2. Dissection of mice infected with S. japonicum Put the executed mouse in a dish; open abdominal cavity and expose mesenteric vein and portal vein; break vessel wall by needle to expose adult worms; observe the motion and morphology of worms by taking them into a plate full of saline. Cut a piece of tissue of pathogenic liver or vessel wall, press between two slides and observe eggs granuloma under microscope. Observe the morphological characters of eggs, larva and adults of S. japonicum. Chapter VI Protozoa I 1. Mastery of morphological character of the cysts of Entamoeba histolytica, Entamoeba coli and Giardia lamblia 2. Knowing morphological character of the trophozoites of Entamoeba histolytica, Entamoeba coli, Giardia lamblia and Trichomonas vaginalis. Slides, microscope Saline, iodine

12 Detection of cysts of Entamoeba histolytica, Entamoeba coli and Giardia lamblia by direct smear and iodine stain. Observe the morphological characters of trophozoites and cysts of Entamoeba histolytica, Entamoeba coli and Giardia lamblia by direct smear and iodine stain. Chapter VII Protozoa II 1. Mastery of the morphological characters of the erythrocytic stage of Plasmodium vivax and P. falciparum 2. Mastery of the morphological characters of trophozoites of Toxoplasma gondii 3. Mastery of the procedure of blood smear and Giemsa stain 4. Knowing the morphological characters of promastigotes and amastigotes of L. donovani Slides, microscope Saline, Giemsa stain, oil 1. Preparation of thick and thin blood films 1 Thick smears Thick smears consist of a thick layer of dehemoglobinized (lysed) red blood cells (RBCs). The blood elements (including parasites, if any) are more concentrated (app. 30 ) than in an equal area of a thin smear. Thus, thick smears allow a more efficient detection of parasites (increased sensitivity). However, they do not permit an optimal review of parasite morphology. For example, they are often not adequate for species identification of malaria parasites: if the thick smear is positive for malaria parasites, the thin smear should be used for species identification. (1) Place a small drop of blood in the center of the pre-cleaned, labeled slide. (2) Using the corner of another slide or an applicator stick spread the drop in a circular pattern until it is the size of a dime (1.5 cm). (3) A thick smear of proper density is one, which, if placed (wet) over newsprint, allows you to barely read the words. (4) Lay the slides flat and allow the smears to dry thoroughly (protect from dust and insects!). Insufficiently dried smears (and/or smears that are too thick) can detach from the slides during staining. blood. The risk is increased in smears made with anticoagulated At room temperature, drying can take several hours; 30 minutes is the minimum; in the latter case, handle the smear very delicately during staining. the drying by using a fan or hair dryer. prevent heat-fixing the smear. 2 Thin smears You can accelerate Protect thick smears from hot environments to

13 Thin smears consist of blood spread in a layer such that the thickness decreases progressively toward the feathered edge. monolayer, not touching one another. In the feathered edge, the cells should be in a (1) Place a small drop of blood on the precleaned, labeled slide, near lobe its frosted end. (2) Bring another slide at a angle up to the drop, allowing the drop to spread along the contact line of the 2 slides. (3) Quickly push the upper (spreader) slide toward the unfrosted end of the lower slide. (4) Make sure that the smears have a good-feathered edge. This is achieved by using the correct amount of blood and spreading technique. (5) Allow the thin smears to dry. (They dry much faster than the thick smears, and are less subject to detachment because they will be fixed.) (6) Fix the smears by dipping them in absolute methanol. 2. Stain: When the films are dry, fixed and stain the thin films in the conventional manner but be careful about the ph of the stain, a slightly alkaline stain is recommended (ph 7.2) as an acid stain may fail to show the parasites. When only a few thick films are to be stained it is best to use dilute Giemsa stain (1/20), using a staining jar so that the film is in an upright position, which will allow any debris to fall to the bottom of the jar. Do not fix the sample prior to staining. Stain for about 30 minutes, wash gently with clean water and allow to drying. If available use a positive control. 3. Under the microscope examine the thick film first, using an oil immersion to determine if parasites are present. Parasites may appear distorted if the patient has been treated or has had inadequate or ineffective prophylaxis. Observe the morphological characters of the erythrocytic stage of Plasmodium vivax and P. falciparum, the trophozoite of Toxoplasma gondii and promastigotes and amastigotes of L. donovani. Notes Under field conditions, where slides are scarce, national malaria programs (and CDC staff) prepare both a thick and a thin smear on the same slide. makes sure that of the two smears, only the thin smear is fixed. This works adequately if one Chapter VIII Medical Arthropods 1. Mastery of the morphological characters of adults of mosquito and fly, 2. Mastery of the morphological characters of flea, louse, bed-bugs, tick and mite 3. Knowing the morphological characters of other stages of mosquito and fly microscope Observe the morphological characters of mosquito, fly, flea, louse, bed-bugs, tick and mite.