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Welcome to Microbiology at Delta College!

Microbiology & Infection Control

Joyce Howard, Delta College 

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CD Homework Assignment: Parasitology-Protozoa

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Use this handout to complete the CD homework assignment: Parasitology-Protozoa. To complete this assignment, you will need to make use of the CD Microbes in Motion, your textbook, and Appendix A of the Isolation Precautions Guidelines. Note:  In Part 2 you will be using the Internet to learn more about waterborne disease outbreaks in the United States.

Please notice as you go through the assignment, I have added in additional information for you. You are responsible for this information on your exam, so please read through it thoroughly!

Information Literacy Outcome: The student will be able to access, analyze, and use information of the discipline.

Specific Objectives:

• Learn how to use the CD-ROM program, Microbes in Motion, the textbook, and Appendix A of the Isolation Precautions Guidelines to complete an assignment.
• Learn how to evaluate source and quality of information gathered through various resources for currency, appropriateness, and relevancy.

Specific Objectives:
• Learn how to integrate concepts, reflect, draw logical conclusions, and make predictions based on evidence.
• Learn to identify trends and patterns.
• Learn to distinguish between simple correlation and cause-and-effect.

Specific Objectives - Level One:

• The two broad categories of parasites.
• An in-depth description of a protozoan. Include information about its cytoplasm, cell wall, and possible shapes.
• What is meant by a "direct life cycle."
• Describe the trophozoite and the cyst stages in the protozoal life cycle.
• How transmission occurs in amoebic dysentery.
• Name and describe the stages in the infection of amoebic dysentery, caused by Entamoeba hystolytica.
• Name the form that is ingested and the form that is released in the feces in amoebic dysentery.
• The infective stage and means of transmission for Giardia lamblia.
• How long the cyst of G. lamblia can survive and where Giardia lamblia has been isolated.
• The stages in the life cycle of Giardia lamblia which includes humans as a host.
• The known reservoirs are for Giardia.
• What mode of transmission of Giardia day care settings are at high risk for.
• What stage of the sporozoan life cycle, Crytosporidium parvum , is shed in the feces, and what stage of C. parvum attaches to the intestinal villi within the new host, and the known reservoirs for Cryptosporidium.
• The infective stages and means of transmission for Cryptosporidium parvum and Cyclospora.
• How transmission of Trichomonas vaginalis occurs.
• The life cycle of T. vaginalis.
• The infection caused by T. vaginalis.
• The four species of Plasmodium which cause malaria.
• The type of mosquito that serves as the vector for Plasmodium.
• The infective form for Plasmodium in humans.

Specific Objectives - Level Two:

• The two intestinal protozoans most commonly responsible for infections in areas of the world where sewage and water treatment plants are well designed and monitored and the means by which they do it.
• The intestinal protozoan most commonly responsible for infection in areas of the world where sewage and water treatment plants are inadequate.
• What must be done to water supplies to assure removal of Giardia.
• What must be done to water supplies to assure removal of Cryptosporidium.
• The best way to disinfect drinking water while camping.
• The recommendations for persons infected with HIV for their water.
• What stages of Toxoplasma gondi can be infective and how they are transmitted.
• The infective form of Toxoplasma gondi that is shed in cat feces and how T. gondi is spread to humans from the cat feces.
• The disease caused by Toxoplasma gondi, what percent of infected people actually develop symptoms, and list the three categories of patients.
• The symptoms of toxoplasmosis in the immunologically normal patient, how long symptoms last, and how they are treated.
• The symptoms of congenital (or fetal) toxoplasmosis, what the consequences are if it occurs during the first trimester, and what the consequences are if it occurs in the last trimester.
• The symptoms of toxoplasmosis in the immunodeficient patient and what might be the outcome of infection in these patients.

Specific Objectives - Level Three:

• For each organism listed below, describe the type of diarrhea that results, the site of invasion, the mechanism of invasion, and the clinical signs of infection.
• Entamoeba histolytica
• Giardia lamblia
• Cryptosporidium parvum
• Cyclospora
• E. coli
• Norovirus (Norwalk-like virus)
• Shigella
• For each disease you must learn the following:  1) name of disease, 2) causative agent(s) and its description, 3) symptoms, 4) incubation period, 5) pathogenesis, 6) epidemiology, 7) treatment (Note: Be specific!), 8) prevention, 9) control, and 10) isolation precautions employed in a healthcare setting for the disease.
• Giardiasis
• Cryptosporidiosis (also known as Coccidial Diarrhea)
• Amebiasis (also known as Am(o)ebic Dysentery)
• Trichomoniasis (also known as Vaginosis or Vaginitis)
• Malaria
• Toxoplasmosis in the Immunocompromised Patient (ex: AIDS patient) & Congenital (Fetal) Toxoplasmosis
• Cyclosporiasis

Please open up the CD Microbes in Motion on your computer. (Note: All clicks to open various functions of the CD will be done using the left mouse key.)

Please notice that, where possible, I have given you a text or lab manual reference by each question.  If you feel uncertain about the answer to the question, you can go to your text or manual to read the corresponding information.  Unfortunately, it's impossible to give references for every question.

Note: At the end of each section, there will be a short quiz to help you to determine if you understood the information covered in that section. Please try the quizzes! If you get a question wrong, choose the option given to review that information. Remember, the point of this activity is to learn and understand the information. Quizzing and reviewing reinforces your understanding. The CD does not keep a record of your scores.

Follow these steps to open the CD:

• Make certain you have the Microbes in Motion III CD in your CD player.
• Note:  Some computers automatically open the CD, other computers open it from an icon off the main window, while others require you to open it from the main menu.
• If the second option is what works for your computer, find the "Shortcut to Microbes" icon on your desktop and double click on it.
• If you need to use option three, go to the main menu and find the link for the CD.
• If the CD does not open up full screen, use the Maximize button (middle button on the top, right of the screen) to make it full screen.
• Click on the book, Parasitology.
• Click on the videotape icon (Play video). It is the top icon on the left side of the screen.  Watch the short video on parasitic protozoa. (Note: If you cannot get the video to play, click on the bottom left icon to see the text from the video.)
• Click on Protozoa Classification from the list on the left of your screen.
• Click on the audiotape icon (Play Audio). It is the top icon on the left side. Listen to the tape. (Note: If you cannot get the audio to play, click on the bottom left icon to see the text from the audio.)
• Click on Protozoa Classification.

The book, Parasitology, contains two topics: Protozoa classification and Helminth classification. You will only be doing the first three chapters of the book on Protozoa classification! You are not required or expected to do the section on Helminth classification.

Part 1: Main Menu ---- Bookcase --- Protozoa Classification

1. Using the information on the screen, what are the two broad categories of parasites? 

2. Using the same screen, describe a protozoa.  (Text reference: p. 10)

3. Using the same screen, describe a helminth. (Reference:  A dictionary!)

4. Click on the next screen. List the most common protozoal diseases and the organism which causes each disease. (Text reference: p. 306-7)

5. Use the next screen to give a more in-depth description of a protozoan. Include in your description, information about its cytoplasm, cell wall, and possible shapes. (Text reference: p. 305-6)

6. Use the same screen. What is a trophozoite? (Text reference: p. 306)

7. Use the same screen. What is a cyst? (Text reference: p. 306)

8. Click on the next screen. In what stage does Trichomonas vaginalis live its life cycle? Watch the short video clip. (Text reference: p. 658)

So far you've studied bacteria which we classify according to the results of the Gram stain, their shape, arrangement, etc.  (Ex:  Staphylococcus is Gram positive.) You've studied viruses which we classify according to the kind of nucleic acid they have and if they have an outer coat. (Ex: HIV virus is an enveloped RNA virus.) Classification of protozoa can get quite complicated!  If you look in the text you'll go "huh??"
You will use two methods of grouping protozoa to keep it as simple as possible:

• Protozoa will be grouped according to their basic shape & pattern of motility.
• Protozoa will be grouped according to where they like to live in the human body.

• Ameboid Protozoa
• Ciliated Protozoa
• Flagellated Protozoa
• Sporozoan Protozoa, including Coccidia and Microsporidia

9. Click forward two screens. Name the medically important ameboid protozoa.

10. Watch the video clip on the same screen. Describe the process by which ameboid protozoa gain motility.

Ciliated Protozoa 

11. Click to the next screen. Name the medically important ciliated protozoan. These organisms gain motility via their cilia. Watch the video clip on the same screen.

Flagellated Protozoa 

12. Click to the next screen.Describe the methods by which flagellated protozoa gain motility.

13. Using the same screen, how do flagellated protozoa reproduce?

14. Using the same screen, name the ways that transmission of flagellated protozoa can occur.

15. Using the same screen, name the medically important flagellated protozoa.

Sporozoan Protozoa  

16. Click on the next screen. Describe sporozoan protozoa with regard to motility and reproduction.

17. Use the same screen to name the ways that transmission of sporozoan protozoa can occur.

18. Coccidia are sporozoan protozoa. Click to the next screen to name the medically important coccidia (sporozoan protozoa).

19. Microsporidia are sporozoan protozoa. Click on the next screen to name the medically important microsporidia (sporozoan protozoa).

Part 2: Main Menu ---- Bookcase --- Intestinal Protozoa

When classified according to where they like to live in the human body, protozoa are subdivided into the following groups:

• Intestinal Protozoa
• Tissue & Blood Protozoa

Section 1: Intestinal Protozoa Life Cycles

• Click on Intestinal Protozoa.
• Click on the eye icon to see an overview of the intestinal protozoa. Notice that the Intestinal Protozoa are divided into:
• Ameboid Intestinal Protozoa
• Ciliated Intestinal Protozoa
• Flagellated Intestinal Protozoa
• Sporozoan Intestinal Protozoa (which includes both the Coccidia and the Microsporidia)
• Click on Life Cycles.

1. Use the information on the first screen to give an example of an ameboid intestinal protozoan that lives a direct life cycle.

2. Click on the next screen.  Use the buttons. How does transmission occur in amoebic dysentery?

3. Using the same screen and buttons, name and describe the stages in the infection of Amoebic Dysentery, caused by Entamoeba hystolytica. Include information on what form is ingested and what form is released in the feces.

Ciliated Intestinal Protozoa 

4. Click on the next screen. Name the only ciliated intestinal protozoa to cause human disease.

5. Using the same screen, explain what form is ingested and what form is released in the feces.

6. Using the same screen, name the animal that serves as the primary host.

7. Use the next screen to explain how humans become accidental hosts.

Flagellated Intestinal Protozoa (Text reference: p. 625-6)

8. Click on the next screen. Giardia lamblia is a flagellated intestinal protozoan. Describe how transmission occurs with Giardia lamblia.

9. Using the same screen, how long can the cyst of Giardia lamblia survive?

10. Using the same screen, the primary reservoir for Giardia lamblia is unclear. Where has Giardia lamblia been isolated?

11. Use the next screen to describe the stages in the life cycle of Giardia lamblia which includes humans as a host.

Sporozoan Intestinal Protozoa - Coccidia  (Text reference: p. 627-8)

12. Use the next screen to answer questions about Cyclospora. 

a. Who is the only known host of Cyclospora? 

b. What have outbreaks been associated with?

c. What is the form that is released in the feces and what is it resistant to?

13. Click to the next screen. Use the eye icon to answer the following.

a. Who is the only known host of Isospora? 

b. What have outbreaks been associated with?

c. What is the form that is released in the feces?

14. Click forward two screens. Name the three main types of intestinal coccidia. (Note: You have just studied two of these three!)

15. Using the same screen, explain the derivation of the name Cryptosporidium.  (Text reference: p. 626-7)

16. Use the next screen. What stage of the sporozoan life cycle is released in the feces?

17. Using the same screen, what life threatening infection is Crytosporidium parvum responsible for?

Section 2: Intestinal Protozoa Epidemiology 

Click on "Epidemiology" from the list at the left of your screen. You will now do a review of the epidemiology of the intestinal protozoa. Use the information on the screen to answer questions 18-24.

18. List the infective stage and means of transmission for Entamoeba histolytica, an amoeboid intestinal protozoa.

19. List the infective stage and means of transmission for Balantidium coli, a ciliated intestinal protozoa.

20. List the infective stage and means of transmission for Giardia lamblia , a flagellated intestinal protozoa.

(Skip Dientamoeba fragilis)

21. List the infective stage and means of transmission for Cryptosporidium parvum, a sporozoan intestinal protozoa.

22. List the infective stage and means of transmission for Cyclospora, a sporozoan intestinal protozoa.

23. List the infective stage and means of transmission for Isospora belli, a sporozoan intestinal protozoa.

24. List the infective stage and means of transmission for Microsporidia, a sporozoan intestinal protozoa.

Surveillance for Waterborne Disease Outbreaks -- United States   

Next you will study waterborne diseases, many of which involve protozoa!  You will, however, look at bacteria and viruses which are also responsible for many waterborne disease outbreaks.

25 a. Click to the next screen. In areas of the world where sewage and water treatment plants are well designed and monitored, such as in the U.S., what are the two means by which most intestinal protozoal infections occur?

b. Name the two intestinal protozoans most commonly responsible for these infections.

26. a. Use the same screen. In areas of the world where sewage and water treatment plants are inadequate, name the intestinal protozoan most commonly responsible for infection.

b. Name the life threatening infection caused by this protozoan.

27. Click forward two screens and use the eye icons. What are the known reservoirs for Giardia?  (Text reference: p. 787-90 & 613-4)

28. Use the same screen and icons. Day care settings are at high risk for what type of transmission of Giardia?  (Text reference: p. 787-90 & 613-4)

29. Use the same screen and icons. What is the only country in the world where Giardia has not been found and why?  (Text reference: p. 787-90 & 613-4)

30. Click on the next screen and use the eye icon. What are the known reservoirs for Cryptosporidium?   (Text reference: p. 787-90 & 614-5)

Next you will use a CDC link to look at the latest Surveillance Summary for Waterborne-Disease Outbreaks ---
United States, 1997-1998. It is from the MMWR, 5/26/00, Vol 49, Surveillance Summary 4.  Since it takes a couple of years to gather all the needed statistics, this is the latest summary that has been produced on waterborne outbreaks in the U.S..

Here is the link:  http://www.cdc.gov/mmwr/preview/mmwrhtml/ss4904a1.htm

Scroll down to Figure 4, which is near the bottom of the article. Use the 1997-1998 statistics in Figure 4 to answer the following questions.

31. List the data from the upper left pie chart on Etiologic Agent.  List the organisms/diseases listed and the %'s for each.

32. Look at the footnotes for the charts.  What do AGI and NLV stand for?

So here's what we have (Note: You are to fill in the %'s below):

• The protozoan, Cryptosporidium parvum, leading the pack at ________%.
• The bacterium, E. coli, coming in second at ________%.
• AGI, with no tests run to determine the cause, at ________%. (So who knows where this really fits into the stats!!)
• The viruses, Noroviruses (formerly Norwalk-like Viruses, NLV), following close behind at ________%.
• The bacterium, Shigella sonnei, bringing up the rear at ________%.

33. Use the upper right pie chart on Type of Exposure. In this summary, water is only divided into treated or fresh water. List the two categories given and the % for each.

34.  Look at the two bottom pie charts.  Now they separate fresh water and treated water, then give the etiologic agents found in each type.  In which type, fresh or treated water, is Cryptosporidium parvum the real problem and what is the %?

Yes, C. parvum survives through treated water!!!  That means that the main chemical - chlorine - which is used to treat water does not effect Cryptosporidium!!!  Major bummer!!!  You will learn more about this as the lesson continues.

35.  Using the bottom left pie chart, what group of viruses has appeared as a major cause of waterborne infectious disease in fresh water?

36. Using the bottom two pie charts, tell me about E. coli in both treated and fresh water.

Section 3: Intestinal Protozoa Disease

Gastroenteritis  

Gastroenteritis is the presenting symptom with intestinal protozoa. But each protozoan infects in its own way and causes its own form of gastroenteritis.

37. Return to the CD and click on the next screen. For each organism listed below, describe the type of diarrhea that results, the site of invasion, the mechanism of invasion, and the clinical signs of infection.

a. Entamoeba histolytica.

b. Balantidium coli.

c. Giardia lamblia.

d. Cryptosporidium parvum.

e. Isospora belli.

f. Cyclospora.

g. Microsporidia.

Now you need to look at the other culprits, E. coli, Norwalk-like Viruses, and Shigella to review the type of gastroenteritis each of them causes.

38. Turn to pages 614-16 in the text to review the information on E. coli Gastroenteritis. Describe the type of diarrhea that results, the site of invasion, the mechanism of invasion, and the clinical signs of infection.

39. Turn to pages 619-20 in the text to review the information on Norwalk Virus Gastroenteritis. Describe the type of diarrhea that results, the site of invasion, the mechanism of invasion, and the clinical signs of infection.

40. Turn to pages 613-14 in the text to review the information on Shigellosis. Describe the type of diarrhea that results, the site of invasion, the mechanism of invasion, and the clinical signs of infection.

Section 4: Intestinal Protozoa - Control, Physical & Chemical   (Text reference: p. 625-8)

Next you will look at how we can protect our water supplies from outbreaks!

41. Click on the next screen. What must be done to water supplies to assure removal of Giardia? Why?

42. Click on the next screen. What must be done to water supplies to assure removal of Cryptosporidium? Why?

With Cryptosporidium parvum, the water supply must be both chlorinated and filtered!  This works fine as long as the water table stays at its normal level.  But in times of heavy rains or flooding, the water table rises.  When this happens, water treatment plants lose their ability to adequately filter water of Cryptosporidium (and other potentially harmful organisms).  That's why when it rains alot and/or floods, it is recommended that you boil your water.  The EPA recommends a vigorous 1-minute boil.  To learn more about this, use this link: http://www.epa.gov/ogwdw000/faq/emerg.html

Persons infected with HIV have to be especially careful about their water.  Here are the recommendations:

• Don’t drink water straight from lakes, rivers, streams, or springs.
• Because you cannot be sure if your tap water is safe, you may wish to avoid tap water, including water or ice from a refrigerator ice-maker, which is made with tap water.
• Always check with the local health department and water utility to see if they have issued any special notices for people with HIV about tap water.
• You may also wish to boil or filter your water, or to drink bottled water.
• Processed carbonated (bubbly) drinks in cans or bottles should be safe, but drinks made at a fountain might not be because they are made with tap water.
• If you choose to boil or filter your water or to drink only bottled water, do this all the time, not just at home.
• Boiling is the best way to kill germs in your water. Heat your water at a rolling boil for 1 minute. After the boiled water cools, put it in a clean bottle or pitcher with a lid and store it in the refrigerator. Use the water for drinking, cooking, or making ice.
• Water bottles and ice trays should be cleaned with soap and water before use. Don’t touch the inside of them after cleaning. If you can, clean your water bottles and ice trays yourself.

There is a publication called "Cryptosporidium and Water:  A Public Health Handbook" which may be of interest to you.  It's link is:  http://www.cdc.govncidod/diseases/crypto/crypto.pdf

(NOTE: This is a pdf file and will open slowly! Give it time!)

43. Return to the CD. Use the eye icon on the same screen. What is the best way to disinfect drinking water while camping?

44. Use the next screen. There are no drugs available to treat which protozoan infection?

Part 3: Main Menu ---- Bookcase --- Tissue and Blood Protozoa

Tissue and blood protozoa refers to a subgroup of protozoa that inhabit either the tissues or the blood of their host. It includes members from the groups: amoeboid protozoa, flagellated protozoa, and sporozoan protozoa.

• Click on Tissue and Blood Protozoa.
• Click on the audiotape icon (Play Audio). It is the top icon on the left side. Listen to the tape.
• Click on Life Cycles.

2. Use the same screen to name the flagellated protozoa that infect tissues and blood.  

3. Use the same screen to name the sporozoan protozoa that infect tissues and blood.  

Trichomonas vaginalis - Flagellated Protozoa of the Blood and Tissues.  (Text reference: p. 657-8)

4. Now you will concentrate on the flagellated protozoa that inhabit tissues and blood. The first one mentioned is Trichomonas vaginalis. Humans are the only host for this parasitic protozoan. How does transmission occur?

5. Use the same screen to describe the life cycle of Trichomonas vaginalis.

6. Use the Glossary portion of the CD-ROM, or your textbook, to determine the infection caused by Trichomonas vaginalis.

How to use the Glossary:

• Click on Tools, which is the green button found on the upper left of the screen.
  
• Click on Glossary, which is the yellow button to the left of the TV screen.
  
• Click on the letter T.
• Scroll through the T's until you get to T. vaginalis (Trichomonas vaginalis).
  
• Click once on the genus-species name (T. vaginalis). The information given will appear below the name. It will include the name of the STD (sexually transmitted disease).
• Click on the audio icon to the left of the genus-species name (T. vaginalis) to hear the pronunciation of the organism.

• Now return to the main CD and the next disease by clicking 9 times on the right arrow button at the bottom of the screen. (Stop when you get to the first screen on Toxoplasma gondi! It says "Life Cycle - Toxoplasma Gondi" at the top.)

Toxoplasma gondi - Sporozoan Protozoa of the Blood and Tissues (Text reference: p. 755-7)

7. Use the information on the screen. What are the animal hosts for Toxoplasma gondi?

8. Use the same screen. Transmission of Toxoplasma gondi can occur by different stages in its life cycle, depending on the mode of transmission. Please explain what stages can be infective and how they are transmitted.

9. Use the same screen. How is Toxoplasma gondi spread to humans from cat litter?

10. Click forward 2 screens.What is the infective form (stage) of Toxoplasma gondi that is shed in the cat feces?

11. Use your textbook, pages 755-7, to answer the following questions concerning Toxoplasma gondi.

a. What is the name of the disease caused by Toxoplasma gondi?

b. What percent of infected people actually develop symptoms?

c. List the three categories of patients.

d. Describe the symptoms of toxoplasmosis in the immunologically normal patient. How long do symptoms last? How are they treated?

e. Describe the symptoms of congenital (or fetal) toxoplasmosis. What are the consequences if it occurs during the first trimester? What are the consequences if it occurs in the last trimester?

f. Describe the symptoms of toxoplasmosis in the immunodeficient patient, such as an AIDS patient.What might be the outcome of infection in these patients?

Plasmodium - Sporozoan Protozoa of the Blood and Tissues   (Text reference: p. 731-4)

12. Return to the CD. Plasmodium is another sporozoan protozoa which infects blood and tissues. Use the next screen to name the four species of Plasmodium which cause malaria.

13. Click on the next screen. What type of mosquito is the insect vector for Plasmodium?

14. Use the same screen. What is the infective form (stage) for Plasmodium in humans? (What form does the mosquito inject into the person?)

Note: Your are done with the CD! Do not proceed any further! 

Note: This is a REQUIRED section! Every student MUST do these diseases! (It is NOT optional. It will NOT be covered by a group activity.)

There are seven parasitic protozoan infections/diseases which we want to concentrate on in this course. The names of those infections and their text references are given below. For each disease, I've given you an Internet reference link. You do not have to use the link I've provided and are free to utilize other references.

• Giardiasis - pages 625-6;    
  
• CDC link: http://www.cdc.gov/ncidod/dpd/parasites/giardiasis/default.htm
• Cryptosporidiosis (also known as Coccidial Diarrhea) - pages 626-7;  
  
• CDC link:  http://www.cdc.gov/ncidod/dpd/parasites/cryptosporidiosis/default.htm   
  
• CDC link:  http://www.cdc.gov/hiv/pubs/brochure/oi_cryp.htm
• Amebiasis (also known as Amoebic Dysentery) - pages 627-9;   
  
• CDC link:  http://www.cdc.gov/ncidod/dpd/parasites/amebiasis/default.htm
• Trichomoniasis (also known as Vaginosis or Vaginitis) - pages 657-8; 
  
• CDC link:  http://www.cdc.gov/ncidod/dpd/parasites/trichomonas/default.htm
• Malaria - pages 731-4;     
  
• CDC link: http://www.cdc.gov/ncidod/dpd/parasites/malaria/default.htm
• Toxoplasmosis in the Immunocompromised Patient (ex: AIDS patient) & Congenital (Fetal) Toxoplasmosis - pages 755-7;   
  
• CDC link:  http://www.cdc.gov/ncidod/dpd/parasites/toxoplasmosis/default.htm 
  
• CDC link: http://www.cdc.gov/hiv/pubs/brochure/oi_toxo.htm      
  
• Note: Distinguish between Toxoplasmosis in AIDS patients and Fetal Toxoplasmosis
• Cyclosporiasis - pages 627-8;    
  
• CDC link: http://www.cdc.gov/ncidod/dpd/parasites/cyclospora/default.htm

An important area for you is the employment of isolation precautions for patients suffering from these infection/diseases. To complete this part of the assignment, you will use Appendix A of the Isolation Precautions Guidelines . You printed this document from the CDC. Please recall that we expanded the patient population description of diapered and incontinent patients with regard to gastroenteral infections/diseases.

For each disease you will summarize the following:  1) name of disease, 2) causative agent(s) and its description, 3) symptoms, 4) incubation period, 5) pathogenesis, 6) epidemiology, 7) treatment (Note: Be specific!), 8) prevention, 9) control, and 10) isolation precautions employed in a healthcare setting for the disease (including information contained in footnotes).

Disease Information:

• The name of the disease is usually given to you. (How else would you know what we're studying!)
• The causative agent(s) is (are) the microorganism(s), known as the pathogen(s), causing the disease. The name the pathogen and a brief description of the organism are usually given. (Examples are: Genus-species name of the bacterium? Gram-positive or negative?  Rod or cocci? Aerobic or facultative anaerobe or anerobobe?  Motile? Other characterisitics of the bacterium?)
• The symptoms are what the patient experiences and healthcare workers recognize as part of their diagnosis.
• The incubation period is the range of time during which the disease begins to develop within the patient.
• The pathogenesis is the process by which the disease develops. What is it about the pathogen that enables it to cause this disease? Does the pathogen have particular virulence factors? How does the disease progress within the patient?
• The epidemiology is the study of factors influencing the frequency and spread of the disease. How is it spread? Are there typical age groups that are effected? Are there seasonal effects? How does transmission most frequently occur?
• The treatment involves the therapy measures employed. These may include antimicrobials, fluid & electrolyte replacement, and controlling the symptoms (such as fever). Note: You must be specific in your answers! For example, you cannot simply state that a particular disease is treated by antiprotozoals. There are many antiprotozoals. Which ones are specifically used for the disease you are researching???
• The prevention are measures used to stop the transmission of the disease. Prevention is before the disease happens in a person or to prevent its spread within a community.  Examples are immunizations, good hygiene practices, isolating infected children.
• The control are measures used to control the spread of the disease. Now the disease is in the person or the community.  We must make every effort to stop it from spreading any further!  Ex: mosquito control, good sanitation systems, and use of isolation precautions.
• The isolation precautions always include the use of Standard Precautions.  They may include the use of Airborne, Droplet, and/or Contact Precautions. Use Appendix A from the Isolation Precaution Guidelines to find this information. When you use this information during the semester, you must include any additional notes given in the footnotes of the appendix. (For example, you would give information about the duration of the illness.) Please recall that we expanded the patient population description of diapered and incontinent patients with regard to gastroenteral infections/diseases. Here is the link to the appendix: http://www.cdc.gov/ncidod/hip/isolat/isoapp_a.htm

Causative agent(s): Give the name(s) and a description.

Symptoms.

Incubation Period.

Pathogenesis.

Epidemiology.

Treatment.

Prevention.

Control.

Isolation precautions employed.

2. Cryptosporidiosis (also known as Coccidial Diarrhea)

Causative agent(s): Give the name(s) and a description.

Symptoms.

Incubation Period.

Pathogenesis.

Epidemiology.

Treatment.

Prevention.

Control.

Isolation precautions employed.

3. Amebiasis (also known as Amoebic Dysentery)

Causative agent(s): Give the name(s) and a description.

Symptoms.

Incubation Period.

Pathogenesis.

Epidemiology.

Treatment.

Prevention.

Control.

Isolation precautions employed.

4. Trichomoniasis (also known as Vaginosis or Vaginitis)

Causative agent(s): Give the name(s) and a description.

Symptoms.

Incubation Period.

Pathogenesis.

Epidemiology.

Treatment.

Prevention.

Control.

Isolation precautions employed.

5. Malaria

Causative agent(s): Give the name(s) and a description.

Symptoms.

Incubation Period.

Pathogenesis.

Epidemiology.

Treatment.

Prevention.

Control.

Isolation precautions employed.

6. Toxoplasmosis in the Immunocompromised Patient (ex: AIDS patient) & Congenital (Fetal) Toxoplasmosis

Causative agent(s): Give the name(s) and a description.

Symptoms.

Incubation Period.

Pathogenesis.

Epidemiology.

Treatment.

Prevention.

Control.

Isolation precautions employed.

7. Cyclosporiasis

Causative agent(s): Give the name(s) and a description.

Symptoms.

Incubation Period.

Pathogenesis.

Epidemiology.

Treatment.

Prevention.

Control.

Isolation precautions employed.

Part 5: Personal Reflection.

What field do you plan to enter?

Please reflect upon how your knowledge of parasitic protozoa and protozoan infections will help you in your chosen career. Please be specific and thorough in your answer. Your response is worth 15% of your grade on this assignment.

In order for the questionnaire to serve as an accurate gauge of what you learned, it is necessary that you stop and fill it out right now. It will only take a few minutes.

Your answers to the post-assignment assessment will serve as a guide to you, and me, to determine how much you learned as a result of doing the assignment. Here's how to proceed:

• First, try to answer the questions as thoroughly as you can without looking back in the assignment.
• If you find you are "stumped" and don't know the answer, this would indicate you didn't really understand the process or concept. Go back in the assignment and review this part. Then complete the question.
• Answer all the questions as thoroughly as possible. This post-assessment is worth 15% of your grade on the assignment. It will become an important study tool for exams. The more thoroughly you review and draw together concepts now, the closer you will be to being prepared for exams.

2. Please describe what you know about congenital (fetal) toxoplasmosis.

3. Please describe what you know about malaria.

4. Please explain the meaning of the following terms:

Insect vector.

Trophozoite.

Cyst.

Oocyst.

5. Give me the name of a protozoal disease that you are aware of (besides the ones mentioned above). Describe the signs and symptoms of the disease. Describe any treatments for the disease that you are aware of.

You must be prepared for questions on the following:

• Protozoa Classification:
• The two broad categories of parasites.
• An in-depth description of a protozoan. Include information about its cytoplasm, cell wall, and possible shapes.
• What is meant by a "direct life cycle."
• Describe the trophozoite and the cyst stages in the protozoal life cycle.
• Ameboid Intestinal Protozoa:
• How transmission occurs in amoebic dysentery.
• Name and describe the stages in the infection of amoebic dysentery, caused by Entamoeba hystolytica.
• Name the form that is ingested and the form that is released in the feces in amoebic dysentery.
• Flagellated Intestinal Protozoa:
• The infective stage and means of transmission for Giardia lamblia.
• How long the cyst of G. lamblia can survive and where Giardia lamblia has been isolated.
• The stages in the life cycle of Giardia lamblia which includes humans as a host.
• The known reservoirs are for Giardia.
• What mode of transmission of Giardia day care settings are at high risk for.
• Sporozoan Intestinal Protozoa:
• What stage of the sporozoan life cycle, Crytosporidium parvum, is shed in the feces, and what stage of C. parvum attaches to the intestinal villi within the new host, and the known reservoirs for Cryptosporidium.
• The infective stages and means of transmission for Cryptosporidium parvum and Cyclospora.
• Water Treatment:
• The two intestinal protozoans most commonly responsible for infections in areas of the world where sewage and water treatment plants are well designed and monitored and the means by which they do it.
• The intestinal protozoan most commonly responsible for infection in areas of the world where sewage and water treatment plants are inadequate.
• What must be done to water supplies to assure removal of Giardia.
• What must be done to water supplies to assure removal of Cryptosporidium.
• The best way to disinfect drinking water while camping.
• The recommendations for persons infected with HIV for their water.
• Gastroenteritis:
• For each organism listed below, describe the type of diarrhea that results, the site of invasion, the mechanism of invasion, and the clinical signs of infection.
• Entamoeba histolytica
• Giardia lamblia
• Cryptosporidium parvum
• Cyclospora
• E. coli
• Norovirus (formerly Norwalk-like virus)
• Shigella
• Flagellated Protozoa of the Blood and Tissues:
• How transmission of Trichomonas vaginalis occurs.
• The life cycle of T. vaginalis.
• The infection caused by T. vaginalis.
• Sporozoan Protozoa of the Blood and Tissues:
• Toxoplasma gondi:
• What stages of Toxoplasma gondi can be infective and how they are transmitted.
• The infective form of Toxoplasma gondi that is shed in cat feces and how T. gondi is spread to humans from the cat feces.
• The disease caused by Toxoplasma gondi, what percent of infected people actually develop symptoms, and list the three categories of patients.
• The symptoms of toxoplasmosis in the immunologically normal patient, how long symptoms last, and how they are treated.
• The symptoms of congenital (or fetal) toxoplasmosis, what the consequences are if it occurs during the first trimester, and what the consequences are if it occurs in the last trimester.
• The symptoms of toxoplasmosis in the immunodeficient patient and what might be the outcome of infection in these patients.
• Plasmodium:
• The four species of Plasmodium which cause malaria.
• The type of mosquito that serves as the vector for Plasmodium.
• The infective form for Plasmodium in humans.
• For each disease you will summarize the following:  1) name of disease, 2) causative agent(s) and its description, 3) symptoms, 4) incubation period, 5) pathogenesis, 6) epidemiology, 7) treatment (Note: Be specific!), 8) prevention, 9) control, and 10) isolation precautions employed in a healthcare setting for the disease.

• Giardiasis - pages 625-6;    
  
• CDC link: http://www.cdc.gov/ncidod/dpd/parasites/giardiasis/default.htm
• Cryptosporidiosis (also known as Coccidial Diarrhea) - pages 626-7;  
  
• CDC link:  http://www.cdc.gov/ncidod/dpd/parasites/cryptosporidiosis/default.htm   
  
• CDC link:  http://www.cdc.gov/hiv/pubs/brochure/oi_cryp.htm
• Amebiasis (also known as Amoebic Dysentery) - pages 627-9;   
  
• CDC link:  http://www.cdc.gov/ncidod/dpd/parasites/amebiasis/default.htm
• Trichomoniasis (also known as Vaginosis or Vaginitis) - pages 657-8; 
  
• CDC link:  http://www.cdc.gov/ncidod/dpd/parasites/trichomonas/default.htm
• Malaria - pages 731-4;     
  
• CDC link: http://www.cdc.gov/ncidod/dpd/parasites/malaria/default.htm
• Toxoplasmosis in the Immunocompromised Patient (ex: AIDS patient) & Congenital (Fetal) Toxoplasmosis - pages 755-7;   
  
• CDC link:  http://www.cdc.gov/ncidod/dpd/parasites/toxoplasmosis/default.htm 
  
• CDC link: http://www.cdc.gov/hiv/pubs/brochure/oi_toxo.htm      
  
• Note: Distinguish between Toxoplasmosis in AIDS patients and Fetal Toxoplasmosis
• Cyclosporiasis - pages 627-8;    
• CDC link: http://www.cdc.gov/ncidod/dpd/parasites/cyclospora/default.htm

This assignment is worth a 2% of your final grade in the course. The grade for the assignment is based upon a 100-point scale. You will be evaluated according to the following scale:
 

Grading (Based on a 100-point scale.)

Completion, quality, and correctness of part one questions - 5 points possible Completion, quality, and correctness of part two questions - 20 points possible Completion, quality, and correctness of part three questions - 10 points possible Completion, quality, and correctness of part four summary- 35 points possible Completeness of personal reflection - 15 points possible Completion of the post-assessment questionnaire - 15 points possible

Please note that each portion of the assignment is worth a maximum number of points. You can earn all or some of those points, depending on the quality of your work.

If the assignment is turned in after the scheduled due date, there will be a minimum of 10 points subtracted from the total score. Total points subtracted will be determined by the degree of lateness. The later an assignment is turned in, the greater the points subtracted.

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