This clinical simulation deals with tetanus, a life-threatening infection. Tetanus is caused by an exotoxin synthesized by the bacterium Clostridium tetani. The toxin is released after a wound is infected by this bacterium. This toxin causes muscle spasm, which may lead to death if not treated correctly. Spasms of the masseter (jaw) muscles have led to the name lockjaw. Every time a patient with a wound is examined, the physician must determine the appropriate immunization for the prevention of tetanus. This simulation will help you understand the different approaches to the prevention of tetanus as well as the indications for each approach. The immunologic concepts addressed in this problem are fundamental to the understanding of many other diseases.

When you have completed this activity you should be able to

1) define and give several examples of immunity.

2) compare and contrast the terms antigen and antibody.

3) differentiate between active and passive immunization and be able to give examples of each.

4) compare and contrast the primary and secondary immune responses in terms of their time course and magnitude.

5) state differences between adaptive (acquired) and innate immunity, as well as between specific and non- specific immunity.

6) state which cell types are involved with cell-mediated and antibody-mediated immunity.

7) compare tetanus toxin and tetanus toxoid relative to toxicity and ability to cause an immune response.
Question: Using the following graph, how many days does it take to detect antibody in the serum after a primary and a secondary immunization, respectively? The arrows above "Ag" refer to the times when antigen injections were given to the patient. The term "mg% Antibody" refers to the amount of antibody (in milligrams) detected in 100 ml of the patient's serum.

(A) 15 and 10

(B) 10 and 15

(C) 10 and 4

Each of the four group members has a different case history. First, deal with your own patient. After reading your patient's case history, decide the therapy you would use, the reasons for the choice, and the consequences of alternative therapy. Next, fill out your answer sheet concerning your patient. After everybody has finished his/her problem, the group member with the first patient should present that case history to the other three group members and allow them time to individually decide therapy, the reasons for their choice, and the consequences of alternative therapy. They should then fill out their answer sheets for that patient (i.e., commit themselves to therapy before the group discussion). The group member who has the first patient should then present his/her choice of therapy to the group and defend it. Members who disagree with this choice, the reasons for it, or consequences of it should present their ideas and defend them. After discussion of the first patient is completed, compare your answers with those on the correct answer sheet for each patient.

This process will then be repeated for the other three cases. Patients should be presented in numerical order. At first glance, the patients' cases seem repetitious, but there are subtle and important differences that will help you decide how to treat the patient! These will be highlighted with italics and bolding.

A 25 year old ex-serviceman arrives at your office with a one-inch laceration (cut) of his right forearm caused by a dog bite through his wool shirt. The dog, which belongs to a neighbor, has had rabies shots and is chained so that he can be watched to be certain he doesn't have rabies. But your real concern is possible infection, especially tetanus, since that is the most immediate life-threatening consequence of the event. Joe tells you that he received a tetanus vaccine when he joined the Army after graduating from high school. On the therapy sheet, first decide which treatments would be effective. Then decide which would be best, and write down your reasons for your decision. Indicate your therapy on the "Joe Alsop" part of the Tetanus Immunity Clinical Problem Answer Sheet (next page).

Check the box(es) that indicate(s) the preferred therapy for each patient. Then briefly write the reasons for your choice in the space provided. Finally, describe the consequences of each of the other therapies in the space provided under each therapy. Commit yourself in writing before the discussion begins and have your group mates do the same. The answer sheet will not be collected.

1. Give tetanus toxin.

2. Give tetanus toxoid.

3. Give tetanus antitoxin (horse).

4. Give tetanus immune globulin (human).

1. Give tetanus toxin.

2. Give tetanus toxoid.

3. Give tetanus antitoxin (horse).

4. Give tetanus immune globulin (human).

1. Give tetanus toxin.

2. Give tetanus toxoid.

3. Give tetanus antitoxin (horse).

4. Give tetanus immune globulin (human).

1. Give tetanus toxin.

2. Give tetanus toxoid.

3. Give tetanus antitoxin (horse).

4. Give tetanus immune globulin (human).

The purpose of this exercise is to allow you to apply your knowledge of active vs passive immunization and primary vs secondary immune response to a common medical problem.

Each of the four group members has a different case history. First, deal with your own patient. After reading your patient's case history, decide the therapy you would use, the reasons for the choice, and the consequences of alternative therapy. Next, fill out your answer sheet concerning your patient. After everybody has finished his/her problem, the group member with the first patient should present that case history to the other three group members and allow them time to individually decide therapy, the reasons for their choice, and the consequences of alternative therapy. They should then fill out their answer sheets for that patient (i.e., commit themselves to therapy before the group discussion). The group member who has the first patient should then present his/her choice of therapy to the group and defend it. Members who disagree with this choice, the reasons for it, or consequences of it should present their ideas and defend them. After discussion of the first patient is completed, compare your answers with those on the correct answer sheet for each patient.

This process will then be repeated for the other three cases. Patients should be presented in numerical order. At first glance, the patients' cases seem repetitious, but there are subtle and important differences that will help you decide how to treat the patient! These will be highlighted with italics and bolding.

Second Patient: Kathleen Williams
A 65-year-old woman has just come into your office with a deep puncture wound in the calf of her leg caused by a pitchfork in a gardening accident. She could not remember if she had previously been immunized to tetanus. After treating the wound, what would you do to prevent tetanus? On the therapy sheet, first decide which treatments would be effective. Then decide which would be best, and write down your reasons for your decision. Indicate your therapy on the "Kathleen Williams" part of the Tetanus Immunity Clinical Problem Answer Sheet. (next page)

The purpose of this exercise is to allow you to apply your knowledge of active vs passive immunization and primary vs secondary immune response to a common medical problem.

Each of the four group members has a different case history. First, deal with your own patient. After reading your patient's case history, decide the therapy you would use, the reasons for the choice, and the consequences of alternative therapy. Next, fill out your answer sheet concerning your patient. After everybody has finished his/her problem, the group member with the first patient should present that case history to the other three group members and allow them time to individually decide therapy, the reasons for their choice, and the consequences of alternative therapy. They should then fill out their answer sheets for that patient (i.e., commit themselves to therapy before the group discussion). The group member who has the first patient should then present his/her choice of therapy to the group and defend it. Members who disagree with this choice, the reasons for it, or consequences of it should present their ideas and defend them. After discussion of the first patient is completed, compare your answers with those on the correct answer sheet for each patient.

This process will then be repeated for the other three cases. Patients should be presented in numerical order. At first glance, the patients' cases seem repetitious, but there are subtle and important differences that will help you decide how to treat the patient! These will be highlighted with italics and bolding.

Third Patient: Tommy Criton

A 5-day-old baby has just been brought to your office by his mother, a Peace Corps nurse. Mother and baby have just flown in from Africa, where the baby was born. The mother is concerned because the baby was cared for by a native friend. She discovered that the umbilicus (umbilical cord) of the baby was coated with cow manure, a primitive local custom, and she is concerned about neonatal tetanus. You find out that the mother was vaccinated for tetanus when she joined the Peace Corps two years earlier. What do you plan to do? On the therapy sheet, first decide which treatments would be effective. Then decide which would be best, and write down your reasons for your decision. Indicate your therapy on the "Tommy Criton" part of the Tetanus Immunity Clinical Problem Answer Sheet. (next page)

The purpose of this exercise is to allow you to apply your knowledge of active vs passive immunization and primary vs secondary immune response to a common medical problem.

Each of the four group members has a different case history. First, deal with your own patient. After reading your patient's case history, decide the therapy you would use, the reasons for the choice, and the consequences of alternative therapy. Next, fill out your answer sheet concerning your patient. After everybody has finished his/her problem, the group member with the first patient should present that case history to the other three group members and allow them time to individually decide therapy, the reasons for their choice, and the consequences of alternative therapy. They should then fill out their answer sheets for that patient (i.e., commit themselves to therapy before the group discussion). The group member who has the first patient should then present his/her choice of therapy to the group and defend it. Members who disagree with this choice, the reasons for it, or consequences of it should present their ideas to the group and defend them. After discussion of the first patient is completed, compare your answers with those on the correct answer sheet for this patient.

This process will then be repeated for the other three cases. Patients should be presented in numerical order. At first glance, the patients' cases seem repetitious, but there are subtle and important differences that will help you decide how to treat the patient! These will be highlighted with italics and bolding.

A 35-year-old migrant worker arrives at your office with a three-inch jagged wound on her head. She was hit with a brick. Ten years ago she fell off a tractor while tilling a field and received a six-inch laceration (cut) of her left thigh. At that time, she was given tetanus antitoxin from a horse because she had never been immunized against tetanus. But she and her fellow migrant workers left town before her physician could immunize her with tetanus toxoid. What do you do to prevent tetanus? On the therapy sheet, first decide which treatments would be effective. Then decide which would be best, and write down your reasons for your decision. Indicate your therapy on "Alice Whipple" part of the Tetanus Immunity Clinical Problem Answer Sheet.

Check the box(es) that indicate(s) the preferred therapy for all patients. Then briefly write the reasons for your choice in the space provided. Finally, describe the consequences of each of the other therapies in the space provided under each therapy. Commit yourself in writing before the discussion begins. The answer sheet will not be collected.

1. Give tetanus toxin.

2. Give tetanus toxoid.

3. Give tetanus antitoxin (horse).

4. Give tetanus immune globulin (human).

1. Give tetanus toxin.

2. Give tetanus toxoid.

3. Give tetanus antitoxin (horse).

4. Give tetanus immune globulin (human).

1. Give tetanus toxin.

2. Give tetanus toxoid.

3. Give tetanus antitoxin (horse).

4. Give tetanus immune globulin (human).

1. Give tetanus toxin.

2. Give tetanus toxoid.

3. Give tetanus antitoxin (horse).

4. Give tetanus immune globulin (human).

Congratulations, you have finished the clinical problems! Now you should answer these posttest questions below, individually. After you’ve completed them, check your answers against the posttest answer sheet.

Instructions: Please mark your answers to the following questions on this sheet. Choose the one correct or best answer.

1. A 23 year old medical student had four injections of diphtheria, pertussis, and tetanus (DPT) in her first year of life and a booster at age 5, but no booster for tetanus after that. She was bitten by a mouse while doing an experiment. She should be given

1. (A) tetanus toxoid, which will passively immunize her.

2. (B) tetanus antiserum (human), which will passively immunize her.

3. (C) tetanus toxoid, which will actively immunize her.

4. (D) tetanus antiserum (human), which will stimulate a memory response.

1. (A) a mixture of tetanus toxoid and tetanus antiserum (human) as one injection.

2. (B) a tetanus toxoid injection now, and an injection of tetanus antiserum (human) three weeks later.

3. (C) separate injections of tetanus toxoid and tetanus antiserum (human) in different sites now.

4. (D) a tetanus antiserum (horse) injection this visit.

3. A 3-year-old boy has received the standard DPT immunization series starting at 3 months of age. But he has no detectable antibody to diphtheria, pertussis, or tetanus and therefore is probably deficient in producing antibodies. He has a deep puncture wound in his foot, which he got while playing near his grandfather's barn. The best treatment to prevent tetanus for him would be

1. (A) active immunization with tetanus toxoid.

2. (B) active immunization with tetanus toxin.

3. (C) passive immunization with tetanus antiserum(horse).

4. (D) passive immunization with tetanus antiserum (human).

4. A healthy 6-year-old boy is being given tetanus antiserum (human) after getting a deep cut on his thigh, and no other treatment. His doctor should also consider

1. (A) that active immunization with tetanus toxoid should also be done, so he has prolonged protection.

2. (B) the possibility that serum sickness will occur.

3. (C) the possibility he may develop an IgE response.

4. (D) that his blood type and that of the antiserum donor must match

5. Serum sickness can be a serious problem after which of the following?

1. (A) Injection of tetanus toxoid

2. (B) Injection of tetanus antiserum (horse)

3. (C) Injection of tetanus antiserum (human)

4. (D) Injection of tetanus toxin

6. Active immunization after exposure to an infectious disease can be done to prevent that disease if

1. (A) the incubation period of the disease is longer than the time required to produce immunity to it.

2. (B) the immunity is antibody-mediated.

3. (C) the patient is very sick.

4. (D) the immunity is cell-mediated.

7. Your accident-prone, 10-year-old brother, has gotten a deep puncture wound on his foot. He had a standard DPT series as a baby and a tetanus booster at age 5 and again six months ago after another bad cut. The best treatment for him would be

1. (A) tetanus toxoid.

2. (B) tetanus immune globulin (human).

3. (C) tetanus toxoid and tetanus immune globulin (human) at two different sites.

4. (D) no tetanus immunization.

8. Diphtheria toxoid, like tetanus toxoid, is an effective inducer of active immunity because it is

1. (A) both immunogenic and antigenic.

2. (B) neither immunogenic nor antigenic.

3. (C) chemically identical to diphtheria toxin.

4. (D) an active toxin.

9. Immunity induced by tetanus toxoid injection is

1. (A) innate and nonspecific.

2. (B) cell-mediated and innate.

3. (C) antibody-mediated and active.

4. (D) nonspecific and passive.

10. Protection by administration of passive antibody from humans has one primary advantage over active immunization with toxoid, which is that it

1. (A) induces a memory response.

2. (B) gives higher antibody titers.

3. (C) provides antibody more quickly.

4. (D) provides antibody for a longer time.