front 1 Case 1 | back 1 You are at dinner with four of your friends. A local outbreak of Escherichia coli O157:H7 has been in the news. The news stories suggest that the source of infection was unpasteurized apple cider, but the group wants to know if hamburgers are safe. They remember that there was a big outbreak of E. coli associated with burgers from a fast-food restaurant in the Northwest. They turn to you, since you are a nurse. You tell them to order steaks. They ask if you're buying! |
front 2 Why steaks instead of hamburgers? | back 2 Beef is contaminated after processing. Steak comes from one part of the cow, where as beef can come from different parts of the cow which can include part of the intestine. steaks are muscle, one cut, so the bacteria is only on the surface of the meat and you can cook it off |
front 3 2. One of your friends acts disgusted and says she’ll order a salad instead. Will this guarantee her safety? Why or why not? | back 3 Fresh produce is often cross-contaminated with E. coli and other pathogenic microorganisms. Contamination through manure or contaminated water used in grow vegetables, improper washing, spreading of bacteria from unclean handlers, and contact with uncooked or contaminated meat could transfer to fruits and vegetables and cause infection. There have been many outbreaks associated with produce, and it's important to always wash your vegetables properly. But even doing so, this does not guarantee safety from infection. |
front 4 3. One of your friends says that her sister gives her baby apple juice every day. Should she stop? Explain your answer | back 4 Yes because apple juice is awful for babies, but besides the point. Ultimately though no, apple juice is not connected to unpasteurized apple cider. Apple juice is pasteurized so bacteria is not present. |
front 5 4. What are the symptoms of E. coli O157:H7 infection? | back 5 Vomitting, bloody diarrhea, abdominal cramps, occasional
fever |
front 6 5. Another friend says that his family has always eaten rare hamburgers and no one has ever gotten sick. He thinks it's all a bunch of overblown media coverage and says he will continue to eat his favorite delicacy, raw hamburger meat on crackers. What should you tell him? | back 6 When the beef is ground the bacteria on the surface is mixed into the meat and contaminates it. I would recommend that my friend stick to whole cuts of beef that can be seared on the outside to eliminate the surface bacteria. This would present a safer option to enjoy raw beef with a reduced risk of infection. |
front 7 Case 2 | back 7 Last week you were on a clinical rotation at the local hospital as
part of your second-year nursing program. On this rotation, your
instructor took a hands-off approach and left you on your own for
hours at a time. You spent most of your time hanging around at the
nursing station, following nurses as they went about their duties from
bed to bed, and listening to conversations between doctors and nurses
about patients. Then, one day one of the nurses who had just emerged
from his fourth trip to the bathroom collapsed behind his desk. He had
been losing weight and today looked especially pale. You ran to get
the attending physician who was just across the hall. He took one look
at the prostrate nurse and said something like "see dif" to
the nursing instructor who had arrived on the scene. She replied that
he had been on multiple antibiotics for the past few months in attempt
to treat a particularly nasty sinus infection. |
front 8 1. Your Internet search of all kinds of different spellings of "see dif" yields nothing. What section of your microbiology text would likely contain the help you need? What clues lead you in that direction? | back 8 Chapter 24 Digestive System Infections. |
front 9 2. Now that you've found the right category of infections, can you can identify what "see dif" is? | back 9 C.diff, also known as Clostridium difficile, is a bacterium that causes severe diarrhea and inflammation of the colon. C.difficile gains a foothold in a host when the gut microbiota is disturbed, usually as a result of antibiotic therapy. |
front 10 3. Your book has only a small paragraph on this infection. But now you know what to search for on the Internet to find more information. Your instructor wants you to report on the epidemiology of the infection. You find that it is referred to as an opportunist and this accounts for its epidemiological patterns. First of all, what is an opportunist? | back 10 An opportunistic microbe is a microbe that takes advantage of a immunocompromised host, for example the nurse was on antibiotic this can lower you immune system and can wipe out good bacteria and can create and opportunity for c-diff to strike. |
front 11 4. Part of an epidemiological description of an infection involves knowing who is most often affected by it. Let's consider opportunistic infections as a group. People in which age groups are most likely to suffer symptoms from an opportunistic infection? | back 11 Elderly or very young |
front 12 5. In this case the affected nurse is in his mid-30s. Is it his age or something else that predisposes him to the infection? Discuss. | back 12 No, the antibiotic made him more susceptible and likely his exposure came from working in the hospital, or he is immunocompromised. |
front 13 6. What is the major virulence factor for this microorganism? | back 13 Endospores are a major virulence factor because they withstand extremes like alcohol-based cleaning solutions and torrents of diarrhea attempting to flush them out of the lower GI. They also have the ability to stay in a dormant state until they are picked up by a new host. |
front 14 Case 3 | back 14 Your sister Pam called you last night, upset about her recent visit to the pediatrician (she has a 3-year-old son). Actually, she was upset about the discussion she had afterward with her husband, who was adamantly opposed to having their son vaccinated against hepatitis B virus (HBV). Pam called you because the doctor had convinced her that it was necessary. Her husband believes that hepatitis B is mostly acquired through sexual contact and drug use and that it's ridiculous to vaccinate a 3-year-old. Pam wants your advice before continuing this discussion with her husband. |
front 15 1. First of all, is Pam's husband correct about transmission of the virus? Elaborate. | back 15 Pam's husband is partially correct. It is true that Hepatitis B can be acquired through sexual contact. However, it can also be acquired through blood contact, from mother to child at birth, shared syringes, or contact with another's bodily fluids such as saliva. It is still quite possible for their child to get infected with Hepatitis B despite not having any type of sexual contact. |
front 16 2. How severe is this infection for young children? | back 16 Not common in children but if exposed HBV can be chronic and cause liver failure and liver disease in babies and young children. |
front 17 3. Pam says she'll also remind him that in the last year the newspapers have reported at least three hepatitis outbreaks traced to restaurants. Respond to her statement. | back 17 Hep A is the one that can be transmitted fecal-oral. |
front 18 4. While you're on the phone with Pam, her husband comes home from work. He hears your conversation and says in a loud voice, "That vaccine is not safe! It's one of those genetically engineered things!" What can you tell Pam about how the vaccine is made and whether it is safe or not? | back 18 This vaccine is genetically engineered and the antigen is artificially made in a lab. It is actually safer if it is genetically engineered because it cannot turn into a toxin producing antigen like others naturally made in the body |
front 19 Case 4 | back 19 One summer in the late 1990s, a group of tourists from the United
Kingdom became ill after they all stayed at the same hotel in Greece.
Epidemiologists conducted surveys among all the people who had stayed
at the hotel during the two-and-a-half-week period in which people
were reporting their illnesses. They did this in an attempt to
determine the cause of the symptoms, which were primarily diarrhea and
nausea. They surveyed 239 people; 224 of them reported having been ill
while they were still on vacation or shortly after their return. Their
diarrheal symptoms lasted 10-15 days. |
front 20 1. Microscopic analysis of the stool samples revealed the presence of small oval-shaped structures, with defined outer walls and two to four nuclei inside that looked like seeds. What is your diagnosis? | back 20 Protozoan: Ghiardia lamblia, Giardiasis |
front 21 2. What organisms should be included in the differential diagnosis of this infection? | back 21 It would be standard practice to test for common pathogens associated with food or water contamination, such as E. coli, S. aureus, Shigella, Salmonella . |
front 22 3. What feature of the symptoms suggests that the causative organism is not likely to be Staphylococcus aureus? | back 22 Commonly Staph is on the skin, but Staphylococcus aureus is the cause of most food poisoning. Typical symptoms of staphylococcal food poisoning include severe nausea and vomiting. In this case, the reason S. aureus is not the causative agent is because some of the tourists did not get sick until after returning home from vacation. In staphylococcal intoxication, symptoms start very quickly - about 2 to 8 hours after the contaminated food is eaten. |
front 23 4. Epidemiologists interviewed the patients about their vacation activities and food intake to try to identify the environmental source of the infection. There was no relationship between the illness and a person's attending one of the scheduled children’s activities at the hotel. Only two types of food available in the dining room seemed to be associated with the illness: raw vegetables and salad. There was also a statistically significant relationship between illness and having consumed orange juice made from a mix (with hotel water). So what was the source? | back 23 Contaminated water. Water would likely have been used to wash the vegetables and salad, and water was used to mix orange juice. |
front 24 5. Why would an epidemiologist even ask about a person's attendance at children's activities? | back 24 Children often don't wash their hands after using the bathroom and as we all know, kids "get their hands on everything!" They easily spread infection through fecal-oral transmission. |
front 25 6. Are there any symptoms that would help to distinguish this kind of diarrheal illness from others? | back 25 Ghiardia found in stool. Also the symptoms were no blood, disease lasted longer, diarrhea not described as foul smell. |
front 26 Case 5 | back 26 On Christmas Eve of 1998, the Ohio State Health Department announced
that two elderly people had died during the previous six weeks,
apparently after ingesting tainted meat. Ten additional nonfatal cases
were reported in the state during this period. |
front 27 1. What is the most likely causative microorganism in this outbreak? | back 27 Listeria monocytogenes |
front 28 2. Why is this infection associated with processed meats (hot dogs and deli meats), but usually not with hamburger or cuts of meat including pork, beef, or chicken? | back 28 L. monocytogenes is able to reproduce and survive well under refrigeration. Therefor, if infected meats such as hot dogs and deli meats are not heated adequately or become occupied by L. monocytogenes after processing, the bacterium can survive and multiply. Typically, hamburger, pork, beef and chicken are heated adequately and the bacterium is killed off in the process. The meat will likely remain un-contaminated as long as the leftovers are refrigerated and eaten within 3-4 days. |
front 29 3. Epidemiologists describe a microorganism's pathogenicity as the proportion of people who become ill after being exposed to the microorganism. (An infection that is subclinical in most people who acquire it is considered to have low pathogenicity.) After considering the types of people at high risk for the disease, would you suppose that this organism has high or low pathogenicity? Explain your answer. | back 29 Low pathogenicity because it's limitation to high risk groups (pregnant people and neonates) |
front 30 Case 6 | back 30 You are working as a receptionist at the only family practice in a
small town in Idaho while you are studying to become a physician's
assistant. On a Saturday morning you are the only office worker there
when a call comes in from a local church. The congregation is hosting
a family that moved to the United States from Peru six weeks ago and
is helping them find housing and work. In the meantime, the family is
staying at a church-owned house and relying heavily on church members
for help negotiating this new country and for translation while their
English is still sketchy. |
front 31 1. When the doctor opens the door you whisper that you think there's a case of _____ on the phone. | back 31 Vibrio cholera |
front 32 2. The doctor's eyes widen and she asks you how you came to that conclusion. What is your reply? | back 32 Came from Peru where Cholera is endemic. Also, rice-water stools. |
front 33 3. Why was the doctor initially dubious about your diagnosis and why does the patient's recent immigrant status convince her that your diagnosis was correct? | back 33 Cholera is not endemic to the U.S. Travel from Peru makes it much more likely. Modern sewage and water treatment have virtually eliminated cholera in industrialized countries. |
front 34 4. The doctor asks you to tell Leslie to call 911. The sick woman should be transported to an emergency room right away and the doctor will call ahead and meet her there. What is the first intervention likely to be performed when the patient arrives? | back 34 Rehydration therapy, the primary treatment for cholera patients, refers to the prompt restoration of lost fluids and salts. Antibiotic treatment reduces fluid requirements and duration of illness, and is indicated for severe cases of cholera. |
front 35 5. The incubation period for this disease is one to four days. Can you think of any way that the young mother could have been infected so recently even though she has been in this country for six weeks? | back 35 Cholera infection is most often asymptomatic or results in mild gastroenteritis. Approximately one in 20 people will have severe disease, with profuse painless, watery diarrhoea described as 'rice water stools' and vomiting leading to rapid volume depletion. Another family member may have had the disease mildly, infected food brought back. asymptomatic carrier or convalescent carrier. |
front 36 6. The next day you ask the doctor about the patient's status. She says that currently the patient is receiving a course of the antibiotic ciprofloxacin, though it won't help her. Why won't it help her and why was it prescribed if it won't? | back 36 In most countries, doxycycline is recommended as first-line treatment for adults (including pregnant women) and children. If resistance to doxycycline is documented, azithromycin and ciprofloxacin are alternative options. |
front 37 Case 7 | back 37 You went to get a haircut yesterday and your stylist was having a conversation with another stylist in the shop. The second stylist said that her live-in boyfriend of three years just got a blood test and discovered he has hepatitis C. Your stylist shrugged her shoulders and said her boyfriend has never had any symptoms so she wasn't going to worry about it. |
front 38 1. After the second stylist walks away, your stylist asks you about hepatitis C. Her first question is, "Is it serious?" Answer this question as thoroughly as you can. | back 38 Yes, it is chronic and can cause liver damage. |
front 39 2. How is it transmitted? | back 39 Transmitted almost exclusively through blood. It is NOT transmitted through saliva, sneezing, and seldom by sex like with hepatitis B. Blood was not tested until 1992, so many acquired it through blood transfusions. Also, tattoos, body piercings, and injecting illicit drugs. |
front 40 3. Can she be vaccinated against it? | back 40 No vaccine for hepatitis C |
front 41 4. Your stylist has heard of hepatitis A and hepatitis B, but never hepatitis C. Is it new? Explain. | back 41 Hepatitis C was first established in 1988 when able to reliably detect it in the blood. Infection peaked in the 80s so it is relatively new. |