CASESTUDYThe Kissing BugJosh couldn’t believe how much he had learned during his summer volunteer program working in a village clinic in northern Brazil. Even after completing his first year of medical school, Josh was shocked to learn about infectious disease morbidity in this underdeveloped region. He recalled his first appointment of the morning: Photograph shows the eyes of a boy where the area around the right eye along with the eyelid is swollen.Teresa had traveled a long distance to bring her 6-year-old son, Marco, to the clinic. She was very worried because the boy was feverish and irritable but had also suffered from diarrhea and a severely swollen eye for more than a week (see the Figure). Josh was asking Teresa about any recent eye injuries Marco might have sustained as he carefully examined the swelling and struggled to connect the symptoms and make a diagnosis.Overhearing this conversation, Dr. Thomas stepped into the examining area to assist. He showed Josh several tiny marks near Marco’s lips and said, “When you see Romaña’s sign, the characteristic swelling around one eye, you’ll often find tiny bites around the lips. Marco is in the acute phase of Chagas disease.”“You mean he’s been bitten by the kissing bug,” Josh replied. “I do see the tiny marks now that you’ve pointed them out. But what is the connection with Romaña’s sign?”1. REVIEW: What pathogen causes Chagas disease?2. What role does the kissing bug play in this infection?3. After examining the photo, what do you conclude about the connection between Romaña’s sign and Chagas infection?Dr. Thomas explained Marco’s condition to Teresa and gave her a 30-day supply of nifurtimox with strict instructions to dose Marco four times every day and return to the clinic for a follow-up appointment. “Josh, you need to tell Teresa why it is so important to give Marco the medicine.”Struggling to translate, Josh told Teresa that Marco’s symptoms would eventually disappear on their own, but the microorganism would remain and cause serious damage that would show up in 10 to 20 years when the chronic phase of the infection begins. The only way to prevent this is to take the medicine as directed now. Josh warned Teresa that even though the nifurtimox could cause some unpleasant side effects in Marco, it was very important for her to continue giving the medication according to the directions.4. To what long-term damage does Josh refer?5. INVESTIGATE: What are the side effects of nifurtimox? Why can they be more problematic in children than adults?Before they left the clinic, Dr. Thomas also gave Teresa two spray cans of a pyrethroid insecticide with instructions to spray the cracks and crevices in their mud hut once a week.6. Why did Dr. Thomas give Teresa insecticide spray?Think critically and try the interactive case study related to pathogens discussed in this chapter.Copyright © 2017 John Wiley & Sons, Inc. All rights reserved.CASESTUDYA Norovirus Outbreak Among NursesWorking night shifts at the emergency department, Gretchen avoided children with projectile vomiting because it made her queasy. She asked her friends if she could trade the child with diarrhea and vomiting for the older gentleman with kidney stones. Except for the occasional teasing from her coworkers, the system worked, until the gastroenteritis outbreak in the daycare facilities in the area.REVIEW1. List two viral pathogens that cause gastroenteritis.2. How would a child with gastroenteritis typically be treated?As the week progressed and more children were treated in the hospital, Gretchen noticed that her coworkers began to call in sick. Handling a gastroenteritis outbreak was not unusual for the emergency department, but losing most of the nursing staff to illness in the process was. The gastroenteritis outbreak had spread to the emergency department staff. During the peak of the outbreak, Gretchen and only one other nurse from her shift were healthy and able to work.As those that were ill returned to work, one of her friends commented, “We’ve treated plenty of gastroenteritis cases before, so I can’t figure out how so many of us got sick. What do you think was different about this one?”“The only thing I can figure out it that it must have been a norovirus outbreak,” replied Gretchen. “Why else would so many adults get sick?”3. How could norovirus be transmitted to the nursing staff?4. Why does norovirus infect both adults and children? Photograph shows a nursing staff standing beside a young boy who is vomiting.5. How could the nurse in the photo reduce the risk for acquiring norovirus?