1. Clinical Cases RESP 312

2. Case 1 A 68-year-old a heavy smoker, noted that he had nasal congestion, and muscle. Then he developed a shaking chill, cough, and severe pain on the right side of his chest that worsened with breathing. The cough was productive of rust-colored (blood-tinged) sputum. In the emergency his temperature was 40°C. His respiratory rate was 30 breaths/minute. Breath sounds over the right side of the thorax were diminished. What is the most probable causative agent? Log book question: What are the microscopic and culture features of this bacteria?

3. What investigations should you request? WBC count, chest x-ray, sputum gram stain and culture, blood culture. White blood cell count was 23,000/μL. Chest radiograph revealed a dense infiltrate in the right lung. Gram stain of the sputum showed many neutrophils and lancet-shaped Gram-positive diplococci. How are you going to treat this patient? Fluoroquinolones or macrolide. Both the blood cultures and sputum cultures were positive for the Streptococcus pneumoniae.

4. Because the isolate was found to be sensitive to penicillin, the antibiotic regimen was revised. Where did he acquire this organism? From who? And what host factors contributed to his infection? There is no way to know from whom he acquired pneumococcus. The factors that contributed to pneumonia were his age, smoking and his recent viral infection. Is this type of infection preventable? How? Yes, by pneumococcal conjugated vaccine.

5. Case 2 A 7-year-old girl, who previously had been in good health, developed fever, headache, and a dry cough. Her 12-year-old brother had had similar symptoms 2 weeks earlier. Over the next 2 days, her temperature increased and the cough worsened, producing small amounts of clear sputum. Her physician noted that she appeared slightly pale and had a temperature of 39.3°C and a respiratory rate of 40 breaths per minute. Scattered rales were heard through the stethoscope over the lungs. What investigations should you request? CBC, X-ray, sputum culture and cold agglutinin.

6. White blood cell count was normal, 8,600 per μL, with a normal differential count. She was slightly anemic (hematocrit* of 29%) and had an increased number of reticulocytes. Chest radiograph showed an infiltrate of the lungs. Gram stain of sputum revealed only a few neutrophils and no bacteria. Culture on grew oral normal flora. Cold agglutinin test was positive. Would you prescribe penicillin for this case? Why? Macrolide, tetracycline or fluoroquinolones. How can a definitive diagnosis of mycoplasma infection be made? Test for IgM antibody to Mycoplasma pneumoniae, PCR or culture (delayed and need special media).

7. Case 3 Mr. O., a 63-year-old shepherd, awoke early with nausea, vomiting, and confusion. He also experienced fatigue, fever, chills, anorexia, and sweats. In the emergency room he denied cough, chest pain, dyspnea, abdominal pain, or skin rash. On physical examination, he was alert and interactive but spoke nonsensically and was not oriented to person, place, or time. His temperature was 39.2°C, his heart rate was 109 beats per minute, and his blood pressure and respiratory rate were normal. Initial pulmonary, heart, and abdominal examinations were normal, and his neck was not stiff. What tests should you request? WBC, CSF and blood gram stain and culture.

8. WBC count was normal, but the platelet count was low. CSF showed red blood cells, increased WBC count with neutrophilia, decreased glucose, and increased protein. Microscopy examination of the CSF showed many Gram-positive bacilli. After only 7 hours of incubation of the CSF culture, Bacillus anthracis was isolated, and blood cultures were positive within 24 hours of incubation. A chest radiograph showed prominence of the superior mediastinum and a possible small left pleural effusion. What treatment should you prescribe? multiple intravenous antibiotics as soon as possible.

9. He received penicillin G, levofloxacin, and clindamycin. In spite of that combination therapy, his condition progressively deteriorated, with seizures, hypotension and worsening renal function. He died on the 3 rd day. What finding do you you expect on postpartum examination of the chest and skull? Hemorrhagic inflammation of the mediastinal lymph nodes, and extensive hemorrhage in the leptomeninges.

10. Case 4 A 35-year-old day care worker experiencing cough and weight loss. Over 2 months, she developed gradually worsening cough productive of yellow sputum. She also noted decreased appetite, daily fever, and drenching night sweats. She did not improve despite being prescribed a routine antibiotic for 1 week. On further questioning, she described visiting South Africa several years earlier, where she worked briefly on an AIDS ward. What investigations will you request? Chest x-ray, tuberculin test, sputum for ZN stain, culture and PCR. And HIV test

11. ZN staining and microscopy of her sputum showed acid-fast bacilli. chest radiograph revealed infiltrates in the apices of both lungs. Tuberculin skin test showed no induration when examined 48 hours later. What stage of tuberculosis is she presenting with now? Secondary tuberculosis. Why did it take so long for she to develop active tuberculosis (TB)? How are you going to manage this case? Isolation and anti-tuberculosis direct observation treatment for 6 months.

12. By what route did the tubercle bacilli most likely arrive at the apices of her lungs? By blood stream and lymphatics. How would her illness have differed if she had had AIDS? If she had had both AIDS and tuberculosis, she would have been more likely to have disseminated tuberculosis involving multiple organs, and she would not have developed cavities in the apices of her lungs. Pulmonary cavitation is due to a vigorous hypersensitivity reaction to the organisms that is impaired or absent in AIDS.

13. Case 5 A 19-month-old boy, developed a runny nose, hoarse-ness, cough, and a low-grade fever. Then he developed a barking cough. His breathing was forced and noisy, especially with inspiration. What is the most probable diagnosis? What is the most possible causative organism? How are you going to treat this patient?

14. Case 6 8-year-old boy was brought to the pediatrician because of fever, rash and sore throat. On examination he had a temperature of 38.3°C. His oropharynx was erythematous. His tonsils were enlarged and coated with patchy white exudates. Anterior cervical lymph nodes were enlarged and tender. What is the most probable etiology and what are the microscopic and culture characteristics of the causative organism?

15. What bacterial process caused the rash? What are the common local and systemic complications of streptococcal pharyngitis? If the mother of the boy told you that he suffers the same symptoms frequently. What test are you going to request?

16. Case 7 B., an unvaccinated 7-year-old boy, visited Egypt with his family. He developed fever and sore throat 1 week after returning to California, followed by cough, coryza, and conjunctivitis. Three days later a cephalocaudal maculopapular rash appeared on his body. He continued to attend school during this illness, and when symptoms persisted, he was evaluated by a pediatrician. What are the differential diagnosis? Scarlet fever, adenovirus pneumonia, chicken pox, measles… Scarlet fever was excluded on the basis of a negative rapid test for Streptococcus pyogenes. Why was the diagnosis of measles not considered by B.’s physicians?

17. How could this illness be diagnosed as measles? Is there a concern that he might transmit the infection to others? he boy remained ill blood specimens were collected for measles antibody testing. No isolation precautions were instituted at the hospital. The child’s serum tested positive for measles virus IgM, and subsequently, 839 exposed individuals were identified. Eleven secondary cases of measles occurred, including seven infants less than 12 months old??.

18. One of these infants was hospitalized and had a prolonged convalescence; another infant traveled to Hawaii leading to further exposures. Forty-eight infants too young to be vaccinated following exposure were quarantined at home for the 21-day contagious period. Many exposed persons were vaccinated, and several high-risk patients were administered measles immune globulin as passive prophylaxis. The estimated cost was more than $176,000.