A 22-year-old construction worker was hospitalized in early December because of increasing shortness of breath and a cough with blood-stained sputum that had developed over a 2-day period.
Question 1 - Single Best Answer
What organ or organ system should you concentrate on to determine this young man's problem?
A) heart
B) gastro-intestinal
C) upper respiratory
D) lower respiratory
E) urinary tract
Except for various injuries suffered on the job and allergies to a variety of environmental substances, he had always been in good health. One week before hospitalization, this patient had developed a cold characterized by a mild sore throat and nonproductive cough, malaise, and a generalized dull headache. The day before hospitalization, just as he was leaving work at the Army Chemical Warfare plant at 4 o'clock, the patient experienced a severe shaking chill that lasted for ten minutes. Following this, the cough became worse and more productive of sputum. It became frankly bloody a few hours before admission to the hospital.
Question 2 - Single Best Answer
What is the most likely cause of his "cold"?
A) influenza virus
B) respiratory syncytial virus
C) rhinovirus
D) Bordetella pertussis
E) Haemophilus influenzae
Question 3 - Single Best Answer
The symptoms that brought him to the hospital are most likely due to?
A) reactivation of his cold
B) allergy
C) a "Strep" throat
D) nitrogen oxide or chlorine gas poisoning
E) pneumonia
Question 4 - Single Best Answer
What physical signs could help you decide on the disease and cause?
A) pulse and respiration only
B) fever blisters only
C) chest sounds only
D) temperature only
E) all of the above
Physical examination revealed a temperature of 104 and a pulse rate of 130/min; blood pressure was 112/70, and respirations were 38/min. Each respiration was accompanied by an audible grunt. The chest was hypo-resonant to percussion and filled with inspiratory and expiratory wheezes. Fine crackling rales were heard on inspiration over the lower anterior chest just to the right of the sternum.
Question 5 - Single Best Answer
What diagnosis would you make at this point?
A) poison gas
B) pneumonia
C) heart attack
D) allergy
Question 6 - Single Best Answer
What organisms should be included in your differential diagnosis?
A) Klebsiella, Legionella, Mycoplasma, Chlamydia
B) Streptococcus pneumonia, Klebsiella, Staphylococcus aureus
C) Pseudomonas aeruginosa, Brucella abortus, E. coli
D) Afipia felis, Vibrio cholera, Campylobacter jejuni
E) Listeria monocytogenes, Francisella, Chlamydia
Question 7 - Single Best Answer
What laboratory data would you request?
A) blood counts only
B) chest x-ray only
C) sputum gram stain only
D) blood cultures only
E) all of the above
Question 8 - Single Best Answer
Why is it important to determine the causative agent?
A) treatment
B) epidemiology
C) prognosis
D) all of the above
Initial laboratory data included a total leukocyte count of 12,100 per cubic millimeter, with 71% segmented neutrophils, 17% band forms, 11% lymphocytes, and 1% eosinophils. Freshly collected sputum was Gram stained and revealed many neutrophils and a mixture of Gram-positive rods and cocci. Chest x-ray showed a distinct infiltrate involving the right middle lobe.
Question 9 - Single Best Answer
Do any of these results help you determine the cause?
A) yes
B) no
Blood and sputum cultures were done. From two of the blood cultures, a Gram-positive, lancet shaped diplococcus was isolated. It was catalase negative, alpha hemolytic, and optichin sensitive. The third blood culture was negative and the sputum culture grew only normal oral flora.
Question 10 - Single Best Answer
What organism was in the blood culture?
A) Streptococcus pyogenes
B) Streptococcus pneumoniae
C) Staphylococcus aureus
D) Klebsiella pneumoniae
E) Legionella pneumophila
Question 11 - Single Best Answer
What is alpha hemolysis and how is it determined?
A) increase in the amount of soluble hemoglobin in a standard preparation of red blood cells.
B) decrease in the number of red blood cells, determined by direct count, in a standard preparation of red blood cells.
C) a clear zone surrounding a colony on a blood agar plate
D) no hemolysis seen on a chocolate blood agar plate
E) a greenish discoloration of the agar on a blood agar plate
Question 12 - Single Best Answer
What is the major virulence factor for the causative organism?
A) intracellular growth
B) streptolysin
C) M protein
D) polysaccharide capsule
E) adhesin
Question 13 - Single Best Answer
Why was the sputum culture negative?
A) S. pneumoniae is never isolated from sputum
B) 50% of people with S. pneumoniae pneumonia have negative sputum cultures.
C) The sputum became contaminated with saliva
D) S. pneumoniae is an obligate intracellular pathogen and cannot be cultured in the laboratory
E) All the S. pneumoniae was in the blood so there was none in the lungs.
Question 14 - Single Best Answer
What was the relationship of the young man's cold to his subsequent pneumonia?
A) the pneumonia and cold were caused by the same organism
B) the interferon induced by the cold virus stimulated the bacterium
C) the cold virus denuded the ciliated epithelium, and interfered with the natural mechanism by which bacteria are cleared from the lung.
D) the cold virus inactivated the IgG in the lung
E) there was no relation - it was coincidental
Question 15 - Single Best Answer
What was the most likely origin of the S. pneumoniae immediately before he got pneumonia?
A) the raw oysters he had after work the day before.
B) his cat that had scratched him on the face the night before.
C) his girlfriend who had an insatiable sexual appetite.
D) the dust in the construction work.
E) his normal flora
Question 16 - Single Best Answer
What is the cause of the disease (dis-ease) and death, when it occurs, in pneumococcal pneumonia?
A) endotoxemia
B) endocarditis
C) inflammatory response in the alveoli
D) cytotoxin
E) cytokine production