A 30-year-old woman presents with the acute onset of fever, pleuritic chest pain, and a productive cough. The patient's history is unremarkable except for recurrent cystitis for which she takes trimethoprim-sulfamethoxazole. She smokes cigarettes. On physical examination her temperature is 40 °C, pulse rate is 120/min, respiration rate is 36/min, and blood pressure is 130/80 mm Hg. Abnormalities are localized to the right lung where crackles, rhonchi, and egophony are heard. Oxygen saturation is 85% by pulse oximetry. Chest radiograph shows a right lower lobe pneumonia. Sputum Gram stain is purulent with few epithelial cells and a predominance of gram-positive diplococci.
Which of the following antimicrobial agents would be the best initial therapy for this patient?
Infectious Disease review Questions Hail M. Al-Abdely, MD
A 68-year-old man is brought to the emergency department by his wife because of increased cough and confusion. The patient's usual cough had increased over the past 3 days and is associated with increased sputum production and dyspnea. He has an 80-pack-year smoking history. His wife noted confusion for the first time this morning.
On physical examination, the patient is somnolent. His neck does not move easily to passive flexion. Neurologic examination is nonfocal. A sputum sample cannot be obtained. Chest radiograph shows a lobar infiltrate. Lumbar puncture with cerebrospinal fluid examination reveals polymorphonuclear pleocytosis with a low glucose, elevated protein, and negative Gram stain. Blood cultures have been drawn.
Which of the following antibiotic regimens should be started promptly?
A 60-year-old woman comes to the emergency department because of a very painful right thigh. She has arthritis and is taking nonsteroidal anti-inflammatory agents for control of joint pain. She also has type 2 diabetes mellitus treated with a sulfonylurea. On Friday morning, she noted pain in her right upper thigh and thought that it might be an exacerbation of her arthritis, so she took an extra dose of ibuprofen. Late that night, the thigh became swollen and exquisitely tender. She went to the emergency department where she is seen by a resident.
On physical examination, she is obese and in slight distress. Her temperature is 38.9 °C. Mild tachycardia is noted. The joint examination shows a pattern consistent with osteoarthritis. Her right thigh is swollen and extremely tender to deep touch. There is a small (4 x 5 cm) red patch in the middle of the tender area. A radiograph of the thigh shows no gas in the soft tissues and no bony changes aside from features of osteoarthritis in the hip and knee. She is given cefazolin, 1 g every 8 hours, and is admitted to the hospital with a diagnosis of cellulitis. The next day, her pain is worse, and the red area on her thigh is slightly larger (5 x 5.5 cm). Fever is still present, and she looks more ill. A CT scan of the thigh is performed without intravenous contrast and shows no gas in the soft tissues and diffuse swelling of the muscle groups. Cefazolin is continued at the same dose. On the third day, she is somewhat delirious and requires intravenous morphine for pain control.
Which of the following is the most appropriate next step?
Epidural placement of a catheter for better pain control
A 65-year-old woman is seen in a clinic because of cough, shortness of breath, and fever. She has mild Alzheimer's disease and type 2 diabetes mellitus controlled with oral hypoglycemic agents. On physical examination, her temperature is 37.8 °C, pulse rate is 85/min, respiration rate is 24/min, and blood pressure is 145/75 mm Hg. She denies headache. Her neck is supple. Bibasilar crackles and decreased breath sounds are auscultated at the right lung base. Cardiac examination shows an S4 gallop rhythm but no murmur. The abdominal examination is unremarkable. There is mild edema of both ankles. Chest radiograph shows an infiltrate in the right lower lobe without a pleural effusion. The patient is unable to produce sputum for examination. Leukocyte count is 16,000/µL with 93% polymorphonuclear neutrophils, 5% band forms, and 2% lymphocytes. Results of blood cultures are pending.
Which of the following is the most appropriate therapy for this patient?
A 67-year-old man develops a fever while in the intensive care unit following partial colectomy for removal and drainage of a peridiverticular abscess. CT scan of the abdomen shows an intraabdominal abscess, which is drained by placing a percutaneous catheter. Catheter drainage and blood cultures are positive for Enterobacter cloacae . Intravenous catheters are changed, and ceftriaxone and metronidazole are begun. The patient becomes afebrile, and a follow-up blood culture is negative. Four days later, fever recurs, and a blood culture is again positive for E. cloacae . A repeat abdominal CT scan is unchanged.
Which of the following is the most likely explanation for the recurrent findings?
Recurrent central venous catheter sepsis
Resistance of the initial strain of E. cloacae to ceftriaxone
Emergence of a mutant, ceftriaxone-resistant strain of E. cloacae
A 78-year-old woman presents to the emergency department with sudden onset of increasing abdominal pain and fever. On physical examination, her temperature is 39.4 °C, respiration rate is 24/min, and blood pressure is 110/55. Her abdomen is distended and tender, and bowel sounds are decreased.
Laboratory studies: Leukocyte count 21,000/µL Polymorphonuclear neutrophils74% Band forms10% Lymphocytes10% Monocytes 6% Serum total bilirubin 40 mol/dL Serum Alk phos 250 U/L AST35 U/L After intravenous fluids and imipenem-cilastatin are begun, fever resolves and blood pressure normalizes. On the eighth hospital day, diarrhea and abdominal pain develop. An assay for Clostridium difficile toxin is positive, and oral vancomycin is added to imipenem-cilastatin. On the 14th hospital day, fever recurs and blood cultures are obtained. The microbiology laboratory reports the next day that the blood cultures are growing gram-positive cocci in short chains that are resistant to vancomycin. The central venous catheter is changed.
A 78-year-old man presents with a 4-day history of fever and cough productive of thick sputum. He has never smoked. Clarithromycin, given for the past 2 days, has been ineffective. A blood culture drawn in the office is reported to be growing gram-positive cocci in pairs. Chest radiograph shows an infiltrate in the right lower lobe. The patient is unable to produce sputum for examination.
Which of the following antibiotics, administered intravenously, is the most appropriate initial therapy?
A 45-year-old man presents with fever, cough productive of thick sputum, diarrhea, and abdominal cramps of 4 days' duration after returning from Spain. On physical examination, his temperature is 38.9 °C . Lung examination shows occasional scattered wheezes but no crackles. No cardiac murmur is audible. His abdomen is slightly tender with hyperactive bowel sounds but no guarding or rebound. Leukocyte count is 13,000/µL with 90% polymorphonuclear neutrophils and 10% lymphocytes. A test for fecal leukocytes is positive. After cultures of blood and stool are obtained, the patient is started on ciprofloxacin.
For which of the following potential diarrheal pathogens in this patient is resistance to ciprofloxacin most likely?
A 29-year-old man who currently uses injection drugs presents with fever and rigors. On physical examination, his temperature is 40 °C. There are hemorrhagic papular lesions on his distal left index finger and right great toe and petechiae in the palpebral conjunctivae. The lungs are clear. Cardiac examination shows a grade 2/6 systolic ejection murmur and a grade 2/4 diastolic murmur at the upper right and lower left sternal border. Abdominal examination is unremarkable, and there are no joint effusions or tenderness. Leukocyte count is 19,000/µL, and serum creatinine is 1.2 mg/dL. Four sets of blood cultures grow gram-positive cocci in clusters, and vancomycin and gentamicin are begun. The next day, the blood isolates are identified as methicillin-susceptible Staphylococcus aureus . You choose to continue gentamicin.
Which of the following changes should also be made in the antibiotic regimen?
A 42-year-old woman presents after having symptoms of upper respiratory tract infection for 4 days that were followed by 2 days of coughing productive of yellowish phlegm, mild pleuritic chest pain, and fevers to 38.9 °C. The medical history includes type 2 diabetes mellitus but no previous pneumonia. The only medication is an oral contraceptive. The patient reports smoking 5 cigarettes a day for 15 years and denies any risk factors for HIV infection. The review of systems shows mild anorexia, but the patient is able to take oral liquids and food and to go about her daily activities.
Patient appears mildly ill but in no distress. Her dentition is good. The temperature is 38.5 °C. The pulse rate is 100/min, respiration rate is 24/min with mild splinting, and blood pressure is 110/60 mm Hg. The chest examination shows dullness to percussion, bronchial breath sounds, and coarse crackles at the left base. The findings of the cardiac, abdominal, and extremity examinations are unremarkable. The leukocyte count is 11,300/µL with 20% band forms. Oxygen saturation is 96% while the patient is breathing room air. A chest radiograph shows left lower lobe consolidation with a blunted left costophrenic angle that suggests a small effusion.
What pathogens must be kept in mind in designing an antibiotic regimen for this patient?
A 66-year-old man with a history of significant renal failure due to poorly controlled hypertension is admitted to the intensive care unit following a large subarachnoid hemorrhage. He required intubation on arrival and has remained ventilated for 3 weeks. Seven days after admission, he developed a catheter-associated urinary tract infection due to Escherichia coli , which was treated with ceftriaxone for 7 days. Two days ago (4 weeks after admission), he developed a fever to 39.2 °C, and thick, purulent sputum was suctioned from his endotracheal tube. A chest radiograph showed evidence of a new right lower lobe infiltrate. A Gram's stain of an endotracheal tube aspirate showed abundant polymorphonuclear cells and gram-negative rods. Blood samples were obtained for culture, and the patient was started on empiric therapy with ceftriaxone.
This morning, the patient is still febrile and requires vasopressors to maintain his blood pressure. You receive a call from the microbiology laboratory to tell you that the patient's blood cultures are positive for gram-negative rods. The microbiologist also informs you that the endotracheal aspirate is growing E. coli with the following sensitivity pattern:
A 63-year-old woman is hospitalized for symptomatic hyperglycemia and acidosis as complications of diabetes. She has no history of loss of consciousness, confusion, or other neurologic process. She has had two similar hospitalizations over the previous 4 years. After admission, she has a good response to insulin and fluid therapy, but on the third day of hospitalization, she develops a fever, and a chest radiograph reveals an infiltrate in the left upper lobe. Her admission chest radiograph, which had been read as normal, was, in retrospect, found to show a small patch of infiltrate in that same area. Culture of an expectorated sputum specimen shows many leukocytes and some gram-positive diplococci among mixed flora interpreted as normal respiratory flora. The patient's physician prescribes levofloxacin for "community-acquired pneumonia." The patient's fever persists, and a sputum culture done before antibiotics were started is found to show a predominance of pneumococci and normal respiratory flora. Another sputum specimen is sent for culture, and this time, there is essentially a pure growth of pneumococci. Both isolates of pneumococcus are tested for susceptibility according to laboratory protocol, and the results show a penicillin minimal inhibitory concentration (MIC) of 0.05 µg/mL, which is interpreted as "highly susceptible." Levofloxacin was continued for community-acquired pneumonia, but the patient did not improve and continued to produce sputum containing leukocytes and pneumococci. Chest radiographs continued to show an infiltrate in the left upper lobe, without evidence of cavitation or pleural disease. Blood and urine cultures were repeatedly negative.
An 80-year-old woman is admitted to the coronary care unit following a large inferior myocardial infarction. She required immediate intubation and ventilatory assistance. One week after her admission, she developed pneumonia, for which she was treated with a 2-week course of imipenem. During this time, she also developed moderate renal failure, which was believed to be due to poor renal perfusion, and an indwelling urinary catheter was inserted to monitor her urine output.
Her clinical status gradually improved, and she was extubated 4 weeks after admission. She was transferred to a medical ward 3 days later. Five weeks after admission, the patient developed a fever and rigors, and blood cultures grew methicillin-resistant Staphylococcus aureus , which was believed to have originated from an infected peripheral intravenous catheter site. The catheter was removed, and she was treated with a 2-week course of vancomycin.
She continued to improve slowly with daily physical and occupational therapy. Six weeks after admission, a urine specimen was taken from the indwelling catheter as it was being changed and was sent for culture. Forty-eight hours later, the following identification and sensitivity report was issued from the microbiology laboratory:
An 84-year-old woman with a 10-year history of dementia is transferred from a nursing home to the hospital for evaluation of a new fever. She is being fed through a gastrostomy tube, and she requires both an indwelling bladder catheter and a diaper. She has no known allergies. She has had three prior episodes of fever in the last 6 months. When she had a fever in the nursing home, she was given ciprofloxacin through the gastrostomy tube. On physical examination in the emergency room, the patient has a temperature of 38.8 °C, pulse rate of 84/min, respiration rate of 24/min, and blood pressure of 94/48 mm Hg. She is unresponsive. Her neck is supple, and her lungs are clear. There is an S4 gallop but no significant murmurs. The abdomen is soft and nontender, with no masses or organomegaly. The extremities are warm but not swollen or red. Rectal examination is normal, and the stool is brown and negative for occult blood. The Foley catheter is filled with cloudy urine. In urinalysis and urine culture reports available from 2 days earlier, urinalysis showed trace protein, many leukocytes, rare erythrocytes, and copious bacteria, and urine culture showed Klebsiella pneumoniae . The susceptibility report was limited and indicated that the organism was susceptible to ceftriaxone and resistant to ceftazidime, ciprofloxacin, tobramycin, and tetracycline.
Which of the following antimicrobial agents would be most likely to be effective for this woman?
A 31-year-old married man comes to a local health clinic because of a 2-day history of dysuria and urethral discharge. Otherwise, his health has been good. He takes no medications except ranitidine for occasional heartburn. He is allergic to cephalexin, with which he developed a rash 2 years earlier. He is just back from a trip to sout-east Asia where he had several sexual contacts. Physical examination shows a healthy-looking man in no distress. His vital signs are normal, and the only finding is a copious, yellow urethral discharge. Gram's stain of the discharge shows many polymorphonuclear leukocytes and intracellular and extracellular gram-negative diplococci. The patient is given a single dose of ciprofloxacin and a single dose of azithromycin and told to abstain from sexual activity until all symptoms have been gone for at least 48 hours. He returns to the clinic 3 days later with persistent dysuria and discharge. Gram's stain of the urethral discharge again shows numerous leukocytes and gram-negative intracellular and extracellular diplococci.
The most likely reason for his persistent symptoms is:
Poor ciprofloxacin absorption secondary to H2-receptor antagonist therapy
A 68-year-old diabetic man was recently discharged from the hospital after treatment for congestive heart failure. While in the hospital, he was found to be colonized with methicillin-resistant Staphylococcus aureus (MRSA) and received chlorhexidine baths and intranasal mupirocin. He was also found to have peripheral neuropathy and a chronic, inactive, small ulcer over the head of the right metatarsal.
The patient's son calls this morning to tell you that his hather is very confused, feverish, and sweaty and that his right foot is swollen and red. You ask him to bring him to the hospital, and you meet him in the emergency room. On physical examination, the patient's right foot is inflamed and foul-smelling.
Leukocyte count 13,000/µL Hemoglobin 11.8 g/dL Blood glucose16 mol/dL Gram's stain of a specimen from the foot ulcer Gram-negative bacilli, gram-positive cocci in chains, and gram-positive cocci in clusters
Which of the following is the best therapy for this patient?
A 68-year-old paraplegic man is transferred to the hospital from the nursing home because he has fever and mild confusion. His general physical examination is unchanged since his last office visit, except that over the sacrum he has a deep decubitus ulcer that has developed and progressed rapidly. The admitting physician performs local débridement and wound care and prescribes imipenem for possible sepsis. On the third hospital day, the patient is clinically better, and a blood culture from admission and deep-tissue cultures from the débridement both show Klebsiella pneumoniae with the following resistance phenotype: Ampicillin-Resistant Cefazolin-Resistant Ceftriaxone-Susceptible Ceftazidime-Resistant Imipenem-Susceptible Ciprofloxacin-Resistant Tobramycin-Susceptible
Which of the following treatment choices is most reasonable at this point?
Change to ceftriaxone; add anaerobic coverage
Change to tobramycin; add anaerobic coverage
Change to moxifloxacin alone for broader-spectrum fluoroquinolone coverage
Stop antibiotics, as dèbridement has removed the source of the infection
A previously healthy 40-year-old mother of two is evaluated because of a 9-day history of malaise, runny nose, scratchy throat, and cough. She has no fever, chest pain, or shortness of breath. Nasal secretions were clear but now are yellowish; cough is usually nonproductive, except in the morning when it produces green sputum.
What is the most appropriate management strategy for this patient?
A previously healthy 26-year-old medical student is evaluated because of a 7-day history of abundant, thick, yellow nasal secretions and post-nasal drip. He has no fever and only mild sinus tenderness. He mentions that he has had "sinusitis" before and has always needed an antibiotic. He even suggests which antibiotics could be prescribed.
What is the most appropriate management strategy for this patient?
A 42-year-old woman is evaluated because of a 2-day history of dysuria. She had one prior urinary tract infection 7 years earlier and responded to a short course of trimethoprim-sulfamethoxazole. After the urine dipstick shows a strongly positive reaction for nitrites, she asks whether she could again take trimethoprim-sulfamethoxazole.
Which of the following would be the best answer?
No, trimethoprim-sulfamethoxazole is no longer considered a first-line treatment for urinary tract infection
Yes, trimethoprim-sulfamethoxazole is still an effective treatment for urinary tract infection even when resistance is measured in vitro
Yes, if local resistance patterns to trimethoprim-sulfamethoxazole show only a small probability of resistance
No, prior treatment with trimethoprim-sulfamethoxazole makes it unlikely that the organisms causing the infection are susceptible to trimethoprim-sulfamethoxazole
A 30-year-old otherwise healthy man is evaluated because of a 10-day history of cough. The cough was initially productive of small amounts of clear sputum, which has now turned yellowish. He has no fever, chills, or shortness of breath but has difficulty sleeping because of the persistent cough. On physical examination, his vital signs are normal and examination of the lungs reveals no wheezing, crackles, or rhonchi.
In addition to symptomatic relief with antitussives, what is the most appropriate treatment strategy for this patient?
Salmeterol metered-dose inhaler as needed at bedtime
A 56-year-old businessman is planning a trip to east Asia for a period of 3 weeks. He is in generally good health except for chronic bronchitis. His medicines control his illness fairly well, but he asks if he should carry antibiotics with him in case he should develop an exacerbation. He agrees not to take anything with him, but on his return from the trip he calls from the airport sounding very short of breath and coughing. On examination that day, he has a fever of 38.3 °C and loud rhonchi and some wheezes. A chest radiograph shows some patchy lesions that look worse than on his baseline radiograph. His capillary oxygen saturation is the same as his baseline level.
In addition to treatment for his airway disease, which of the following is the next step in this patient's management?
A 34-year-old man is evaluated because of a 4-day history of sore throat. He is able to swallow but indicates that the pain is significant. He has taken analgesics inconsistently. He has no febrile sensation or cough. On examination, he is afebrile. His pharynx is erythematous, but no plaques are visible, and he has no tender enlarged cervical lymph nodes. He is concerned because he has small children, and they currently have symptoms of upper respiratory infection, including sore throat and fever.
What would be the next appropriate step in managing this patient?
Get a rapid strep test and if positive start antibiotics
Treat symptoms only
Send off a throat culture and treat with antibiotics until result comes back
A 19 year-old Saudi female with sickle-cell disease presented to the ER with 2 day history of fever, cough and SOB. O/E was febrile 39C, RR 30 and BP 80/50. Has crackles bilaterally and CXR revealed bilateral lower lobe consolidation. WBC 24000 with 35% band forms, HgB 39 gm/l.
The appropriate antibiotic regimen for this patient is:
Penicilin G 3 MU every 4 hours
Ceftriaxone 2gm every 24 hours
Ceftazidime 2gm every 8 hours and gentamicin 2mg/kg every 12 hours
Vancomycin 1gm every 12 hours and Ceftriaxone 2gm every 24 hours
Nafcillin 2gm every 4 hours and ciprofloxacin 400mg i.v every 12 hours
A 60 year-old Saudi male, heavy smoker for 40 years. Presented to ER with 4 months history of fever and yellowish sputum. He lost 10 kgs over 2 months. He was treated with antibiotics twice in another hospital over the past month. He had temporary improvement but got worse after stopping the antibiotics. He is otherwise well with no other illnesses. CXR shown.
A 24 year-old Saudi female with sickle-cell disease presents to ER with a 10-day history of fever and dry cough and 2 days history of severe bone pain and rigors. Temp 39 C and chest examination was unremarkable. CXR revealed a left upper lobe infiltrates with cavitations. CXR 10 days earlier was normal. The patient is on methotrexate weekly and prednisone daily for rheumatoid arthritis.
All the followings are possible causes of the chest infiltrates except.