Cases in infectious diseases

Clinical Presentation: A Man With MRSA
The patient is a 48-year-old man with methicillin-resistant
Staphylococcus aureus (MRSA) bacteremia. He was on dialysis and had
rigors, fever, and hypotension.
Blood cultures were obtained and he was admitted to the hospital after
a dose of vancomycin and ceftazidime. Within 18 hours his blood
cultures were positive for what would be identified as MRSA.

History and Physical Examination
History. The patient has had insulin-dependent diabetes since he was a
teenager, and currently his A1c is approximately 10 mmol/mol. He has
neuropathy, retinopathy, and nephropathy. He has a dilated
cardiomyopathy after myocardial infarctions and an ejection fraction of
22%.
Physical examination. On physical examination, the following were
noted:
•The patient was febrile and tachycardic
•HEENT: no emboli; he is legally blind
•Heart: 3/6 systolic murmur
•Lungs: basilar crackles
•Abdomen: nontender
•Extremities: 2+ edema, no emboli

Labs and imaging. As expected, the patient's lab studies indicated that
he was diabetic, had an infection, and was in renal failure.
Hospital course. The patient's fever gradually resolved over 7 days. His
blood cultures were positive on day 3 (but not day 5) for MRSA with a
minimum inhibitory concentration (MIC) to vancomycin of 1.0 µg/mL.
The organism was resistant to all other antibiotics except linezolid and
daptomycin. The dialysis catheter was removed, and a tip culture was
negative. A transthoracic echocardiogram showed vegetation on the
mitral valve. He was sent home on a 6-week course of vancomycin and
he completed the course, the vancomycin trough levels never falling
below 18 µg/mL.

One week after completion of antibiotics, the patient was again febrile
and hypotensive on dialysis and his blood cultures grew the same
MRSA, with a MIC of 1.0 µg/mL to vancomycin. His evaluation in the
hospital was identical to that of his last admission.
Neither the thoracic surgeon nor the patient wished to proceed with
valve replacement, the former because of worries about infecting the
prosthetic valve, and the latter simply not wanting the intervention
https://www.medscape.com/viewarticle/731329

Clinical Presentation
A 19-year-old girl who has just returned to the United States from West
Africa presents with fever and jaundice.
History and Physical Examination
History. This 19-year-old has returned to the United States after
spending a year in West Africa, where she taught in a rural village.
While she was in Africa, she experienced 2 episodes of undiagnosed
fever that were treated as malaria. One month before leaving, she
experienced 3 days of severe diarrhea that resolved without therapy.
For the last 3 days she has had fevers to 104°F with shaking, chills, and
drenching sweats that began at the airport when she was waiting to
leave Africa. Upon arrival in the United States, she noticed that her
eyes were yellow and she came to the emergency department (ED).
While she was in Africa, she took no prophylactic medications.

Medical history: None
Medications: None
Allergies: None
Habits: None
Animal exposure: Exposed to multiple animals in rural Africa including
cattle and goats
Diet: In Africa, she ate and drank the local food and water
Travel: West Africa, mostly Ghana
Immunizations: Had the standard immunizations for travel to West
Africa
Sports/water exposure: Swam in the local river in West Africa
Infectious disease exposure: Bug bites too numerous to count

Physical examination. On physical examination, the following were
noted.
Vital signs: Temperature was afebrile in the ED, but subsequently
became febrile to 104°F; pulse, 110 beats/minute; respirations, 16
breaths/min; blood pressure, 120/90 mm Hg
General: Tired and ill-appearing young woman
HEENT: Yellow sclera
Lungs: Clear
Heart: No pathology
Abdomen: Mild to moderate right upper quadrant tenderness with
palpable liver
Extremities: Normal
Skin: Jaundiced
Genitourinary: Normal
Neurologic: Normal

Diagnostic Evaluation
Lab results. The following results were obtained.
White blood cell count: 2.1 x 109/L
Hemoglobin: 9.8 g/dL
Differential: 15%
Platelets: 95,000/mL
Bilirubin: 4.5 mg/dL
Transaminases: Lactate dehydrogenase, 600 U/L; alanine
aminotransferase, 434 U/L
Urinalysis: Negative except bilirubin
Imaging. Chest radiograph is normal.

What is the diagnosis? (One or more may be correct.)
Amoebic liver abscess
Malaria
Yellow fever
Meningococcal serotype X
Hepatitis E
https://www.medscape.com/viewarticle/754380_2