Final ExamFor each case of the follow 3 cases:

• Description of Disease: Include in this section the agent of disease (bacterial, viral, protozoan, fungal or other), identify as well as possible (genus, species- if adequate information is available, subtype, etc.), symptoms of disease, progression of disease if no treatment were available.
• Immune response: Include in this section how the body would responds. Include details of innate immune response and the adaptive (cellular and humoral branches) of immunity.
• Treatment: How would you suggest treating this patient (which antimicrobial drug or other treatment) and how it would work.
• Epidemiology: Describe how the disease is spread.

Case 1

Background

A man in his thirties presented in mid-winter with rapidly progressive generalized weakness, myalgias and respiratory distress. The patient was well until approximately three weeks before admission, when diffuse weakness and myalgias developed, followed by increasing rapidly progressive respiratory distress. He went to a hospital and a diagnosis of a viral illness was made. Supportive treatment was advised, and he returned home.

Two days later, increasing weakness developed, associated with diarrhea, non-productive cough, fevers and chills. One week after the onset of symptoms, he went to the emergency room of another hospital. He reported weight loss of 4.5 kilograms since the onset of symptoms.

On examination, there was hypotension, fever and acute respiratory distress with oxygen saturation of 80%. Computed tomography (CT) of the chest revealed bilateral minimal pleural effusion, right middle lobe and lingular lobe consolidation. CT of the abdomen revealed splenomegaly. Transesophageal echocardiography (TEE) showed a left ventricular ejection fraction of 54% and a large pericardial effusion, with features of cardiac tamponade.

He was admitted to the intensive care unit and his clinical condition rapidly deteriorated. The trachea was intubated because of respiratory failure and vasopressors were administered for blood pressure support.

Analysis of the pericardial fluid revealed lactate dehydrogenase 1533 IU/L, protein 3250 g/dL, glucose 86 mg/dL, and white cells 31,000 /cumm with a lymphocytic predominance; the results were thought to be consistent with an exudative process. Pathological examination showed reactive changes and fibrin deposition consistent with acute and chronic inflammation. No evidence of malignancy was seen, and culture of the pericardial fluid was sterile. Serum antineutrophil cytoplasmic antibodies (ANCA) and antinuclear antibodies (ANA) were negative. Diagnoses of idiopathic myopericarditis, hospital acquired pneumonia and septic shock were made. Intravenous vancomycin, aztreonem and high-dose methylprednisolone were administered.

The patient's clinical condition continued to worsen and he was transferred, approximately three weeks after the onset of his symptoms, to another hospital for further evaluation and treatment.

Suspected exposure to cleaning solvents and other chemicals. His wife had been ill with respiraotyr symptoms previously. There was no history of recenet travel or exposure to animals.

He had a slight temperature. The hematocrit was 35.0% (reference range 41.0-53.0 in men), white blood count 7700/cubic millimeter (reference range 3800 - 9800), and platelets 49,000/cubic millimeter (reference range 140,000 - 440,000). The serum level of total bilirubin was 3.0 mg/dl (reference range 0.3 - 1.1), direct bilirubin 2.1 mg/dl (reference range 0.0 - 0.3), aspartate aminotransferase 352 U/L (reference range 11 - 47), alanine aminotransferase 265 U/L (reference range 7 - 53), and creatinine 3.08 mg/dl (reference range 0.70 - 1.30).

Testing for antibodies to human immunodeficiency virus (HIV) was negative. Cultures of the blood culture, urine and cerebrospinal fluid (CSF) were sterile. A chest radiograph revealed multiple areas of airspace consolidation throughout all lobes of both lungs, which were thought to represent multifocal pneumonia

Cultures of the pericardial fluid for bacteria, fungus and acid-fast bacilli remained sterile. Fevers persisted, and the antibiotics were changed to vancomycin, cefepime, and metronidazole. Continuous veno-venous hemodialysis and extracorporeal membrane oxygenation were begun because of renal failure and respiratory distress syndrome.

Chest Radiograph.

What is the most likely diagnosis and answer the questions above.

Case 2

An elderly man presented with a five-month history of non-pruritic macular rash. He noted diminished sensation over the skin lesions and in the feet. He had received several topical treatments, without improvement, and denied fever or other systemic symptoms.

Past Medical History

He had hypertension. There were no known allergies.

Medications

His medications included enalapril.

Allergies

There were no known allergies.

Epidemiological History

The patient was born in Spain, and lived in a rural area of Venezuela for the previous 20 years. He was a smoker, but did not use illicit drugs or alcohol. He had several domestic animals at his home.

Physical Examination

He appeared in good health. The temperature was 95.2°F (35.1°C) and respirations 14 breaths per minute. There were several macular lesions present on his body, up to eight centimeters in diameter (Figures 1 and 2). Pain and temperature sensation were diminished over the skin lesions, the ulnar area of left hand, the right thumb, and the right foot. The remainder of the examination was normal.

Figure 1

Figure 2.

Choose from the following possible diagnoses and answer the questions above:

• Syphilis
• Leishmaniasis
• Leprosy
• Granuloma annulare
• Sarcoidosis

Case 3

Background

A woman in her thirties, with a history of leukemia, was in complete remission three months after allogeneic peripheral blood stem cell transplant when she presented after 4 days of diffuse abdominal pain, diarrhea and fever. She had received azithromycin one week before presentation for bronchitis.

Past Medical History

She had had acute myeloblastic leukemia (AML), and was status post allogeneic stem cell transplant as above.
Medications
She had received VP-16 three months before admission, and was taking acyclovir prophylaxis. Epidemiological History

She reported that she drank city water, and had no exposures to animals or travel history.

Physical Examination

The temperature was 39.4°C (102.9°F), blood pressure 90/60 mm/Hg, pulse 130 beats/minute, and respirations 24 breaths per minute. The examination of the abdomen revealed hypoactive bowel sounds and mild generalized abdominal tenderness.
Studies

The white blood cell count (WBC) was 22,000 cells per cubic millimeter (88% neutrophils), the serum level of urea nitrogen (BUN) was 32 mg/dL and creatinine 3.1 mg/dL. An abdominal scan is shown in Figure 1.

Clinical Course Prior to Diagnosis

Sigmoidoscopic examination revealed diffuse bowel wall edema, without pseudomembranes (Figure 2).

Figure 1

Figure 2.

What is the most probable diagnosis? Answer the questions above for that diagnosis.

• Clostridium difficile colitis
• Cytomegalovirus (CMV) colitis
• Ulcerative colitis
• Amebic colitis
• Graft-versus-host-disease