General Objective: The student must be able to diagnose a case of infectious disease and characterize the causative agent. Specific Objectives: PART I Given the history of a case of an infectious disease, the student must be able to: Give the diagnosis Give the differential diagnosis State the possible causative organisms. Discuss the steps to be taken to arrive at the diagnosis. PART II The student must be able to discuss the etiologic agent as to: General characteristics (morphology, cultural, biochemical) Method of transmission Pathophysiology Clinical manifestations Specific laboratory diagnosis Treatment Prevention CASE------------------------------------------------------------------------------------------------------------------------------------------ A 35-year-of man was admitted to the hospital because of prolonged fever. The patient had been in excellent health until 3 weeks earlier, when malaise developed. 10 days before admission, he attended a convention. The next day he had fatigue, anorexia, and malaise, which waxed & waned. 4 days before admission, his temperature rose to 40.6 degree Celsius, with rigors, sweats and difficulty concentrating. 2 days later, the patient had a severe occipital headache. 1 day before admission, the patient came to the emergency department of the hospital. The temperature was 38.7 degree Celsius, pulse was 120, and the respirations were 20. The blood pressure was 135/80 mm Hg. The results of a physical examination and radiographic studies of the chest were normal the results of laboratory tests are shown below. A specimen of cerebrospinal fluid and 2 specimens of blood were sent for culture, and the patient was discharged with a prescription for oxycodone-acetaminophen. On the following day, blood cultures yielded gram-negative rods. The cerebrospinal fluid culture was sterile. The patient was contacted, and he returned to the hospital. The patient worked in a sedentary professional capacity. He resided in a city and had a monogamous relationship with a woman; his household included a health cat. He frequently had meals at restaurants. He had not traveled recently outside the United States and had no known exposure to sick persons. He had passed only 2 stools during the five days before admission. The patient had no risk factors for human immunodeficiency virus (HIV) infections, and there was no history of inflammatory bowel disease, constipation abdominal pain, stiffness of the neck, or visual changes or other neurologic symptoms. The temperature was 38.2 degree Celsius, the pulse was 92, and the respirations were 24. The blood pressure was 130/70 mm Hg. On the examination, the patient had shaking chills. No rash, lymphadenopathy, or scleral injection was found. A grade 1 systolic murmur was present along the left sternal border. Abdominal examination revealed mild, diffuse tenderness without organomegaly. The results of a rectal examination were normal, and a stool specimen was negative for occult blood. CBC on admission: HCT = 40% WBC = 3,500 per cumm Differential count: PMN = 54% Bands = 15% Lymphocytes = 29% Monocytes = 2 Palatelets = 149,000
