Exam 11: Travelers Diarrhea: Identifying the Causative Agent

Repeated Neisseria meningitidis septicemias in an individual should raise physician awareness of what underlying condition?

A 45-year-old man had mental degeneration after a prolonged but inapparent infection. At autopsy, a subacute spongiform encephalopathy is found. What is the nature of the most likely causative agent?

A patient presents with explosive, watery, noninflammatory diarrhea along with headache, abdominal cramps, nausea, vomiting, and fever. Symptoms began the day after eating raw oysters in August. What is the most likely causative agent?

Anti-A isohemagglutinins are present in persons with which one of the following blood types?

An autoimmune state characterized by a triad of thrombocytopenia, eczema, and recurrent infections is

A mother brings her 8-year-old son to your office and reports that about 10 days ago he had a flu-like disease with a minor fever. Three days ago he had a very red face which turned normal color when touched, and now he has a red rash on his arms and legs which also blanches to touch. She states he had all the normal childhood shots. The most likely infectious cause of his symptoms is

A 59-year-old man presents at the emergency department with labored breathing and a sharp stabbing pain behind the breast bone. He complains of being weak and tired. He has a low-grade fever and an electrocardiogram shows elevated ST segments. The most likely infectious cause of these symptoms is

A neonate is suspected to have combined immunodeficiency disease (SCID). (One previous sibling died of this.) Which of the following would confirm the diagnosis?

Which complement component is most closely related to anaphylatoxin?

The Pap smear of a 19-year-old female college soccer player contains koilocytotic cells. The disease associated with the appearance of the cells could most likely have been prevented by previous administration of a(n)

Mobile genetic elements that code for antibiotic resistance genes in bacteria but are incapable of self-replication are

A 40-year-old man presents to the ED with a painful and swollen jaw. Two days ago he had a tooth extraction where the gums and jaw were swollen and painful. "Nodules" are felt below the surface of the tissues which are not lymph nodes. Which member of the gingival normal flora will grow contiguously into the damaged tissues, producing tissue swelling and ultimately, if untreated, will develop sinus tracts that will erupt to the surface, liberating the "nodules"?

A Peace Corps volunteer who recently returned from rural Africa develops symptoms of liver damage and a blocked bile duct after general anesthesia for a knee replacement. What is the nature of the most likely causative agent?

Which of the following childhood vaccines is most likely to prevent otitis media in young children?

Latent infection of neurons occurs with

It is August. A 30-year-old man appears at your office complaining of difficulty in breathing, headache, and joint and lower back pain. He has a 101°F fever and a prominent cough. During your history taking, only one unusual activity, the thorough cleaning of an old hunting shack, was noted. The cleaning involved removal of old food containers, pots, and bedding, plus some rodent nests. He also deployed new mouse traps. Based on this history, what agent is most likely causing his symptoms?

A 15-year-old boy on antibiotics to clear up a community-acquired methicillin-resistant Staphylococcus aureus has clindamycin added to his treatment regimen to slow the production of the various toxins including Panton-Valentine leukocidin. He recovers but develops Clostridium difficile diarrhea. Why does C. difficile cause diarrhea?

An RNA tumor virus associated with the neurologic disease tropical spastic paraparesis is

An 11-day-old neonate has been brought to his pediatrician because the infant has developed a sharp cough. Physical examination also reveals a mild conjunctivitis with some pus; a chest film confirms pneumonia. No organisms are seen on Gram stain of the pus. What is the most likely causative agent?

A 2-year-old infant's mother reported her son has had three infections in the past 6 months. Which of his serum values (mg%) would indicate he had an immunodeficiency disease?