CASE 2

A 20-year-old college student comes to his campus health center for treatment. His chief complaint is dysuria, especially at the beginning of urine flow, and urethral itching. He first noticed these symptoms four days ago and they have persisted since then. For the last two days, he has also been experiencing increasing production of a yellowish, mucoid urethral discharge. He is not experiencing urinary frequency or urgency. His vital signs are normal. A physical exam detects urethral tenderness to palpitation, but no other abnormalities. A history is taken and the student reveals that he attended a large party 10 days ago, at which he consumed a considerable amount of alcohol, and met an attractive young woman (for the first time) with whom he later had intercourse. Unfortunately, he cannot remember if any precautions were taken during their intimate interlude.

Question 2.1: What is your preliminary diagnosis and what tests would confirm it?

Question 2.2: Do these findings confirm your diagnosis? What is the causative agent of this infection?

Question 2.3: What measures should be observed when taking and handling a urethral smear for culturing and subsequent laboratory analysis?

Question 2.4: What biological characteristics of this causative agent are important with respect to its virulence and how it is transmitted?

Question 2.5: How can this causative agent be distinguished from other members of the same genus, some of which are nonpathogenic members of the human mouth flora?

Question 2.6: How should this infection be treated?

CASE 3

A 23-year-old woman was married a year ago. Since then, she has experienced five attacks of acute cystitis, all characterized by dysuria, increased frequency, and urgency. Each case was diagnosed on the basis of the clinical picture and a laboratory finding of bacteriuria. The urine bacterial counts in these cases ranged from 104 to 106 organisms/ml. Lab tests indicated that the first, second, and fifth infections were caused by Escherichia coli, while the third infection was caused by an enterococcus and the fourth infection was caused by Proteus mirabilis. Each infection responded to short-term treatment with trimethoprim sulfamethoxazole. The recurrences occurred at intervals of 3 weeks to 3 months following completion of antibiotic therapy. For the past two days, the woman has once again been experiencing dysuria, increased frequency, and urgency, so she goes to see her physician. Her vital signs are T = 37.2°C, P = 100, R = 18, and BP = 110/75 mm Hg. Physical examination reveals a mild tenderness to palpation in the suprapubic area, but no other abnormalities. A bimanual pelvic examination reveals a normal-sized uterus and adnexae with no apparent adnexal tenderness. No vaginal discharge is noted. The cervix appears normal.

Question 3.1: What is the differential diagnosis for this set of symptoms? What is your preliminary diagnosis?

Question 3.2: What tests should you order to confirm your preliminary diagnosis?

Question 3.3: Do the test results support your preliminary diagnosis? What is the most likely identity of the causative agent in this case?

Question 3.4: What things must be considered when taking a sample for analysis in a case like this? What instructions should be given to the lab?

Question 3.5: What are the possible causes of recurrent lower UTIs? Which of these is most likely in this case?

Question 3.6: How should this case be treated?

CASE 4

A 22-year-old man sees a physician because of a purulent discharge from his penis. The diagnosis of gonorrhea is made (and later confirmed by a lab) and he is given a single dose of ceftriaxone (a cephalosporin) by intramuscular injection. He improves initially but, after a few days, he notices a milder but persistent urethral discharge and dysuria. He is worried that he might not have been cured, so he comes to see you for a second opinion. He tells you that he has not had sexual intercourse since his visit to the original physician. He also brings his latest sexual partner, a 20-year-old woman, with him, even though she does not have any pain or vaginal irritation. On physical examination, the patient has a small amount of clear urethral discharge and his female partner has greenish discharge emanating from the mouth of her cervix. Her cervix is inflamed and bleeds easily when a swab is used to remove adherent secretions. Gram stains from both patients reveal numerous neutrophils, but no evidence of Gram-negative diplococci.

Question 4.1: What is your preliminary diagnosis of the male patient's condition and what test(s) would you order to confirm it?

Question 4.2: Was the original physician's treatment of the male patient appropriate?

Question 4.3: What are possible causative agents of this disease?

Question 4.4: What type of sample should be taken to confirm your diagnosis and how should it be collected?

Question 4.5: What is the prevalence of this disease? In what groups is it seen most often?