Chlamydia

CASE 1

• A 25 year old single man comes to the clinic complaining of a penile discharge for three days. Two days earlier, he went to a pharmacy and was given an oral cephalosporin to treat for gonorrhoeae, but there was no improvement.

• A Gram stain of the urethral discharge was performed. Numerous neutrophils were seen, but there were no visible bacteria (see below).

• The patient was treated with a single large dose of azithromycin and an injection of ceftriaxone.

• The sexual history revealed that the patient had been having sexual relations with only one female partner during the past 6 months. She was informed by the patient of the need to come to the clinic for an evaluation.

• The girlfriend had no symptoms and felt well. However, a pelvic examination revealed a small amount of mucopus emanating from her cervical os (below, see blue arrows).

• She was given an injection of ceftriaxone and a single large dose of azithromycin.

Questions:

1. What is the diagnosis of the male patient?
2. Why did his discharge not improve after treated with an oral cephalosporin?
3. Why are there no bacteria seen in his urethral smear?
4. Are you surprised that his girlfriend had no symptoms? Do you think that she was infected? If so, how long might she have been infected?
5. Why were they both treated with azithromycin? Why ceftriaxone?

CASE 2

• A 32 year old man complained of swelling on both sides of his groin. Six weeks ago, he noted a small pustule on his penis the opened, drained and resolved. This developed after he returned from a long stay in Niger, where he had occasional sexual contact with a prostitute. He subsequently developed enlarged nodules in the left inguinal region, then a week later, on the right as well. These areas have been gradually enlarging since.

• He is afebrile. There are matted lymph nodes in both inguinal and femoral regions bilaterally. One node on the left feels fluctuant (filled with fluid/pus).

• He was diagnoses with lymphogranuloma venereum (LGV) and treated with a prolonged course of doxycycline (a tetracycline antibiotic). After three months, he returned to normal.

Questions:

1. Is this infection caused by the same pathogen as in Case #1? Are there any differences?
2. Is this disease as common as the disease presentation in Case #1?
3. What problems would this patient encounter if not treated?

CASE 3

• A 10 year old boy is blind in his left eye and has redness of the right eye. He has been advised to use an ointment in the right eye regularly to treat infection with Chlamydia trachomatis and to avoid becoming totally blind.

• The right eye has early signs of trachoma, specifically the development of follicles under the upper eyelid.

• The left eye has scarring of the conjunctiva and scarring with opacification of the cornea.

Questions:

1. Is eye infection with C. trachomatis common?
2. How does this disease cause blindness? Can it be prevented?
3. How is trachoma acquired? What environmental factors play an important role in transmission?

CASE 4

• A 35 year old farmer has high fever, severe cough, and shortness of breath. A chest x-ray showed patchy infiltrates in the right upper and left lower lobes.

• No one else in the patient's household has been ill. He has three dogs, a cat, and raises chickens and turkeys on his farm. Some of the turkeys have recently lost weight and died from a respiratory illness.

• A sputum Gram stain and culture are unremarkable. However, some of the sputum is examined by health department officials using a fluorescent-labeled antibody against Chlamydia psittici. The test showed particulate fluorescent in numerous cells in the smear, confirming the diagnosis of psitticosis (see below).

Questions:

1. What was the source of C. psittici that caused this patient lung infection? What other birds are potential sources?
2. How was the pathogen acquired?
3. Is this disease common? Which other Chlamydia species is a much more common cause of atypical pneumonia?
4. Can the fluorescent antibody technique used in this case also be used to diagnosis C. trachomatis and C.pneumoniae infection? What other diagnostic techniques might be used to detect Chlamydia in some laboratories?
5. Is it possible for the laboratory to culture Chlamydia from patient specimens? How would this be done?
6. How will this patient be treated? How would he be treated if he had infection with C. pneumoniae?