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74 Cards in this Set
- Front
- Back
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What is NGU?
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NGU stands for non-gonococcal urethritis, which is usually caused by Chlamydia trachomatis but can also be caused by Ureaplasma urealyticum.
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How can urethritis be differentiated from cystitis using urinalysis?
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Compare a first-void sample to a midstream sample.
Finding a greater number of PMNs in the first void sample as compared to the midstream sample strongly suggests urethritis. In patients with cystitis, approximately equal number of PMNs should be found in both samples. |
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Is chlamydia an intracellular or extracellular parasite?
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Chlamydia trachomatis is an obligate intracellular parasite, requiring a host cell's ATP as an energy source to carry out its own cellular activities.
In this sense it is an energy parasite. It differs from a virus, however, in that it has both DNA and RNA as well as in its ability to synthesize its own proteins. |
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What is trachoma?
Which organism causes trachoma? |
This is a tricky question, since it is not a sexually transmitted infection.
Trachoma is an infectious disease causing a characteristic roughening of the inner surface of the eyelids. It is also called granular conjunctivitis. Trachoma is the leading cause of blindness in the world. The causative organism is Chlamydia trachomatis. |
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What are the three species of chlamydia known to cause disease in humans?
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Chlamydia trachomatis
Chlamydophila pneumoniae Chlamydophila psittaci |
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What is the standard first-line therapy for trachoma?
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Oral azithromycin, a macrolide antibiotic.
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Why are all newborns in the U.S. given erythromycin drops prophylactically?
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Erythromycin drops are given to preven inclusion conjunctivitis and opthalmia neonatorum. Inclusion conjunctivitis is caused by Chlamydia trachomatis and opthalmia neonatorum is caused by Neisseria gonorrhoeae, both of which can be passed on to the infant's eyes from the mother's birth canal.
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Which organism is responsible for inclusion conjunctivitis in newborns?
Which antibiotic is given prophylactically to prevent this? |
Inclusion conjunctivitis is caused by Chlamydia trachomatis.
Erythromycin eye drops are given prophylactically to all newborns in the U.S. to prevent this infection. |
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What is the most common sexually transmitted infection? Which organisms are responsible?
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Non-gonococcal urethritis (NGU).
NGU is primarily caused by Chlamydia trachomatis and Ureaplasma urealyticum. |
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Which two organisms are most often responsible for NGU?
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Chlamydia trachomatis followed by Ureaplasma urealyticum
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Name complications of urethritis in men:
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Epididymitis
-presents as unilateral scrotal swelling, tenderness, pain, feve Prostitis Urethral stricture |
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What is the most common causative agent of reactive arthritis (also called Reiter's syndrome)?
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Chlamydia trachomatis
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What is Reiter's syndrome?
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Reiter's syndrome is reactive arthritis.
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Name a complication of urethritis specific to women:
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Cervicitis and pelvic inflammatory disease (PID)
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Name some complications of chlamydial/gonococcal urethritis:
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In men:
-epididymitis In women: -pelvic inflammatory disease (PID) -Fitz-Hugh-Curtis syndrome In both sexes: -Reiter's syndrome (reactive arthritis) -urethral stricture |
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What is Fitz-Hugh-Curtis syndrome?
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Fitz-Hugh-Curtis syndrome, also called perihepatitis, is infection of the liver capsule and presents as right upper quadrant pain. It occurs almost exclusively in women and results from chlamydial or gonococcal infection following PID.
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What forms can infection with chlamydia take?
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1) Urethritis
2) Cervicitis 3) PID 4) Reiter's syndrome 5) Fitz-Hugh-Curtis syndrome 6) Pneumonia |
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Which organism causes gonorrhea?
What's the scientific name for gonorrhea? |
Gonorrhea is caused by Gram-negative cocci of the species Neisseria gonorrhoeae.
Gonorrhea is also called gonococcal urethritis. |
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"The clap" is a slang term for which STI?
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Gonorrhea, or gonococcal urethritis
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What is the etymology of gonorrhea?
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Greek, "seed flux," so called because the purulent discharge was thought to be a discharge of semen.
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How does urethritis present clinically in men?
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Most men with gonococcal or chlamydial urethritis are symptomatic and have dysuria with a purulent or mucousy discharge from the urethra.
Some men may be unsymptomatic. |
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How does urethritis present clinically in women?
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Most women are asymptomatic, though like men they may also experience dysuria with a purulent to mucousy discharge from the urethra.
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What is inflammation of the uterus called?
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Endometritis
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What is inflammation of the fallopian tubes caled?
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Salpingitis
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What is inflammation of the ovaries called?
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Oophoritis
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Name a serious complication of urethritis/cervicitis in women:
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Pelvic inflammatory disease (PID)
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How does pelvic inflammatory disease present clinically?
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Fever
Lower abdominal pain beginning during or immediately after menses Menstrual irregularities |
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What is pelvic inflammatory disease?
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Pelvic inflammatory disease is Infection and inflammation of the uterus, fallopian tubes, and potentially the ovaries, usually by N. gonorrhoeae or C. trachomatis.
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Name 5 potential complications of PID:
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Sterility
Ectopic pregnancy Abscesses in fallopian tubes Peritonitis Fitz-Hugh-Curtis Syndrome |
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What is opthalmia neonatorum and what is the responsible organism?
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Opthalmia neonatorum is an eye infection that develops in infants due to vertical transmission of N. gonorrhea from the birth canal to the baby's eyes.
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How is gonococcal/chlamydial urethritis diagnosed?
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First-void and midstream urinalysis (rule out cystitis)
Gram stain and culture (will pick up N. gonorrhoeae) If nothing on Gram stain, assume NGU. |
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How is gonococcal urethritis treated?
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Ceftriaxone
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Which physical exam finding is strongly suggestive of PID?
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Cervical motion tenderness
and/or Purulent endocervical discharge |
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What is the most common cause of genital ulcers in the United States?
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Herpes simplex virus (classicaly HSV-2, but genital infection with HSV-1 is now recognized as common)
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What is chancroid?
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Chancroid is the name of a sexually transmitted infection characterized by painful sores on the genitalia.
Chancroid is caused by infection by Gram-negative bacilli of the species Haemophilus ducreyi. |
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Which organism causes chancroid?
How is this organism classified? |
Haemophilus ducreyi, Gram-negative bacilli
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Name the three most common causes of genital ulcers in North America:
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1) Herpes simplex virus (HSV-2 > HSV-1)
2) Haemophilus ducreyi (chancroid) 3) Treponema pallidum (syphilis) |
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What are patients with genital ulcers at increased risk of?
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An ulcer, by definition, is a dicontinuation of the ski or mucous membrane, a vital immunologic defense.
Genital ulcers render the individual particularly vulnerable to HIV infection. |
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Why is C. trachomatis not susceptible to cell-wall synthesis inhibitors?
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Chlamydia trachomatis has no peptidoglycan cell wall layer.
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How is chlamydia treated?
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Protein-synthesis inhibitor such as doxycycline or erythromycin.
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Chlamydia trachomatis can be passed from mother to newborn to cause which eye disease?
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Inclusion conjunctivitis
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Neisseria gonorrhoeae can be passed from mother to newborn to cause which eye disease?
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Opthalmia neonatorum
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Which organism is responsible for syphilis and how is this organism classified?
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Treponema pallidum, a Gram-negative spirochete
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What is a chancre?
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A chancre is a painless ulceration formed during the primary stage of syphilis.
Chancres are highly infectious. |
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How long after initial inoculation with T. pallidum does a chancre erupt at the site of infection?
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3-6 weeks
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How long after intial eruption until a chancre resolves?
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4-6 weeks
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What are the clinical signs/symptoms of primary syphilis?
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Chancre
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What are the clinical signs/symptoms of secondary syphilis?
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Fever
Generalized lymphadenopathy Macular rash Condyloma lata |
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Describe the characteristics and location of the rash of secondary syphilis:
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Small erythematous macular lesions symmetrically distributed over the body , particularly invoving he palms, soles, and mucous membranes of the oral cavity.
The skin lesions can become papular (bumpy) and even pustular. |
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What are condyloma lata?
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A condyloma latum is a painless, wart-like lesion caused by infection with T. pallidum. Condyloma lata appear during secondary syphilis. The lesions are packed with spirochetes and highly contagious.
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How long after chancre resolution do the symptoms of secondary syphilis appear?
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6 weeks
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How long does the secondary stage of syphilis typically last?
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6 weeks
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What percentage of patients with latent syphilis will progress to tertiary syphilis?
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1/3
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How long must a person with syphilis remain asymptomatic until they are considered non-contagious?
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4 years
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Describe the natural history of syphilis:
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To describe the course of syphilis we can use the rule of sixes:
6 axial filaments 6 week incubation 6 weeks for ulcer to heal 6 weeks after the ulcer heals, secondary syphilis develops 6 weeks for secondary syphilis to resolve 66% of latent syphiliti cs have resolution (no tertiary syphilis) 6 years to develop tertiary syphilis (at least) |
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Which test can defintively diagnose syphilis during the primary or secondary stages?
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Direct observation of spirochetes using dark field microscopy.
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What is the first-line treatment for syphilis?
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Penicillin G
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What is the molecular difference between a non-specific and specific treponemal test?
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Non-specific tests such as VDRL and RPR look for antibodies against tissue lipids released by cellular damage.
Specific tests lok for antibodies against the spirochete itself. |
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What are the two most common non-specific treponemal tests?
When are they used? |
1) Venereal Disease Research Laboratory (VDRL)
2) Rapid Plasma Reagin (RPR) test These tests are anti-lipoidal tests not specific to infection with T. pallidum. They are used as screens and must be confirmed with a more specific test, such as FTA-ABS. |
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Name the most common specific treponemal test.
What is the principal drawback of this test? |
Indirect Immunofluorescent Treponemal Antibody-Absorption (FTA-ABS)
The main drawback is that this test will be positive forever once a person has been infected, so new cases of re-infection cannot be confirmed using FTA-ABS. |
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What is the Jarisch-Herxheimer phenomenon?
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The Jarisch-Herxheimer phenomenon is an acute worsening of symptoms of syphilis immediately following initiation of antibiotic therapy.
Symptoms include fever, malaise, and muscle aches. Killed bacteria release a pyrogen believed to be a cause of this phenomenon? |
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What is the acute worsening of syphilitic symptoms immediately following initiation of antibiotic therapy called?
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Jarisch-Herxheimer phenomenon
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How is non-primary syphilis diagnosed?
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Non-primary syphilis must be diagnosed using serologic testing.
Non-specific tests include VDRL and RPR, while specific tests include FTA-ABS. |
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What is the technical definition of AIDS?
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AIDS is now defined as having a CD4 count of less than 200 with serologic evidence of HIV infection.
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How is HIV diagnosed?
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1) Sensitive but not specific ELISA test (serology)
2) Western Blot for confirmation |
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How long after initial inoculation does it take for a person with HIV to seroconvert?
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Seroconversion in patients with HIV takes about 6 weeks.
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Why is chlamydia underdiagosed?
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Chlamydia is underdiagnosed becaue the majority of cases are asymptomatic.
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How is chlamydia diagnosed?
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Culture or nucleic acid amplification test (NAAT)
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What is the preferred treatment in adults for chlamydia infection of the urethra, cervix, rectum, or conjunctiva.
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1) Doxycycline 100 mg PO bid for 7 days
OR 2) Azithromycin 1 g PO in a single dose. Doxycycline is recommended over azithromycin because it is much cheaper. However, if poor compliance with the 1 week regimen is suspected the single dose azithromycin should be used. |
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How is infection with N. gonorrhoeae diagnosed?
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Gram stain
Culture Nucleic acid amplification test |
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What is the preferred treatment of gonorrhea in adults?
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Cefixime 400 mg PO in a single dose
Cefixime is a third generation cephalosporin. Others of this class (e.g. ceftriaxone can be substituted) |
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How is genital herpes diagnosed in the lab?
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Culture
NAAT (PCR) Tzanck smear Serology for antibodies |
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Is genital herpes curable?
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NO!
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Describe the pharmacological management of genital herpes:
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Aciclovir
OR Famciclovir OR Valacyclovir |
