STIs Flashcards
What are the three ulcerative STDs?
Syphilis
Chancroid
Genital herpes
What are the three non-ulcerative STDs?
- Gonorrhea
- Trichomoniasis
- Chlamydia
Once syphilis is latent late, what are the three options for the disease?
- spontaneous cure in ∼1/3 of cases
- seropositivity w/o disease in ~1/3 of cases
- tertiary syphilis in ~1/3 of cases
What is used for the presumptive dx of syphilis? Confirmatory?
P: Cardioleptin floccuation (VDRL, RPR)
C: specific antibody test (FTA-ABS, MHS-TP)
G- diplococcus with kidney bean shaped cells; fastidious growth requirements
Neisseria Gonorrhoeae
G- spirochete with slow rotational motility; obligate parasite
Treponema Pallidum
Two primary VF of Neisseria Gonorrhoeae
IgA Protease for colonization
Plasmid for resistance
also antigenic variation of pili and porin proteins
Why has there been a rise in gonorrhea cases?
Changed sexual mores and practices
Ineffective methods for detection of asymptomatic cases
Presence of beta-lactamase positive strains
Lack of public appreciation of its importance
Complications of gonorrhea
Acute salpingitis or pelvic inflammatory disease (PID)- most common
Disseminated Gonococcal Infection (DGI)
What does DGI of gonorrhea consist of?
Bacteremia leads to fever rash and mucopurulent arthritis (most common)
can also lead to endocarditis and meningitis
What tests are used to look for N. gonorrhea?
Agglutination, DNA probe, biochemical tests are used for confirmation
Nucleic acid amplification (PCR) is now the gold
standard
What are some complications of chlamydia?
sterility and ectopic pregnancy
>50% of infants born to infected mothers show conjunctivitis
5-10% present with pneumonia
What is the best way to diagnose chlamydia? What is the gold standard?
Nucleic acid probes (95%)–Normal flora can cause a positive test
Gold standard is isolation for a week in culture (HeLa cells)
What mycoplasmas are involved in NGU?
Mycoplasma genitalium
Ureaplasma urealyticum
What is the main reservoir for ureaplasma urealyticum?
genital tract of sexually active persons
(Colonization is present in >80% of persons who have had 3 or more sex partners)
~50% of nongonococcal, nonchlamydial urethritis in men
What are the three main causes of vaginitis?
Trichomoniasis
Bacterial vaginosis
Yeast vaginitis
Extracellular, anaerobic, flagellated protozoan
trichomonas vaginalis
What are the forms of trichomonas vaginalis?
trophozoite only
T. vaginalis In the female
- Is usually symptomatic
* Profuse vaginal discharge: frothy and malodorous
What is the most common way to diagnose T. vaginalis? The best?
Wet mount; culture (more sensitive)
What usually occurs as normal flora but then becomes problematic due to an overgrowth of opportunistic pathogen in vagina due
to change in pH? What else puts them at risk?
Bacterial vaginosis-NON-STI
• History of previous STDs
• History of sexual activity
• Current use of intrauterine devices
What is found in the vaginal secretions of pt with bacterial vaginosis as opposed to normal secretions?
Clue cells and pH of 5.0-6.0
Any three of which 5 characteristics will classify bacterial vaginosis? (top 3 esp)
• Homogeneous quality of secretions • Presence of CLUE CELL • Release of fishy amine odor when 10% KOH is added • A vaginal pH of >4.5 • Presence of curved gram negative or gram variable rods
Which two causes of vaginitis are difficult to distinguish?
trichomonas and vaginosis
What is the most commonly encountered opportunistic mycoses (fungal
infections) worldwide?
Candidiasis
What are some (3) underlying causes of candidiasis?
1) Absence of competing normal flora (broad spectrum abx)
2) Introduction to abnormal site
3) “Pathologic” change in microenvironment
Thick, white, frothy discharge in women (no
odor). Which has an odor?
Candidiasis; t. vaginalis
Which form of c. albicans is most adhesive?
Germ tube is more adhesive than yeast cell
What can be used to diagnose c. albicans?
Chromagar to determine species
Hyphae and pseudohyphae under microscopy, also look for the appearance of germ tubes
soft border, painful chancre that bleeds readily
hemophilus ducreyi
chancroid vs chancre sore
soft ragged edge with pus vs
hard raised edge
What is PID? What are typical agents?
Anything not PGN or surgery related that causes endometritis, salpingitis, pelvic peritonitis, or tuboovarian abscess
• Neisseria gonorrhoeae or Chlamydia trachomatis
