E3- STIs Flashcards
What STIs are ulcerative?
- Syphilis
- Chancroid
- Genital hepes
What STIs are nonulceative?
- Gonorrhea
- Trichomoniasis
- Chlamydia
What genus includes nonpathogenic species that are normal flora on mucosal surfaces, species that cause non-STD diseases, and species that produce STD diseases?
Treptonema
How are non-STD treptonema infections spread?
Person-to-person via direct contact (occur in developing countries)
What is the etiology of syphilis?
Treptonema pallidum
Is Treptonema pallidum (syphilis) gram positive/negative? What shape?
Gram negative spirillum
What type of pathogen is Treptonema pallidum (syphilis)?
Obligate intracellular parasite (requires mammalian host)
What are Treptonema pallidum’s (syphilis) virulence factors?
- Outer membrane proteins (promote adherence to host cells)
- Hyaluronidase (facilitates perivascular infiltration)
- Fibronectin coat (antiphagocytic)
What are Treptonema pallidum (syphilis) lesions primarily the result of?
The host’s inflammatory response
How is Treptonema pallidum (syphilis) transmitted?
Usually via direct sexual contact with a person who has active primary or secondary lesions Can also occur via: -Lesion near mouth -Needle sharing -Transplacental
Treptonema pallidum enters into subepithelial tissues and undergoes local multiplication and dissemination to ___ via ___.
Nearby lymph nodes via circulation
What is the name of the primary/principal lesion associated with Treptonema pallidum (syphilis)?
Chancre
Chancres typically begin as a what?
Papule
How long does it take an untreated primary Treptonema pallidum (syphilis) lesion to heal?
3-8 weeks with fibrosis
What is the disease progression of Treptonema pallidum (syphilis)?
- Primary syphilis
- Dormancy period
- Secondary syphilis
- Latent syphilis
- Spontaneous cure, seropositive w/o disease, or tertiary syphilis
What is typically seen clinically with secondary syphilis?
- Development of superficial lesion of high infectivity (Maculopapular rash)
- Mucosal warty lesions (condylomata lata)
- Immune complexes
What is typically seen clinically with latent syphilis?
Absense of clinical signs and symptoms
What is considered an “early” latency syphilis?
Within 1 year of infection
What is considered an “late” latency syphilis?
More than 1 year after infection
What is typically seen clinically with tertiary syphilis?
- Neurosyphilis
- Cardiovascular syphilis
- Granulomata (gummas)
When does tertiary syphilis manifest?
5-30 years after infection
What is the typical progression of congenital syphilis?
Most infants are born apparently healthy and develop symptoms at ~3 weeks of age
What does earlier onset of congenital syphilis symptoms suggest?
Poor prognosis
What is the clinicial presentation of congenital syphilis?
- Maculopapular cutaneous lesions
- Nasal obstruction with mucoid discharge (infectious)
- Osteitis of nasal bones
- Neurosyphilis
What is Hutchinson’s Triad and what disease is it associated with?
Congenital syphilis
- Notched incisors
- Interstitial keratitis
- 8th nerve deafness
What should every genital lesion be considered until proven otherwise?
Syphilis
How is syphilis dx?
- Darkfield microscopy
- Serology (nontreponemal vs. treponemal)
What syphilis serological test is non-specific and used for screening?
Nontreponemal test
What syphilis serological test is specific for antibodies and used for confirmation?
Treponemal test
What is the causative agent of gonorrhea?
Neisseria gonrrhoeae
Is Neisseria gonrrhoeae gram positive/negative? What shape?
Gram negative diplococcus
What are the virulence factors of Neisseria gonrrhoeae? (5)
- Antigenic variation of pili
- Nonpiliated phase variants
- Porin protein
- IgA protease
- Plasmid and chromosome mediated resistance to abx
What age group has the highest incidence of Neisseria gonrrhoeae?
Adolescents
What is the function of antigenic and nonpiliated phase variations of pili in N. gonrrhoeae?
To confuse the hosts immune system so we don’t made antibodies
What is the function of porin proteins?
Aid in attachment
Who are major reservoirs for Neisseria gonrrhoeae?
Asymptomatic patients
What is the first step of Neisseria gonrrhoeae infection?
Attachment to the epithelium via pili and surface proteins
How does Neisseria gonrrhoeae cause injury to cells?
Releases Lipooligosaccharide and peptidoglycan
What kind of discharge is seen with Neisseria gonrrhoeae infections in males?
Thick, mucopurulent discharge
What are three complications of Neisseria gonrrhoeae in females?
- Acute salpingitis
- Pelvic inflammatory disease
- Disseminated Gonococcal infection
What can present with bacteremia, fever rash, endocarditis, and/or meningitis?
Disseminated Gonococcal infection
What is the most common presentation of Disseminated Gonococcal infection?
Purulent arthritis
How is Neisseria gonrrhoeae dx?
- Gram stain
- Culture (Nucleic acid amplification/PCR) *GOLD STANDARD
What are 3 causative agents of nongonococcal urethritis?
- Chlamydia trachomatis
- Mycoplsma spp
- Ureaplasma urealyticum
What type of pathogen is Chlamydia trachomatis?
Obligate intracellular bacteria (requires mammalian host)
Is Chlamydia trachomatis gram positive/negative?
Gram negative
What is the infectious form of Chlamydia trachomatis?
Elementary body
What is the fragile intracellular form of Chlamydia trachomatis?
Reticulate body
What age group has the highest incidence of Chlamydia trachomatis infections?
Teenagers
Ascesion of Chlamydia trachomatis in females can lead to what?
- Acute salpingitis
- Pelvic inflammatory disease
Infants born to mothers infected with chlamydia usually present with what?
Inclusion conjunctivitis
What are the possible presentations of a Chlamydia trachomatis infection? (7)
-Salpingitis
-PID
-Inclusion conjunctivitis (newborns)
-Cervicitis
-Urethritis
-Lymphogramuloma venereum
-Epididymitis (watery discharge)
“SPICULE”
Certain toxin-producing strains of Chlamydia trachomatis may lead to what?
Chronic inflammation
How is Chlamydia trachomatis dx?
- Isolation in cell culture = GOLD STANDARD
- NAAT
What is the etiology of Trichomoniasis?
Trichomonas vaginalis
What type of pathogen is Trichomonas vaginalis?
- Flagellated protozoan
- Extracellular anaerobe
- Exists only as a trophozoite
What is the typical presentation of Trichomonas vaginalis in males?
- Usually asymptomatic
- Scanty, clear to mucopurulent discharge (yellow-gray)
What is the typical presentation of Trichomonas vaginalis in females?
- Usually symptomatic
- Profuse vaginal discharge, frothy and malodorous
- Creates an environment for bacterial vaginosis
How is Trichomonas vaginalis dx?
- Wet mount is commonly used
- Culture is more specific
Is bacterial vaginosis an STI?
NO
Caused by an overgrowth of opportunistic pathogen in the vagina die to a change in pH
What is the normal vaginal pH?
< 4.5
What pH is seen in bacterial vaginosis?
5-6
What is the criteria for dx bacterial vaginosis?
- Presence of clue cells
- Release of amine odor when 10% KOH is added
- Vaginal pH > 4.5
- Presence of curved gram negative or gram variable rods
What type of discharge is seen with Trichomoniasis? Vaginosis?
Trichomoniasis: Thin and yellow-gray
Vaginosis: Thin and grey
What is the most common opportunistic mycoses (fungal infection) world wide?
Candidiases
What is the etiology of Vulvovaginal candidiases (yeast infection)?
Majority- Candidia albicans
Minority- Candidia tropicalis, Candidia glabrata
What type of discharge is seen with Vulvovaginal candidiases (yeast infection)?
Thick, white, frothy discharge
No odor
What is the etiology of chancroid?
Haemophilus ducreyi
Is Haemophilus ducreyi gram positive/negative? What shape?
Gram negative coccobacillus
How does a typical Haemophilus ducreyi (chancroid) lesion present?
Tender papule on the genitalia that develops into an ulcer with sharp margins and no induration
What is a soft chancre?
A lesion associated with Chancroid:
- Soft ragged edge
- Painful
- Pus
- Bleeds readily
- No induration
What is a chancre sore?
A lesion associated with syphilis
- Hard raised edge
- Painless
- Indurated
How is Haemophilus ducreyi (chancroid) dx?
- ID from genital ulcer or swollen lymph node
- PCR
What can occur when microorganisms ascend into the endometrium, fallopian tubes and contiguous structures?
Pelvic Inflammatory Disease
What are the most common etiologies of Pelvic Inflammatory Disease? (2)
- Neisseria gonorrhoeae
- Chlamydia trachomatis
How is PID dx?
Evidence of inflammation
- Fever
- Leukocytosis
- Elevated ESR