202/204: Microbiology of STIs and Reproductive Impact Flashcards
Which organisms are most commonly associated with urethritis in people with a vagina? (5)
- Chlamydia
- Gonorrhea
- HSV
- Trichomonas vaginalis
- Gardnerella (anything that causes bacterial vaginosis)
Which pathogens can be transmitted to a neonate via breastmilk? (2)
HIV
HBV
Which of the following maternal and neonatal outcomes is NOT increased by maternal infection with clamydia?
- Ectopic pregnancy
- Spontaneous abortion
- Chronic pelvic pain
- Infertility
- Neonatal pneumonitis and conjuctivitis
b. Spontaneous abortion
All of the following may cause lesions on the genitalia except:
- HSV
- Treponema pallidum
- Haemophilus ducreyi
- Nesseria gonorrhoeae
- HPV
d. Nesseria gonorrhoeae
* No lesions, just lots of inflammation and discharge*
All others cause legions
Notably, treponema (syphilis) and HPV will be painless, HSV and ducreyi will be super painful
How does hormonal status affect chlamydia transmission?
Chlamydia target cells = columnar epithelium of the cervix
- Younger women tend to have more exposed endocervical cells due to increased estrogen/progesterone
Name a parasite (1) and a bacteria (1) likely to cause vaginitis
Parasite: Trichomonas vaginalis
Bacteria: Gardenerella vaginella
What is the most important determinant in whether an HIV(+) mother will transmit HIV to the fetus?
How can risk of transmission be reduced?
Maternal viral load
HAART is highly effective in reducing transmission
C-section also plays a role, if mother has high viral load
Remember, HIV can be tranmitted transplacentlaly but also transvaginally during birth and through breastmilk!
Is chlamydia more likelty to be asymptomatic (and therefore undiagnosed) in men or women?
Women
Rank the following STIs in order from most to fewest new cases/year
Chlamydia, HIV and HPV
- HPV (most)
- Chlamydia
- HIV
Why are women more susceptible to the acquisition of HIV than men thorugh vaginal/penile intercourse?
Women are exposed to more body fluids over a greater surface area for a long period of time
Young women are more likely to have a cervical ectropion -> target cells are more exposed to HIV
(Cervical ectropion = columnar cervical epithelium is present on the ectocervix)
Which STI is most strongly associated with cervical, vaginal, and vulvar cancer?
HPV
(High-risk = HPV-16, 18, 31, 33)
- 6 and 11 are low risk, cause genital warts*
- Thank you @Will Schwartz!*
Which STIs can be transmitted both transvaginally and transplacentally during gestation?
HIV, HBV
(also CMV, not an STI)
Transvaginal only: chlamydia
Transplacental only: Syphilis
How is syphilis (treponema) diagnosed?
BOTH of the following tests:
- Non-trepomenal serologic assay
- Measures things associated with syphilis infection, but not trepona directly
- Can be used to measure treatment response
- Treponemal serologic test (FTA-ABS)
- Detects antibodies against trepona
- Stays positive forever (can’t be used to track treatment response)
Which STI is most likley to present with swollen, painful joints and a sore throat?
Gonorrhea
(Especially if acquired through oral-genital contact)
What factors increase liklihood of HIV infection following an exposure? (3)
-
More virus particles introduced to the lumen
- Semen has the most HIV particles of any body fluid
-
More target cells (Langerhans cells = specific type of macrophage that have HIV coreceptor)
- There will be more of these cells if there is an existing STI
-
Disrupted epithelial surface
- Vaginal and anal epithelium are at baseline most susceptible to infection
- Progesterone and spermicide (nonoxyol-9) can increase breaks in mucosa
Which perinatal infections can be transmitted transplacentally?
STIs and non-STIs
Must cross syncytiotrophoblasts
- STIs
- HIV
- Syphilis
- HBV
- Non-STIs
- CMV
- Rubella
Which STIs can cause neonatal conjunctivis after perinatal transmission? (2)
- Chlamydia
- Delayed, milky discharge
- Gonorrhea
- Very soon after birth, thick/waxy discharge
chlamydia also causes neonatal pnemonitis!
Which STI can cause neonatal pneumonia and conjunctivitis?
Chlamydia
Gonorrhea can cause chlamydia but not pneumonia
What factors influence a person’s “rate of partner change” (3)
- Context:*
- Rate of spread = efficiency of transmission * rate of partner change * duration of infectiousness*
- Total number of partners
- Prevalence of infection in one’s social network
- Multiple concurrent partners (vs. one after the other)
Which cells are targeted by gonorrhoeae and chlamydia?
Columnar epithelial cells
- Reproductive tract
- Anal epithelium
What percentage of new STIs occur in young people?
50% in ages 15-24
What sequelae can occur due to gonorrhea or clamydia infection in the female reproductive tract?
- Ascending infection -> Pelvic Inflammatory Disease
-
Results in tubal scarring
- -> Tuboovarian abscess -> sepsis -> death
- -> Ectopic pregnancy -> hemorrhage -> death
According to trend data, which demographic accounts for 75% of newly diagnosed primary and/or secondary syphilis cases?
Men who have sex with men (MSM)
Which STI can cause intrauterine growth restriction (IUGR) when passed transplacentally?
Syphilis
Can also cause stillbirth, congenital syphilis infection, death
Which organisms are commonly associated with urethritis in people with a penis? (3)
- Chlamydia
- Gonorrhea
- HSV
All three of these are common in people with a vagina as well
Describe the process of HIV transmission
(Which cells are infected? How does it spread?)
- HIV targets Langerhan’s cells in subepithelial
- More of these cells will be present if there is an existing infection or inflammation
- These cells are programmed to migrate to lymph nodes
- In the lymph nodes, virus is transmitted to other cells
Which non-STIs can cause intrauterine growth restriction (IUGR) when passed transplacentally?
CMV and Rubella
Which infections are transmitted transvaginally?
- STIs
- HIV (also placentally)
- Chlamydia
- HBV
- Non-STIs
- CMV
- Group B Strep
- Possibly COVID?
Why is somebody with an active gonorrhea infection more likely to acquire HIV?
Genital tract inflammation -> more inflammatory cells -> more target cells that HIV can infect
This is true for any inflammation from syphilis, bacterial vaginosis, chlamydia, gonorrhea
What is the equation for rate of spread of an STI?
Rate of spread = beta * c * d
- beta = efficiency of transmission
- c = rate of partner change
- d = duration of infectiousness
What are the affects of congenital CMV?
Deafness, blindness, developmental disabilites
What STI has NOT demonstrated an increased incidence trend in the last 5 years?
HIV
(chlamydia, gonorrhea and congenital syphillis are all increasing)
What kind of bacteria is gonorrhea?
Neisseria gonorrhoeae
Gram negative diplococci
What are the determinants of pathogenicity of gonorrhea?
Pili- help adhere to epithelial cells
Opa proteins- anchor bacterium
What is the treatment for gonorrhea?
Ceftriaxone plus doxycycline
(doxycycline also treats chlamydia!)
Increasing antibiotic resistance for gonorreha
What kind of bacteria is chlamydia?
Chlamydia trachomatis
Obligate intracellular pathogen
Neisseria gonorrhoeae
Gram negative diplococci
What kind of bacteria causes syphillis?
Treponema pallidum
Spirochete, very slowly dividing
How is syphillis treated?
Penicillin G
No resistance!
Jarisch-Herxheimer reaction - feel worse in first 24 hours when all bacteria lyse at once
Treponema pallidum
Syphillis
