Lecture 13: Sexually Transmitted Infections Flashcards
What structure of Gonorrhea have
Gram-negative diplococcus (coffee beam shape)
What is Gonorrhea’s causative agent
Neisseria gonorrhoeae
What age group is gonorrhea most common in
20-25
How is Gonorrhea transmitted
through contact of mucous membranes (sexually or perinatally)
Is Gonorrhea better or worse than the 1990s
getting worse
what does Gonorrhea require for culture
enriched medium (so it doesn’t dry out) and CO2
How is Gonorrhea most commonly detected
PCR
What are the clinical manifestations of Gonorrhea in men and women separately
Men: Mucopurulent urethritis (drainage or milk discharge in men from urethra)
Women: Mucopurulent cervicitis (inflammation of the cervix),
Pelvic inflammatory PID, which can lead to reduced fertility
What are the clinical manifestations of Gonorrhoea in both males and females
Pharyngitis (inflammation of the throat)
Conjunctivitis (inflammation of the eyes)
Disseminated gonococcal infection (spread throughout body) especially joint pain
Gonorrheal ophthalmia neonatorum (bacterial eye infection in new borns)
How is gonorrhea diagnosed
Nucleic acid amplification testing (NAAT) like PCR
Culture of urethral or cervical swabs
Is NAAT or culture more sensitive and specific in Gonorrhea testing
Sensitive: NAAT is more sensitive than culture as molecular methods can also detect dead organisms
Specific: Very specific because if you grow gonorrhea on a plate there is no mistaking what it is
What medication is used to treat Gonorrhea
Cerfixime (cephalosporin, beta lactam) administered orally
or
Ceftriaxone (cephalosporin, beta lactam) administered intramuscularly through injection
With azithromycin for possible Chlamydia co-infection
What medication is now not used with Gonorrhea
Ciprofloxacin (fluoroquinolione) because of resistance
Many guidelines dont use Cerfixime anymore because it is becoming resistant so go straight to Ceftriaxone
What drug is given to someone who travelled or has multiple partners
Ceftriaxone
What STI is considered A-typical
Chlamydia
What is the causative agent of Chlamydia
Chlamydia trachomatis
Why is Chlamydia Atypical
Obligate intracellular bacteria with no cell wall, so cant be gram-stained
What STI has different serotypes
Chlamydia
Lymphogranuloma centrum (LGV) not in Canada
Eye diseases (trachoma) found in newborns and found in tropics
How is Chlamydia detected
cannot be grown on artificial media, requires culture in cultured cells (human or animal cells to grow)
Molecular amplification testing (panther)/ NAAT
What is the reticulate body
actively replicating form found within cells
When mature, it causes cell rupture and fragments into many elementary bodies
What is the elementary body
Inert infectious form found on the surface of cells, invades cells (Transmitted form)
Don’t replicate within themselves they transfer to new hosts and bodies turn into reticulate bodies so they can replicate in the new host
What form of Chlamydia infects and how
Elementary bodies
Infects urethral, cervical, and conjunctival epithelial cells (eyes)
What form of Chlamydia infects and how
Elementary bodies
Infects urethral, cervical, and conjunctival epithelial cells (eyes)
How is Chlamydia transported
through sexual contact or perinatally, direct contact to conjunctiva (eye)
What age group is most common to have Chlamydia
15-25 years old, females tend to younger than males
What does nongonococcal mean
See nothing on a gram stain, Chlamadia
What are the clinical manifestations of Chlamydia in men and women separately
Men:
- Mucopurulent urethritis (drainage or milk discharge in men from urethra)
- Epididymitis (inflammation of an area in the back of the testicle)
Women:
- Mucopurulent cervicitis (inflammation of the cervix)
- Pelvic inflammatory disease, complications include ectopic pregnancy and sterility secondary to scarring
What are the clinical manifestations of Chlamydia in men and women both
Reactive arthritis (formally Reiter’s syndrome)
Urethritis: inflammation of the urethra
Proctitis: inflammation around rectum or anus
Conjunctivitis: pink eye, espically in new borns
Trachoma: severe form of conjunctivitis in the tropics
How are Chlamydia specimens obtained
Men:
urine samples (Now)
Urethral swabs (Past)
Women:
Self-taken vaginal swabs
Urine
Endocervical swabs had to have a pap to have this done (past)
Treatment for Chlamydia
Doxycycline: can’t use beta lactams because does have a cell wall to attack
or azithromycin or erythromycin
What is syphilis’s structure
Tightly coiled spirochaete (5-15 um length, 0.09-0.5 um diameter)
Who is syphilis most common in
increasing since 2000 in men with multiple male partners
How is syphilis transmitted
through sexual contact or transplacemntal (to fetus)
How is sphyilis viewed
Not easily cultured in lab, animal tissues are needed
Too fine to gram stain, so we use “dark field microscopy”
What is dark field microscopy
Put organism on a black background and bounding light off the organism trying to encentuate its size (only done in Toronto)
used on primary chancre
What are the congenial effects of Chlamydia
Bone, teeth, brain damage
What are the clinical presentations of syphilis
Primary syphilis (localized)
Secondary syphilis (systemic)
Tertiary syphilis (late)
What is latent infection
when you are asymptomatic and bypass the secondary stage of sypilis and go directly to the tertiary stage
What is primary syphilis
Presents 1-4 weeks post infectious contact
Produces a chancre (painless ulceration)
Heals spontaneously within weeks
What is secondary syphilis
Spirochactes are now in the blood
full body skin rash (doesn’t spare the palms or soles)
“flu like illness”
lymphadenopathy (swelling in lymph nodes)
What is tertiary syphilis
Cardiovascular (heart failure) and neurological (dementia, seizures, paralysis)
Gumma (late cutaneous, bony, or visceral masses) in organs and soft tissues
What is the main way syphilis is diagnosed
serology is the main route of diagnosis
Subdivided into
1) Nonspecific tests (non treponema tests)
VDRL
PRP
2) Specific tests (Treponemal tests)
TPPA
EIA
What is the treatment for syphilis
penicillin is the treatment of choice, doxycycline as an alternative (if allergy)
Followed by PRP for response can be followed
Longer treatment if CNS is involved
What is PRP
Rapid Plasma Reagin: used to follow resolution after established diagnosis
Cheap but can lead to false positives as you read with your eyes
You dilute blood serums- 1:1, 1:2, 1:4, 1:8
If you are positive at 1:2 but negative after, then you have low levels of organism
Can test RPR over treatment to see if you are getting better
What is a common co-infection in Syphilis
HIV
What is genital herpes structure
linear double stranded DNA virus
Neurotropic
invades nerves and becomes dormant (latent) within them, regrowth with cold sores or genital sores gives reactivation of infection
Who is genital herpes most common in
all
What are the types of gential herpes
herpes simplex virus (HSV) type 1 or 2
How are genital herpes transmitted
through contact with person shedding virus
what is the sereoprevelance of HSV-2
20-80% have antibodies
What is the clinical presentation of genital herpes
- Primary infection:
fever, headache, malaise, myalgia
Painful lesions on genitalia
Dysuria (burning during urination) more common in women
Vaginal or urethral discharge
Tender inguinal adenopathy (groin nodes area)
- Latent
Shedding of virus without any lesions
What type of Genital herpes infection is more likely to reoccur
HSV-2 more than HSV-1
usually much less severe than primary infection usually localized to genital area
50% have prodromal symptoms (tingling, pain)
What does congential herpes look like
localized, CNS, disseminated (especially if mother has primary infection at delivery)
What type of diagnosis is used for genital herpes
Swabs of local lesions
i) NAAT
ii) culture on cells (less sensitive, laborious)
Serology rarely used
What is the treatment for genital herpes
Antivirals (acyclovir, valaciclovir, famciclovir)
Longterm prophylaxis may be necessary in frequency recurrent disease
What is genital warts caused by
human papillomaviruses
Many serotypes, some found at different body sites that are not all STIs
How are genital warts transmitted
by direct sexual contact
What do genital warts look like
Skin growths on genitalia, perianal area
May be asymptomatic
Usually transient infection, resolving in months
How can Genital warts be removed
chemical means, freezing, or surgery
