4/17 STD: iBook Ch 12 Flashcards Preview

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Flashcards in 4/17 STD: iBook Ch 12 Deck (59)

List some of the long-term health consequences of STDs (beyond any acute genital syndromes) (4)

-Reproductive tract cancers (HPV, HBV, HTLV-1, EBV, HHV-8)

-Impaired fertility (PID, ectopic, tubal factor infertility)

-Adverse pregnancy outcomes (preterm, spontaneous abortions, congenital infections, perinatal infections)

-HIV acquisition and transmission (genital ulcers serve as a portal of entry and associated inflammation brings target CD4+ cells and exposes them at surface of ulcer; with genital ulcer, have greater HIV shedding in the genital tract)


Populations at risk for STDs? (5)

-Youth (CDC defines as up to age 24)


-Multiple sex partners (commercial sex workers and some MSM [men who have sex w men])

-People on the social margins: runaways, homeless, incarcerated, migrant workers, mentally ill, substance abusers

-Native to STD endemic areas: refugees and immigrants (??)


Chlamydia:  what causes it? describe the characteristics of the bacteria. what are the 2 forms?

Do we culture for it?

Caused by Chlamydia trachomatis: serovars D-K.

They are small, obligate intracellular bacteria. Lack the typical peptidogylcan cell wall of bacteria. 

Two forms: Elementary Body (extracellular) and Reticulate Body (Intracellular replicative form). 

We do not routinely culture for it: requires tissue culture for isolation. 


Chlamydia: Pathophys?

CT binds to surface of columnar epithelial cells. Taken up by receptor-mediated endocytosis. Secondary inflammation may be mild or fulminant.


Chlamydia: Epidemiology?

Most prevalent STD in developed and underdeveloped countries!

Asymptomatic carriage rates are 5-30%.


Chlamydia: what is its impact on pregnant women/fetuses?

cause of infertility.

causes perinatal infection if woman is not screened/treated prior to birth

70% of infants born to infected women have serum antibody to CT; other 30% are ill with pneunomia or conjunctivitis


Chlamydia: Clinical syndromes in adults (7)?







-Reactive Arthritis


Chlamydia: clinical syndromes in neonates (2)?

-Inclusion conjunctivitis ("cobblestoning" without exudate)

-Interstitial pneumonia


Chlamydia: Diagnosis?

DNA based: Ligase chain reaction, PCR, or NAAT on urine or genital specimens

Women: self-collected vaginal swabs

Men: first catch urine

For proctitis, a rectal specimen for NAAT can be sent - may be better than culture (not FDA approved)


What is NAAT?

Nucleic Acid Amplification Test

umbrella term: includes any test that directly detects the genetic material of the infecting organism or virus: PCR, reverse transcriptase PCR, Ligase Chain Reaction

Designed to detect a virus or bacterium earlier than an antibody test


Chlamydia: Treatment?

Azithromycin 1g orally single dose


Doxycyclin 100mg orally BID for 7d


Chlamydia: How do we test to see if patient is cured? what patients do we re-test?

Re-test 3-4 weeks after treatment: recommended for pregnant women, those with compliance issues, persistent symptoms, or possible re-infection

For other patients, re-test 3m after treatment


Chlamydia: Who do we screen?

-Females: annual screening of all sexually active females <= 25y is recommended. Screen older women with new sex partners or multiple sex partners. Screen all pregnant women during third trimester

-Males: Selective screening for those in adolescent clinics, corrections programs, national job training programs, < 30y, STD history, military

-Those with symptoms

(Also offer HIV testing)


Gonorrhea: Microbiology - what is the organism? what does it need to live?

Neisseria gonorrhea: gram-neg diplococci

Require a warm, moist, CO2-rich environment.


Gonorrhea: Pathophys: how does the bug attach? what tissues are affected? What if it invades?

Neisseria gonorrhea attach to mucosal surfaces by pili (urethra, cervix, pharynx, rectum). 

Multiple mucosal sites may be affected depending on sexual practice.

It may invade:

local tissues -->PID

blood --> disseminated GC

joints --> arthritis


Gonorrhea:  more likely to be asymptomatic in women or men?

Women: majority will have no symptoms (FINALLY!)

Men: majority will have symptoms


Gonorrhea: Mode of transmission?

Oral sex from male to receptive partner

Sexual intercourse


Gonorrhea: rates are highest in what groups?

young adults, young urban poor adults, minorities, commercial sex workers, MSM


Gonorrhea: mucosal sites that can be invaded?


-Anorectal infections (incl prostatitis)


-Conjunctivitis: Opthalmia neonatorum and adult (exudative)

-Cervicitis (women)

-Epididymitis, Prostatitis (men)


Gonorrhea: 4 complications of invasion?


-Perihepatitis (Fitz-Hugh-Curtis)

-Disseminated gonococcal infection (bacteremia)

-Septic arthritis


Gonorrhea: diagnosis using discharge in men v women?

Gram stain of urethral or cervical discharge for gram-neg intracellular diploccci

-Men: >95% sensitivity

-Women: low sensitivity


Gonorrhea: diagnosis using DNA techniques - what are preferred specimens?

-Preferred specimens are self-collected vag swabs (women) and first catch urine (men)

NAATs can be sent from rectal and pharyngeal sites, may be better than culture (not FDA approved)


Gonorrhea: diagnosis using a culture?

-for sterile site (ie joint) use chocolate agar or modified Thayer-Martin agar (selective; contains antibiotics)

-for non-sterile site (cervix, rectum, pharynx) use special transport medium or plate and get to lab immediately. Culture multiple non-sterile sites.


Gonorrhea: what treatments is the pathogen now resistant to?

In past, treated with PCN or tetracycline. Resistance is now common to both of these.

beta-lactamase production has been reported

chromosomally-mediated resistance has been reported

Resistance to ciprofloxacin is climbing. 

All isolates should be tested for sensitivity!



Gonorrhea: treatment of uncomplicated infection?

is re-testing recommended?

For anogenital or oropharyngeal: Ceftriaxone IM

For anogenital only: Cefixime PO

ALSO give Azithromycin 1gm single dose OR doxycycline 100mg PO x7d

Test-of-cure not indicated unless symptoms persist.


Gonorrhea: treatment of complicated infection (PID, disseminated disease)?

Ceftriaxone IV or IM every 24 h for 7-10 days.

ALSO give Azithromycin 1gm single dose OR doxycycline 100mg PO x7d


Gonorrhea treatment: why do we give azithromycin or doxy?

Because of high rate of clinically silent co-infection with Chlamydia


If gonorrhea is diagnosed, what else should we screen for?

syphilis is indicated, consider HIV


Gonorrhea: screening guidelines?

Both women and men: sexually active and at increased risk (<25y, previous STDs, commercial sex work, new or multiple partners, inconsistent condom use, drug use, MSM, minorities)

Retest 3 m after treatment

screen symptomatic patients

HIV testing recommended.


Syphilis Microbiology: what is the agent? how is it visualized? can it be cultured?

Agent = Treponema pallidum. Thin, coiled spirochete.

Difficult to see with light microscope: use darkfield microscopy or direct IF staining

Cannot be cultured in vitro.


Syphilis pathophys: how does the T pallidum get into our systems?

Rapidly penetrate mucus membranes and skin with micro-abrasions.

Disseminate in blood. CNS infection occurs early.

Syphilitic lesions at all sites involve a vasculitis-like process and granuloma formation.


What are the 2 main ways to transmit syphilis?

Intimate contact can result in transmission from lesions at any body site.

Sexual intercourse and kissing are the two main modes of transmission.


List the 6 stages of syphilis infection

1. Asymptomatic incubation period (3w)

2. Primary skin lesion

3. Secondary bacteremic stage

4. "Latent" stage

5. Late or tertiary stage

6. Neurosyphilis


Syphilis: describe the primary skin lesion. how long does it last?

(Follows the initial 3w asymptomatic incubation period)

-"chancre" at site of inoculation. Generally not painful. Bacteremia will accompany this. Heals in 2-4 weeks.


Syphilis: describe the Secondary Bacteremic stage. When does it start? what are the symptoms?

(Follows the Primary skin lesion)

Starts 6-24 weeks after infection. Associated with mucocutaneous lesions (condyloma lata on genitals and others) and and generalized lymphadenopathy. May involve any organ system, often associated with constitutional symptoms


Syphilis: describe the Latent stage. 

Seroreactivity without evidence of disease. 

Divided into early latent (< 1 yr, high rate of relapse) and late latent (> 1yr, low rate of relapse)


Syphilis: describe the Late/Tertiary stage. when does it occur? what are the clinical manifestations?

Evolves years to decades after infection. 

3 clinical manifestations:

1. Benign gummatous (large granulomas at any location)

2. Cardiovascular: ascending aortitis

3. Neurosyphilis (next card)


Syphilis: describe neurosyphilis. when does it occur? what are the possible presentations?

Can occur at any time after infection. May be:

-asymptomatic with abnormal CSF


-meningovascular - presents as stroke

-parenchymatous - tabes dorsalis (demyelination of posterior colums of spinal cord and dorsal roots) or general paresis (dementia)


Syphilis: diagnosis via microscopy?

Cannot use light microscopy: must use darkfield microscopy or direct IF staining of exudate from chancres and secondary skin lesions.

Only available at specialized research centers or STD settings.


Syphilis: serologic diagnosis not using treponema?


Measure antibodies to cardiolipin, cholesterol, and lecithin.

Many false positives. 

Sensitivity = best in secondary infection (bacteremic stage, 6-24 w post infection). May be positive in primary infection or late latent/tertiary disease. 

Screening test in primary infection.


Syphilis: serologic diagnosis using treponema?

-Treponemal specific antibody (FTA-ABS; fluorescent treponemal antibody absorption). Confirmatory test. Sensitivity best in secondary and tertiary disease.

-Enzyme Immunoassay. IgG assay which detects Treponema IgG. Screening test for primary syph. Positive tests are sent for IgM and quantitative RPR testing. 


Syphilis: treatment?

-Penicillin IV or IM

(Doxycyclin in patients allergic to PCN)

Dose and duration depends on stage of disease and HIV-status


Syphilis: screening?

-All pregnant women

-Prior to marriage license (in some states)

-High risk sexual exposure: multiple partners, MSM, other STDs

-Symptomatic patients

-HIV testing recommended


when should you screen for multiple STDs?

Patients at risk for or diagnosed with one STD have exposure risk for multiple agents. screening for STDs often will reveal multiple asymptomatic infections.


When should you screen for STIs at multiple (anatomic) sites?

High-risk individuals (including esp MSM) should be screened at multiple anatomic sites (oropharynx, urine, rectum) based on sexual practices.


Do we treat asymptomatic infections if they are STDs?

Yes we do - in contrast with many other diseases. Due to public health implications and possible long-term health consequences we treat these whenever we find them, regardless of symptoms.


What is the guiding principle for treating STDs, on a social level?

Treat as though the patient may be lost to follow-up. Ie, patients may not return for test results, so preferred treatment is pre-emptive, administered by the clinic, single-dose therapy.


What can we do to treat sexual partners?

Partners of pts with STDs need to come in for eval and treatment

Some states allow us to write a prescription for the partner without actually seeing them. "expedited partner therapy"

Some states offer assistance in notifying partners about exposures and helping them get treatment.


What diseases are reportable to the state health department?

chlamydia, gonorrhea, syphilis, HIV, viral hepatitis.

Provider has to report.

Some labs also report.


Genital ulcers: what are the 2 possible causes?

what diagnostic tests should be done?

Genital herpes (common)

Syphilis (rare)


herpes: culture, direct immunofluorescence, or PCR, darkfield examination, possible serology

syphilis: serology


Non-ulcerated genital lesions: what is likely cause?

Human papilloma virus (genital warts)


what is urethritis? what are the most common causes?

inflammation of the urethra.

result: dysuria (M and F), penile discharge (males only)

Causes: gonorrhea, chlamydia


what is non-gonococcal urethritis?

what usually causes it?

NGU: historically described male urethritis which didn't have gram-neg diplococci on a gram stain. 

5-40% caused by chlamydia.

Now the term describes urethritis that persists after treatment for GC and CT. ie, more unusual pathogens.


what is cervicitis?

inflammation of the cervix.

may be asymptomatic, may present with abnormal discharge or vag bleeding. yellow endocervical exudate may beb visible with many leukocytes on gram stain


what is vaginitis?

what are the 3 most likely causes?


vaginal discharge or vulvar itching or irritation.

Causes: candidiasis, bacterial vaginosis, or trichomoniasis

Diagnosis: direct exam, micro exam, pH and KOH testing of discharge


what is PID?

most common causes?

upper genital tract infections.

sx: lower abdominal pain, adnexal tenderness, cervical motion tenderness. 

Gonorrhea, chlamydia are likely pathogens. 

May also be due to anaerobes, enteric gram-neg rids, genital mycoplasmas, streptococcal species.


what is proctitis?

associated with what diseases?

In men: rectal pain, discharge, tenesmus, constipation

Associated with gonorrhea, HSV, chlamydia, syphilis, genital warts


what is epididymitis? prostatitis?

what diseases?

Epididymitis: unilateral scrotal pain/swelling

Prostatitis: rectal pain, with or without dysuria

Both associated with gonorrhea, chlamydia, enteric flora


STDs associated with systemic infections without genital manifestations?

Hep B