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x. ID > 4/17 STD: iBook Ch 12 > Flashcards

4/17 STD: iBook Ch 12 Flashcards

1
Q

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

A
  • 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)
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2
Q

Populations at risk for STDs? (5)

A
  • Youth (CDC defines as up to age 24)
  • Minorities
  • 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 (??)
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3
Q

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

Do we culture for it?

A

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.

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4
Q

Chlamydia: Pathophys?

A

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

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5
Q

Chlamydia: Epidemiology?

A

Most prevalent STD in developed and underdeveloped countries!

Asymptomatic carriage rates are 5-30%.

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6
Q

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

A

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

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7
Q

Chlamydia: Clinical syndromes in adults (7)?

A
  • Asymptomatic
  • Urethritis
  • Cervicitis
  • Epididymitis
  • Proctitis
  • PID
  • Reactive Arthritis
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8
Q

Chlamydia: clinical syndromes in neonates (2)?

A
  • Inclusion conjunctivitis (“cobblestoning” without exudate)
  • Interstitial pneumonia
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9
Q

Chlamydia: Diagnosis?

A

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)

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10
Q

What is NAAT?

A

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

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11
Q

Chlamydia: Treatment?

A

Azithromycin 1g orally single dose

OR

Doxycyclin 100mg orally BID for 7d

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12
Q

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

A

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

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13
Q

Chlamydia: Who do we screen?

A

-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)

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14
Q

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

A

Neisseria gonorrhea: gram-neg diplococci

Require a warm, moist, CO2-rich environment.

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15
Q

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

A

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

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16
Q

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

A

Women: majority will have no symptoms (FINALLY!)

Men: majority will have symptoms

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17
Q

Gonorrhea: Mode of transmission?

A

Oral sex from male to receptive partner

Sexual intercourse

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18
Q

Gonorrhea: rates are highest in what groups?

A

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

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19
Q

Gonorrhea: mucosal sites that can be invaded?

A
  • Urethritis
  • Anorectal infections (incl prostatitis)
  • Pharyngeal
  • Conjunctivitis: Opthalmia neonatorum and adult (exudative)
  • Cervicitis (women)
  • Epididymitis, Prostatitis (men)
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20
Q

Gonorrhea: 4 complications of invasion?

A
  • PID
  • Perihepatitis (Fitz-Hugh-Curtis)
  • Disseminated gonococcal infection (bacteremia)
  • Septic arthritis
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21
Q

Gonorrhea: diagnosis using discharge in men v women?

A

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

  • Men: >95% sensitivity
  • Women: low sensitivity
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22
Q

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

A

-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)

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23
Q

Gonorrhea: diagnosis using a culture?

A
  • 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.
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24
Q

Gonorrhea: what treatments is the pathogen now resistant to?

A

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!

25
Q

Gonorrhea: treatment of uncomplicated infection?

is re-testing recommended?

A

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.

26
Q

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

A

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

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

27
Q

Gonorrhea treatment: why do we give azithromycin or doxy?

A

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

28
Q

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

A

syphilis is indicated, consider HIV

29
Q

Gonorrhea: screening guidelines?

A

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.

30
Q

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

A

Agent = Treponema pallidum. Thin, coiled spirochete.

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

Cannot be cultured in vitro.

31
Q

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

A

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.

32
Q

What are the 2 main ways to transmit syphilis?

A

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

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

33
Q

List the 6 stages of syphilis infection

A
  1. Asymptomatic incubation period (3w)
  2. Primary skin lesion
  3. Secondary bacteremic stage
  4. “Latent” stage
  5. Late or tertiary stage
  6. Neurosyphilis
34
Q

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

A

(Follows the initial 3w asymptomatic incubation period)

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

35
Q

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

A

(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

36
Q

Syphilis: describe the Latent stage.

A

Seroreactivity without evidence of disease.

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

37
Q

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

A

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)
38
Q

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

A

Can occur at any time after infection. May be:

  • asymptomatic with abnormal CSF
  • meningeal
  • meningovascular - presents as stroke
  • parenchymatous - tabes dorsalis (demyelination of posterior colums of spinal cord and dorsal roots) or general paresis (dementia)
39
Q

Syphilis: diagnosis via microscopy?

A

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.

40
Q

Syphilis: serologic diagnosis not using treponema?

A

VRDL and RPR

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.

41
Q

Syphilis: serologic diagnosis using treponema?

A
  • 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.
42
Q

Syphilis: treatment?

A

-Penicillin IV or IM

(Doxycyclin in patients allergic to PCN)

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

43
Q

Syphilis: screening?

A
  • All pregnant women
  • Prior to marriage license (in some states)
  • High risk sexual exposure: multiple partners, MSM, other STDs
  • Symptomatic patients
  • HIV testing recommended
44
Q

when should you screen for multiple STDs?

A

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

45
Q

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

A

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

46
Q

Do we treat asymptomatic infections if they are STDs?

A

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.

47
Q

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

A

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.

48
Q

What can we do to treat sexual partners?

A

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.

49
Q

What diseases are reportable to the state health department?

A

chlamydia, gonorrhea, syphilis, HIV, viral hepatitis.

Provider has to report.

Some labs also report.

50
Q

Genital ulcers: what are the 2 possible causes?

what diagnostic tests should be done?

A

Genital herpes (common)

Syphilis (rare)

Dx:

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

syphilis: serology

51
Q

Non-ulcerated genital lesions: what is likely cause?

A

Human papilloma virus (genital warts)

52
Q

what is urethritis? what are the most common causes?

A

inflammation of the urethra.

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

Causes: gonorrhea, chlamydia

53
Q

what is non-gonococcal urethritis?

what usually causes it?

A

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.

54
Q

what is cervicitis?

A

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

55
Q

what is vaginitis?

what are the 3 most likely causes?

diagnosis?

A

vaginal discharge or vulvar itching or irritation.

Causes: candidiasis, bacterial vaginosis, or trichomoniasis

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

56
Q

what is PID?

most common causes?

A

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.

57
Q

what is proctitis?

associated with what diseases?

A

In men: rectal pain, discharge, tenesmus, constipation

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

58
Q

what is epididymitis? prostatitis?

what diseases?

A

Epididymitis: unilateral scrotal pain/swelling

Prostatitis: rectal pain, with or without dysuria

Both associated with gonorrhea, chlamydia, enteric flora

59
Q

STDs associated with systemic infections without genital manifestations?

A

Hep B

HIV

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