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35 Cards in this Set
- Front
- Back
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Syphilis serology
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1. Screening: non-specific non-treponemal test (antibody to host cardiolipin): RPR, VDRL; sensitive but not totally specific
2. Confirmatory test: TPHA, TPPA; treponemal test (antibody to protein antigens) Or... 1. Tp 2. Confirmatory test with RPR, VDRL |
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Cannot culture...
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Syphilis
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Do not readily form antibodies
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Chlamydia
Gonorrhea Cannot diagnose with serology |
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Demographics of syphilis
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Peak is higher (in age) and broader for men
Trend for women looks like other STIs: peak is low and narrow Majority of cases in US are MSM |
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Syphilis and HIV
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Synergism
Genital ulcers caused by syphilis increase susceptibility to HIV infection HIV+ individuals have higher viral load if infected with syphilis If HIV+, greater risk of developing neurosyphilis |
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Stages of syphilis
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1. Exposure (few weeks)
2. Primary infection: painless chancre on anogenital skin and/or mucus membranes; oral 3. Asymptomatic 4. Secondary: spread of spirochetes through blood; malaise, myalgia, fever, lymphadenopathy, headache, sore throat, hepatitis, hair loss, RASH, CONDYLOMA LATA 5. Latent syphilis (early and late) 6. Tertiary: breakdown of latent control: gummatous lesions, cardiovascular and neuro symptoms |
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Congenital syphilis
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50% of pregnancies in infected women end in miscarriage
40-70% of infants born to infected mothers have congenital syphilis Bone, eye, ear, brain damage Moon shaped incisors: Hutchinson's incisors |
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Treponema pallidum: bacterial features
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Spirochete
Very thin- does not gram stain Has an inner and outer membrane Outer membrane has NO LPS Lipoproteins on surface (very few) Flagella wraps around the organism in the periplasmic space for motility Cannot be cultured; grown in rabbit testes for research |
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T. pallidum pathogenesis
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"Attachment, invasion, dissemination"
Corkscrew motility and proteins that bind ECM proteins -- allow access to spaces between cells Non-specific for particular cell type |
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Syphilis immune response
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Innate: no TLR4 activation because no LPS; TLR2 instead: release of TNF and pro-inflammatory cytokines and chemokines cause ulcerations
Cellular: T infiltrates: CD4, CD8; INFgamma Activated macrophages can clear infection Humoral: Abs to protein antigens and cardiolipin; antibody activity is not protective Some ability to form memory response; partial |
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Primary ulcers of syphilis clinically indistinguishable from...
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Chancroid caused by H. ducreyi
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Syphilis treatment
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Penicillin - still effective
Azithromycin can be used but resistance is increasing |
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Prevalence of trich and age
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Prevalence of trichomonas vaginalis increases with age
Contrast with chlamydia that decreases with age |
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Trich and HIV
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Synergy
Higher HIV viral load in HIV+ Recruitment of HIV-susceptible cells to infected mucosa TREATMENT of trich decreases HIV viral load in vaginal fluid |
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Clinical presentations of trichomoniasis: women
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Vagina, urethra, endocervix susceptible
Frothy discharge Strawberry cervix: punctate hemorrhages caused by inflammation on ectocervix; highly specific Itching, odor, dysuria Lower abdominal pain Elevated vaginal pH, amines Can be asymptomatic |
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Clinical presentation: trichomoniasis in men
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Non-gonococcal, non-chlamydial urethritis
Urethral discharge: watery; not highly inflammatory Dysuria Lower abdominal pain Commonly asymptomatic |
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Characteristics: T. vaginalis
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Protozoan pathogen- related to giardia
Free-swimming: roughly size of WBC Attached to epithelial cells: transforms into ameboid shape 4 flagella on top - motility Lacks mitochondira; uses hydrogenosome for energy metabolism |
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Immune response: trichomoniasis
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Inflammation, influx of PMNs
IL-8 --> TLR4 --> TNFalpha Antibodies; not protective |
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Diagnostic: trichomoniasis
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Wet mount, culture, antigen-detection, NAAT
Wet mount: vaginal swab or male urine sediment Org must be motile and viable Must be performed <15 min after collection Diagnostic but not very sensitive |
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Treatment: trichomoniasis
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Metranidazole: anti-protozoa, anti-amoeba, anti-anaerobic bacteria
Drugs are activated within hydrogenosomes Generate toxic nitro radicals and damage parasite DNA proteins Resistance infrequent but increasing |
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Neisseria gonorrhea: bacteria features
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Gram negative diplococcus
Round with two halves like a kidney bean Ability to transform: take up naked DNA NO CAPSULE (N. meningititis does) Pili - long range attachment Opacity proteins - sponsor tight adherence Porins - nutrient uptake (and identifying serotypes) LOS (lipid A) |
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Gonorrhea pathogenesis
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"Attachment, Antigenic variation, Antibiotic resistance"
Use of pili, opacity proteins, porins, LOS Ability to transform: antigenic variation |
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Treatment: gonorrhea
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Highly resistant to antibiotics
Penicillin, tetracyclines, fluoroquinolones no longer effective Treat with ceph triaxone |
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Uncomplicated gonorrheal infection (UGI)
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Anterior urethral (men)- urethritis
Cervical and urethral (women)- cervicitis Pharyngeal Rectal (usually MSM) |
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Differential: gonorrhea
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Women/pharyngeal/rectal: typically asymptomatic; difficult to distinguish from other STIs
Urethritis (men): usually symptomatic; abrupt onset, dysuria, profuse, purulent discharge (the drop, the clap) Cervicitis: analagous to urethritis in men: purulent discharge from os (neutrophils) Gonococcal conjunctivitis: in newborns delivered vaginally in infected mothers Prophylaxis is silver nitrate, antibiotic ointment |
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Complicated gonococcal infection
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PID: tends to happen after symptomatic infection
Occurs within few days of menses: extra iron as nutritional factor for organism Cervical mucus aids in ascension of bacteria into URT Salpingitis; adhesions; swelling; tubal pregnancy DGI: disseminated; invasion of the blood stream --> skin and large joints |
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Chlamydia species
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Human pathogens:
Trachomatis (sexually transmitted) Pneumoniae: respiratory, most common Psittaci: zoonotic |
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Chlamydia epidemiology
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Infections climbing
Women more likely to be infected than men |
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Chlamydia trachomatis disease
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Ocular, genital, LGV strains
Ocular: trachoma; eyelashes curl in; blindness can occur LGV: lymphogranuloma venereum: invasive lymphoid disease; looks like genital warts; misshapen skin tags Genital: Men: non-gonococcal urethritis (less common, less purulent); epididymitis, rectal Women: cervicitis with copious clear, watery, less purulent discharge; urethritis; PID |
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PID and GC and Chlamydia
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PID more severe in chlamydia
Local inflammation more severe in gonorrhea |
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Chlamydia trachomatis: life cycle
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Elementary bodies extracellularly: infectious but not metabolically active
Attachment of EB at clathrin coated pits --> internalized Conversion to reticulate body (RB) intracellular form: metabolically active but not infectious Forms inclusions like cloaks that recruits host cell mitochondria for energy Modifies inclusion membrane by inserting proteins with T3SS --> causes inflammation RBs begin to transform back to EBs in preporation for lysis Lyse apically or basolaterally |
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Chlamydia: bacteria features
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Gram negative
LPS on outer leaflet MOMP proteins: porins that designate serovar |
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Chlamydia pathogenesis
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Infected cells produce pro-inflammatory cytokines and chemokines
PMNs, NK cells activate APCs, phagocytes Chronic inflammation --> necrosis, cell proliferation, scarring |
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Diagnosis: GC and chlamydia
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NAAT is gold standard- sensitive and specific
Becomes negative 10-14 days after successful treatment Non-invasive specimens possible |
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Treatment: chlamydia
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Azithromycin
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