Term
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Definition
- Gonorrhea
- Chlamydia
- Trichomoniasis
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Term
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Definition
- Herpes Simplex
- Syphilis
- Chancroid
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Term
| Name 6 factors that affect the transmission of STIs |
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Definition
- Age
- Gender
- Genetic susceptibility
- Sexual practices
- Contraceptive and "hygienic" practices
- Circumcision
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Term
| Why are younger women more susceptible to certain STIs? |
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Definition
| Young women are more likely to have exposed columnar epithelium in their cervical os, which is more easily infected than the normal stratified squamous epithelium. |
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Term
| Name 4 determinants of the duration of infectivity in STIs. |
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Definition
- Etiologic agent
- tendency to asymptomatic carriage
- antimicrobial resistance
- Access and utilization of health care
- Compliance with therapy
- Contact tracing
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Term
| What does gonorrhea require for propagation? |
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Definition
| Gonorrhea propagation requires a core transmitter group that has >50 sex partners per year. |
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Term
| Of the three diseases gonorrhea, chlamydia, and syphilis, which are more prevalent among kids, and which are more prevalent among older adults? |
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Definition
| Gonorrhea and chlamydia are more common among teenagers, whereas Syphilis is more common in older adults. |
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Term
| How do STIs affect the transmission of HIV. Give two specific examples. |
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Definition
STIs increase the transmission of HIV
- inflammatory STIs increase HIV transmission x5
- genital ulcers increase transmission x12!
- aside: program to treat STIs in Tanzania decreased HIV transmission by 40%
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Term
| How does HIV effect the expression of STIs? Give 3 specific examples. |
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Definition
HIV can make other STDs worse
- HIV accelerates HPV-associated tumors
- facilitates spread of gonococcus
- alters the natural course of syphilis
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Term
| Name 6 infections caused by gonococci and chlamydiae. Which is commonly found in newborns? |
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Definition
- Urethritis
- Cervicitis
- Epididymitis
- Proctitis (inflammation of rectum & anus)
- Pharyngitis
- Eye Infection (in newborns of infected mothers)
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Term
| If you suspect Gonococcus infection, are you more worried about acquisition from a recent contact or a contact from the remote past? What about for Chlamydia? |
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Definition
- Gonococcus is acquired from a recent contact.
- Chlamydia may have been acquired from a contact from the remote past.
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Term
| Which disease is more likely to be asymptomatic in both men and women Gonococcus or Chlamydia? |
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Definition
Chlamydia is more likely to be asymptomatic than Gonococcus.
- 5% of males and 50-80% of females infected with Gonococcus are asymptomatic, whereas
- 50% of males, and 85% of females infected with Chlamydia are asymptomatic
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Term
| True or false: Neisseria Gonorrhoeae is a strict human pathogen |
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Definition
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Term
| How does Neisseria Gonorrhoeae Gram stain, what is its shape, and how does it present on an oxidase test? |
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Definition
| Neisseria Gonorrhoeae is a Gram- diplococcus, and it is oxidase-positive. |
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Term
| On what kind of agar is Neisseria Gonorrhoeae cultured? Why? How long can the sample sit before being cultured? |
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Definition
Neisseria Gonorrhoeae is cultured on modified Thayer-Martin media, that is impregnated with vanco-colistin-nystatin-trimethoprim antibiotics to prevent growth of the ample local flora.
The sample needs to be cultured in agar right away. |
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Term
| Name 2 Gonorrhoeae proteins that allow adherence to host epithelium? |
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Definition
- Type 4 pilus
- Opa proteins (also allow for invasion)
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Term
| Name 2 gonorrhoeae proteins that are antigenic, and 2 ways by which these proteins evade the immune system. |
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Definition
Antigenic proteins:
- Type 4 Pilus (PilE portion)
- LOS (Lipo-oligosaccharide)
Immune evasion:
- antigenic variation
- sialation of the LOS to resemble host
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Term
| Name 2 ways Gonorrhoeae evades anitbodies that are not related to its specific antigenic proteins (i.e. PilE, and LOS). |
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Definition
- IgA1 protease: cleaves/inactivates IgA1
- Rmp: porin associated protein that induces blocking antibodies
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Term
| How do bacteria antigenically vary pili? |
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Definition
Variation of pili is a cassette phenomenon, and assembling pili is similar to assembling Ig.
Genes are spontaneously arranged at DNA replication. |
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Term
| What three tests are used to diagnose gonorrhea? |
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Definition
- Gram stain (Highly sensitive and specific for Male urethritis)
- Culture
- Nucleic acid tests (PCR)
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Term
| What does gonorrhea positive pus look like under the microscope? |
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Definition
| A sheet of PMNs, some with Gram- diplococci inside. |
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Term
| How do you treat gonococcal infections? What two drugs were used in the past, but are not used anymore and why? |
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Definition
- for uncomplicated gonorrhea: treat with 125 mg IM ceftriaxone or 400mg oral cefixime (both cephalosporins)
- very commonly also administered with anti-chlamydial treatment
- Ciprofloxaciin and levofloxacin were used in the past, but bacteria have since developed resistance.
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Term
| What's special about Chlamydia's cell wall? |
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Definition
| Chlamydia's cell wall lacks peptidoglycan, therefore you cannot use drugs like penicillin or vancomycin to treat these infections. |
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Term
| Where does Chlamydia live within the host. |
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Definition
| They are obligate intracellular bacteria that obtain amino acids and ATP from the host. |
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Term
| What are the 3 forms of Chlamydia trachomatis? |
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Definition
- Elementary Body (EB): spore-like infectious form
- Reticulate Body (RB): replication stage
- Persistence: latent stage
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Term
| How do Chlamydia elementary bodies obtain a rigid cell wall? |
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Definition
| Disulfide cross-linking of outer membrane |
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Term
| How do Elementary bodies enter host cell, and how do they mediate intracellular survival? |
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Definition
- Elementary bodies enter a host cell via receptor-mediated endocytosis
- EB translocate >20 proteins by type III secretion to mediate intracellular survival
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Term
| Can chlamydia reticulate bodies survive outside of the host cell? |
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Definition
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Term
| Where do chlamydia reticulate bodies divide? |
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Definition
| In cellular endosomes by fission. |
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Term
| What structural difference distinguishes RB from EB? |
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Definition
EB have rigid disulfide cross-linked outer membrane, whereas RB have reduced disulfide bonds (EB outer membrane reduced by stored ATP)
RB need to convert to EB before leaving the host cell. |
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Term
| What cells do Chlamydia target? |
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Definition
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Term
| What role do the CD4 Th1 and Th2 cells play in Chamydia pathogenesis? |
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Definition
- Th1 cells induce IFN-γ which inhibits bacterial replication
- Th2 cells induce a destructive response to Chlamydia heat shock protein-6 (cHSP60) - this is responsible for most of Chlamydia's problems
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Term
| Name two results of having immunity to cHSP60 |
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Definition
- cHSP60 immunization enhances disease
- women with anti-cHSP60 antibodies are likely to be infertile
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Term
| How do antibodies to the major outer membrane protein (MOMP), and LPS affect chalmydia infection? |
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Definition
| antibodies against MOMP and LPS prevent reinfection, but not primary infection. Reason for this is unknown. |
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Term
| Name 4 infections that can be caused by Chlamydia that are also common to Gonorrhea. Name 3 that are specific to Chlamydia. |
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Definition
Common:
- Urethritis
- Epididymitis
- Proctitis
- (Mucopurulent - only in chamydia) cervicitis
Chlamydia only:
- Pelvic inflammatory disease (PID)
- Trachoma (eye infection)
- LGV (lymph nodes)
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Term
| How do you detect Chlamydia infection? What is not useful? |
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Definition
| Detect Chlamydia infection with Nucleic Acid Amplification Techniques (NAAT), ex - PCR. Other tests not very good, serology is almost useless. |
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Term
| How do you treat uncomplicated Chlamydial infections? |
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Definition
- Azithromycin 1gm p.o. (one dose)
or
- Doxycycline 100mg p.o. bid x 7days
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Term
| Name 2 ways to prevent mucosal STIs (Gonorrhea, Chlamydia). Name one way that was thought to work but really doesn't. |
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Definition
- Screening for selected groups (high risk, sexually active women)
- Condoms (lubricated)
- Does NOT work: spermicides (non-oxynol-9)
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Term
| What kind of animal is Trichomonas vaginalis, and what does it cause? |
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Definition
| Trichomonas vaginalis is a protozoan. And it normally causes vaginitis in women (itching, thin frothy discharge, increased pH from normal), and is usually asymptomatic in infected males. |
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Term
| How do you diagnose Trichomonas vaginalis infection? |
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Definition
- Increased vaginal pH
- Vaginal swab or urine for culture (microscopy)
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Term
| How is Trichomonas vaginalis treated? |
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Definition
- Metronidazole 2gm, po (single dose)
or
- Metronidazole 500 mg, po, bid, 7days
- If possible treat both partners.
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Term
| What is Pelvic inflammatory disease (PID)? What bugs commonly cause it? |
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Definition
| PID is an acute clinical syndrome associated with the spread of microorganisms through the vagina into the uterus, fallopian tubes, and ovary (upper genital tract). It is commonly caused by gonorrhea and chlamydia. |
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Term
| What percentage of women with untreated cervical gonorrhea or chlamydia infection go on to have PID? |
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Definition
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Term
| Name 5 symptoms of PID and how prevalent they are. |
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Definition
- Lower abdominal pain: found in all
- Vaginal discharge: found in 1/2
- Vaginal bleeding: 1/2
- Dysuria: 1/4
- nausea, vomiting, anorexia: 1/4
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Term
| Name 7 clinical signs of PID and, if possible, specify how prevalent are they? |
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Definition
- Abdominal/adnexal tenderness: all
- cervical tenderness: all
- adnexal enlargement: ~1/3
- fever: ~1/3
- RUQ tenderness: <1/3
- tuboovarian abscess
- peritonitis, perihepatitis
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Term
| How does primary gonorrhea/chlamydia infection affect other bugs in the area? |
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Definition
| Primary infection does damage that facilitates secondary [bacterial] infection. |
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Term
| Describe the antimicrobial therapy for PID |
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Definition
Must include activity against a wide array of local cervical flora:
- 2nd generation cephalosporin + doxy
- Clindamycin + gentamicin
- Ampicillin/sulbactam + doxy
- metronidazole + doxy
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Term
| Name 4 consequences of PID. |
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Definition
- Chronic pain
- Subsequent PID
- Infertility
- Ectopic pregnancy
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Term
| True or False: Women can be asymptomatic for chlamydia or gonorrhea, and subsequently infertile. |
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Definition
| True for 50-60% of infertile women |
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Term
| List in order of prevalence in genital ulcer infections: chancroid, HSV, syphilis |
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Definition
| HSV >> syphilis >> chancroid |
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Term
| What bug causes Chancroid, how does it gram stain, and what does it look like? |
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Definition
| Chancroid is caused by Haemophilus ducreyi, which is a Gram- coccobacilli |
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Term
| How is Chancroid diagnosed? |
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Definition
| Usually clinically by ruling out other genital ulcer infections. |
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Term
| Are men or women most affected with chancroid? Who is associated with transmission of this disease? |
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Definition
| Men are more affected with chancroid than females. Transmission is associated with female commercial sex workers. |
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Term
| How is Chancroid treated? |
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Definition
| Ceftriaxone or azithromycin (single dose) - like gonorrhea treatment |
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Term
| What bug causes syphilis, how does it Gram stain, what does it look like, can it be grown in culture? |
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Definition
| Syphilis is caused by Treponema pallidum, which is a Gram- (like) spirochete with axial filaments. It can NOT be grown in culture. |
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Term
| What conventional virulence factors does Syphilis present? What is the pathology of lesions? |
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Definition
| Syphilis has NO conventional virulence factors. Lesions are caused by obliterative endarteritis (inflammation of inner lining of artery causes occlusion) |
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Term
| How long does it take for syphilis to replicate? |
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Definition
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Term
| Where in the US is syphilis found? |
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Definition
| Cities and rural souther US. |
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Term
| Name 2 manifestations of 1o Syphalis. How long between contact and symptoms? |
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Definition
- Chancre (painless, but highly contagious)
- Congenital (pass mother to child)
- symptoms ~3 weeks after contact, can range from 3-90 days
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Term
| How does 1o Syphilis become 2o? |
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Definition
| Without treatment, it will disseminate |
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Term
Name 7 manifestations of 2o Syphalis. How long between contact and symptoms?
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Definition
- Rash
- Lesions (mucus patches on palms and soles, condyloma lata)
- Fever
- Lymphadenopathy
- Aseptic meningitis
- Eye lesions
- Mild hepatitis
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Term
| Of the people with untreated 2o Syphilis, how many of them develop 3o syphilis? |
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Definition
| 72% have spontaneous resolution, however 28% of 2o Syphilis patients develop 3o Syphilis. |
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Term
| Name the three main systems affected by 3o Syphilis. |
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Definition
- Neurosyphilis
- Cardiovascular
- Late benign (gummas)
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Term
| Name 2 particular symptoms of Neurosyphilitis |
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Definition
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Term
| Name a specific manifestation of Cardiovascularly disseminated Syphilis |
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Definition
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Term
| Name 3 ways to diagnose Syphilis? |
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Definition
- Darkfield microscopy (look like white spirals)
- Non-treponemal tests (antigen screening tests - titers)
- If screening negative, further test with Treponemal tests (+ or -)
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Term
| How do you treat Syphilis? |
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Definition
| Penicillin, dosing depends on stage of disease, Jarisch-Herxheimer reactions can result with mass lysis of bacteria and subsequent release of toxins. Historically people also used mercury and arscenic. |
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