Sexually Transmitted Diseases Flashcards
What bacteria causes syphilis?
Treponema pallidum
What type of bacteria is Treponema pallidum?
Gram-negative spirochete
How is primary syphilis characterized?
Single, Hard, Painless chancre
How is secondary syphilis characterized?
Systemic so Fever, Rash, Condyloma Latum
How is tertiary syphilis characterized?
15-20 years later so Chronic meningitis, Ataxia, Aortic valve insufficiency, Gummas
What occurs in congenital syphilis?
Rhinitis Skin and mucus lesions Hepatosplenomegaly Hutchinson's teeth Saddle-shaped nose
How is syphilis diagnosed?
Dark field microscopy
Fluorescent antibodies
Nonspecific serology
Specific serology
What are the nonspecific serology tests for syphilis?
Venereal disease research laboratory test (VDRL)
Rapid plasma reagin test (RPR)
What is used as the antigen in nonspecific tests and why?
Cardiolipin from beef hearts
Spirochetes cannot be cultured for use as an antigen
What are nonspecific serology used for and why only that?
Only for screening
Can be a false positive from damaged normal cells
What are the specific serology tests for syphilis?
Fluorescent treponemal antibody absorption test (FTA-ABS) Microhemagglutination test (MHA-TP)
How is FTA-ABS test done?
Patient serum first absorbed with nonpathogenic treponemes to remove any anti-treponema antibodies that are not specific for only the bacteria
How is MHA-TP test done?
Treponemal antigens on RBC to see if they agglutinate
What occurs nonspecific and specific tests after effective treatment?
Nonspecific: are negative
Specific: are positive
Easy way to remember is a syphilis test is specific?
It has “T” in the abbreviation
What antibody is looked for in congenital syphilis?
IgM not IgG because IgG can cross the placenta but IgM cannot
What do you treat syphilis with?
Penicillin
Doxycycline if they are allergic to penicillin
What causes gonorrhea?
Neisseria gonorrhoeae
What is Neisseria gonorrhoeae?
Gram-negative diploccus
Where is Neisseria gonorrhoeae seen?
Inside neutrophils
What does Neisseria gonorrhoeae have to help stay attached in urethra?
Pilus
Which patients present with gonorrhea symptoms?
Men
Females are asymptomatic until it is very advanced
What occurs in women once gonorrhea advances?
Pelvic inflammatory disease
Infertility
Tubal pregnancy
Why does infertility and tubal pregnancy occur in women in advanced stages of gonorrhea and chlamydia?
Scar tissue in fallopian tubes occurs not allowing fertilized egg down
What can occur in blood with gonorrhea?
Disseminated gonorrheal infections that manifest in skin and joints
How is gonorrhea treated?
Cefixime and Ceftriaxone (1 dose) and Doxycycline (7 days)
Why is doxycycline given in gonorrhea?
To treat the chlamydia that often is accompanied by it
What causes genital chlamydia infections?
Chlamydia trachomatis serotypes D-K
What is Chlamydia trachomatis?
Gram-negative intracellular
What is gonorrhea discharge like?
Yellow and purulent
What is chlamydia discharge like?
Clear or white
Chlamydia symptoms in males and females?
Males: dysuria
Females: asymptomatic
What agar is Chlamydia trachomatis grown on?
McCoy agar
What does Chlamydia trachomatis form when cultured?
Inclusion bodies (intracellular) Elementary bodies (extracellular/infectious form)
What do you treat Chlamydia with?
Doxycycline or azithromycin
What is lymphogranuloma venereum (LGV)?
A systemic Chlamydia trachomatis infection
What causes LGV?
Chlamydia trachomatis serotypes L1, L2, L3
LGV symptoms:
Transient ulcer
Enlarged lymph nodes
Proctitis (rectum inflammation) (what most come to doctor for)
What is chancroid?
A soft chancre
What is a soft chancre?
Soft multiple painful ulcers
What causes chancroid?
Haemophilus ducreyi
What are Haemophilus ducreyi?
Gram-negative bacilli
What is bacterial vaginosis?
Overgrowth of bacterial in the vagina
What is the most common cause of bacterial vaginosis?
Gardnerella vaginosis
What is Gardnerella vaginosis?
Gram variable pleomorphic bacillus
What characterizes bacterial vaginosis?
Fishy smelling vagina
pH greater than 4.5
What causes overgrowth of bacteria in the vagina?
Decreased estrogen which decreases the amount of glycogen created in epithelial cells not allowing lactobacilli to thrive
Treatment of bacterial vaginosis?
Metronidazole
What does Metronidazole kill?
Anaerobes
Flagellates
Amoeba
What is seen in a vaginal swab of bacterial vaginosis?
Clue cells: epithelial cells with fuzzy borders due to excessive amounts of bacteria attached to them
What is the cause of the fishy smell in vaginosis?
Trimethylamine
What causes vulvovaginitis?
Overgrowth of endogenous Candida albicans
Treatment of vulvovaginitis/thrush?
Nystatin (topical) Amphotericin B (IV)
What is seen with a vulvovaginitis swab?
Pseudohyphae
How can vaginal thrush occur?
Too much glycogen (increase in estrogen)
How does trichomoniasis present in men and women?
Men: asymptomatic
Women: smelly discharge
How is trichomoniasis characterized compared to vaginosis in women?
Trichomoniasis: Large amount of discharge
Vaginosis: smelly discharge not alot
What causes trichomoniasis?
Trichomonis vaginalis
Treatment of trichomoniasis?
Metronidazole (its a flagellate)
General rule for herpes virus?
HSV-1: above belt
HSV-2: below belt
Where does dormant HSV reside?
Dorsal root ganglia
What does HSV cause in babies?
Diffuse neonatal encephalitis
Treatment of HSV?
Acyclovir (IV)
Valacyclovir (oral)
What causes condyloma acuminatum?
HPV genotypes 6 and 11
What causes cervical cancer and lesions?
HPV 16 and 18
Condyloma acuminata versus lata?
Acuminata: raised multiple from HPV
Lata: flat top, secondary syphillis
Why is prevalence of HIV high despite incidence being down?
Prevalence: amount of people with it (still alive)
Incidence: new cases
What two HIVs are found and where?
HIV-1: pandemic globally and US more infectious
HIV-2: West Africa not as infectious
HIV-1 groups?
M
N
O
Most common HIV-1 group and subtypes of the group?
M most common
Subtypes: A-J
HIV-2 subtypes?
A-F
Three functional genes of HIV?
gag
pol
env
What does gag encode?
Capsid protein p24
Matrix protein p17
(core proteins)
What does pol encode?
Protease
Reverse transcriptase
Integrase
What does env encode?
Viral glycoproteins: gp41 and gp120
What glycoproteins are found on HIV?
GP120 (head)
GP41 (stem)
What is looked for in the diagnosis of HIV?
p24
What cells does HIV infect?
Cells with CD-4 receptors (helper cells)
What are the co-receptors found on cells with CD-4 receptors?
CCR5
CXCR4
What binds the receptors then the co-receptors?
gp120
What is the preference of HIV to co-receptors?
Initially wants CCR5 (needed to start infection) then evolves more so to CXCR4
What from HIV fuses with the cells membrane?
gp41
How does HIV infection begin?
HIV picks helper cells (dendritic or macrophages) to become a pro-virus host and allows it to replicate (for its own DNA to be replicated also); Virus makes its way to the GALT
What is CTL/CD-8 cells role in HIV infection and why is it important?
They attack and kill infected CD-4 cells; however, CTL cells kill the CD-4 cells that are needed for their own activation
Why does HIV switch from CCR5 to CXCR4 co-receptor?
CCR5 is on mature CD-4 cells when they kill are the mature ones they switch to CXCR4 which is found on naive CD-4 cells
What is acute HIV syndrome or acute retroviral syndrome?
Fever and lymphadenopathy in the initial infection
Why is HIV easier to transmit rectally than vaginally?
Rectum has simple columnar epithelium and the vagina has stratified squamous epithelium; the more layers the harder to penetrate
Is HIV transmitted intrauterine?
No, only when going through vaginal canal like HSV
How long does acute retroviral syndrome last, what does it mimic and why does it subside?
Lasts 2-4 weeks
Looks like mononucleosis
Immune system responds to suppress
What characterizes AIDS?
CD-4 T cells less than 200 cells/mm cubed
What are three common infections reactivated in AIDS?
HSV
Toxoplasma
JVC
What is JVC?
Demyelinating disease called progressive multifocal leukoencephalopathy (oligodendrocytes targeted)
What are six common opportunistic infections and tumors associated with AIDS and their symptoms?
EBV: hairy leukoplakia along lateral side of tongue
Candida: oral thrush
Kaposi sarcoma-associated herpesvirus (HHV-8): sarcomas in the immunosupressed
Pneumocystis jerovecii: pneumonia
CMV: retinitis and blindness
Cryptosporidium: diarrhea
Where does HIV naturally like to go?
It is neurotropic so microglial cells in CNS
What is HAART (highly active antiretroviral therapy)?
2 NRTI + 1 PI/NNRTI/INSTI
targets pol genes effects
Ways drugs stop HIV?
CCR5 blocker gp41 blocker (fusion inhibitor)
What is a more specific test for HIV than ELISA?
Western blot
Vertically transmitted infections mnemonic?
ToRCHeS
What is in ToRCHeS?
Toxoplasma gondii Rubella Cytomegalovirus Herpes, HIV, HBV (hepatitis B) Syphilis
