STDs Flashcards
Transmission?
Transmission via skin, placenta, rectum, mouth, genitalia
What kind of microbes cause Stds?
Mainly bacteria, viral, protozoa, parasites, fungi
name a few bacterial stds.
syphilis, chlamydia, gonorrhoea, chancroid
name a few viral std’s
genital herpes + warts, AIDs
Who is at high risk?
multiple partners, medically unsupervised, IV drug user
Who are are low risk?
monogamous relationships
Who is at no risk?
abstinence
Are Std’s more common in men or women? Explain.
Higher risk in women, often internal (in Cervix & vagina) -> not readily detectable
Lower risk in men, often external (on the penis) -> easily detectable
Genital herpes?
herpes simplex type 2. Neurotropic microbe -> prefers neural cells (infects neurons). Systemic, recurrent infection
Spread of genital herpes?
via contact with lesions or secretions (sexual contact) and the virus is spread systemically
Incubation periods of genital herpes?
2-10 days
Manifestations of genital herpes?
- subclinical development until about 3-7 days post contact -> burning, painful vesicles at site
- shedding lesion
shedding lesion?
the lesion excretes bodily fluid containing the virus, increasing the potential for disease transmission and infection
treatment of genital herpes?
antivirals (eg. Acyclovir) & symptomatic management
Genital warts?
human papilloma virus strains 6 and 11
spread of genital warts?
genital or anorectal -> you must make skin to skin contact with the warts
incubation period for genital warts?
1.5-8 months
Manifestations of genital warts?
mostly asymptomatic and transient (lasts for a short time, not permanent)
Treatment of genital warts?
remove genital warts:
- topical drugs (anti mitotic or cytostatic drugs that prevent viral cells from dividing or cytotoxic drugs that are toxic to the cells)
- surgery
- cryotherapy
What should you monitor for if a pt has genital warts?
monitor for cancer (strains 16 & 18 of HPV)
microbe that causes syphilis?
treponema pallidum
Treponema pallidum?
spirochete (spiral-shaped) bacterium
How is syphilis spread?
this bacteria is spread through shedding lesions containing microbial particles during sexual contact and can be via placental transmission from an infected
What are some systemic complications in syphilis? and how did they occur?
blindness, paralysis, heart disease and death; they occur from bacteria entering the circulatory and lymphatic systems
What does HAART stand for?
highly active anti retrovirus therapy
This type of STD has benign, multiple growths.
Genital warts
Mnfts that occur in the first stage of syphilis?
- painless chancre @ contact sites (non bleeding, oval -shaped ulcer; heals in about 3-12 weeks)
- regional lymphadenopathy
Mnfts that occur in the second stage of syphilis?
up to 6 months
- begins 6-8 weeks post-infection
- maculopapular rash on palms of hands and soles of feet.
- patches on mucous membranes
- flat papules
- generalized lymphadenopathy
- fever, malaise
- latent period (can last up to 50 years)
Mnfts that occur in the third stage of syphilis?
- typically this stage occurs ~1-35 years after the first infection if untreated;
- the bacteria can still be eradicated at this point, but irreversible damage to the bone, joints, CVS, and NS has already occurred
Treatment of syphilis?
- long acting antibiotic (eg. penicillin)
why is a long-acting antibiotic used to treat syphilis?
because spirochetes have a long generation time of ~30 hours
What is a complication of HIV?
AIDS
What kind of virus occurs in HIV/AIDs?
Retrovirus
What does the retrovirus do in HIV?
it targets the immune system
Explain what a retrovirus is.
Usually deoxyribonucleic acid transcribes into ribonucleic acid and that forms proteins. these viruses take RNA and put it in the DNA of the host (works backwards). It results in profound immunosuppression -> develop infections and cancers very readily.
Etiology and transmission of HIV and AIDs?
- HIV (HIV 1 and HIV2)
- sexually transmitted -> semen can contain the virus; virus can be carried in blood; maternal
3 stages in HIV/AIDs?
- primary infection
- latent period
- Overt AIDs
What occurs during the primary infection stage?
- weeks to months
- window period (during this time the pt would test negative for HIV)
- seroconversion
- high viral loads (# of viral particles)
- decreased CD4 count)
Window period?
time it takes for the antibodies to form
Seroconversion?
Formation of antibodies
CD4?
Clustered differentiation 4 = surface protein on T help cells, macrophages and some epithelial cells, CD4 could is an indirect measure of the # of T cells
What occurs during the latent period stage?
- Could be asymptomatic for years
- lymphatic tissue damage (lymphadenopathy)
- recurrent resp infection
What occurs during the overt aids stage?
- ~10 yrs majority causes are known as typical progressors
- ~5 yrs : rapid progressors
- ~15 yrs: slow progressors
- Long-term non progressors (2-5%) -> do not develop AIDs
patho of HIV/AIDs?
Target T helper cells (CD4) -> responsible for cell-mediated response, if these cells are damaged then cytokines are not generated for immune cells to communicate with each other and the immune system is compromised. Also targets macrophages and B cells (responsible for Ab formation, if these are targeted then Ab formation is inhibited). Destroys the immune system -> decreases immunity and defenses -> many new infections and via latent pathogens. Many organs are affected.
Dx of aids/hiv?
- clinical presentation
- ELISA
- Western blot assay
- PCR
- CD4 counts and viral loads
- Quick tests: new rapid serum and saliva tests -> P24 ANTIGEN
ELISA?
enzyme-linked immunosorbent assay
What occurs in ELISA?
the bodys production of antibodies measured against the entire virus using an enzymatic method. If this test is positive, they confirm it with the western blot
PCR?
Polymerase Chain Reaction; amplifies genetic material and measures the viral particle itself
P24 ANTIGEN?
protein found in the viral core and makes its appearance early (bw times of infection and seroconversion, when antibodies are detectable)
Manifestations of HIV/AIDS?
- extensive, involves many body systems;
- opportunistic infections infect respiratory tract (defense compromised so recurrent infections cannot be prevented such as TB & pneumonia)
- GI infections from normal flora and ingested microbes
- NS: dementia; encephalopathy
- Opportunistic cancers: malignant cells in the early stage are controlled by the immune system
Name 3 opportunistic cancers that can occur?
Kaposi’s sarcoma; cervical cancer; non-hodgkins lymphoma
Treatment of HIV/AIDs?
- cannot be cured
- HAART
- Polypharmacy: antiviral agents (at least 3): each drug targets different steps
HAART?
highly active anti retrovirus therapy; HIV is a retrovirus so this therapy targets the reverse transcription used by the virus.
