4.24 - STDs Flashcards
List the 3 pathogens that cause sexually transmitted infections. For the 8 most common
pathogens, indicate what category they fall into with regard to pathogen type and
whether they are curable.
bacteria, viruses, parasites
4 currently curable:
bacterial: syphilis, gonorrhea, chlamydia
parasitic: trichomoniasis
4 viral infections which are incurable:
hepatitis B (HBV), herpes (HSV), HIV, HPV
Distinguish between sexually transmitted infections and diseases.
first begin as infections, when std first enters body and begins multiplying, may be asymptomatic
may progress into disease - when the bacteria, virus, or parasite officially disrupts body’s normal functions and processes
Indicate how STIs can be transmitted.
spread predominantly by sexual contact
or via blood or blood products (HIV, Ebola, Zika)
-can also be transmitted from mother to child during pregnancy and childbirth
-syphilis, hep B, HIV, chlamydia, gonorrhea, herpes, HPV
Discuss why untreated STIs and STDs are a major health concern.
-mother-to-child transmission of STIs can result in stillbirth, neonatal death, low-birth weight , prematurity, sepsis, pneumonia, neonatal conjunctivitis, congenital deformities
-increased risk of acquiring another STI
-cancer and death
-infertility
Distinguish between the incidence, prevalence, and mortality of STIs.
prevalance is greater than incidence because STD can be treated but not cured
Be able to recognize the symptoms of chlamydia
women
-may be asymptomatic in 65% of women
-unusual vaginal discharge
-burning while urinating
-lower abdominal pain
-bleeding between periods
-low fever
men
-may be asymptomatic in 25% of men
-discharge from penis
-burning while urinating
-pain and swelling of testicles
Discuss which age groups, sexes and race/ethnicities are most affected by STDs. Know
what the rate per 100,000 means and how it is different from the number of cases
age 20-24, females, black/AA
Discuss the different body fluids and tissues that can be used to diagnose STIs. Indicate
what is tested for chlamydia
-NAAT (nucleic acid amplification test) for chlamydia
-HPV: pap smear
-gonorrhea and chlamydia: swab and urine test
-HIV: oral swab and blood test
-herpes: blood test
-hepatitis: blood test
-trichomoniasis and bacterial vaginosis: vaginal swab and urine test
Indicate which STDs are nationally reportable and why the information is collected
-allows for collection of data and statistics, permits identification of disease trends, tracking of outbreaks, and contact-tracing
nationally reportable:
-chancroid, chlamydia, gonorrhea, hep B, HIV, syphilis
List treatment options for bacterial, parasitic and viral STDs
antibiotics:
-three bacterial STIs (chlamydia, gonorrhea, and syphilis), and one parasitic STI (trich) are generally curable with single-dose regimens of antibiotics
anti-virals:
-for herpes and HIV, the most effective meds available are antivirals that can modulate the course of the disease, but they cannot cure the disease
-for hep B, antiviral meds can help to fight the virus and slow damage to the liver
List 6 methods proposed to prevent STIs.
-sex ed
-abstinence
-decrease risky behaviors
-condoms
-vaccines
-male circumcision (reduces risk of heterosexually acquired HIV infection in men by ~60%)
Describe the anatomy of the penis. Include mention of the foreskin, glans, shaft,
urethral meatus and frenulum. Indicate which structures are mucosal versus keratinized
epithelium and why this is important physiologically. Indicate which structures are altered during circumcision.
mucosal - inner lining of foreskin, frenulum, and urethral meatus are mucosal epithelium, which is thin, moist and susceptible to abraision
keratinized - glans and shaft are covered with keratinized epithelium, which provides protection against friction, microbial invasion and desiccation.
Circumcision appears to decrease the risk of HIV infection during heterosexual vaginal
intercourse in sub-Saharan Africa. Explain how circumcision can provide this benefit
based on the anatomy of the penis. Include mention of Langerhan’s cells, CD4+ helper
lymphocytes, macrophages, dendritic cells, frenulum micro-abrasions, and ulcerating
lesions in your discussion
potential entry points for HIV:
1. warm, moist inner mucosal epithelium of foreskin has high concentration of Langerhan’s cells, CD4+ helper lymphocytes, macrophages and dendritic cells (targets of HIV infection)
–foreskin is pulled down during intercourse exposing entire inner surface of foreskin to vaginal secretions
2. highly vascularized frenulum is susceptible to micro-abrasion trauma during intercourse
3. ulcerating lesions associated with other STDs
4. foreskin sac may serve as reservoir for HIV-containing secretions resulting in prolonged contact time after exposure to secretions
–
stratified squamous keratinized epithelium covers penile shaft and can therefore act as protective barrier to HIV infection
-glans is keratinized
-distal urethra is lined with mucosal epithelium but contains relatively few Langerhan’s cells
–
circumcision in sub-saharan africa
-most HIV is transmitted by heterosexual intercourse
-pop prevalence is 6-19%
-men were HIV-negative and then half were circumcised after enrollment in study
-circumcision significantly decreased HIV acquisition by 53-60%
Explain why circumcision may not decrease the risk of HIV infection for men in the
United States. Include a comparison of rectal versus vaginal/cervical mucosal secretions
in your discussion.
-most HIV transmitted through MSM
-pop prevalance is 0.4%
–only 15% acquired through female sex
-rectal mucosal secretions have higher conc of HIV than vaginal or cervical secretions
–viral excess may overwhelm protective effect of circumcision
-there may be a protective effect but it has not been demonstrated yet so it cannot be used to justify routine circumcision in US
