Lecture 15: STI's A Flashcards
STI I
Incidence
Estimated number of people that are newly infected during a specific time period
Prevalence
Estimated number of people in a population with the disease
Rate
A measure of the frequency of an event compared with the number of persons at risk for an event
Describe the burden of sexually transmitted infections
15-24 year olds, most common is HPV
What are the three factors that determine the rate of spread of an STI?
Rate of exposure to suscpetible people
Efficiency of transmission per exposure
Duration of infectivity of those infected
Describe some ways an STI can spread from person to person
-Sex
-Oral-genital contact or in other non-sesxual ways
-IV drugs
-Congenital transmission
Which gender is more geneticcally prone to STI’s ?
Women
Describe some harm reduction strategies for preventing STI acquisition
Abstinence, practising safe sex, monogamous relationship, reduce number of sexual partners, vaccinatio n
Name 3 bacterial STIs
-Treponema pallidum
-Chlamydia trachomatis
-Neisseria gonorrhea
Name 3 viral STIs
HIV, HPV, HSV
Name a parasitic STI
Trichomonas vaginalis
Which disease is refererred to as the “great imitator” and what is it caused by?
Syphilis, treponema pallidum
Where are we seeing a large outbreak of syphilis?
Old age homes and MSM
Describe the pathogenetis of syphilis
Infection with T. Pallidum, primary syphillus, secondary syphilis, latent syphilis, then either no further complications of tertiary syphilis
Primary Syphilis
-Abrasions in dermis or mucuous membrane; manifests as cancre at SOI
-Cancre typically non-purulent and painless
Which locations is the syphilis chancre in men compared to women?
Women: labia or cervix, inconspicious and can be easily missed
Men: on penis usually, but could be in oral cavity, anus, or rectum
Secondary syphilis
Hours: syphilis dissemination into tissues
Symptoms: non-specific with sore throat, muscle aches, malaise, weight loss
Desseminated rash
Disseminated secondary syphilis rash
On the palms and soles of your feet, frequently found in secondary syphilis
What disease can secondary syphilis also manifest as?
Hepatitus, and lead to glomerulonephritis-immunoglobin antigen complexes that can lead to kidney damage
Tertiary Syphilis
20-40 years after initial infection, rare in post-antibiotic period
May lead to: Cardiovascular, neurological disease manifestations and death
CNS: personality changes, emotionaly instability, memory impairment, hallucinations
Treatment for syphilis?
Penicilin
How do we diagnose syphilis?
Treat: Syphilis specific antibodies (treponemal tests IgG, IgM) and test for non-syphilis proteins (RPR- rapid plasma reagen VDRL)
RPR is used for __________
Treponemal tests ________
Monitor therapy response, diagnosis
Chlamydia trachnomatis
Bacterial STI, caused by intracellular bacteria: chlyamydia trachomatis (CT)
Higher rate in females than males, rates likely underreported
What is the leading cause of bacterial genital infections in developing countries?
C. trachomatis
Majority of chlamydia is…
asymptomatic
Trachoma
-Caused by C. trachomatis serovars A, B, Ba, and C
-It is an ocular infection that can lead to blindness if untreated, often spread through direct contact or contaminated surfaces.
Lymphogranuloma Venereum (LGV)
-Caused by serovars L1, L2, and L3
-A sexually transmitted infection that affects lymph nodes and can lead to ulcers and inflammation in the genital area.
Genital Infection
-Caused by serovars D-K, most commonly E, F, and D
-These are the most common sexually transmitted C. trachomatis infections, leading to conditions like urethritis, cervicitis, and pelvic inflammatory disease.
Incubation period for chlamydia?
1-3 weeks
What disease is commonly comorbid with chlamydia?
Neisseria gonorrhoea; also increases your risk for acquisition of other STIS like HIV
Which cells does chlamydia infect?
Columnar epithelial cells, increeasing the risk in young females beucase the cells extend further into the ectocervix.
Cells recruit neutrophils to the region and lead to inflammatory response
What can chlamydia lead to?
Ectopic pregnancies, women with PID can develop perihepatitis
Describe the presentation of chlamydia in men?
-Itchy penis
-Pain when peeing
-Discharge
-Pain or swelling in balls
-Half of men have no symptoms
Describe the presentation of chlamydia in women?
-Burning when peeing
-Bleeding between periods
-Increases in pain in intercourse or menstruatin
-Abdominal or lower back pain
-Fever and chills
Describe the presentation of chlamydia in men and women?
Discharge, redness, painful BMs, itchiness
Describe lab detection of chlamydia?
Swabs, insert 3-5mm into urethra, cannot send semen or purulent discharge
Avoid cotton swabs. use Dacron or rayon (specific)
Also test for Neeisseria gonorrhea
Can collect from endocervix or cervic
Send swabs for PCR of CT and NG
Neisseria Gonorrhoea
Gram negative diplocooi
Pathogenic
Only host for organism is humans
Where does a N.gonorrhoea infection take place in the body?
Infects the mucous membranes in the body (genital tract, rectum, pharynx, eyes)
Describe pathogenesis of N.gonorrhoeae in women
Mucuous membrane of reproductvei tracr, cervix, fallopian tubes etc.. In men it travels along seminal vesicle, prostate and then urethral structures which impair male fertility
Explain why there is a risk of infertility and ectopic pregnancy with gonorrhea
Pelvic inflammatory disease that can lead to internal abscesses, directly damaging the fallopian tubes
(T/F) ejaculation must happen for gonorrhea to be transmitted?
False
Describe the symptoms of gonorrhea
Complications from this infection can include variosus systems.
-Colourful discharge
-Pain
-Burning when peeing
-swelling
-Swollen glands
Desseminated gonococcal infection
Arthritis, endocarditis, meningitis
How do people often present with gonorrhea?
Asymptomatic in 10% men, and 50% of women are also asymptomatic
Cases resolve after a few weeks, but you should always seek treatment
What is the current line of treatment and what phenomenon has followed gonorrhea?
Increasing resistance, now we use ceftiaxone and azithromycin (as of 2015)
How do we diagnose N.Gonorrhea?
Sample anterior region of urethra 2cm and rotate, remove mucous plugging the cervix,
Dacron and Rayon swabs
Send for PCR and culture
