Lecture 15: STI's

Question 1

Incidence

Answer 1

First time infected/finite time

Question 2

Prevalence

Answer 2

General level/time

Question 3

Rate

Answer 3

Frequency (#of events/size of population) ex. attack rate

Question 4

Do condoms work to eliminate HPV?

Answer 4

NO, just lower chances

Question 5

Most common age for STI’s

Answer 5

15-24

Question 6

3 factors determining rate of spread of STI’s

Answer 6

a) rate of exposure of susceptible ppl
b) efficiency of transmission per exposure
c) duration of infectivity of those infected

Question 7

HPV

Answer 7

Major cause of human disease. Rate very high. Can cause cancer. Could get it, it lies dormant, and suddenly in your 40’s you have cervical cancer

Question 8

STI transmission + acquiring

Answer 8

• Sex (vag/anal)
• Oral-gen
• I.V drugs (sharing needles)
• Congenital transmission (mom->baby)
• Women tend to be more bio prone to STI’s

Question 9

Harm reduction strategies for preventing STI acquisition

Answer 9

• Abstinence (dumb)
• Practice safe sex
• Monogamous relationship (dumb)
• Reduce the # number of sexual partners
• Vaccination (HPV)

Question 10

Bacteria STI’s

Answer 10

• Treponema pallidum
• Chlamydia trachomatis
• Neisseria gonorrhea

Question 11

Viruses STI’s

Answer 11

• Human immunodeficiency virus
• Human Pappiloma Virus (HPV)
• Herpes Simplex Virus (HSV)

Question 12

Parasites STI

Answer 12

Trichomonas vaginalis

Question 13

Syphilis

Answer 13

• Caused by Treponema palladum
• Less common STI but on the rise
• Doesn’t produce painful sores
• Can be treated with penicillin
• Can be asymp
• Diagnoses: Treponemal Tests (IgG and IgM) as well as testing for non-syphilis specific proteins non-treponemal test

Question 14

Stage 1 Syphilis

Answer 14

Shanker (non painful @ first sign of contact) -> then randomly dissolves

Question 15

Stage 2 Syphilis

Answer 15

Develops a rash -> on palms and soles of feet
Rash is hard to see with freckles or dark skin then disappears

Question 16

Stage 3 Syphilis

Answer 16

Can activate in brain, heart, etc causing severe complications
Can make you go mad
CNS involvement can lead to personality changes, emotional instability, memory impairment, etc

Question 17

Chlamydia trachomatis

Answer 17

• Common, caused by intracellular bacteria called Chlamydia trachomatis
• Transmitted via sex (any kind), or from mom-baby
• Occurs worldwide
• Common in females vs males
• Incubation is 1-3 weeks
• Can ascend up gen tract leading to ectopic preg, and PID in women

Question 18

Chlamydia trachomatis: 3 specific entities based on anatomical site

Answer 18

1. Trachoma: ocular and leading cause of blindness
2. Lymphogranuloma venereum: causes infection in rectal mucosa
3. Genital infection: Inflammation of reproductive tract

Question 19

Chlamydia trachomatis Types

Answer 19

1. Trachoma: Ocular trachoma Serovar A, B, Ba, and C
2. Lymphogranuloma venereum: Serovar L1, L2, and L3
3. Genital Infection: D-K serotypes most commonly E, F, D

Question 20

Chlamydia trachomatis diagnosis

Answer 20

Urine sample for both genders
40% of females who have Chlamydia trachomatis also have gonorrhea

Question 21

Science of Chlamydia trachomatis (pathogenesis)

Answer 21

• Infects columnar epithelial cells, increases risk in adolescent females since these extend further into ectocervix in adolescents
• Epithelial cells as a result of infection recruit neutrophils to region which then lead to an inflammatory response

Question 22

Chlamydia trachomatis symptoms MEN

Answer 22

• Itchiness
• Pain
• Discharge
• Swelling
  1/2 will be asymp

Question 23

Chlamydia trachomatis symptoms FEMALE

Answer 23

• Burning
• Vag discharge
• Bleeding
• Pain
• Lower back or ab pain
• Possible fevers and chills
• Itchiness

Question 24

Lab detection of Chlamydia trachomatis

Answer 24

• Swabs are least traumatic method of collection for diagnosis
• Avoid cotton swabs
• Also test for gonorrhoea
• Cervical specimens can be collected
• Send the swabs for PCR for the detection of CT and NG

Question 25

Neisseria gonorrhoea

Answer 25

- Always considered pathogenic and is not a notifiable disease - Gram -'ve cocci - Humans are the only host for the pathogen - 2nd most common bacterial STI - Infects the mucous membrane in body including gen tract, rectum, pharynx, eyes - Can lead to ectopic pregnancies - Sex acquires or from mom to baby - Rapidly developing multi-drug resistance - 15-24 yr olds - Incubation period of 2-8 days

Question 26

How is Neisseria gonorrhoea diagnosed

Answer 26

With a swab as it needs to be cultured to determine how to treat it

Question 27

Complications of Neisseria gonorrhoea

Answer 27

Potential systematic infections - Arthritis - endocarditis -meningitis

Question 28

Epidemiology and Transmission of Neisseria gonorrhoea

Answer 28

- Majority occur in 15-24 year olds - Incubation period is 2-8 days - 10% men and 50% women are minimally symptomatic or asymptomatic - most cases will resolve in several weeks - ALWAYS SEEK TREATMENT

Question 29

Neisseria gonorrhoea and resistance

Answer 29

- Increasing resistance - Associated with treatment failure "untreatable gonococcal infection" - One of the WHO list priority organisms for emerging resistance over the next 10 yrs

Question 30

Diagnosis of Neisseria gonorrhoeae

Answer 30

- Swab 2cm and rotate anterior portion of meal urethra - Samples should be obtained after removal of mucous - Dacron and Rayon swabs - Send for PCR and Culture

Question 31

STI Summary

Answer 31

- Highly prevalent especially in 15-24 year olds - Significant proportion of individuals are asymptomatic - ALWAYS seek medical treatment - Emerging resistance is a problem with some such as (Neisseria gonorrhoeae) and not others (Treponema palladum)