Pathogenesis of HIV and the major sexually Transmitted Infections

Question 1

What is the definition of STI?

Answer 1

Sexually transmitted infection

infetions which are transmitted person to person by sexual contact

Question 2

What is the definition of STD?

Answer 2

Sexually transmitted infection

evidence of disease i.e. signs and symptoms present

Question 3

How are STI caused specifically via sexual contact?

Answer 3

mucous membrane contact

exchange of body fluids

Question 4

What are 3 common concepts of STI’s?

Answer 4

risk of transmissions = number of sexual partners - increased risk with use of non barrier/no contraception
Patients with one STD likely to have other STD’s
Tracing of people who may have come into contact with infected person is important

Question 5

What kind of an organism is Neisseria gonorrhoeae?

Answer 5

gram negative

diplococcus - in pairs

Question 6

Where does gonorrhoeae multiply and therefore how does the body destroy it?

Answer 6

intra-cellularly

therefore destroyed via phagocytosis by neutrophils

Question 7

How does gonorrhoeae attach to mucosal epithelial cells?

Answer 7

pili on the surface

Question 8

Where does gonorrhoeae present at in the body?

Answer 8

GU tract
rectum
oropharynx

Question 9

What are the symptoms of gonorrhoeae?

Answer 9

urethral discharge

dysuria

Question 10

What are the complications of gonorrhoeae? (inc in pregnancy)

Answer 10

epididymitis
prostitis
barthonilitis - inflammation of Bartholin’s glands in the vagina
salpingitis - inflammation of the fallopian tubes
PID
peritonitis
Fitz-Hugh-Curtis Syndrome (perihepatitis)
Diseminated Gonococcal Infection - spread of infection to the rest of the body e.g. Conjuctivitis
Pregnancy: spontaneous abortion, premature labour

Question 11

What is the treatment for gonorrhoeae?

Answer 11

B-lactams e.g. BenzylPenicillin

Cephalosporins e.g. cefixime

Question 12

What two pathogens cause non gonococcal urethritis?

Answer 12

chlamydia trachomatis

Ureaplasma urealyticum

Question 13

How is gonorrhoeae, syphilis, HIV and chlamydia diagnoised?

Answer 13

Nucleic acid amplification test (NAAT)

Question 14

What is the treatment for non gonococcal urethritis?

Answer 14

Doxycycline

Question 15

What are the symptoms of chlamydia?

Answer 15

dysuria
frequency
urgency
discharge
abnormal bleeding e.g. after sex, between periods

Question 16

What are the complications of chlamydia?

Answer 16

PID
Epididymitis
Conjuctiva (inc neonates)
Reiters syndrome

Question 17

What is Reiters syndrome?

Answer 17

Arthritis
Conjuctivitis
Urethritis
Skin lesions

Question 18

What is the treatment for chlamydia?

Answer 18

Azithromycin

Doxyclycline

Question 19

What is the treatment for HPV warts?

Answer 19

Burn
Freeze
Cut
Imiquimod - immune response modifier
Salicylic acid
Liquid nitrogen

Question 20

What are the signs and symptoms of genital herpes?

Answer 20

pain
itching
dysuria
vaginal/urethral discharge
ulcers

Question 21

What is the treatment of genital herpes?

Answer 21

aciclovir

Question 22

What are the complications of genital herpes?

Answer 22

dissemination
meningitis
encephalitis
sacral nerve parasthesiae which causes urinary retention

Question 23

What organism causes syphilis?

Answer 23

Treponema pallidium

Question 24

Where does treponema pallidium penetrate and travel round the body?

Answer 24

penetrates intact mucous membranes

disseminates within days via lymphatics/bloodstream

Question 25

What is obliterative endarteritis and what infection is it associated with?

Answer 25

inflammation of the intima or inner lining of an artery results in an occlusion of the lumen of the artery Syphilis

Question 26

What do the 3 stages of syphilis involve?

Answer 26

1) Painless lesion 2) Redness. Rash, wart like lesions on genitalia, mucous patches, lymphadenopathy, headache, fever, malaise, weight loss 3) serious CNS symptoms e.g. hemiplegia, seizures, CV symptoms - aortic regurgitation, saccular aneurysm Other: granulomatous reactions

Question 27

What is the treatment for syphilis?

Answer 27

penicillin based

Question 28

What is Jarish-Herxheimer reaction?

Answer 28

``` commonest in secondary stage of syphilis fevers chills myalgia hypersensitivity reaction - organism lysis NOTE: feels worse with penicillin ```

Question 29

What pathogen causes trichomoniasis?

Answer 29

trichomonas vaginalis | protazoa

Question 30

What are the symptoms of trichomoniasis?

Answer 30

green frothy vaginal discharge | mucosal inflammation

Question 31

What is the treatment for trichomoniasis?

Answer 31

metronidazole

Question 32

What is bacterial vaginosis (BV)?

Answer 32

Caused by reduced vaginal lactobacilli | increased Gardnerella vaginalis and anaerobes

Question 33

How is HIV transmitted?

Answer 33

Sexual - genital/colonic mucosa Exposure to other infected fluids e.g. blood/blood products Mother to infant

Question 34

Why do opportunistic infections occur in those with HIV?

Answer 34

loss of CD4 T cells | Reporting of stage based on CD4 count

Question 35

For more HIV questions see...

Answer 35

Antivirals

Question 36

What has been implemented to prevent STI's?

Answer 36

``` Referral to GUM clinics Free barrier contraception Chlamydia screening Universal HIV screening for those with STI's Encouraging contact tracing Vaccinations e.g. HPV ```

Question 37

What 2 organisms can cause PID?

Answer 37

N.gonorrhoea | C.trachomatis

Question 38

How is trichomoniasis diagnoised?

Answer 38

Vaginal swab - microscopy and culture

Question 39

What is the treatment for bacterial vaginosis?

Answer 39

Metronidazole

Question 40

What are the symptoms of bacterial vaginosis?

Answer 40

watery, fishy odoured discharge