W11 L3 Fri STI

Question 1

What is STI

Answer 1

• Sexually Transmitted/Transmissible Infections
• Spread primarily through person-to-person
  sexual contact (horizontal).
  – Some can also be transmitted from mother to child (ie vertically)
  – blood products and tissue transfer (blood borne viruses BBV)

Question 2

Classification of STI

Answer 2

-Bacteria (chlamydia, gonorrhea, syphilis)
-Viral (all name start with H)
-Parasitic (trichonomas, pubic lice, scabies)

Question 3

HIV history

Answer 3

• 1884 - 1924 SIV transfere to humans as HIV
  HIV 1: chimpanzee origin from cameroon, Congo (high virulence)
  HIV2 sooty mangabe from monkey, less virulent

Question 4

Epidemology of HIV

Answer 4

-Up to 39 million people world wide
-1.3 million newly acquired per year
-630000 people die per year
-there has been a decline in number of people acquiring HIV and HIV related death globally over time

Question 5

HIV epidemiology in AUD

Answer 5

• HIV in Australia (end of 2021)
  – 27,390 people living with HIV
  – HIV notifications coming down
  – 68% new notifications are amongst Men who have sex with men
• 27% Heterosexuals
• <2% Injecting drug use

Question 6

HIV infection method

Answer 6

-unprotected sexual intercourse with an infected partner
-vertical transmission ( utero, delivery or breast milk)
-injection drug use ( shared needle, blood transmissions)

Question 7

Pathophysiology of HIV

Answer 7

`-Virus bind to CD4 receptor
-binding to coreceptor CCR5 or CXC4
-the virus fuse and release it’s viral load
-the viral RNA is reverse transcript and integrated into the genome
-cell produce viral mRNA, translation and make new virus

Question 8

Management of HIV

Answer 8

• in the past, need to take anti-viral tablet at precise time
  -now, only one pill per day (combinational drug), allow them to have a normal live
  -long acting treatment, injection once every 2 month(6 month injection might be available)

Question 9

What is pelvic inflammatory disease

Answer 9

-Spectrum of inflammatory disorders of the upper female genital tract
* Polymicrobial infection
* Sexually transmitted pathogens more likely in younger, sexually active women

Question 10

common organisms that can cause pelvic inflammatory disease

Answer 10

– Chlamydia (50%)
* ~10% of chlamydial cervical infection ascend to cause PID
– Gonorrhea (25%)
* Overseas contact, remote Aboriginal communities
– Mycoplasma genitalium (?%)
– Bacterial vaginosis (?%)

Question 11

Epidemiology of Chlamydia and gonorrhea notifications (VIC)

Answer 11

-increase in infection per year, only slowed down a bit due to covid but infection rate has increasing since then

Question 12

epidemiology of PID

Answer 12

• ‘silent epidemic’
• ~10,000 Australian women treated for PID in
  hospital each year
  – Aged 20-29 years have highest incidence

Question 13

Pathophysiology of PID

Answer 13

-STD bacteria enter vagina with semen
-bacteria pass through cervix, into uterus. finally into ovarian tubes and ovary. become infected
-from there, it can spread to other region of the body

Question 14

Clinical manifestations of PID

Answer 14

• Range from no symptoms to severe
  – Lower abdominal pain
  – Menstrual disturbances
  – Vaginal discharge
  – Deep pain during sex
  – Fever

Question 15

consequences of PID

Answer 15

– Tubal infertility (1 in 8)
– Chronic pelvic pain
– Ectopic pregnancy
due to inflamed and scarring of ovary and fallopian tube

Question 16

Management of PID

Answer 16

• Triple antibiotics
  – BUT is it too late??
  – (doesn’t reverse damage)
• Reduce chlamydia, gonorrhea incidence
  – Consistent condom use
  – Monogamy

Question 17

Herpes Simplex Virus epidemiology

Answer 17

• Genital herpes caused by HSV 2
  – But rising numbers of HSV1 cause over recent years
• > 50% initial genital episodes now caused by HSV 1
• Most (2/3rd ) HSV infections are asymptomatic
  – ~80% unaware
• Seroprevalence
  – HSV 1 – 20-80%
  – HSV 2 – 12%
• 80% FSW, 60% MSM, 50% STD clinic attendees

Question 18

Pathophysiology of herpes

Answer 18

• Double stranded DNA virus
• Phases of herpes infection
  – Primary infection (flue like illness)
  – Latency * Nerve cell ganglia
  – Re-activation

Question 18

Clinical manifestations of herpes

Answer 18

• First episode
  – Flu like symptoms
  – Genital ulcers
  – Swelling/pain genital area
  – More subtle features( Erythema with tingling/itching, Fissures)
• Recurrences
  – Less painful, shorter duration than first episode

Question 19

Why is herpes consider bad

Answer 19

• Psychosexual morbidity
• Enhanced HIV transmission
• Eye disease (corneal ulceration, keratitis, acute retinal necrosis)
• Neurological (meningitis)
• Neonatal herpes

Question 20

Neonatal herpes

Answer 20

• Rare but serious
• Disseminated infection – Untreated 90% mortality
• “Localized” – skin, eyes, mouth (SEM)
• CNS infection

Question 21

Management of herpes

Answer 21

• No cure but manageable
  – Analgesia
  – Antivirals (Episodic, Suppressive)
  – Psychosexual counseling

Question 22

Epidemiology of syphillis

Answer 22

• Overall prevalence ~20 million (2016)
• 6.3 million incident cases annually worldwide
  – Mainly heterosexual adults
  – BUT congenital syphilis continues to be a major issue
• In high income countries, MSM are primary risk group (with about half coinfected with HIV)
  increase regconisation in low income countries too

Question 23

Transmission of syphillis

Answer 23

– Most through sexual contact
* Vaginal, anogenital, orogenital
– Congenital
* In utero, (birth canal)

Question 24

Pathophysiology of syphillis

Answer 24

• Penetrates intact mucous membranes or dermal microabrasions
• Enter lymphatics and blood to spread throughout body
• Attaches to endothelial lining of blood vessels causing inflammation (endarteritis,periarteritis)
  – Later, hypersensitivity response to organism causing gummatous lesions and necrosis

Question 25

Clinical features of syphillis

Answer 25

• Primary ulcer (chancre) – Appears 9-90 days after direct contact
• Secondary stage
  – 6 weeks to 6 months after infection
  – Maculopapular rash in 50-70%, may affect palms and soles
  Tertiary stage
  Most common presentation (~15%) = gummas
• Deep seated destructive nodules in bone, skin, other organs
• Cardiovascular invt -> damage to aortic valve and ascending aorta

Question 26

Human papillomavirus epidermology

Answer 26

• Most prevalent STI in the world – “common cold”
• Lifetime prevalence >50% in sexually active

Question 27

Pathophysiology of Human papillomavirus epidermology

Answer 27

• Double stranded DNA virus
• > 100 types
• 40 that affect genital region
  – Oncogenic
  – Non-oncogenic
• Most cleared spontaneously depending on HPV type and host immunity

Question 28

HPV associated cancer

Answer 28

– Cervical
– Oropharyngeal
– Vaginal/Vulval
– Penile
– Anal

Question 29

MAnagement for HPV

Answer 29

• Warts
  – Local destructive therapies
• Cryotherapy
• Creams (Imiquimod, Podophyllin)