HIV/STI epidemiology and prevention

Question 1

Describe trends of HIV in AU

Answer 1

• Globally, trending downwards (new, deaths)
• Overall prevalence up i.e. more people living with HIV
• diagnoses have been trending downwards in AU since mid-80s
• ## Australia is considered a low prevalence country (0.1% estimated)

Question 2

Describe trends of STIs in Australia

Answer 2

• chlamydia, high rates, 2/3s young, female
• high and increasing among PLHIV and MSM
• gonorrhea 2/3s men, increasing in past decade
• high among PLHIV and Indigneous people
• syphilis: increasing, 80% male; higher in Indigenous, remote
• ## not changing among MSM

Question 3

What are determinants of HIV transmission?

esp pop groups

Answer 3

• HIV is a slow virus
• long incubation period
• attacks immune system
• transfers via bodily fluids: via mucous membranes, PC exposure, non-intact skin
• infects CD4+, macrophages, DCs

• majority of new cases in MSM, gay, bisexual men
• most research and prevention in this population
• injecting population»>
• declining diagnoses in MSM, particularly AU born
• hetero population stable
• likely acquisition here (if MSM)
• but: LATE diagnoses up – hetero most liely

Question 4

What are determinants of STI transmission?

Answer 4

• gender (Chlamydia female, gonorrhea male)
• remoteness
• indigeneity
• PLHIV - gonorrhea and chlamydia

Question 5

Give background to HIV reduction strategies

Answer 5

• multiple commonwealth strategies: national HIV strategy, Natioanl STI strategy
• goals of HIV strategy
  1. virtually eliminate transmission within life of strategy
  2. stustain virtual elimination among inject, sex workers, congenital
  3. reduce mort and morb
  4. eliminate stigma, discrimination, legal and human rights impact on health
  5. minimise social and personal imapct

Targets include:
Increase HIV diagnosis/testing, HIV treatment, viral suppression; reduce HIV incidence in MSM; increase PrEP use; increase quality of life for PLHIV; decrease experiences of stigma reported by PLHIV

• working in partenrsip: reason for success: research, clinical, govt, community and NGOS

Question 6

Describe the elements of HIV and STI prevention

Answer 6

Via testing
- reduce infectiousness via immediate treatment e.g. HIV TasP
- prevent expisure: condoms (highly effective at preventing HIV, less so fro STI, MSM greater uptake, but generally not popular), risk reduction, sterile injecting equipment
- reduce susceptibility: PrEP (two antiretroviral daily or before/after; adherence = effectiveness; on-deman oral PrEP effective for planned; LA-CAB, others emerging), PEP, STI treament and prophylaxis

In order to: reduce stigma AND increase access

Question 7

Describe and analyse STI reduction strategies

Answer 7

see abive but also:
STIs are increasing in many population groups, but especially in MSM due to increases in biomedically-protected condomless sex.

Interest is growing in two forms of antibiotic prophylaxis for STIs:
STI-PrEP: Taking low-dose antibiotics daily
STI-PEP: Taking one antibiotic pill after an episode of sex

Due to concerns about antimicrobial resistance, focus appears to be shifting towards STI-PEP.

RCTs have shown reductions in gonorrhoea, chlamydia and syphilis in MSM taking doxycycline STI-PrEP