Dr Luke Cannon( left) Advanced trainee at Sydney Sexual Health Centre, Sydney, NSW.

Clinical Professor Louise Owen( right) Sexual health physician, currently on secondment as a staff specialist at Sydney Sexual Health Centre; clinical professor at the school of medicine, University of Tasmania, Tasmania.

First published online on 21 March 2025

HIV IN AUSTRALIA

AUSTRALIA has made great strides

in reducing new HIV infections. There has been a 33 % decline in new diagnoses in the past 10 years, with 722 new HIV infections in 2023; this is largely due to increased testing, treatment as prevention( TasP) and pre-exposure prophylaxis( PrEP). 1

TasP is the concept that those living with HIV on treatment who have an undetectable viral load cannot transmit the virus to sexual partners, even during unprotected intercourse. Current antiretroviral( ARV) treatment is effective at reducing the viral load, with viral load usually undetectable in most patients within 3-6 months after initiation of treatment.

ARVs are fixed-drug combinations of two or three medications, and thus enable many patients to take a single tablet daily. In Australia, ARVs are S100 medications, and prescribers are required to undertake an accredited prescriber course run by

ASHM. This organisation represents healthcare professionals in HIV, bloodborne viruses( BBVs), and sexual and reproductive health. ASHM partners and collaborates to enhance workforce capacity and strengthen health systems to address stigma and barriers to care. There are multiple S100 prescribers in Australia, and many patients living with HIV are managed in the community by experienced GPs.

An initial ARV regimen usually consists of three active drugs with data also supporting the use of two drug regimens in some situations. The viral load at diagnosis, HIV genotype, hepatitis B status, concomitant medications, lifestyle and comorbidities are all taken into consideration when choosing initial and subsequent ARV regimens. 2

Lifelong compliance with medication is key to ensuring an ongoing undetectable viral load. Some patients switch regimens once they have achieved undetectable viral

load for simplification or because of adverse effects and, for some people, an injection every eight weeks of ARV therapy may be an alternative to daily medication. The side effect profiles of the ARVs have improved considerably; while there are potential drug-drug interactions, the newer agents are well tolerated.

PrEP has also played a significant role in the reduction of new diagnoses. In Australia, between April 2018 and June 2023, some 68,250 people( 97.7 % male) had PBS-subsidised PrEP dispensed at least once. 3 The number of individuals who had PrEP dispensed within the previous 12 months increased to a new high of 42,304 in the second quarter of 2023. 3

There are an unknown number of Medicare-ineligible patients who are purchasing PrEP privately; this is important to note, as a key target population are gay men born overseas, with the highest notification rate of new HIV infections in those

born in South-East Asia( 7.4 per 100,000). 1

Sexual health professionals, primary health clinicians, other providers of healthcare and local community organisations continue to work together to promote information around PrEP, post-exposure prophylaxis( PEP), condom use and regular HIV testing. The priority populations to target include Aboriginal and Torres Strait Islander people, and culturally and linguistically diverse groups; this is to ensure equitable access and uptake. 4 In 2022, the HIV notification rate increased to 3.2 per 100,000 among Aboriginal and Torres Strait Islander people compared to non-Indigenous people, at 2.2 per 100,000. 5

There are an estimated 30,010 people living with HIV in Australia with an estimated 8 % undiagnosed, equating to 2408 cases. 1

“ The estimated proportion with undiagnosed HIV was highest among people born in South-East Asia and