By mapping transmission and identifying groups of people at elevated risk of HIV infection, a study examining HIV cases reported in Victoria between 2000 and 2020 details a new approach that can make public health efforts more timely and more effective.
In a study published in The Lancet Regional Health Western Pacific, researchers used a technique called molecular epidemiology to better understand HIV-1 transmission in Victoria, the most common type of human immunodeficiency virus (HIV). By linking genetic data from the virus with traditional epidemiological information, the researchers identified transmission groups among people living with HIV-1. The findings could help improve public health strategies to lower the rates of HIV-1 transmission.
University of Melbourne’s Dr George Taiaroa, a Research Fellow at the Doherty Institute and the study’s first author, said that just as cartographers create detailed maps to navigate landscapes, researchers can construct genetic maps to better understand how viruses have moved through populations, charting paths of transmission and outbreaks.
“Strategies employing these approaches could be valuable in guiding public health responses, with this work providing an evidence base and foundation for those considering the application of these methods more routinely in Australia,” said Dr Taiaroa.
A few smaller transmission groups represented probable transmitted drug resistance (TDR) to antiretroviral therapies. These therapies include those that prevent the virus from maturing and becoming infectious, as well as those that stop the virus from replicating.
“Identification of transmitted drug resistance can allow for more targeted selection of antivirals,” added Dr Taiaroa.
Characteristics of large HIV-1 transmission groups within Victoria, Australia. (A) Distribution of samples for molecular transmission groups. B–E) Summary of the proportion of different sexes (B), risk groups (C), SDRM (D), age groups (E), probable place of acquisition (F) and subtype or CRF (G) within major transmission groups. (H) Distribution of CD4+ T-cell counts within major transmission groups. Box plots indicate median and IQR, with whiskers representing highest and lowest values within 1.5 × IQR of the upper and lower quartiles, and dots representing outliers. (I) Distribution of per node links within major transmission groups. Box plots indicate median and interquartile range (IQR), formatted as above.
Australia has comparably low rates of new HIV infection compared to many high-income countries, thanks to world-leading models of care for the prevention and management of HIV infection. However, disruptions in healthcare caused by the COVID-19 pandemic have set back some of the progress, and higher rates of infection continue to disproportionally affect Aboriginal and Torres Strait Islander people and migrant communities.
University of Melbourne’s Professor Sharon Lewin, Director of the Doherty Institute, international HIV expert and co-senior author of the paper, said that as Australia aims to reduce HIV transmission further, integrating molecular approaches may play a critical role while respecting the complex ethical framework for handling genetic data.
“We are working closely with affected communities to understand the evidence related to the acceptability of these approaches in Australia. Ensuring informed consent and addressing potential stigmatisation are essential steps,” said Professor Lewin.
Importantly, this work included significant engagement with community groups and stakeholders throughout, including the National Association of People with HIV Australia (NAPWHA), Living Positive Victoria and Melbourne Sexual Health Centre.
Richard Keane, CEO of Living Positive Victoria, applauded the Doherty Institute’s commitment to engage with the community.
“The efforts made by the Doherty Institute over the last two years to prioritise meaningful engagement of people living with HIV in the potential implementation of phylogenetic tracing of HIV in Victoria provides a template for a genuine partnership approach, one that looks to examine ethical and potential legal implications of the use of this emerging technology,” said Mr Keane.
Doherty Institute researchers regularly attended state and national meetings with community groups to communicate the research method and findings, hear the participants’ views, respond to possible concerns and discuss what would be required for the appropriate and effective use of this approach in Australia.
“As CEO of Living Positive Victoria and a person living with HIV, understanding that the introduction of new technologies may create potential barriers to testing and trust in the institutions implementing it is essential for the community’s understanding of its role in the broader prospects of enabling us to move toward virtual elimination of HIV in Australia,” added Mr Keane.
Aaron Cogle, Executive Director of the NAPWHA said, “Molecular epidemiology is an exciting new technology that holds much potential to help the Australian HIV response to achieve virtual elimination of HIV transmissions by 2030.”
“Over the course of this study, the Doherty Institute has set an impressive example of how to continuously and meaningfully engage people with HIV at both the National and State/Territory levels. They have facilitated discussions about how to safely implement real-time phylogenetic analyses within an appropriately robust ethical framework and in a decriminalised environment.
“NAPWHA looks forward to continuing this approach with the Doherty as we advocate for a policy environment which will allow us to safely reap the maximum benefits from the phylogenetic tracing of HIV in Australia,” added Mr Cogle.
The appropriate introduction of molecular epidemiology for HIV in Australia, with community input and support, has the potential to greatly enhance public health efforts with findings from this deidentified study illustrating how this could be a transformative approach for public health.
Peer review: Taiaroa G, et al. Characterising HIV-1 transmission in Victoria, Australia: a molecular epidemiological study. The Lancet Regional Health Western Pacific, (2024). https://doi.org/10.1016/j.lanwpc.2024.101103
Collaboration: University of Melbourne, Victorian Department of Health, Alfred Health, Living Positive Victoria, Melbourne Sexual Health Centre, Monash University, National Association of People with HIV Australia (NAPWHA).
Funding: National Health and Medical Research Council, Australian Research Council