BackgroundIn Australia the incidence of HIV has declined steadily, yet sustained reduction of HIV transmission in this setting requires improved public health responses. As enhanced public health responses and prioritisation of resources may be guided by molecular epidemiological data, here we aimed to assess the applicability of these approaches in Victoria, Australia.MethodsA comprehensive collection of HIV-1 pol sequences from individuals diagnosed with HIV in Victoria, Australia, between January 1st 2000 and December 31st 2020 were deidentified and used as the basis of our assessment. These sequences were subtyped and surveillance drug resistance mutations (SDRMs) identified, before definition of transmission groups was performed using HIV-TRACE (0.4.4). Phylodynamic methods were applied using BEAST (2.6.6), assessing effective reproductive numbers for large groups, and additional demographic data were integrated to provide a high resolution view of HIV transmission in Victoria on a decadal time scale.FindingsBased on standard settings for HIV-TRACE, 70% (2438/3507) of analysed HIV-1 pol sequences were readily assigned to a transmission group. Individuals in transmission groups were more commonly males (aOR 1.50), those born in Australia (aOR 2.13), those with probable place of acquisition as Victoria (aOR 6.73), and/or those reporting injectable drug use (aOR 2.13). SDRMs were identified in 375 patients (10.7%), with sustained transmission of these limited to a subset of smaller groups. Informative patterns of epidemic growth, stabilisation, and decline were observed; many transmission groups showed effective reproductive numbers (Re) values reaching greater than 4.0, representing considerable epidemic growth, while others maintained low Re values.InterpretationThis study provides a high resolution view of HIV transmission in Victoria, Australia, and highlights the potential of molecular epidemiology to guide and enhance public health responses in this setting. This informs ongoing discussions with community groups on the acceptability and place of molecular epidemiological approaches in Australia.FundingNational Health and Medical Research Council, Australian Research Council.

Background Cytomegalovirus (CMV) can cause symptomatic CMV syndrome or tissue-invasive CMV disease in immunocompromised individuals, including solid-organ transplant and hematopoietic stem cell transplant recipients. In these populations, monitoring of CMV load is essential, assessing both risk of disease and response to antiviral therapy.High throughput commercial assays are currently available for CMV quantitation, but they are often evaluated independently, with few studies comparing these assays. This study evaluated CMV quantitative assays for use with the Roche cobas 6800, Abbott Alinity m and Hologic Panther platforms using stored patient plasma. Methods Analytical evaluation was performed using the 1st WHO international standard for human CMV for Nucleic Acid Amplification Techniques (cobas and Alinity m) or the Hologic CMV QC Calibrator 6 (Aptima). Parallel testing of 136 clinical plasma samples was performed across the three platforms. Results Linearity for each assay ranged from 98.6% to 99.96% and precision and limit of quantitation were as expected with little variation between platforms. 136 clinical plasma samples were evaluated with similar agreement observed between each assay. The greatest positive agreement was between the Aptima Quant and Alinity m assays (95.6%, 95% CI 89-98.6%) and the lowest between the Aptima Quant and cobas assays (94.1%, 87.4-97.5%). Conclusions All assays were sensitive and accurate when quantifying CMV, and performance across all 3 assays was comparable for monitoring CMV viral loads in patient plasma.

Background Baseline genotyping is part of standard-of-care treatment. It reveals that transmitted drug resistance (TDR) continues to be important for the management of HIV infection. Attention is typically focused on determining whether resistance to the protease inhibitors (PI) and reverse transcriptase inhibitors (RTI) occurs. However, the increasing use of integrase inhibitors (INIs) raises a concern that TDR to this class of antiretroviral drug may also occur. Methods: PI and RTI drug resistance genotyping was performed on blood samples collected between 2005 and 2015 from 772 treatment-naïve Victorian patients infected with HIV within the previous 12 months. Integrase genotyping was performed on 461 of the 485 patient samples collected between 2010 and 2015. Results: In the period 2005–10, 39 of 343 patients (11.4%) had at least one PI- or RTI-associated mutation, compared with 34 of 429 (7.9%) during the period 2011–15. Compared with 2005–10, during 2011–15 there was a significant decline in the prevalence of the non-nucleoside-associated mutation K103N and the nucleoside-associated mutations at codons M41 and T215. One patient was detected with a major INI resistance mutation, namely G118R. However, this mutation is rare and its effect on susceptibility is unclear. A small number of patients (n = 12) was infected with HIV containing accessory resistance mutations in the integrase gene. Conclusions: The lack of transmitted resistance to INIs is consistent with a low level of resistance to this class of drugs in the treated population. However, continued surveillance in the newly infected population is warranted as the use of INIs increases.