Polymicrobial arcanobacterium haemolyticum intracerebral abscess: A case report and review of the literature.

Objective: This article describes a case of polymicrobial Arcanobacterium haemolyticum pharyngitis and sinusitis complicated by intracranial complications and reviews similar cases in the literature. Case summary: A 21-year-old immunocompetent male presented with symptoms of sore throat, rhinorrhoea, lethargy, headache, and rash. Imaging demonstrated sinusitis, pre-septal sinusitis, peritonsillar abscess formation, subdural empyema and cerebritis. He was managed with endoscopic sinus surgery, craniotomy for evacuation of subdural empyema and antibiotics. Microbiological samples demonstrated growth of A. haemolyticum, strep. anginosus, and fusobacterium necrophorum. He subsequently developed a cerebral abscess requiring stereotactic needle drainage. After a prolonged course of antibiotics, the patient was discharge and made a good recovery. Discussion: A. haemolyticum is an uncommon cause of non-streptococcal pharyngitis that may occur alongside other microorganisms and is rarely associated with severe intracranial complications. This organism and its antibiotic susceptibility patterns should be considered in complicated upper respiratory tract infections in immunocompetent hosts. Penicillins and macrolide antibiotics form the mainstay of therapy for A. haemolyticum.

Associations between antiretroviral regimen and changes in blood pressure: results from the D2EFT study.

In this randomised, controlled study in 14 low- and middle-income countries, individuals taking dolutegravir with darunavir/ritonavir for 48 weeks had a greater increase in systolic and diastolic blood pressure than individuals taking two nucleoside reverse transcriptase with darunavir/ritonavir. The difference remained significant after controlling for confounding factors including weight gain.

Clinical and laboratory features of COVID-19 illness and outcomes in immunocompromised individuals during the first pandemic wave in Sydney, Australia.

People with immunocompromising conditions are at increased risk of SARS-CoV-2 infection and mortality, however early in the pandemic it was challenging to collate data on this heterogenous population. We conducted a registry study of immunocompromised individuals with polymerase chain reaction (PCR)-confirmed SARS-CoV-2 infection from March-October 2020 in Sydney, Australia to understand clinical and laboratory outcomes in this population prior to the emergence of the Delta variant. 27 participants were enrolled into the study including people with a haematologic oncologic conditions (n = 12), secondary immunosuppression (N = 8) and those with primary or acquired immunodeficiency (i.e. HIV; N = 7). All participants had symptomatic COVID-19 with the most common features being cough (64%), fever (52%) and headache (40%). Five patients demonstrated delayed SARS-CoV-2 clearance lasting three weeks to three months. The mortality rate in this study was 7% compared to 1.3% in the state of New South Wales Australia during the same period. This study provides data from the first eight months of the pandemic on COVID-19 outcomes in at-risk patient groups.

Characteristics of Human Immunodeficiency Virus (HIV) Seroconversions in a Large Prospective Implementation Cohort Study of Oral HIV Preexposure Prophylaxis in Men Who Have Sex with Men (EPIC-NSW).

BACKGROUND: Most human immunodeficiency virus (HIV) seroconversions in people who have initiated preexposure prophylaxis (PrEP) occur in the context of insufficient adherence. We describe participants who seroconverted after being dispensed PrEP in a large PrEP implementation study in Australia. METHODS: Expanded PrEP Implementation in Communities in New South Wales was an implementation study of daily oral PrEP in individuals aged ≥18 years at high risk for acquiring HIV. HIV seroconversions were defined as a positive HIV test by either antigen, antibody, or detectable HIV viral load after enrollment. Insufficient adherence, measured by dispensing logs or participant self-report, was defined as <4 PrEP doses per week. RESULTS: A total of 9596 participants were enrolled and dispensed PrEP between 1 March 2016 and 30 April 2018; 30 were diagnosed with HIV by 31 March 2019. The median (interquartile range [IQR]) age was 31 (25-38) years, all identified as male, 29 (97%) identified as gay or homosexual, and 20 (69%) lived in a postcode with a low concentration of gay male residents. The median (IQR) days from first PrEP dispensing to diagnosis was 409 (347-656). There was no evidence that participants who seroconverted had been sufficiently adherent to PrEP. Nineteen (63%) participants who seroconverted were diagnosed with chlamydia, gonorrhoea, syphilis, or new hepatitis C infection. One participant had resistance to emtricitabine (M184V mutation) at diagnosis. CONCLUSIONS: Participants who seroconverted were insufficiently adherent to PrEP despite being at high risk for acquiring HIV. Understanding the reasons for poor PrEP adherence in individuals who subsequently acquire HIV is critical to improving PrEP effectiveness.

Multispecies Outbreak of Nocardia Infections in Heart Transplant Recipients and Association with Climate Conditions, Australia.

A multispecies outbreak of Nocardia occurred among heart transplant recipients (HTR), but not lung transplant recipients (LTR), in Sydney, New South Wales, Australia, during 2018-2019. We performed a retrospective review of 23 HTR and LTR who had Nocardia spp. infections during June 2015-March 2021, compared risk factors for Nocardia infection, and evaluated climate conditions before, during, and after the period of the 2018-2019 outbreak. Compared with LTR, HTR had a shorter median time from transplant to Nocardia diagnosis, higher prevalence of diabetes, greater use of induction immunosuppression with basiliximab, and increased rates of cellular rejection before Nocardia diagnosis. During the outbreak, Sydney experienced the lowest monthly precipitation and driest surface levels compared with time periods directly before and after the outbreak. Increased immunosuppression of HTR compared with LTR, coupled with extreme weather conditions during 2018-2019, may explain this outbreak of Nocardia infections in HTR.

The Association of Baseline Plasma SARS-CoV-2 Nucleocapsid Antigen Level and Outcomes in Patients Hospitalized With COVID-19.

BACKGROUND: Levels of plasma SARS-CoV-2 nucleocapsid (N) antigen may be an important biomarker in patients with COVID-19 and enhance our understanding of the pathogenesis of COVID-19. OBJECTIVE: To evaluate whether levels of plasma antigen can predict short-term clinical outcomes and identify clinical and viral factors associated with plasma antigen levels in hospitalized patients with SARS-CoV-2. DESIGN: Cross-sectional study of baseline plasma antigen level from 2540 participants enrolled in the TICO (Therapeutics for Inpatients With COVID-19) platform trial from August 2020 to November 2021, with additional data on day 5 outcome and time to discharge. SETTING: 114 centers in 10 countries. PARTICIPANTS: Adults hospitalized for acute SARS-CoV-2 infection with 12 days or less of symptoms. MEASUREMENTS: Baseline plasma viral N antigen level was measured at a central laboratory. Delta variant status was determined from baseline nasal swabs using reverse transcriptase polymerase chain reaction. Associations between baseline patient characteristics and viral factors and baseline plasma antigen levels were assessed using both unadjusted and multivariable modeling. Association between elevated baseline antigen level of 1000 ng/L or greater and outcomes, including worsening of ordinal pulmonary scale at day 5 and time to hospital discharge, were evaluated using logistic regression and Fine-Gray regression models, respectively. RESULTS: Plasma antigen was below the level of quantification in 5% of participants at enrollment, and 1000 ng/L or greater in 57%. Baseline pulmonary severity of illness was strongly associated with plasma antigen level, with mean plasma antigen level 3.10-fold higher among those requiring noninvasive ventilation or high-flow nasal cannula compared with room air (95% CI, 2.22 to 4.34). Plasma antigen level was higher in those who lacked antispike antibodies (6.42 fold; CI, 5.37 to 7.66) and in those with the Delta variant (1.73 fold; CI, 1.41 to 2.13). Additional factors associated with higher baseline antigen level included male sex, shorter time since hospital admission, decreased days of remdesivir, and renal impairment. In contrast, race, ethnicity, body mass index, and immunocompromising conditions were not associated with plasma antigen levels. Plasma antigen level of 1000 ng/L or greater was associated with a markedly higher odds of worsened pulmonary status at day 5 (odds ratio, 5.06 [CI, 3.41 to 7.50]) and longer time to hospital discharge (median, 7 vs. 4 days; subhazard ratio, 0.51 [CI, 0.45 to 0.57]), with subhazard ratios similar across all levels of baseline pulmonary severity. LIMITATIONS: Plasma samples were drawn at enrollment, not hospital presentation. No point-of-care test to measure plasma antigen is currently available. CONCLUSION: Elevated plasma antigen is highly associated with both severity of pulmonary illness and clinically important patient outcomes. Multiple clinical and viral factors are associated with plasma antigen level at presentation. These data support a potential role of ongoing viral replication in the pathogenesis of SARS-CoV-2 in hospitalized patients. PRIMARY FUNDING SOURCE: U.S. government Operation Warp Speed and National Institute of Allergy and Infectious Diseases.

The relationship between the epigenetic aging biomarker "grimage" and lung function in both the airway and blood of people living with HIV: An observational cohort study.

BACKGROUND: Age-related comorbidities such as chronic obstructive pulmonary disease (COPD) are common in people living with human immunodeficiency virus (PLWH). We investigated the relationship between COPD and the epigenetic age of the airway epithelium and peripheral blood of PLWH. METHODS: Airway epithelial brushings from 34 PLWH enrolled in the St. Paul's Hospital HIV Bronchoscopy cohort and peripheral blood from 378 PLWH enrolled in The Strategic Timing of Antiretroviral Treatment (START) study were profiled for DNA methylation. The DNA methylation biomarker of age and healthspan, GrimAge, was calculated in both tissue compartments. We tested the association of GrimAge with COPD in the airway epithelium and airflow obstruction as defined by an FEV1/FVC<0.70, and FEV1 decline over 6 years in blood. FINDINGS: The airway epithelium of PLWH with COPD was associated with greater GrimAge residuals compared to PLWH without COPD (Beta=3.18, 95%CI=1.06-5.31, P=0.005). In blood, FEV1/FVC

Disseminated Aspergillus lentulus Infection in a Heart Transplant Recipient: A Case Report.

We present the first published case of successfully treated disseminated Aspergillus lentulus infection in a solid organ transplant recipient with invasive pulmonary disease, endophthalmitis, and a cerebral abscess. This case highlights important challenges associated with treating A. lentulus, particularly regarding antifungal resistance and toxicities associated with long-term antifungal therapy.

Low Prior Exposure and Incidence of Hepatitis C in Human Immunodeficiency Virus-Negative Gay and Bisexual Men Taking Preexposure Prophylaxis (PrEP): Findings From the Expanded PrEP Implementation in Communities-New South Wales Prospective Implementation Study.

BACKGROUND: The use of preexposure prophylaxis (PrEP) for the prevention of human immunodeficiency virus (HIV) has raised concerns of increased sexual risk behaviors. These behaviors may be associated with increased incidence of sexually acquired hepatitis C virus (HCV) among gay and bisexual men. METHODS: The Expanded PrEP Implementation in Communities-New South Wales (EPIC-NSW) study was a cohort study of daily coformulated tenofovir disoproxil fumarate and emtricitabine for HIV prevention. We recruited 9596 people at high risk of HIV acquisition from 31 clinics across New South Wales and the Australia Capital Territory in Australia. We report prior exposure to HCV and incidence in this cohort between 2016 and 2019. RESULTS: At least 1 HCV test result was available for 8658 (90.2%) participants. These individuals had a median age of 34 years (interquartile range, 28-43), most of whom were male (8530, 98.5%), identified as gay (7944, 91.8%), and were born in Australia (51.8%). Prior exposure to HCV was detected among 81 participants at baseline (0.9%; 95% confidence interval [CI]: .71.2). Twenty of 8577 participants were diagnosed with incident infection (rate 0.2/100 person-years [95% CI: .1-.3/100 person-years]). They were significantly older (median age 41 years vs 34 years, P = .044), and more likely to report methamphetamine use at baseline (incidence rate ratio, 2.7 [95% CI: 1.00-7.2]) than those without incident infection. CONCLUSIONS: In this population of PrEP users, HCV prior exposure and incidence were low. With high levels of HCV and HIV testing and treatment, the dual goals of HIV and HCV elimination could be achieved in this population. Clinical Trials Registration: number NCT02870790.

Overcoming barriers to HIV pre-exposure prophylaxis (PrEP) coverage in Australia among Medicare-ineligible people at risk of HIV: results from the MI-EPIC clinical trial.

Background Overseas-born people who are ineligible for government-subsidised health care experience barriers to accessing HIV pre-exposure prophylaxis (PrEP) in Australia. This study aimed to assess a program providing free PrEP to overseas-born adults at risk of acquiring HIV. Methods Medicare-Ineligible Expanded Implementation in Communities (MI-EPIC) was a single-arm, open-label trial of daily tenofovir disoproxil fumarate/emtricitabine as PrEP. Six clinics recruited Medicare-ineligible adults who met HIV risk criteria in New South Wales, Australia. We recorded data on HIV and sexually transmitted infection (STI) diagnoses, and PrEP dispensing from July 2019 to June 2020. PrEP adherence as a medication possession ratio (MPR) was calculated as pills dispensed divided by days. We administered an optional survey on behaviours and attitudes to PrEP and sexual health. Results The 221 participants (206 men; 93.2%) had a median age of 29years (IQR 26-34). Participants were mostly born in Asia (53.4%), Latin America or the Caribbean (25.3%), or Europe (10.9%). Adherence was high; 190 participants (86.0%) had an MPR of >60%. Of 121 survey participants, 42 (34.7%) completed the survey in a language other than English. Of participants who had not used PrEP in the 6months before enrolment (n=45, 37.2%), the most common reasons were cost (n=22, 48.9%), and lack of knowledge about accessing PrEP (n=20, 44.4%). Conclusions Medicare-ineligible people at risk of HIV demonstrate high adherence when given access to free PrEP and translated information. Increasing PrEP awareness and reducing barriers to accessing PrEP in this high-risk population should be priorities in HIV prevention.

Long-term protection from HIV infection with oral HIV pre-exposure prophylaxis in gay and bisexual men: findings from the expanded and extended EPIC-NSW prospective implementation study.

BACKGROUND: Daily pre-exposure prophylaxis (PrEP) is effective in preventing HIV, but few long-term data are available on effectiveness and adherence in real-world settings. Here, we report trends in HIV incidence over 3 years in individuals at high risk who were prescribed PrEP in New South Wales (NSW), as well as adherence before the transition to subsidised PrEP. METHODS: Expanded PrEP Implementation in Communities-New South Wales (EPIC-NSW) was a pragmatic, prospective, single-arm, implementation study of daily, oral PrEP in 31 sites (sexual health clinics, general practices, and a hospital) in NSW, Australia. Eligible participants were HIV-negative adults (aged ≥18 years) who were at high risk of HIV infection as defined in local PrEP guidelines. Participants were prescribed coformulated (once-daily, oral tablet) tenofovir disoproxil fumarate (300 mg) and emtricitabine (200 mg) as HIV PrEP and were followed up with HIV testing, sexually transmitted infection testing, and PrEP dispensing. Originally planned for 3700 participants followed for 1 year, the study was expanded so that all eligible participants in the state could obtain PrEP and extended until publicly subsidised PrEP became available in Australia. The primary outcome was new HIV infection among all participants who were dispensed PrEP at least once and had at least one follow-up HIV test result. Adherence was estimated by medication possession ratio (MPR), defined as the proportion of PrEP pills dispensed in 90 days, assuming daily dosing. This study is registered with ClinicalTrials.gov, NCT02870790. FINDINGS: Between March 1, 2016, and April 30, 2018, we enrolled 9709 participants. 9596 participants were dispensed PrEP, of whom 9448 (98·3%) were gay or bisexual men. Participants were followed up until March 31, 2019, with at least one follow-up HIV test available in 9520 (99·2%) participants. Mean MPR declined from 0·93 to 0·64 from the first to the ninth quarter. There were 30 HIV seroconversions over 18 628 person-years, an incidence of 1·61 per 1000 person-years (95% CI 1·13-2·30). Being younger, living in a postcode with fewer gay men, reporting more risk behaviours at baseline, and having an MPR of less than 0·6 were each univariately associated with increased HIV incidence. In the final year of follow-up, when PrEP was mostly purchased rather than provided free by the study, HIV incidence remained low at 2·24 per 1000 person-years (1·46-3·44). INTERPRETATION: HIV incidence remained low over up to 3 years of follow-up, including during a transition from study-provided to publicly subsidised PrEP. In a setting of affordable PrEP and associated health-care services, very low HIV incidence of 1 to 2 per 1000 person-years can be maintained in gay and bisexual men who were previously at high risk. FUNDING: New South Wales Ministry of Health, Australian Capital Territory Health Directorate, Gilead Sciences.

HIV is associated with an increased risk of age-related clonal hematopoiesis among older adults.

People with human immunodeficiency virus (HIV) have higher rates of certain comorbidities, particularly cardiovascular disease and cancer, than people without HIV1-5. In view of observations that somatic mutations associated with age-related clonal hematopoiesis (CH) are linked to similar comorbidities in the general population6-10, we hypothesized that CH may be more prevalent in people with HIV. To address this issue, we established a prospective cohort study, the ARCHIVE study (NCT04641013), in which 220 HIV-positive and 226 HIV-negative participants aged 55 years or older were recruited in Australia. Demographic characteristics, clinical data and peripheral blood were collected to assess the presence of CH mutations and to identify potential risk factors for and clinical sequelae of CH. In total, 135 CH mutations were identified in 100 (22.4%) of 446 participants. CH was more prevalent in HIV-positive participants than in HIV-negative participants (28.2% versus 16.8%, P = 0.004), overall and across all age groups; the adjusted odds ratio for having CH in those with HIV was 2.16 (95% confidence interval 1.34-3.48, P = 0.002). The most common genes mutated overall were DNMT3A (47.4%), TET2 (20.0%) and ASXL1 (13.3%). CH and HIV infection were independently associated with increases in blood parameters and biomarkers associated with inflammation. These data suggest a selective advantage for the emergence of CH in the context of chronic infection and inflammation related to HIV infection.

High Levels of Prevention-Effective Adherence to HIV PrEP: An Analysis of Substudy Data From the EPIC-NSW Trial.

BACKGROUND: Preexposure prophylaxis (PrEP) prevents HIV infection but relies on good adherence at times of risk, termed "prevention-effective adherence." Most studies assess adherence without reference to sexual behaviur, making it challenging to determine if poor adherence coincides with HIV risk. SETTING: We examined data from a behavioral substudy of a large-scale PrEP implementation trial in New South Wales, Australia. METHODS: Trial participants completed optional brief quarterly surveys, reporting the number of pills taken and sexual behavior with male partners for each day of the "last full week" before each survey. Condomless sex (CLS) was defined as "higher risk" for HIV when with HIV-positive men with detectable/unknown viral loads or unknown HIV status men. Adequate PrEP protection was defined as ≥4 pills for participants assigned male sex at birth and ≥6 pills for participants assigned female sex at birth (including transgender men). RESULTS: Of 9596 participants dispensed PrEP, 4401 completed baseline and ≥1 follow-up survey. Participants reported on 12,399 "last full weeks": 7485 weeks (60.4%) involved CLS and 2521 weeks (33.7% of CLS-weeks) involved higher risk CLS. There were 103 weeks in which participants did not have adequate PrEP protection and had higher risk CLS: 4.1% of higher-risk CLS weeks (n = 103/2521), 1.4% of all CLS weeks (n = 103/7485), and 0.8% of all observed weeks (n = 103/12,399). CONCLUSIONS: In a large PrEP trial, prevention-effective adherence to PrEP was very high at 99%. Our findings illustrate the importance of measuring pill-taking and sexual behavior in the same period so that prevention-effective adherence can be better estimated.

DNA methylation is associated with airflow obstruction in patients living with HIV.

INTRODUCTION: People living with HIV (PLWH) suffer from age-related comorbidities such as COPD. The processes responsible for reduced lung function in PLWH are largely unknown. We performed an epigenome-wide association study to investigate whether blood DNA methylation is associated with impaired lung function in PLWH. METHODS: Using blood DNA methylation profiles from 161 PLWH, we tested the effect of methylation on FEV1, FEV1/FVC ratio and FEV1 decline over a median of 5 years. We evaluated the global methylation of PLWH with airflow obstruction by testing the differential methylation of transposable elements Alu and LINE-1, a well-described marker of epigenetic ageing. RESULTS: Airflow obstruction as defined by a FEV1/FVC<0.70 was associated with 1393 differentially methylated positions (DMPs), while 4676 were associated with airflow obstruction based on the FEV1/FVC

Occurrence of Accelerated Epigenetic Aging and Methylation Disruptions in Human Immunodeficiency Virus Infection Before Antiretroviral Therapy.

BACKGROUND: Whether accelerated aging develops over the course of chronic human immunodeficiency virus (HIV) infection or can be observed before significant immunosuppression on is unknown. We studied DNA methylation in blood to estimate cellular aging in persons living with HIV (PLWH) before the initiation of antiretroviral therapy (ART). METHODS: A total of 378 ART-naive PLWH who had CD4 T-cell counts >500/µL and were enrolled in the Strategic Timing of Antiretroviral Therapy trial (Pulmonary Substudy) were compared with 34 HIV-negative controls. DNA methylation was performed using the Illumina MethylationEPIC BeadChip. Differentially methylated positions (DMPs) and differentially methylated regions (DMRs) in PLWH compared with controls were identified using a robust linear model. Methylation age was calculated using a previously described epigenetic clock. RESULTS: There were a total of 56 639 DMPs and 6103 DMRs at a false discovery rate of <0.1. The top 5 DMPs corresponded to genes NLRC5, VRK2, B2M, and GPR6 and were highly enriched for cancer-related pathways. PLWH had significantly higher methylation age than HIV-negative controls (P = .001), with black race, low CD4 and high CD8 T-cell counts, and duration of HIV being risk factors for age acceleration. CONCLUSIONS: PLWH before the initiation of ART and with preserved immune status show evidence of advanced methylation aging.

Colonic malakoplakia in a dual stem cell and cardiac transplant recipient: A case report and literature review.

We describe the first published case of malakoplakia in a dual stem cell and cardiac transplant recipient. In the 2 months following cardiac transplantation, our patient developed persistent diarrhea and recurrent E coli bacteremia. Biopsies obtained from areas of colonic thickening revealed malakoplakia. Despite improvement in symptoms with prolonged antimicrobial therapy and reduction of his immunosuppression, he eventually died from sepsis. Our case highlights not only the importance of the timely diagnosis of this rare disorder, but also the difficulty in determining optimal treatment duration, particularly where excision of involved areas is not possible, as data on this disease are lacking. Here we describe our case and review the available literature published on malakoplakia in the cardiac transplant population.

Comorbidity Medications Are Dispensed to More People Receiving Antiretroviral Therapy for HIV Compared with the General Population in Australia.

Medical comorbidities occur in more persons with HIV than without HIV. We used a nationally representative 10% sample of 2016 Pharmaceutical Benefits Scheme (PBS) dispensing data to compare the proportions of antiretroviral therapy (ART)-purchasing and non-ART-purchasing patients who also purchased prescriptions for medical comorbidities. Each patient who purchased ART was compared with two gender- and age group-matched patients who did not purchase ART in the same year. We calculated the proportions of patients who also purchased coprescriptions used for hypertension, dyslipidemia, diabetes, cancer, low bone mineral density, and mental health, defined using PBS medication coding categories, and the resulting odds ratios. A total of 1,973 ART-purchasing patients in our sample were matched to 3,946 non-ART-purchasing patients. Compared with non-ART-purchasing patients, a greater proportion of ART-purchasing patients also purchased medications for dyslipidemia (19.8% vs. 16.6%; p-value = .003), low bone mineral density (1.5% vs. 0.8%; p-value = .02), and mental health (29.1% vs. 15.3%; p-value < .0001); a lower proportion purchased diabetes medications (4.8% vs. 6.5%; p-value = .009). These differences remained when our analysis was restricted to persons >55 years of age. Rates of multimorbidity (dispensed ≥2 medications for chronic conditions) were also higher among ART-purchasing patients (19.0% vs. 15.9%; p-value = .003). Using a nationally representative sample of prescription dispensing data, we found that higher proportions of ART-purchasing patients purchased coprescriptions for common comorbidities compared with non-ART-purchasing patients. Our finding that ART-purchasing patients purchased fewer diabetes medications is surprising, but may reflect differences in population characteristics between our two groups.

HIV treatment regimens and adherence to national guidelines in Australia: an analysis of dispensing data from the Australian pharmaceutical benefits scheme.

BACKGROUND: Treatment guidelines for antiretroviral therapy (ART) have evolved to emphasize newer regimens that address ageing-related comorbidities. Using national Australian dispensing data we compare ART regimens with Australian HIV treatment guidelines in the context of treated comorbidities. METHODS: The study population included all individuals in a 10% sample of national data from the Australian Pharmaceutical Benefits Scheme (PBS) who purchased a prescription of ART during 2016. We defined each patient's most recently dispensed ART regimen and characterized them to evaluate regimen complexity and adherence to national HIV treatment guidelines. We then analyzed ART regimens in the context of other co-prescriptions purchased for defined comorbidities. RESULTS: The 1995 patients in our sample purchased 212 different ART regimens during 2016; 1524 (76.4%) purchased one of the top ten most common regimens of which 62.3% were integrase strand transfer inhibitor-based. Among the 1786 (90%) patients that purchased the most common regimens, 83.7% purchased a regimen recommended by the guidelines for initial antiretroviral therapy and 11.4% purchased antiretrovirals that are not recommended for initial therapy; < 1% of the entire cohort purchased medications not recommended for use. While most patients purchased optimal ART regimens with low potential for significant drug interactions, regimen choices in the setting of risk factors for heart disease, renal disease and low bone mineral density appeared suboptimal. CONCLUSIONS: Australian HIV providers are prescribing ART regimens in accordance with updated treatment guidelines, but could further optimize regimens in the setting of important medical comorbidities.