Hepatitis C incidence among patients attending primary care health services that specialise in the care of people who inject drugs, Victoria, Australia, 2009 to 2020.

BACKGROUND: Monitoring trends in hepatitis C virus (HCV) incidence is critical for evaluating strategies aimed at eliminating HCV as a public health threat. We estimate HCV incidence and assess trends in incidence over time among primary care patients. METHODS: Data were routinely extracted, linked electronic medical records from 12 primary care health services. Patients included were aged ≥16 years, tested HCV antibody negative on their first test recorded and had at least one subsequent HCV antibody or RNA test (January 2009-December 2020). HCV incident infections were defined as a positive HCV antibody or RNA test. A generalised linear model assessed the association between HCV incidence and calendar year. RESULTS: In total, 6711 patients contributed 17,098 HCV test records, 210 incident HCV infections and 19,566 person-years; incidence was 1.1 per 100 person-years (95% confidence interval (CI): 0.9 to 1.2). Among 559 (8.2%) patients ever prescribed opioid-related pharmacotherapy (ORP) during the observation period, 135 infections occurred during 2,082 person-years (incidence rate of 6.5 per 100 person-years (95% CI: 5.4 to 7.7)). HCV incidence declined 2009-2020 overall (incidence rate ratio per calendar year 0.8 (95% CI: 0.8 to 0.9) and among patients ever prescribed ORT (incidence rate ratio per calendar year 0.9, 95% CI: 0.75 to 1.0). CONCLUSION: HCV incidence declined among patients at primary care health services including among patients ever prescribed ORP and during the period following increased access to DAA therapy.

The Association between the Australian Alcopops Tax and National Chlamydia Rates among Young People-an Interrupted Time Series Analysis.

A national tax increase, which became known as the "alcopops tax", was introduced in Australia on the 27th April 2008 on ready-to-drink alcoholic beverages, which are consumed predominantly by young people. The affordability of alcohol has been identified as the strongest environmental driver of alcohol consumption, and alcohol consumption is a well-known risk factor in the spread of sexually transmitted infections via its association with sexual risk-taking. We conducted a study to investigate whether there was any association between the introduction of the tax and changes in national chlamydia rates: (i) notification rates (diagnoses per 100,000 population; primary outcome and standard approach in alcohol taxation studies), and (ii) test positivity rates (diagnoses per 100 tests; secondary outcome) among 15-24 and 25-34-year-olds, using interrupted time series analysis. Gender- and age-specific chlamydia trends among those 35 and older were applied as internal control series and gender- and age-specific consumer price index-adjusted per capita income trends were controlled for as independent variables. We hypothesised that the expected negative association between the tax and chlamydia notification rates might be masked due to increasing chlamydia test counts over the observation period (2000 to 2016). We hypothesised that the association between the tax and chlamydia test positivity rates would occur as an immediate level decrease, as a result of a decrease in alcohol consumption, which, in turn, would lead to a decrease in risky sexual behaviour and, hence, chlamydia transmission. None of the gender and age-specific population-based rates indicated a significant immediate or lagged association with the tax. However, we found an immediate decrease in test positivity rates for 25-34-year-old males (27% reduction-equivalent to 11,891 cases prevented post-tax) that remained detectable up to a lag of six months and a decrease at a lag of six months for 15-24-year-old males (31% reduction-equivalent to 16,615 cases prevented) following the tax. For no other gender or age combination did the change in test positivity rates reach significance. This study adds to the evidence base supporting the use of alcohol taxation to reduce health-related harms experienced by young people and offers a novel method for calculating sexually transmitted infection rates for policy evaluation.

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 incidence in Indigenous and non-Indigenous populations in Australia: a population-level observational study.

BACKGROUND: Australia has set a national target of ending HIV by 2020, achieving this will require the inclusion of priority populations (eg, Indigenous Australians) in strategies to reach elimination. To assist in evaluating the target of elimination, we analysed HIV notification data for Indigenous and non-Indigenous Australians. METHODS: Using the National HIV Registry at The Kirby Institute at UNSW, Sydney, NSW, Australia, we collated and analysed annual HIV notification data for 1996-2015. Patients who were not born in Australia were excluded. We calculated the rates of HIV diagnoses with annual trends in notification rates for Indigenous versus non-Indigenous Australians by demographic characteristics, exposure categories, and stage of HIV at diagnosis. For missing data, assumptions were made and verified through sensitivity analyses. Annual rate ratio (RR) and 4 year summary rate ratio (SRR) trends were calculated to determine patterns of HIV diagnosis in the two populations. FINDINGS: Between Jan 1, 1996, and Dec 31, 2015, 11 492 people born in Australia were reported with a diagnosis of HIV, of whom 461 (4%) were recorded as Indigenous Australians and we classified the remaining 11 031 (96%) as non-Indigenous Australians. For exposure to HIV, among Indigenous Australians a higher proportion of diagnoses occurred among women, and through injecting drug use and heterosexual sex than among non-Indigenous Australians (p<0·0001). Among Indigenous Australians, we found a significantly higher SRR of HIV diagnoses among men in the period 2012-15 than in previous periods (SRR 1·53, 95% CI 1·28-1·83; p<0·0001), and significantly higher diagnosis among Indigenous women (4·92, 4·02-6·02; p<0·0001) for the entire study period than among non-Indigenous women. Concurrently, a decrease in HIV diagnoses of 1% per annum (RR 0·99, 95% CI 0·98-0·99; p<0·0001) across the study period was seen among non-Indigenous people. Indigenous Australians were more likely to be diagnosed at an advanced stage of HIV infection than non-Indigenous Australians (20·8% vs 15·1%; p=0·0088). INTERPRETATION: Greater efforts should be made to include Indigenous people in prevention strategies, particularly newer biomedical interventions, such as scale up of pre-exposure prophylaxis and treatment as prevention initiatives in Australia. More involvement of Indigenous Australians in these approaches is also required to prevent widening of the gap in HIV diagnosis rates between non-Indigenous and Indigenous Australians. FUNDING: None.

Chronic hepatitis C burden and care cascade in Australia in the era of interferon-based treatment.

BACKGROUND AND AIM: Interferon-free direct-acting antiviral regimens for hepatitis C virus (HCV) infection have been recently available in Australia, beginning a new era in clinical and public health management of HCV infection. This study provided updated estimates of the HCV infection care cascade and burden in Australia as a reliable platform for assessing the future impact of interferon-free therapies. METHODS: A modeling approach was applied to estimate the number of individuals living with chronic HCV infection and with various liver disease stages. Data from national registries of HCV notification and liver transplantation, literature review, and expert consensus informed the model parameters. HCV notification and Pharmaceutical Benefits Scheme data were used to estimate the number of HCV diagnosed individuals and treatment uptake. RESULTS: In 2014, an estimated 230 470 individuals (range: 180 490-243 990) were living with HCV, among whom 75% were diagnosed (n = 172 720; range: 156 720-188 770), 20% had ever received treatment (n = 45 000; range: 39 280-50 720), and 11% had been cured (n = 24 750; range: 21 520-27 990). Among individuals with HCV infection, the proportion with hepatic fibrosis stage ≥F3 doubled during the last decade, increasing from 9% (n = 18 580) in 2004 to 19% (n = 44,730) in 2014. Individuals initiating HCV treatment increased from 1100 in 1997 to 3840 in 2007, plateaued until 2010 and decreased to 2790 in 2014. CONCLUSIONS: The burden of HCV-related liver disease has increased markedly. Although the proportion diagnosed was high, treatment uptake remained low, with no increase over the last 7 years. Reducing the HCV burden in Australia requires scale-up of interferon-free HCV therapies.