Carolien Giele

Surveillance for newly acquired hepatitis C in Australia

Background:  The purpose of the present paper was to determine recent patterns of hepatitis C virus (HCV) transmission in Australia through a national system of enhanced surveillance of newly acquired hepatitis C.

Characteristics of HIV diagnoses in Australia, 1993-2006.

OBJECTIVE To describe recent trends in the diagnosis of HIV infection in Australia. METHODS National HIV surveillance data from 1993 to 2006 were analysed with a focus on geographic differences by HIV exposure route and late presentation (HIV within 3 months of a first AIDS-defining illness or a CD4 count of less than 200 cells muL(-1)). RESULTS In 1993-99, the number of HIV diagnoses declined by 32%, and then increased by 39% from 1999 to 2006. From 2000 onwards, rates increased significantly in Victoria, Queensland, South Australia and Western Australia. The most frequently reported routes of HIV exposure were male to male sex (71%) and heterosexual contact (18%), and the population rate of diagnoses have increased in both categories. Among the cases reported as heterosexually acquired (n = 2199), 33% were in people born in a high-prevalence country and 19% in those with partners from a high-prevalence country. Late presentation was most frequent in heterosexually acquired infections in persons who had a partner from a high-prevalence country: 32% compared with 20% overall. CONCLUSIONS Recent increases in annual numbers of HIV diagnoses in Australia underline the continuing need for HIV-prevention programs, particularly among men having male to male sex. Early diagnosis and access to care and treatment should also be emphasised, as a substantial proportion of people with HIV infection are unaware of their status until late in the course of disease.

Comparison of pandemic (H1N1) 2009 and seasonal influenza, Western Australia, 2009.

TOC summary: Infections were similar in terms of symptoms, risk factors, and proportion of patients hospitalized.

Household Responses to Pandemic (H1N1) 2009-related School Closures, Perth, Western Australia

Results from closures will determine the appropriateness and efficacy of this mitigation measure.

An increase in overseas acquired HIV infections among heterosexual people in Western Australia.

BACKGROUND There has been a recent increase in the number of heterosexually acquired HIV infections among non-Aboriginal people in Western Australia (WA), which has not been reported in other Australian jurisdictions. This report describes the epidemiological features of this increase. METHODS A descriptive analysis was conducted of newly diagnosed HIV infections among non-Aboriginal WA residents notified to the Department of Health from 2002 to 2006. Analysis outcomes included demographics, exposure categories, and place of HIV acquisition. RESULTS From 2002 to 2006, 258 new HIV diagnoses were notified among non-Aboriginal WA residents. Over this period, the number of notifications increased from 41 cases in 2002 (2.2 cases/100 000 population) to 66 cases in 2006 (3.4 cases/100 000 population). Overall, 107 (42%) of the cases were heterosexually acquired, and the annual number increased threefold from 2002 to 2006 (12 to 36 cases, respectively). Of these cases, 64 (60%) were male and 43 (40%) were female. The majority (89%) of male cases acquired HIV overseas, mostly in countries other than their region of birth; South-east Asia was the most common place of acquisition reported. Over half (56%) of the female cases acquired HIV overseas, mainly in their region of birth (83%), and sub-Saharan Africa was the most common place of acquisition. CONCLUSION There has been a recent increase in heterosexually acquired HIV infections among male and female WA residents, many of whom reported acquiring HIV overseas. Safe sex campaigns in WA should continue to reinforce safe sex messages among people travelling overseas.

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.

Effectiveness of a 3 + 0 pneumococcal conjugate vaccine schedule against invasive pneumococcal disease among a birth cohort of 1.4 million children in Australia

BACKGROUND Most studies use indirect cohort or case-control methods to estimate vaccine effectiveness (VE) of 7- and 13-valent pneumococcal conjugate vaccines (PCV7 and PCV13) against invasive pneumococcal disease (IPD). Neither method can measure the benefit vaccination programs afford the unvaccinated and many studies were unable to estimate dose-specific VE. We linked Australias national immunisation register with health data from two states to calculate IPD incidence by vaccination status and VE for a 3 + 0 PCV schedule (doses at 2, 4, 6 months, no booster) among a cohort of 1.4 million births. METHODS Births records for 2001-2012 were probabilistically linked to IPD notifications, hospitalisations, deaths, and vaccination history (available until December 2013). IPD rates in vaccinated and unvaccinated children <2 years old were compared using Cox proportional hazards models (adjusting for potential confounders), with VE = (1 - adjusted hazard ratio) × 100. Separate models were performed for all-cause, PCV7, PCV13 and PCV13-non-PCV7 serotype-specific IPD, and for Aboriginal and non-Aboriginal children. RESULTS Following introduction of universal PCV7 in 2005, rates of PCV7 serotype and all-cause IPD in unvaccinated children declined 89.5% and 61.4%, respectively, to be similar to rates in vaccinated children. Among non-Aboriginal children, VEs for 3 doses were 94.2% (95%CI: 81.9-98.1) for PCV7 serotype-specific IPD, 85.6% (95%CI: 60.5-94.8) for PCV13-non-PCV7 serotype-specific IPD and 80.1% (95%CI: 59.4-90.3) for all-cause IPD. There were no statistically significant differences between the VEs for 3 doses and for 1 or 2 doses against PCV13 and PCV13-non-PCV7 serotype-specific IPD, or between Aboriginal and non-Aboriginal children. CONCLUSION Our population-based cohort study demonstrates that >90% coverage in the first year of a universal 3 + 0 PCV program provided high population-level protection, predominantly attributable to strong herd effects. The size of the cohort enabled calculation of robust dose-specific VE estimates for important population sub-groups relevant to vaccination policies internationally.