A novel semi-quantitative methodology for national poliovirus reintroduction and outbreak risk assessment.

BACKGROUND: Under the International Health Regulations (2005), World Health Organization Member States need to verify certification of polio-free status annually. In 2018, Australia sought to reassess and comprehensively characterise the risk posed by wild-type and vaccine-derived poliovirus introductions to national health security. However formal guidelines for national polio risk assessment were not publicly available. METHODS: Four risk elements were identified and weighted using an expert-informed modified Delphi method: reintroduction hazard; population susceptibility; detection capability; and response capability. Australian data and qualitative evidence were analysed, documented and scored against risk element indicators to characterise polio risk as a semi-quantitative estimate and qualitative risk category statement. RESULTS: The semi-quantitative risk characterisation calculated likelihood and impact scores of 0.43 and 0.13, respectively (possible range: 0.02-4.5). The assessment concluded that the risk of poliovirus reintroduction, resultant outbreaks of poliovirus infection, and sustained transmission occurring in Australia is very low. CONCLUSIONS: Until poliovirus is eradicated, it remains in countries' strategic health security interest to maintain optimal investment in polio prevention, preparedness, surveillance and response capability to manage their level of risk. We present a structured, transparent and reproducible methodology for national or sub-national polio risk characterisation that generates evidence for targeted investment to maintain polio-free status.

Establishing thresholds and parameters for pandemic influenza severity assessment, Australia.

OBJECTIVE: To implement the World Health Organization's pandemic influenza severity assessment tool in Australia, using multiple sources of data to establish thresholds and measure influenza severity indicators. METHODS: We used data from four reliable sources: sentinel general practitioner surveillance, hospital surveillance, a public health hotline and an influenza-like illness survey system. We measured three influenza severity indicators (transmissibility, impact and disease seriousness) defined using pandemic influenza severity assessment guidelines. We used the moving epidemic method and a seriousness indicator-specific method to set thresholds for indicator parameters using 2012-2016 data. We then applied the thresholds to data from the 2017 influenza season. FINDINGS: We were able to measure and produce thresholds for each severity indicator. At least one laboratory-confirmed influenza parameter was used to measure each indicator. When thresholds were applied to the 2017 season, there was good agreement across all data sources in measuring activity for each indicator. The season was characterized as having high transmissibility and extraordinary impact. Seriousness was characterized as moderate overall and in all age groups except those aged ≥ 65 years for whom it was high. This matched the description of the season produced by the Australian national influenza surveillance committee, based on expert opinion and historical ranges. CONCLUSION: The pandemic influenza severity assessment and moving epidemic method provide a robust and flexible method to enable an evidence-based assessment of seasonal influenza severity across diverse data sources. This is useful for national assessment and will contribute to global monitoring and response to circulating influenza with pandemic potential.

Tuberculosis notifications in Australia, 2010.

The National Notifiable Diseases Surveillance System received 1,353 tuberculosis (TB) notifications in 2010, representing a rate of 6.1 cases per 100,000 population. While rates of 5 to 6 cases per 100,000 population for TB have been maintained in Australia, since first achieved in the mid-1980s, there has been a steady increase in incidence over the past decade. The incidence in the Australian-born Indigenous population was 7.5 per 100,000 population, which is 11 times the incidence reported in the Australian-born non-Indigenous population of 0.7 per 100,000 population. Overseas-born people accounted for 90% of all cases notified in 2010 and represented a rate of 24 per 100,000 population. International students have been recognised as an increasingly important group, representing 25% of all overseas-born cases notified in 2010, and are a focus of this report. Household or other close contact with TB or past residence in a high risk country were the most commonly reported risk factors for TB infection. Outcome data for the 2009 TB cohort indicate that treatment success was attained in more than 95% of cases. As Australia continues to contribute to global TB control it is important to maintain good centralised national reporting of TB to identify populations at risk and monitor trends in TB.

Tuberculosis notifications in Australia, 2011.

The National Notifiable Diseases Surveillance System received 1,385 tuberculosis (TB) notifications in 2011, representing a rate of 6.2 cases per 100,000 population. While Australia has maintained a rate of 5 to 6 cases per 100,000 for TB since the mid-1980s, there has been a steady increase in incidence over the past decade. In 2011, Australia's overseas-born population continued to represent the majority of TB notifications (88%) with a notification rate of 20.2 per 100,000. The incidence of TB in the Australian-born Indigenous population has fluctuated over the last decade and showed no clear trend; however, in 2011 the notification rate was 4.9 per 100,000, which is a notable decrease from the 7.5 per 100,000 recorded in 2010. The incidence of TB in the Australian-born non-Indigenous population has continued to remain low at 0.9 per 100,000. Australia continued to record only a small number of multi-drug-resistant TB (MDR-TB) cases nationally (n=25), all of which were identified in the overseas-born population. To ensure that Australia can retain its low TB rate and work toward reducing rates further, it is essential that Australia maintains good centralised national TB reporting to monitor trends and identify at-risk populations, and continues to contribute to global TB control initiatives.