Influenza-associated hospitalisation and mortality rates among global Indigenous populations; a systematic review and meta-analysis.

BACKGROUND: More than 50 million influenza infections and over 100,000 deaths from influenza occur annually. While Indigenous populations experience an inequitable influenza burden, the magnitude of this inequity has not previously been estimated on a global scale. This study compared rates of influenza-associated hospitalisation and mortality between Indigenous and non-Indigenous populations globally. METHODS: A systematic review and meta-analysis was conducted including literature published prior to 13 July 2021. Eligible articles either reported a rate ratio (RR) comparing laboratory-confirmed influenza-associated hospitalisation and/or mortality between an Indigenous population and a corresponding benchmark population, or reported sufficient information for this to be calculated using publicly available data. Findings were reported by country/region and pooled by country and period (pandemic/seasonal) when multiple studies were available using a random-effects model. The I2 statistic assessed variability between studies. RESULTS: Thirty-six studies (moderate/high quality) were included; all from high or high-middle income countries. The pooled influenza-associated hospitalisation RR (HRR) for indigenous compared to benchmark populations was 5·7 (95% CI: 2·7-12·0) for Canada, 5·2 (2.9-9.3) for New Zealand, and 5.2 (4.2-6.4) for Australia. Of the Australian studies, the pooled HRR for seasonal influenza was 3.1 (2·7-3·5) and for pandemic influenza was 6·2 (5·1-7·5). Heterogeneity was slightly higher among studies of pandemic influenza than seasonal influenza. The pooled mortality RR was 4.1 (3·0-5.7) in Australia and 3·3 (2.7-4.1) in the United States. CONCLUSIONS: Ethnic inequities in severe influenza persist and must be addressed by reducing disparities in the underlying determinants of health. Influenza surveillance systems worldwide should include Indigenous status to determine the extent of the disease burden among Indigenous populations. Ethnic inequities in pandemic influenza illustrate the need to prioritise Indigenous populations in pandemic response plans.

Costing of an Australian general practice COVID-19 drive-through testing and respiratory clinic.

BACKGROUND: Responding to the COVID-19 pandemic requires safe and efficient testing on a large scale over a prolonged period. Outpatient testing facilities can clinically assess and test symptomatic individuals and test asymptomatic contacts. This study identified the resources required to establish and maintain an Australian general practitioner (GP) led testing facility that combined a respiratory clinic for clinical assessment and testing with a drive-through testing facility. METHODS: Data were taken from clinic administrative records to identify the number of patients tested over the period April-June 2020. An independent auditor's report identified the resources used in establishing, running, and staffing both clinics for the same period. Analyses were performed using the minimum and maximum daily throughput to understand the effect of demand on price per sample collected. RESULTS: The respiratory clinic tested an average of 19 patients per day, at an estimated cost of $340.04 AUD. This varied to $687.99 AUD during the lowest demand scenario, and $281.04 AUD during the high demand scenario. The drive-through clinic tested an average of 47 patients per day, at an estimated cost of $153.57 AUD. This varied to $279.51 AUD during the lowest demand scenario, and $99.92 AUD during the high demand scenario. CONCLUSION: This study provides insight into the cost of testing at a drive through and respiratory clinic in Australia. The evidence highlights importance of considering variation in demand and the impact on efficiency, particularly where resource use is fixed in the short term.

Multi-site assessment of rapid, point-of-care antigen testing for the diagnosis of SARS-CoV-2 infection in a low-prevalence setting: A validation and implementation study.

BACKGROUND: In Australia, COVID-19 diagnosis relies on RT-PCR testing which is relatively costly and time-consuming. To date, few studies have assessed the performance and implementation of rapid antigen-based SARS-CoV-2 testing in a setting with a low prevalence of COVID-19 infections, such as Australia. METHODS: This study recruited participants presenting for COVID-19 testing at three Melbourne metropolitan hospitals during a period of low COVID-19 prevalence. The Abbott PanBioTM COVID-19 Ag point-of-care test was performed alongside RT-PCR. In addition, participants with COVID-19 notified to the Victorian Government were invited to provide additional swabs to aid validation. Implementation challenges were also documented. FINDINGS: The specificity of the Abbott PanBioTM COVID-19 Ag test was 99.96% (95% CI 99.73 - 100%). Sensitivity amongst participants with RT-PCR-confirmed infection was dependent upon the duration of symptoms reported, ranging from 77.3% (duration 1 to 33 days) to 100% in those within seven days of symptom onset. A range of implementation challenges were identified which may inform future COVID-19 testing strategies in a low prevalence setting. INTERPRETATION: Given the high specificity, antigen-based tests may be most useful in rapidly triaging public health and hospital resources while expediting confirmatory RT-PCR testing. Considering the limitations in test sensitivity and the potential for rapid transmission in susceptible populations, particularly in hospital settings, careful consideration is required for implementation of antigen testing in a low prevalence setting. FUNDING: This work was funded by the Victorian Department of Health and Human Services. The funder was not involved in data analysis or manuscript preparation.

Sociodemographic and geographical inequalities in notifiable infectious diseases in Australia: a retrospective analysis of 21 years of national disease surveillance data.

BACKGROUND: Australia is a high-income country with a well established and largely publicly funded health-care system. However, some populations within Australia have shorter life expectancy and worse health outcomes than others. We explored geographical variations and sociodemographic inequities in infectious disease notifications in Australia. METHODS: In this retrospective study, we analysed National Notifiable Diseases Surveillance System (NNDSS) notifications from 1991-2011 (n=2·4 million). We assessed the effect of socioeconomic disadvantage and remoteness of residence on national notification incidence. We calculated Gini coefficients, adjusted relative risks (aRRs), population attributable fractions (PAFs), and attributable notifications. We reported aRRs for Indigenous status in three jurisdictions with more than 75% completeness of Indigenous status reporting from the Northern Territory, South Australia, and Western Australia. FINDINGS: Of the eight most commonly notified diseases from Jan 1, 1991, to Dec 31, 2011, gonococcal infection was the most geographically unequal and campylobacteriosis was the most evenly distributed across the country. Overall, notification incidence was higher in remote and very remote areas than in major cities (aRR 3·37), and higher in the most socioeconomically disadvantaged quintiles compared with less disadvantaged quintiles (aRR 1·15). The PAF for socioeconomic disadvantage was high for blood-borne viral hepatitis but decreased in other disease groups. In 2011, sexually transmitted infections had 11 093 notifications attributed to remoteness and 5597 notifications attributable to socioeconomic disadvantage. Notification incidence was higher in Indigenous than in non-Indigenous Australians (aRR 5·3). INTERPRETATION: All diseases had differing geographical concentration and sociodemographic risk. Overall, sociodemographic inequities in infectious disease notifications have decreased, but remain unacceptably high. National communicable disease control is complex, requiring both targeted and population-wide interventions. FUNDING: None.

Imported infections: What information should be collected by surveillance systems to inform public health policy?

BACKGROUND: International travel carries the risk of imported diseases, which are an increasingly significant public health problem. There is little guidance about which variables should be collected by surveillance systems for strategy-based surveillance. METHODS: Surveillance forms for dengue, malaria, hepatitis A, typhoid and measles were collected from Australia and New Zealand and information on these compared with national surveillance forms from the UK and Canada by travel health experts. Variables were categorised by information relating to recent travel, demographics and disease severity. RESULTS: Travel-related information most commonly requested included country of travel, vaccination status and travel dates. In Australia, ethnicity information requested related to indigenous status, whilst in New Zealand it could be linked to census categories. Severity of disease information most frequently collected were hospitalisation and death. CONCLUSIONS: Reviewing the usefulness of variables collected resulted in the recommendation that those included should be: overseas travel, reason for travel, entry and departure dates during the incubation period, vaccination details, traveller's and/or parents' country of birth, country of usual residence, time resident in current country, postcode, hospitalisation and death details. There was no agreement about whether ethnicity details should be collected. The inclusion of these variables on surveillance forms could enable imported infection-related policy to be formulated nationally and internationally.

The global burden of dengue: an analysis from the Global Burden of Disease Study 2013.

BACKGROUND: Dengue is the most common arbovirus infection globally, but its burden is poorly quantified. We estimated dengue mortality, incidence, and burden for the Global Burden of Disease Study 2013. METHODS: We modelled mortality from vital registration, verbal autopsy, and surveillance data using the Cause of Death Ensemble Modelling tool. We modelled incidence from officially reported cases, and adjusted our raw estimates for under-reporting based on published estimates of expansion factors. In total, we had 1780 country-years of mortality data from 130 countries, 1636 country-years of dengue case reports from 76 countries, and expansion factor estimates for 14 countries. FINDINGS: We estimated an average of 9221 dengue deaths per year between 1990 and 2013, increasing from a low of 8277 (95% uncertainty estimate 5353-10 649) in 1992, to a peak of 11 302 (6790-13 722) in 2010. This yielded a total of 576 900 (330 000-701 200) years of life lost to premature mortality attributable to dengue in 2013. The incidence of dengue increased greatly between 1990 and 2013, with the number of cases more than doubling every decade, from 8·3 million (3·3 million-17·2 million) apparent cases in 1990, to 58·4 million (23·6 million-121·9 million) apparent cases in 2013. When accounting for disability from moderate and severe acute dengue, and post-dengue chronic fatigue, 566 000 (186 000-1 415 000) years lived with disability were attributable to dengue in 2013. Considering fatal and non-fatal outcomes together, dengue was responsible for 1·14 million (0·73 million-1·98 million) disability-adjusted life-years in 2013. INTERPRETATION: Although lower than other estimates, our results offer more evidence that the true symptomatic incidence of dengue probably falls within the commonly cited range of 50 million to 100 million cases per year. Our mortality estimates are lower than those presented elsewhere and should be considered in light of the totality of evidence suggesting that dengue mortality might, in fact, be substantially higher. FUNDING: Bill & Melinda Gates Foundation.