Equitable access to COVID-19 diagnostics: factors associated with the uptake of rapid antigen testing in Victoria, Australia, January – February 2022

Abstract Background Accessible and accurate diagnostics are critical to control communicable diseases. Uptake of COVID-19 rapid antigen (RA) testing requires physical and financial access to tests, knowledge about usage, motivation, and ability to report results. We sought to understand patterns of and factors associated with RA test uptake in Victoria during a period of high caseload, RA test promotion, and difficulty accessing RA and PCR testing. We hypothesise RA test uptake is indicated by the ratio of cases diagnosed by RA test (probable) to those diagnosed using PCR (confirmed) (p:c). Methods Analysing case records, trends in p:c were assessed, between regions, sex, age groups, socio-economic strata and cultural diversity. Logistic regression assessed associations between case classification, and median age, postcode-level socio-economic disadvantage, and proportion overseas-born. Results We included 591,789 cases. Mean p:c was lower in socio-economically disadvantaged areas (decile 1 + 2: 0.90 vs. decile 9 + 10: 1.10), and in postcodes where the overseas-born population was above the Victorian average (0.83 vs. 1.05). Conversely, p:c was higher in younger age groups; with no difference between sexes overall. In metropolitan Melbourne, odds of RA test usage increased as socio-economic disadvantage decreased (decile 9 + 10, aOR 1.40, 95%CI 1.37–1.43, vs. decile 1 + 2; p < .001), decreased for cases from areas with a higher overseas-born population (aOR 0.85, 0.83–0.86, p < .001), and with older age. Conclusions Reduced uptake of RA tests in Victoria is associated with socio-economic disadvantage, cultural diversity, and older age. Equitable access to COVID-19 diagnostics requires elimination of financial barriers, and greater engagement with culturally diverse and older groups. Inequitable RA test uptake may lead to case under-ascertainment, affecting resource allocation, effective control strategy development, in turn impacting COVID-19 morbidity and mortality, and could indicate relative engagement with response initiatives

Additional file 1 of Equitable access to COVID-19 diagnostics: factors associated with the uptake of rapid antigen testing in Victoria, Australia, January – February 2022

Supplementary Material

National reporting of deaths after enhanced Ebola surveillance in Sierra Leone.

BACKGROUND:Sierra Leone experienced the largest documented epidemic of Ebola Virus Disease in 2014-2015. The government implemented a national tollfree telephone line (1-1-7) for public reporting of illness and deaths to improve the detection of Ebola cases. Reporting of deaths declined substantially after the epidemic ended. To inform routine mortality surveillance, we aimed to describe the trends in deaths reported to the 1-1-7 system and to quantify people's motivations to continue reporting deaths after the epidemic. METHODS:First, we described the monthly trends in the number of deaths reported to the 1-1-7 system between September 2014 and September 2019. Second, we conducted a telephone survey in April 2017 with a national sample of individuals who reported a death to the 1-1-7 system between December 2016 and April 2017. We described the reported deaths and used ordered logistic regression modeling to examine the potential drivers of reporting motivations. FINDINGS:Analysis of the number of deaths reported to the 1-1-7 system showed that 12% of the expected deaths were captured in 2017 compared to approximately 34% in 2016 and over 100% in 2015. We interviewed 1,291 death reporters in the survey. Family members reported 56% of the deaths. Nearly every respondent (94%) expressed that they wanted the 1-1-7 system to continue. The most common motivation to report was to obey the government's mandate (82%). Respondents felt more motivated to report if the decedent exhibited Ebola-like symptoms (adjusted odds ratio 2.3; 95% confidence interval 1.8-2.9). CONCLUSIONS:Motivation to report deaths that resembled Ebola in the post-outbreak setting may have been influenced by knowledge and experiences from the prolonged epidemic. Transitioning the system to a routine mortality surveillance tool may require a robust social mobilization component to match the high reporting levels during the epidemic, which exceeded more than 100% of expected deaths in 2015

Genomics-informed responses in the elimination of COVID-19 in Victoria, Australia: an observational, genomic epidemiological study.

BACKGROUND: A cornerstone of Australia's ability to control COVID-19 has been effective border control with an extensive supervised quarantine programme. However, a rapid recrudescence of COVID-19 was observed in the state of Victoria in June, 2020. We aim to describe the genomic findings that located the source of this second wave and show the role of genomic epidemiology in the successful elimination of COVID-19 for a second time in Australia. METHODS: In this observational, genomic epidemiological study, we did genomic sequencing of all laboratory-confirmed cases of COVID-19 diagnosed in Victoria, Australia between Jan 25, 2020, and Jan 31, 2021. We did phylogenetic analyses, genomic cluster discovery, and integrated results with epidemiological data (detailed information on demographics, risk factors, and exposure) collected via interview by the Victorian Government Department of Health. Genomic transmission networks were used to group multiple genomic clusters when epidemiological and genomic data suggested they arose from a single importation event and diversified within Victoria. To identify transmission of emergent lineages between Victoria and other states or territories in Australia, all publicly available SARS-CoV-2 sequences uploaded before Feb 11, 2021, were obtained from the national sequence sharing programme AusTrakka, and epidemiological data were obtained from the submitting laboratories. We did phylodynamic analyses to estimate the growth rate, doubling time, and number of days from the first local infection to the collection of the first sequenced genome for the dominant local cluster, and compared our growth estimates to previously published estimates from a similar growth phase of lineage B.1.1.7 (also known as the Alpha variant) in the UK. FINDINGS: Between Jan 25, 2020, and Jan 31, 2021, there were 20 451 laboratory-confirmed cases of COVID-19 in Victoria, Australia, of which 15 431 were submitted for sequencing, and 11 711 met all quality control metrics and were included in our analysis. We identified 595 genomic clusters, with a median of five cases per cluster (IQR 2-11). Overall, samples from 11 503 (98.2%) of 11 711 cases clustered with another sample in Victoria, either within a genomic cluster or transmission network. Genomic analysis revealed that 10 426 cases, including 10 416 (98.4%) of 10 584 locally acquired cases, diagnosed during the second wave (between June and October, 2020) were derived from a single incursion from hotel quarantine, with the outbreak lineage (transmission network G, lineage D.2) rapidly detected in other Australian states and territories. Phylodynamic analyses indicated that the epidemic growth rate of the outbreak lineage in Victoria during the initial growth phase (samples collected between June 4 and July 9, 2020; 47.4 putative transmission events, per branch, per year [1/years; 95% credible interval 26.0-85.0]), was similar to that of other reported variants, such as B.1.1.7 in the UK (mean approximately 71.5 1/years). Strict interventions were implemented, and the outbreak lineage has not been detected in Australia since Oct 29, 2020. Subsequent cases represented independent international or interstate introductions, with limited local spread. INTERPRETATION: Our study highlights how rapid escalation of clonal outbreaks can occur from a single incursion. However, strict quarantine measures and decisive public health responses to emergent cases are effective, even with high epidemic growth rates. Real-time genomic surveillance can alter the way in which public health agencies view and respond to COVID-19 outbreaks. FUNDING: The Victorian Government, the National Health and Medical Research Council Australia, and the Medical Research Future Fund