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Table 2 Impact of clearance testing on contact tracing and quarantine strategies for a community of 1000 people

From: Modelling testing and response strategies for COVID-19 outbreaks in remote Australian Aboriginal communities

Strategy No clearance testing Clearance testing undertaken
  Total cumulative infections Quarantine person-days (first year) Total tests performed during outbreak (first year) Total cumulative infections Quarantine person-days (first year) Total tests performed during outbreak (first year)
No response 999 (999–999) N/A 447.0 (435.5, 458.0) 999 N/A N/A
Quarantine of immediate household contacts (with case isolation) 922.0 (907.5, 936.5) 29,595.5 (28,101.5–31,175.0) 1957.5 (1867–2027) 922.5 (905.0, 933.0) 22,500.5 (21,469.0–23,306.0) 7526.0 (7336–7743)
Quarantine of extended i.e. all household contacts (with case isolation) 831.5 (751.0, 871.0) 86,825.0 (70,334.5–97,662.5) 4042.5 (3463–4305) 655.0 (267.5, 821.0) 50,958.0 (13,511.5, 67,786.0) 13,551.5 (4929.5, 16,729.5)
Quarantine of close contacts based on history (past 2 days) 937.0 (929.0, 945.0) 10,776.5 (9551.5–11,564.5) 1530.5 (1441–1586) 930.5 (917.0, 939.5) 9445.5 (8541.5, 10,191.5) 4673.5 (4549.5, 4780.5)
Quarantine of all contacts based on history (past 2 days) 930.0 (917.0, 941.0) 11,887.0 (11,180.0–12,831.5) 1614.5 (1550–1667) 919.0 (904.5, 931.5) 10,662.0 (9718.0, 11,768.5) 4842.5 (4741.0, 4957.0)
  1. Size of outbreak (total cumulative infections), quarantine person-days (per 1000 population), and total tests performed during an outbreak are shown. Medians are reported, with interquartile ranges (in brackets) from 100 simulations. Note that ‘infections’ refers to all individuals with SARS-CoV-2 infection (whether tested and known to health services or not), whereas ‘cases’ refers to those with SARS-CoV-2 infection who have tested positive, i.e., have been identified. For all scenarios shown in the table, entry testing (which leads to further rounds of contact tracing, isolation and quarantine) is conducted upon entry to quarantine