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. 2020 Jun 24;222(5):715–718. doi: 10.1093/infdis/jiaa352

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© The Author(s) 2020. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.

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Figure 1. — Positive predictive value (PPV) of a serological test (y-axis) at varying levels of population infection prevalence (x-axis), for tests with different sensitivity and specificity profiles. The PPV indicates the probability that an individual who tests positive truly has been infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). For a test with 95% sensitivity and 95% specificity (dashed line), if population infection prevalence is 5%, there is a 50% chance that an individual who tests positive truly has been infected (and a 50% chance that the result is a false positive).