Antibody tests for SARS-CoV-2 are difficult to interpret. Numerous health experts agree that the tests, which browse a blood sample for signs of past infection, are key to reopening the economy, computing the real death rate of Covid-19, and approximating how close we may be to “herd resistance.”
But the results can be deceptive, even when the test carries out as marketed ( which is typically not the case). The difficulty is, when the occurrence of an infection in a population is low, the overall variety of individuals who receive incorrect positives can match and even surpass the number receiving true positives.
The real frequency of infections has a huge effect on these predictive values. See on your own: Attempt running the simulation with various occurrence rates, but without changing specificity or level of sensitivity.
To start, here are a few of the prevalence estimates to emerge from early United States antibody surveys, or serology studies: 2.8%to 5.6%in Los Angeles; 2.49%to 4.16%in Santa Clara; 6%in Miami; 20%in New York City Or attempt the WHO’s international price quote, 2%to 3%.
You can likewise attempt tweaking the se