Fig. 2

Influence of testing (sampling) bias on estimates of disease spread and death rates for symptomatic patients is high for estimation of infection rate measured by active-viral tests, but mitigated in serological tests for acquired immunity. a The infection rates (fraction of population with an active infection) estimated from PCR (or sequencing) based strategy to measure active viral load; Red curve shows the true infection rate; Estimation of infection rates with different biases for H-compartment patients (those with higher disease manifestation) shown in green-black lines; Also shown are fractions calculated in eqs. b Estimation of contraction rates (fraction of population that has contracted the virus at a previous time, are either infected or recovered) from a serological test; Red line is true contraction rate; Green-black lines are estimated contraction rates with different sampling biases for patients with higher disease manifestation. c-d Estimates of death rate (percentage of fatalities within confirmed recovered and dead patients) from a biased sampling strategy for patients with high disease manifestation at different fractions (c) 15% of the infected population with 2% death rate obtained from previously published studies, and (d) 50% of the infected population with .5% death rate; Red lines refer to true death rate and green-black lines refer to biased estimates of death rates. e-f Estimates of case fatality rate (percentage of confirmed fatalities within positively tested population) from a biased sampling strategy as in C, and D for different fractions of population in H and L manifestation, as in c, and d. g-h Estimates of case fatality rate measured with serological testing from a biased sampling strategy for different fraction of populations in H and L manifestation, as in c, and d