The COVID-19 (SARS-CoV-2) Uncertainty Tripod in Brazil: Assessments on model-based predictions with large under-reporting

The paper formulates the “uncertainty tripod” qualitatively and via simulation/plots (if any two of {under-reporting of infections q_I, under-reporting of deaths q_D, true mortality ρ} are known, the third can be inferred), grounded in a multiplicative under-reporting model X_measured = q_X X_real and in the SIRASD definitions where ρ = p ρ_S at epidemic end. The candidate solution supplies the missing algebra: an odds-identity ρ_obs/(1−ρ_obs) = (q_D/q_I)·ρ/(1−ρ) and explicit rearrangements for any unknown. Both agree on required assumptions (constant q_I, q_D; evaluation near epidemic end; time-varying observed ratios otherwise). Thus, the paper’s result is correct but heuristic/incomplete; the model’s solution is correct and more explicit.