Fig. 1.

Illustration and fitting fecal viral shedding dynamics. (A) Illustration of the fecal viral shedding dynamics based on the infection progression. The viral shedding profile is divided into three periods shaded: Exposed (E), Infectious (I), and Recovered (R). The red-shaded region is the period of infectiousness I, which is corresponding to the compartment I in the SEIR model. (B) Fitting of the proposed viral shedding function to viral shedding in hospitalized patients' stool data from (Wolfel et al. 2020). While aggregated data seem to show a viral shedding peak at around day 13–14, declining trends were found in the 9 individual cases. The average viral shedding rate in stool during the infectious period (from day 3 to day 11) is 4.49 × 10⁷ viral RNA per g. The horizontal dashed line is the average fecal viral shedding rate for infectious individuals inferred from the model. The viral shedding peak is set at the 4th day post infection.