Fig. 3: Detection rate and incidence.
From: Underdetection of cases of COVID-19 in France threatens epidemic control
a, Projected number of new symptomatic cases over time (median and 95% confidence interval) and estimated number of virologically confirmed symptomatic cases by week of onset (points) in mainland France (left y axis). The estimated detection rate of symptomatic cases (%) is also shown (red points, median and 95% confidence interval; right y axis). b, Estimated detection rate of symptomatic cases (%) and 95% confidence intervals over time for mainland France (red dots and bars), and for all regions (grey lines, only median values are shown for visualization). c, Map of the estimated detection rate (%) by region in week 26 (22–28 June 2020). d, Estimated detection rate per region compared to the national estimate. Regions are ranked by increasing median detection rate. Box plots represent the median (line in the middle of the box), interquartile range (box limits) and 2.5th and 97.5th percentiles (whiskers). e, Predicted percentage of the population infected (median and 95% confidence interval) compared with estimates from the serological study EpiCov26 performed on a representative sample of the population in mainland France. f, Estimated detection rate of symptomatic cases (%) by region and by week compared with the projected incidence by region and by week. The curve shows the result of a least-square fit to the data with a power-law function, π = a × i−b, where π is the detection rate (expressed as a percentage), i is the weekly incidence (cases per 100,000), a = 66 (95% confidence interval, 52–85) and b = 0.51 (0.41–0.60). g, Estimated incidence of symptomatic cases and 95% confidence intervals in mainland France in week 26 from different sources: virological surveillance data (SI-DEP), participatory surveillance data (COVIDnet.fr, with two estimates) and model projections. h, Projected incidence per region compared to the national estimate. Regions are ranked as in d. Box plots are as defined in d. In all panels, medians and 95% confidence intervals for model projections were obtained from n = 500 independent stochastic runs.
