Figure 2.

SARS-CoV-2 surveillance and all-cause respiratory encounters in individuals aged ≥5 years. A, The percentage of respiratory samples testing positive for influenza, RSV, and SARS-CoV-2 from 2 syndromic respiratory illness surveillance programs in South Africa. B–D, Weekly all-cause respiratory consultations (including COVID-19) among individuals aged ≥5 years relative to the baseline number of consultations expected in the absence of COVID-19 at 3 levels of clinical severity: inpatient (B), outpatient–emergency department (C), and outpatient–general practitioner (D). The band is the 95% prediction interval of the projected seasonal baseline. The dashed line is the number of COVID-coded encounters. The vertical dashed line indicates the start of the model prediction period (1 March 2020), and panel colors indicate the pre-lockdown period (1 March 2020–26 March 2020) and lockdown alert levels from March 2020 to September 2021 (Table 1). Panels are shaded according to the stringency of lockdown measures: dark to light. The area between the projected seasonal baseline and observed consultations has dark shading when observed consultations are below baseline (“averted cases”) and light shading when observed consultations are above baseline (“excess cases”). See Supplementary Figure 8 for a closer view of the 2020–2021 time period. Abbreviations: COVID-19, coronavirus disease 2019; RSV, respiratory syncytial virus; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2.