Table 1.
Summary of COVID-19 cases and estimates by epidemic wave
| Variable | 1st wave (Summer 2020) | 2nd wave (Winter 2020) | 3rd wave (Summer 2021) | 4th wave (Winter 2021) | 5th wave (Summer 2022) | All waves |
|---|---|---|---|---|---|---|
| Number of cases | ||||||
| Suspected cases (A) | 839,120 | 1,789,867 | 2,220,692 | 2,271,708 | 1,662,178 | 8,783,565 |
| Suspected cases with laboratory test (B) | 475,238 | 1,364,011 | 2,118,935 | 1,988,949 | 1,555,062 | 7,502,195 |
| Confirmed cases (C) | 264,792 | 549,962 | 762,884 | 1,047,624 | 771,113 | 3,396,375 |
| Hospitalized cases (D) | 105,681 | 143,977 | 75,836 | 34,648 | 13,504 | 373,646 |
| Intubated cases (E) | 27,437 | 29,899 | 15,078 | 3,804 | 711 | 76,929 |
| In-hospital deaths (F) | 47,835 | 73,160 | 33,088 | 12,021 | 2395 | 168,499 |
| Estimations | ||||||
| Testing percentage among suspected cases [B/Ax100] % (95% CI)* | 56.6 (56.5, 56.7) | 76.2 (76.1, 76.3) | 95.4 (95.4, 95.4) | 87.6 (87.5, 87.6) | 93.6 (93.5, 93.6) | 85.4 (85.4, 85.4) |
| Positivity percentage among tested cases [C/Bx100] % (95% CI)* | 55.7 (55.6, 55.9) | 40.3 (40.2, 40.4) | 36 (35.9, 36.1) | 52.7 (52.6, 52.7) | 49.6 (49.5, 49.7) | 45.3 (45.2, 45.3) |
| Hospitalization among confirmed cases [D/Cx100] % (95% CI)* | 39.9 (39.7, 40.1) | 26.2 (26.1, 26.3) | 9.9 (9.9, 10) | 3.3 (3.3, 3.3) | 1.8 (1.7, 1.8) | 11.0 (10.9, 11.1) |
| Intubation among hospitalized [E/Dx100] % (95% CI)* | 26.0 (25.7, 26.2) | 20.8 (20.6, 21) | 19.9 (19.6, 20.2) | 11 (10.7, 11.3) | 5.3 (4.9, 5.7) | 20.6 (20.5, 20.7) |
| Hospital case fatality rate [F/Dx100] % (95% CI)* | 45.3 (45.0, 45.6) | 50.8 (50.6, 51.1) | 43.6 (43.3, 44) | 34.7 (34.2, 35.2) | 17.7 (17.1, 18.4) | 45.1 (44.9, 45.3) |
| Mean days of hospital admission delay (95% CI)** | 4.55 (4.52, 4.57) | 5.75 (5.73, 5.77) | 5.79 (5.76, 5.82) | 3.48 (3.44, 3.52) | 2.02 (1.98, 2.06) | 5.07 (5.06,5.09) |
| Mean in-hospital days (95% CI)** | 9.59 (9.54, 9.63) | 9.33 (9.29, 9.37) | 9.09 (9.04, 9.15) | 7.83 (7.75, 7.9) | 6.41 (6.31, 6.51) | 9.11 (9.09, 9.13) |
Epidemic waves correspond to the following onset of symptoms periods: the first wave from week 2020-14 to week 2020-40 (from March 29th, 2020 to October 3rd, 2020); the second wave from week 2020-41 until week 2021-21 (from October 4th, 2020 to May 29th, 2021); the third wave from week 2021-22 to week 2021-50 (from May 30th, 2021 until December 18th, 2021); the fourth wave from week 2021-51 to 2022-17 (from December 19th, 2021 to April 30th, 2022); and fifth wave from week 2022-18 to week 2022-34 (from May 1st, 2022 until August 27th, 2022)
Estimations with 95% confidence intervals (95%CI) are shown. *p < 0.001 by Chi-square trend test. **p < 0.001 by one-way ANOVA. Statistically significant results are shown in bold text