Table 4.
Estimated Mean Annual Number and Rates of Influenza-associated Severe Illness (Excluding Deaths) in South Africa, 2013–2015
| Age Group | Influenza-associated Severe Illnessa | |||||
|---|---|---|---|---|---|---|
| Total | Medically Attended | Nonmedically Attended | ||||
| Number (95% CI) | Rateb (95% CI) | Number (95% CI) | Rateb (95% CI) | Number (95% CI) | Rateb (95% CI) | |
| All-respiratoryc | ||||||
| <1 | 13 829 (9469–18 951) | 1166.7 (798.9–1598.8) | 6373 (4610–8169) | 537.7 (388.9–689.2) | 7456 (4857–10 782) | 629.0 (409.8–909.6) |
| 1–4 | 13 049 (8669–18 427) | 283.1 (188.1–399.8) | 6030 (4185–7942) | 130.8 (90.8–172.3) | 7019 (4483–10 486) | 152.3 (97.3–227.5) |
| 5–24 | 8737 (4025–14 941) | 44 (20.3–75.2) | 4054 (1978–6522) | 20.4 (10.0–32.8) | 4683 (2046–8441) | 23.6 (10.3–42.5) |
| 25–44 | 20 147 (14 043–28 167) | 119.8 (83.5–167.6) | 9390 (6850–12 365) | 55.9 (40.7–73.6) | 10 757 (7177–15 805) | 64.0 (42.7–94) |
| 45–64 | 15 329 (9709–22 215) | 177.9 (112.7–257.8) | 7073 (4640–9610) | 82.1 (53.8–111.5) | 8256 (5059–12 611) | 95.8 (58.7–146.3) |
| ≥65 | 12 850 (5811–21 710) | 425.9 (192.6–719.6) | 5861 (2752–9538) | 194.3 (91.2–316.2) | 6989 (3055–12 177) | 231.7 (101.3–403.6) |
| <5 | 26 878 (18 140–37 371) | 463.8 (313.0–644.9) | 12 403 (8797–16 110) | 214.0 (151.8–278.0) | 14 475 (9336–21 265) | 249.8 (161.1–367.0) |
| ≥5 | 57 063 (33 499–87 053) | 118.1 (69.4–180.2) | 26 378 (16 208–38 046) | 54.6 (33.6–78.8) | 30 685 (17 332–49 023) | 63.5 (35.9–101.5) |
| All | 83 941 (51 604–124 594) | 155.2 (95.4–230.3) | 38 781 (24 978–54 283) | 71.7 (46.2–100.3) | 45 160 (26 620–70 329) | 83.5 (49.2–130.0) |
| All-circulatoryd | ||||||
| <1 | 282 (224–671) | 23.8 (18.9–56.6) | 189 (150–449) | 15.9 (12.7–37.9) | 93 (74–221) | 7.8 (6.2–18.6) |
| 1–4 | 339 (297–415) | 7.4 (6.4–9) | 227 (199–278) | 4.9 (4.3–6.0) | 112 (98–137) | 2.4 (2.1–3.0) |
| 5–24 | 326 (186–745) | 1.6 (0.9–3.8) | 140 (80–320) | 0.7 (0.4–1.6) | 186 (106–425) | 0.9 (0.5–2.1) |
| 25–44 | 3202 (1774–5063) | 19.0 (10.6–30.1) | 1377 (763–2177) | 8.2 (4.5–13.0) | 1825 (1011–2885) | 10.9 (6–17.2) |
| 45–64 | 3570 (2273–9116) | 41.4 (26.4–105.8) | 1535 (977–3920) | 17.8 (11.3–45.5) | 2035 (1296–5197) | 23.6 (15.0–60.3) |
| ≥65 | 5974 (2324–10 481) | 198.0 (77.0–347.4) | 2569 (1000–4507) | 85.2 (33.1–149.4) | 3405 (1325–5974) | 112.9 (43.9–198.0) |
| <5 | 621 (522–1080) | 10.7 (9.0–18.6) | 416 (350–723) | 7.2 (6.0–12.5) | 205 (172–357) | 3.5 (3.0–6.2) |
| ≥5 | 13 072 (6446–25 722) | 27.1 (13.3–53.3) | 5621 (2772–11 061) | 11.6 (5.7–22.9) | 7451 (3674–14 662) | 15.4 (7.6–30.4) |
| All | 13 693 (6813–26 785) | 25.3 (12.6–49.5) | 6037 (3004–11 809) | 11.2 (5.6–21.8) | 7656 (3809–14 976) | 14.2 (7.0–27.7) |
| Nonrespiratory and noncirculatoryd | ||||||
| <1 | 4272 (2285–5625) | 360.4 (192.8–474.6) | 1837 (982–2419) | 155 (82.8–204.1) | 2435 (1302–3206) | 205.4 (109.8–270.5) |
| 1–4 | 1644 (600–1888) | 35.7 (13.0–41.0) | 707 (258–812) | 15.3 (5.6–17.6) | 937 (342–1076) | 20.3 (7.4–23.3) |
| 5–24 | 2542 (2217–4381) | 12.8 (11.2–22.1) | 915 (798–1577) | 4.6 (4.0–7.9) | 1627 (1419–2804) | 8.2 (7.1–14.1) |
| 25–44 | 12 764 (8299–23 732) | 75.9 (49.4–141.2) | 4595 (2988–8544) | 27.3 (17.8–50.8) | 8169 (5311–15 189) | 48.6 (31.6–90.4) |
| 45–64 | 5175 (2500–9891) | 60.0 (29–114.8) | 1863 (900–3561) | 21.6 (10.4–41.3) | 3312 (1600–6330) | 38.4 (18.6–73.5) |
| ≥65 | 4142 (1638–8696) | 137.3 (54.3–288.2) | 1491 (590–3130) | 49.4 (19.6–103.8) | 2651 (1048–5566) | 87.9 (34.7–184.5) |
| <5 | 5916 (2882–7579) | 102.1 (49.7–130.8) | 2544 (1239–3259) | 43.9 (21.4–56.2) | 3372 (1643–4320) | 58.2 (28.4–74.6) |
| ≥5 | 24 623 (13 447–47 792) | 51.0 (27.8–98.9) | 8864 (4841–17 205) | 18.4 (10.0–35.6) | 15 759 (8606–30 588) | 32.6 (17.8–63.3) |
| All | 30 539 (16 395–56 578) | 56.5 (30.3–104.6) | 11 408 (6124–21 135) | 21.1 (11.3–39.1) | 19 131 (10 270–35 443) | 35.4 (19.0–65.5) |
| All | ||||||
| <1 | 18 383 (11 976–25 245) | 1550.9 (1010.4–2129.8) | 8399 (5742–11 035) | 708.6 (484.4–931.0) | 9984 (6232–14 208) | 842.3 (525.8–1198.7) |
| 1–4 | 15 032 (9569–20 735) | 326.1 (207.6–449.8) | 6964 (4644–9035) | 151.1 (100.8–196.0) | 8068 (4925–11 702) | 175.0 (106.8–253.9) |
| 5–24 | 11 605 (6430–20 074) | 58.4 (32.4–101.1) | 51,09 (2857–8422) | 25.7 (14.4–42.4) | 6496 (3572–11 674) | 32.7 (18.0–58.8) |
| 25–44 | 36 113 (24 132–56 993) | 214.8 (143.6–339.0) | 15 362 (10 609–23 100) | 91.4 (63.1–137.4) | 20 751 (13 506–33 895) | 123.4 (80.3–201.6) |
| 45–64 | 24 074 (14 499–41 263) | 279.3 (168.2–478.8) | 10 471 (6527–17 110) | 121.5 (75.7–198.5) | 13 603 (7963–24 159) | 157.8 (92.4–280.3) |
| ≥65 | 22 966 (9789–40 946) | 761.3 (324.5–1357.2) | 9921 (4350–17 203) | 328.9 (144.2–570.2) | 13 045 (54,35–23 748) | 432.4 (180.2–787.2) |
| <5 | 33 415 (21 545–46 033) | 576.7 (371.8–794.4) | 15 363 (10 386–20 094) | 265.1 (179.2–346.8) | 18 052 (11 152–25 943) | 311.5 (192.5–447.7) |
| ≥5 | 94 758 (53 445–160 703) | 196.2 (110.6–332.7) | 40 863 (23 848–66 376) | 84.6 (49.4–137.4) | 53 895 (29 637–94 345) | 111.6 (61.4–195.3) |
| All | 128 173 (74 868–208 092) | 236.9 (138.4–384.7) | 56 226 (34 135–87 290) | 103.9 (63.1–161.4) | 71 947 (40 726–120 820) | 133.0 (75.3–223.3) |
Abbreviation: CI, confidence interval.
a
Severe illness is defined as requiring hospitalization, excluding deaths.
b
Rates expressed are per 100 000 individuals in the population.
c
Obtained from case-based surveillance at 5 facilities and extrapolated nationally.
d
Obtained using ratios of respiratory to nonrespiratory (ie, circulatory or nonrespiratory/noncirculatory), from ecological studies.