Table 1.
Estimated mean annual rates of influenza‐associated influenza‐like‐illness, severe acute respiratory illness (symptom duration ≤10 days) and severe chronic respiratory illness (symptom duration >10 days) among any patient (irrespective of HIV serostatus), Klerksdorp and Pietermaritzburg, South Africa, 2013‐2015
| Age group (in years) | Influenza‐associated respiratory illness ratesa (95% CI) | ||
|---|---|---|---|
| Unadjustedb | AF‐adjustedc | Rate differenced (% reduction) | |
| Influenza‐like illness | |||
| <1 | 1282.1 (1158.7‐1416.5) | 1207.0 (1087.1‐1337.2) | ‐75.1 (5.9) |
| 1‐4 | 1452.8 (1386.3‐1522.4) | 1313.2(1249.6‐1389.0) | ‐139.6 (9.6) |
| 5‐24 | 1938.8 (1823.6‐2024.6) | 1747.9 (1712.5‐1883.6) | ‐190.9 (9.9) |
| 25‐44 | 1471.1 (1381.2‐1453.6) | 1308.7 (1274.4‐1443.9) | ‐108.4 (7.6) |
| 45‐64 | 678.8 (643.2‐715.9) | 629.5 (595.0‐665.1) | ‐49.3 (7.3) |
| ≥65 | 193.3 (157.9‐236.0) | 178.0 (143.9‐218.9) | ‐15.3 (7.9) |
| <5 | 1418.7 (1359.3‐1479.5) | 1292.0 (1235.6‐1360.3) | ‐126.7 (8.9) |
| ≥5 | 1473.9 (1452.2‐1495.7) | 1342.6 (1321.9‐1463.4) | ‐131.3 (8.9) |
| All | 1467.7 (1447.3‐1488.2) | 1336.9 (1317.5‐1456.5) | ‐130.8 (8.9) |
| Severe acute respiratory illness (SARI‐10) | |||
| <1 | 433.6 (362.3‐513.6) | 404.2 (335.4‐481.5) | ‐29.4 (6.8) |
| 1‐4 | 108.5 (91.2‐129.1) | 94.2 (77.8‐113.1) | ‐14.3(13.2) |
| 5‐24 | 10.8 (8.2‐14.0) | 9.0 (6.6‐11.9) | ‐1.8(16.2) |
| 25‐44 | 45.3 (39.2‐53.3) | 40.0 (34.1‐46.4) | ‐5.3(11.6) |
| 45‐64 | 62.1 (51.6‐74.0) | 55.7 (45.7‐66.9) | ‐6.4 (10.4) |
| ≥65 | 91.0 (67.0‐121.3) | 82.9 (60.4‐112.4) | ‐8.1(8.9) |
| <5 | 173.5 (153.4‐195.9) | 156.1 (136.8‐177.1) | ‐17.4 (10.0) |
| ≥5 | 34.7 (31.4‐38.2) | 30.7 (27.7‐34.0) | ‐4.0 (11.6) |
| All | 50.3 (46.6‐54.2) | 44.8 (41.3‐48.5) | ‐5.5 (11.0) |
| Severe Chronic respiratory illness (SCRI‐10) | |||
| <1 | 37.0 (18.0‐64.6) | 32.6 (15.7‐60.3) | ‐4.4 (11.9) |
| 1‐4 | 10.5 (5.7‐18.2) | 8.9 (4.5‐16.1) | ‐1.6 (15.5) |
| 5‐24 | 9.6 (7.1‐12.5) | 7.8 (5.7‐10.6) | ‐1.8 (19.4) |
| 25‐44 | 35.2 (29.7‐41.3) | 29.3 (24.4‐35.1) | ‐5.9 (16.6) |
| 45‐64 | 48.1 (38.9‐58.7) | 39.8 (31.3‐49.3) | ‐8.3 (17.4) |
| ≥65 | 102.9 (77.0‐134.5) | 90.8 (67.0‐49.3) | ‐12.1 (11.7) |
| <5 | 15.8 (10.1‐23.4) | 13.6 (8.5‐21.0) | ‐2.2 (13.8) |
| ≥5 | 28.9 (25.9‐32.1) | 24.1 (21.4‐27.0) | ‐4.8 (16.5) |
| All | 27.4 (24.7‐30.3) | 22.9 (20.4‐25.6) | ‐4.5 (16.3) |
CI, confidence intervals; AF, attributable fraction.
a
Rates expressed per 100,000 population.
b
Estimated rates without adjustment for the attributable fraction.
c
Estimated rates adjusted by the attributable fraction.
d
Unadjusted minus attributable fraction‐adjusted rates.