Table 5.
Estimated relative risk (RR) associated with HIV infection for influenza‐associated influenza‐like illness, severe acute respiratory illness (symptom duration ≤10 or ≤7 days), and severe chronic respiratory illness (symptom duration >10 or >7 days), Klerksdorp and Pietermaritzburg, South Africa, 2013‐2015
| Influenza‐associated respiratory illness RRa (95% CI) | ||||||
|---|---|---|---|---|---|---|
| Age group (in years) | Symptoms duration cutoff: 10 days | Symptoms duration cutoff: 7 days | ||||
| Unadjustedb | AF‐adjustedc | RR % increased | Unadjustedb | AF‐adjustedc | RR % increased | |
| Influenza‐like illness | ||||||
| <1 | 1.1 (0.4‐3.1) | 1.2 (0.4‐3.2) | 4.6 | N/A | N/A | N/A |
| 1‐4 | 1.1 (0.8‐1.5) | 1.2 (0.8‐1.6) | 4.8 | N/A | N/A | N/A |
| 5‐24 | 1.4 (1.3‐1.5) | 1.5 (1.4‐1.6) | 4.1 | N/A | N/A | N/A |
| 25‐44 | 3.4 (3.2‐3.6) | 3.7 (3.5‐3.9) | 8.9 | N/A | N/A | N/A |
| 45‐64 | 2.6 (2.3‐2.9) | 2.7 (2.4‐3.0) | 4.2 | N/A | N/A | N/A |
| ≥65 | 2.2 (0.9‐4.8) | 2.3 (1.1‐5.1) | 4.9 | N/A | N/A | N/A |
| <5e | 1.1 (0.8‐1.5) | 1.1 (0.8‐1.6) | 4.4 | N/A | N/A | N/A |
| ≥5f | 2.4 (2.3‐2.5) | 2.5 (2.4‐2.6) | 6.2 | N/A | N/A | N/A |
| Allg | 2.3 (2.2‐2.4) | 2.4 (2.3‐2.6) | 6.0 | N/A | N/A | N/A |
| Severe acute respiratory illness | ||||||
| <1 | 1.5 (0.3‐6.7) | 1.6 (0.3‐7.9) | 1.2 | 1.6 (0.3‐7.7) | 1.6 (0.3‐8.3) | 0.9 |
| 1‐4 | 4.7 (2.5‐8.7) | 4.9 (2.5‐9.4) | 4.3 | 4.9 (2.6‐9.3) | 5.2 (2.7‐10.2) | 6.5 |
| 5‐24 | 10.3 (6.1‐17.4) | 11.8 (6.7‐20.9) | 15.0 | 11.3 (6.6‐19.2) | 12.5 (7.0‐22.2) | 10.7 |
| 25‐44 | 14.5 (9.5‐21.9) | 17.1 (10.7‐27.3) | 18.4 | 26.1 (10.4‐65.3) | 30.8 (10.9‐87.6) | 18.4 |
| 45‐64 | 14.1 (9.3‐21.6) | 15.7 (9.9‐24.8) | 6.5 | 6.3 (3.2‐12.3) | 6.6 (3.2‐13.7) | 5.5 |
| ≥65 | 7.8 (3.8‐15.8) | 7.8 (3.7‐16.5) | 0.6 | 7.9 (2.7‐22.9) | 8.2 (2.7‐24.5) | 3.0 |
| <5e | 3.6 (2.0‐6.3) | 3.6 (2.0‐6.6) | 4.1 | 3.8 (2.1‐6.8) | 3.9 (2.1‐7.3) | 6.1 |
| ≥5f | 12.5 (9.9‐15.8) | 13.8 (10.8‐17.7) | 15.5 | 11.1 (7.9‐15.6) | 12.1 (8.4‐17.4) | 15.2 |
| Allg | 9.7 (8.0‐11.8) | 10.4 (8.5‐12.7) | 15.4 | 7.9 (6.1‐10.3) | 8.4 (6.4‐11.1) | 14.9 |
| Severe chronic respiratory illness | ||||||
| <1 | 2.5 (0.1‐142.3) | 2.5 (0.1‐183.0) | 0.9 | 1.3 (0.1‐39.1) | 1.3 9 (0.1‐40.2) | 0.9 |
| 1‐4 | 8.1 (1.6‐40.6) | 8.6 (1.5‐47.7) | 5.4 | 5.2 (1.3‐20.7) | 5.3 (1.2‐22.5) | 1.3 |
| 5‐24 | 5.4 (2.9‐9.9) | 5.9 (3.0‐11.5) | 8.9 | 5.1 (2.8‐9.2) | 5.4 (2.9‐10.2) | 7.5 |
| 25‐44 | 26.6 (14.6‐48.5) | 32.2 (15.8‐65.5) | 20.8 | 16.9 (11.8‐24.3) | 22.1 (14.3‐34.0) | 30.7 |
| 45‐64 | 8.4 (5.5‐12.9) | 8.5 (5.3‐13.6) | 1.5 | 12.9 (9.2‐18.0) | 13.8 (9.6‐19.8) | 7.5 |
| ≥65 | 6.2 (3.0‐12.8) | 6.3 (2.9‐13.6) | 1.9 | 6.7 (3.7‐11.9) | 6.8 (3.7‐12.5) | 2.3 |
| <5e | 6.3 (1.4‐27.3) | 6.5 (1.4‐31.1) | 5.1 | 3.6 (1.1‐13.0) | 3.6 (1.1‐13.5) | 1.3 |
| ≥5f | 10.2 (7.9‐13.0) | 10.7 (8.2‐14.0) | 17.1 | 11.4 (9.4‐13.8) | 12.6 (10.3‐15.6) | 20.9 |
| Allg | 10.0 (7.9‐12.7) | 10.5 (8.1‐13.7) | 16.4 | 10.9 (9.1‐13.2) | 12.0 (9.8‐14.7) | 20.1 |
RR, relative risk; CI, confidence intervals; AF, attributable fraction.
HIV‐infected vs HIV‐uninfected
Estimated relative risk without adjustment for the attributable fraction.
Estimated relative risk adjusted by the attributable fraction.
Attributable fraction‐adjusted vs unadjusted relative risk.
RR and RR percent increase adjusted by age with the following categories: <1 and 1‐4 years.
RR and RR percent increase adjusted by age with the following categories: 5‐24, 25‐44, 45‐64, and ≥65 years.
RR and RR percent increase adjusted by age with the following categories: <1, 1‐4, 5‐24, 25‐44, 45‐64, and ≥65 years.