Table 1.
Multivariable logistic regression analysis evaluating factors associated with SGTF versus non-SGTF SARS-CoV-2 infection, South Africa, Oct 1–Nov 30, 2021* (n=11 255)
| Non-SGTF† | SGTF† | Odds ratio (95% CI) | Adjusted odds ratio (95% CI) | p value | |
|---|---|---|---|---|---|
| Age group | |||||
| <5 years | 21/948 (2·2%) | 135/10 547 (1·3%) | 1·5 (0·9–2·4) | 1·0 (0·6–1·9) | 0·88 |
| 5–12 years | 41/948 (4·3%) | 581/10 547 (5·5%) | 3·2 (2·3–4·7) | 1·6 (1·0–2·5) | 0·033 |
| 13–18 years | 59/948 (6·2%) | 610/10 547 (5·8%) | 2·4 (1·7–3·3) | 1·8 (1·2–2·6) | 0·004 |
| 19–24 years | 88/948 (9·3%) | 1027/10 547 (9·7%) | 2·7 (2·0–3·6) | 2·6 (1·9–3·7) | <0·001 |
| 25–39 years | 305/948 (32·2%) | 4664/10 547 (44·2%) | 3·5 (2·8–4·3) | 2·8 (2·2–3·7) | <0·001 |
| 40–59 years | 283/948 (29·9%) | 2873/10 547 (27·2%) | 2·3 (1·9–2·9) | 1·7 (1·3–2·3) | <0·001 |
| ≥60 years | 151/948 (15·9%) | 657/10 547 (6·2%) | 1 (ref) | 1 (ref) | .. |
| Sex | |||||
| Male | 417/933 (44·7%) | 4612/10 471 (44·0%) | 1 (ref) | 1 (ref) | .. |
| Female | 516/933 (55·3%) | 5859/10 471 (56·0%) | 1·0 (0·9–1·2) | 1·1 (0·9–1·3) | 0·27 |
| Province | |||||
| Eastern Cape | 0 | 9/10 435 (0·1%) | .. | .. | .. |
| Free State | 67/918 (7·3%) | 55/10 435 (0·5%) | 0·6 (0·4–0·9) | 1·1 (0·7–1·7) | 0·71 |
| Gauteng | 424/918 (46·2%) | 9083/10 435 (87·0%) | 15·6 (12·2–20·0) | 12·1 (9·2–16·0) | <0·001 |
| KwaZulu-Natal | 197/918 (21·5%) | 337/10 435 (3·2%) | 1·2 (0·9–1·7) | 1·0 (0·7–1·3) | 0·81 |
| Limpopo | 12/918 (1·3%) | 245/10 435 (2·3%) | 14·9 (8·0–27·8) | 5·6 (2·9–10·7) | <0·001 |
| Mpumalanga | 10/918 (1·1%) | 231/10 435 (2·2%) | 16·9 (8·6–33·1) | 6·0 (3·0–12·0) | <0·001 |
| North West | 14/918 (1·5%) | 260/10 435 (2·5%) | 13·6 (7·6–24·3) | 6·6 (3·5–12·5) | <0·001 |
| Northern Cape | 67/918 (7·3%) | 41/10 435 (0·4%) | 0·4 (0·3–0·7) | 0·8 (0·5–1·3) | 0·41 |
| Western Cape | 127/918 (13·8%) | 174/10 435 (1·7%) | 1 (ref) | 1 (ref) | .. |
| Hospital admission | |||||
| No | 827/948 (87·2%) | 10 286/10 547 (97·5%) | 1 (ref) | 1 (ref) | .. |
| Yes | 121/948 (12·8%) | 261/10 547 (2·5%) | 0·2 (0·1–0·2) | 0·2 (0·1–0·3) | <0·001 |
| Health-care sector | |||||
| Public | 635/948 (67·0%) | 2391/10 547 (22·7%) | 1 (ref) | 1 (ref) | .. |
| Private | 313/948 (33·0%) | 8156/10 547 (77·3%) | 6·9 (6·0–8·0) | 5·4 (4·5–6·4) | <0·001 |
| Reinfection‡ | |||||
| No | 905/948 (95·5%) | 9447/10 547 (89·6%) | 1 (ref) | 1 (ref) | .. |
| Yes | 43/948 (4·5%) | 1100/10 547 (10·4%) | 2·5 (1·8–3·3) | 1·3 (0·9–1·9) | 0·18 |
Data are n/N (%), unless otherwise specified. SGTF=S gene target failure.
*
Patients with COVID-19 followed up for hospital admission until Dec 21, 2021.
†
SGTF was a proxy for the omicron variant (B.1.1.529).
‡
Reinfection was defined by an individual having at least one positive SARS-CoV-2 test more than 90 days before the current positive SARS-CoV-2 test.