TABLE 1.
Epidemiological and virological characteristics, and outcome of 1159 enrolled severe acute respiratory infection patients, Bahrain, 2018–2021.
| Patient characteristics | Total patients (n = 1159) | Ventilation | ICU admission | Death | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Count | Column N % | OR (CI) | P value | OR (CI) | P value | OR (CI) | P value | |||
| Demographics | Sex | Male | 674 | 58.2% | 1.2 (0.8–1.8) | 0.313 | 0.8 (0.6–1.1) | 0.216 | 1.1 (0.7–1.8) | 0.554 |
| Female | 485 | 41.8% | ||||||||
| Age | <50 | 731 | 63.1% | 1.6 (1.1–2.4) | 0.019 | 0.9 (0.7–1.3) | 0.667 | 3.1 (1.9–4.9) | <0.001* | |
| ≥50 | 428 | 36.9% | ||||||||
| Vaccination | Seasonal influenza vaccine | No | 1134 | 97.8% | 0.4 (0.1–2.9) | 0.361 | 0.7 (0.2–2.4) | 0.601 | ‐ | ‐ |
| Yes | 25 | 2.2% | ||||||||
| Antiviral use | Antiviral use | No | 1029 | 88.8% | 2.2 (1.3–3.6) | 0.003 | 2.3 (1.5–3.5) | <0.001* | 1.3 (0.7–2.5) | 0.458 |
| Yes | 130 | 11.2% | ||||||||
| PCR results | RT‐PCR | Negative | 802 | 69.2% | 1.1 (0.7–1.7) | 0.646 | 1.6 (1.1–2.2) | 0.007 | 1.1 (0.7–1.8) | 0.733 |
| Positive | 357 | 30.8% | ||||||||
| Total influenza viruses (A&B) b | No | 976 | 84.2% | ‐ | ‐ | ‐ | ‐ | ‐ | ‐ | |
| Yes | 183 | 15.8% | ||||||||
| Influenza B | No | 1110 | 95.8% | 0.4 (0.1–1.6) | 0.202 | 0.9 (0.4–2) | 0.768 | 0.9 (0.3–2.9) | 0.826 | |
| Yes | 49 | 4.2% | ||||||||
| Total influenza A | No | 1025 | 88.4% | 1.7 (0.9–3.5) | 0.122 | 1.3 (0.7–2.4) | 0.405 | 1.6 (0.7–3.7) | 0.243 | |
| Yes | 134 | 11.6% | ||||||||
| Influenza A H1N1 | No | 1092 | 94.2% | 1.1 (0.5–2.5) | 0.783 | 2.1 (1.2–3.6) | 0.012 | 0.6 (0.2–2) | 0.424 | |
| Yes | 67 | 5.8% | ||||||||
| Influenza A H3N2 | No | 1151 | 99.3% | 1.5 (0.8–2.5) | 0.182 | 1.7 (1.1–2.7) | 0.014 | 1.1 (0.6–2.2) | 0.786 | |
| Yes | 8 | 0.7% | ||||||||
| Influenza A unsub typed | No | 1100 | 94.9% | 1.1 (0.7–1.9) | 0.654 | 1.5 (1–2.2) | 0.045 | 1 (0.6–1.9) | 0.907 | |
| Yes | 59 | 5.1% | ||||||||
| Respiratory syncytial virus | No | 1108 | 95.6% | 2.1 (1–4.5) | 0.047 | 1.3 (0.7–2.7) | 0.446 | 1.2 (0.4–3.3) | 0.787 | |
| Yes | 51 | 4.4% | ||||||||
| SARS‐CoV2 | No | 1041 | 89.8% | 0.7 (0.3–1.4) | 0.292 | 1.4 (0.9–2.3) | 0.154 | 1.1 (0.5–2.3) | 0.743 | |
| Yes | 118 | 10.2% | ||||||||
| Other viruses a | No | 1156 | 99.7% | ‐ | ‐ | ‐ | ‐ | ‐ | ‐ | |
| Yes | 3 | 0.3% | ||||||||
| Mixed infections (Influenza B + Covid19) | No | 1157 | 99.8% | ‐ | ‐ | ‐ | ‐ | ‐ | ‐ | |
| Yes | 2 | 0.2% | ||||||||
| Underlying conditions | Comorbidities | No | 501 | 43.2% | 1.8 (1.2–2.7) | 0.007 | 1.9 (1.4–2.7) | <0.001* | 3 (1.7–5.2) | <0.001* |
| Yes | 658 | 56.8% | ||||||||
| Diabetes | No | 875 | 75.5% | 1.3 (0.8–2) | 0.241 | 0.8 (0.5–1.1) | 0.201 | 1.5 (0.9–2.5) | 0.087 | |
| Yes | 284 | 24.5% | ||||||||
| Asthma | No | 998 | 86.1% | 0.7 (0.3–1.3) | 0.218 | 0.6 (0.4–1.1) | 0.086 | 0.7 (0.3–1.4) | 0.300 | |
| Yes | 161 | 13.9% | ||||||||
| Heart disease | No | 942 | 81.3% | 1.8 (1.2–2.8) | 0.008 | 1.6 (1.1–2.4) | 0.009 | 2.4 (1.5–3.9) | <0.001* | |
| Yes | 217 | 18.7% | ||||||||
| Other comorbidities a | No | 978 | 84.4% | 2.4 (1.5–3.7) | <0.001* | 1.6 (1.1–2.4) | 0.022 | ‐ | ‐ | |
| Yes | 181 | 15.6% | ||||||||
| Chronic liver disease | No | 1149 | 99.1% | ‐ | ‐ | ‐ | ‐ | 3.4 (0.7–16.4) | 0.123 | |
| Yes | 10 | 0.9% | ||||||||
| Chronic hematological disorder | No | 1115 | 96.2% | 1 (0.3–2.7) | 0.926 | 4.4 (2.4–8.2) | <0.001* | 0.6 (0.2–2.7) | 0.533 | |
| Yes | 44 | 3.8% | ||||||||
| Immune compromised | No | 1094 | 94.4% | 1 (0.4–2.3) | 0.941 | 0.7 (0.4–1.6) | 0.430 | 2.3 (1.1–4.9) | 0.027 | |
| Yes | 65 | 5.6% | ||||||||
| Chronic lung disease | No | 1076 | 92.8% | 3.2 (1.8–5.6) | <.001* | 2.5 (1.5–4.1) | <0.001* | 2.2 (1.1–4.4) | 0.021 | |
| Yes | 83 | 7.2% | ||||||||
| Neuromuscular dysfunction | No | 1124 | 97.0% | 0.9 (0.3–3) | 0.851 | 1.1 (0.5–2.7) | 0.824 | 0.8 (0.2–3.4) | 0.779 | |
| Yes | 35 | 3.0% | ||||||||
| Chronic kidney disease | No | 1103 | 95.2% | 2.5 (1.2–4.9) | 0.010 | 2.2 (1.2–4.1) | 0.009 | 4.2 (2.1–8.2) | <0.001* | |
| Yes | 56 | 4.8% | ||||||||
| >1 Comorbidity | No | 839 | 72.4% | 1.8 (1.2–2.7) | 0.005 | 1.3 (0.9–1.8) | 0.179 | 2.7 (1.7–4.3) | <0.001* | |
| Yes | 320 | 27.6% | ||||||||
Odds ratios were not calculated for some variables due to low numbers.
a
Other viruses and comorbidities were not specified or recorded other than the ones listed above, thus not included in the analysis.
b
Analysis was not conducted for total influenza viruses' results, each subtype was analyzed separately.
*
Significant association at the 0.05 level (2‐tailed).