Table 1.
Demographic information.
| Parameter | Overall (n = 554) | Imported cases (n = 29) | Community cases (n = 100) | Dormitory cases (n = 425) | p-value |
|---|---|---|---|---|---|
| Age (years) | 37 (±12) | 39 (±15) | 46 (±16) | 35 (±9) | <0.001 |
| Gender (male) | 477 (86.9%) | 15 (53.6%) | 51 (51.0%) | 411 (97.6%) | <0.001 |
| Ethnicity | <0.001 | ||||
| Chinese | 91 (16.5%) | 16 (57.1%) | 49 (49.0%) | 26 (6.1%) | |
| Malay | 34 (6.1%) | 1 (3.6%) | 20 (20.0%) | 13 (3.1%) | |
| Indian | 199 (36.0%) | 1 (3.6%) | 17 (17.0%) | 181 (42.6%) | |
| Bangladeshi | 175 (31.6%) | 0 (0%) | 1 (1.0%) | 174 (40.9%) | |
| Others | 55 (9.9%) | 11 (37.9%) | 13 (13.0%) | 31 (7.3%) | |
| Medical comorbidities | |||||
| Prior history of hypertension | 53 (12.3%) | 2 (12.5%) | 30 (57.7%) | 21 (5.8%) | <0.001 |
| Prior history of hyperlipidaemia | 34 (8.1%) | 6 (33.3%) | 23 (51.1%) | 5 (1.4%) | <0.001 |
| Prior history of diabetes mellitus | 21 (5.1%) | 1 (6.3%) | 15 (37.5%) | 5 (1.4%) | <0.001 |
| Prior history of asthma | 6 (1.5%) | 1 (5.9%) | 2 (5.6%) | 3 (0.8%) | 0.024 |
| No previous medical conditions | 367 (90.4%) | 11 (68.8%) | 19 (55.9%) | 337 (94.7%) | <0.001 |
| Newly-diagnosed hypertension | 12 (2.9%) | 2 (12.5%) | 1 (2.9%) | 9 (2.5%) | 0.068 |
| Newly-diagnosed diabetes mellitus | 8 (2.0%) | 0 (0.0%) | 0 (0.0%) | 8 (2.2%) | 0.560 |
| Clinical profile | |||||
| Asymptomatic illness | 66 (11.9%) | 0 (0.0%) | 3 (3.0%) | 63 (14.8%) | 0.001 |
| Day of illness at presentation | 3.5 (±5.1) | 3.8 (±2.5) | 5.8 (±5.2) | 2.9 (±5.0) | <0.001 |
| Length of days with fever | 1.2 (±2.4) | 2.0 (±2.4) | 1.6 (±2.7) | 1.1 (±2.3) | 0.025 |
| Admission temperature (oC) | 37.7 (±3.9) | 37.4 (±0.9) | 37.3 (±0.7) | 37.8 (±4.4) | 0.480 |
| Systolic blood pressure (mmHg) | 130 (±17) | 127 (±16) | 127 (±18) | 131 (±17) | 0.078 |
| Diastolic blood pressure (mmHg) | 81 (±12) | 74 (±13) | 74 (±12) | 83 (±11) | <0.001 |
| Oxygen saturation (%) | 98 (±3) | 97 (±7) | 97 (±4) | 98 (±1) | <0.001 |
| Pulse rate (/min) | 94 (±19) | 89 (±15) | 89 (±14) | 96 (±20) | 0.002 |
| Respiratory rate (/min) | 19 (±7) | 19 (±2) | 19 (±3) | 19 (±6) | 0.888 |
| Baseline laboratory investigations | |||||
| Total white cell count (×109/L) | 6.5 (±2.2) | 6.9 (±3.9) | 6.2 (±2.7) | 6.5 (±1.9) | <0.001 |
| Absolute neutrophil count (×109/L) | 4.18 (±7.9) | 4.89 (±3.91) | 3.90 (±2.37) | 4.19 (±8.88) | 0.849 |
| Absolute lymphocyte count (×109/L) | 1.90 (±2.02) | 1.33 (±0.62) | 1.59 (±1.01) | 2.00 (±2.22) | 0.062 |
| Haemoglobin (g/dL) | 14.9 (±1.6) | 14.1 (±2.1) | 13.4 (±1.6) | 15.2 (±1.4) | 0.119 |
| Platelet count (×109/L) | 228 (±60) | 204 (±48) | 230 (±69) | 229 (±59) | 0.029 |
| Haematocrit (%) | 45 (±23) | 42 (±6) | 40 (±5) | 47 (±6) | 0.007 |
| Sodium (mmol/L) | 138 (±3) | 137 (±3) | 137 (±4) | 138 (±2) | 0.679 |
| Creatinine (mmol/L) | 79 (±30) | 82 (±27) | 81 (±64) | 79 (±14) | 0.038 |
| Albumin (g/L) | 43 (±17) | 40 (±7) | 39 (±4) | 44 (±18) | <0.001 |
| AST (units/L) | 38 (±48) | 83 (±21) | 32 (±19) | 37 (±24) | 0.001 |
| ALT (units/L) | 46 (±44) | 60 (±130) | 29 (±20) | 48 (±38) | 0.009 |
| LDH (units/L) | 436 (±423) | 691 (±110) | 459 (±259) | 418 (±377) | <0.001 |
| C-reactive protein (mg/L) | 14 (±27) | 33 (±46) | 24 (±37) | 11 (±23) | <0.001 |
| Ferritin (ug/L) | 179 (±216) | 404 (±459) | 234 (±392) | 161 (±143) | <0.001 |