Summary of clinical variables and EBV positivity in derivation and validation cohorts
| Symptom/sign | Derivation IM positive n=42 N (%) | Total n=328 N (%) | Validation IM positive n=379 N (%) | Total n=2342 N (%) |
| Temperature >38 | 2 (6.5) | 11 (3.4) | 11 (2.9) | 153 (6.5) |
| Exudate on tonsils | 25 (61.0) | 162 (49.4) | 131 (34.6) | 451 (19.3) |
| Enlarged/tender posterior cervical lymph nodes | 22 (52.4) | 76 (23.2) | 190 (50.1) | 509 (21.7) |
| Cough | 18 (43.9) | 148 (45.1) | 125 (33.0) | 1012 (43.2) |
| Nasal congestion | 21 (51.2) | 185 (56.4) | 163 (43.0) | 1084 (46.3) |
| Headache | 27 (65.9) | 192 (58.5) | 140 (36.9) | 995 (42.5) |
| Muscle aches | 21 (51.2) | 163 (49.7) | 83 (21.9) | 657 (28.1) |
| Sweats/chills | 28 (68.3) | 217 (66.2) | 159 (42.0) | 964 (41.2) |
| Fatigue | 36 (87.8) | 266 (81.1) | 195 (51.5) | 1114 (47.6) |
| Exudate on pharynx | 18 (43.9) | 77 (23.5) | 126 (33.2) | 437 (18.7) |
| Enlarged/tender anterior cervical lymph nodes | 38 (90.5) | 284 (86.6) | 312 (82.3) | 1830 (78.1) |
| Atypical lymphocytosis >10% | 26 (63.4) | 29 (8.8) | 280 (73.9) | 334 (14.3) |
EBV, Epstein-Barr virus; IM, infectious mononucleosis.