TABLE 3—
Sensitivity, Specificity, and Positive Predictive Value of Symptoms and Other Screening Criteria for Identifying Influenza in Arriving International Airline Travelers, Christchurch International Airport, New Zealand, Winter 2008
| Symptom | Sensitivity, % (95% CI) | Specificity, % (95% CI) | Estimated PPV, % |
| Any symptom | 84.0 (70.3, 97.6) | 83.6 (83.0, 84.2) | 5.5 |
| Cough | 59.6 (44.9, 74.3) | 93.1 (92.6, 93.5) | 9.0 |
| Sore throat | 25.0 (15.5, 34.4) | 96.2 (95.9, 96.5) | 7.0 |
| Fever, self-report | 11.3 (5.4, 17.1) | 99.5 (99.4, 99.6) | 20.5 |
| ILI, self-report | 11.5 (5.6, 17.3) | 99.6 (99.5, 99.7) | 24.7 |
| Measured temperature ≥ 37.8 °C | 2.6 (0.5, 4.8) | 99.9 (99.9, 100.0) | …a |
| ILI, using measured temperature | 2.5 (0.4, 4.6) | 100 | …a |
| History of contact with someone who was coughing or sneezing | 43.2 (30.8, 55.5) | 75.5 (74.9, 76.2) | 2.0 |
| Any symptom or contact | 86.4 (74.4, 98.3) | 67.2 (66.4, 67.9) | 2.9 |
| Any symptom and contact | 33.5 (22.2, 44.7) | 92.0 (91.6, 92.5) | 4.6 |
| Any symptom and contact with someone visited, worked, lived, traveled, or stayed with | 29.8 (19.3, 40.3) | 92.4 (92.0, 92.8) | 4.3 |
| Any symptom and age < 25 y | 14.6 (7.2, 22.0) | 94.6 (94.3, 95.0) | 3.0 |
Note. CI = confidence interval; ILI = influenza-like illness (fever and cough or sore throat); PPV = positive predictive value.
a
At near 100% specificity, the PPV cannot be reliably estimated.