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Table 1 The airport screening program mediated by noncontact infrared thermometers (NCITs) followed by laboratory confirmation, 2007–2010: sensitivity, specificity and predictive values

From: Airport sentinel surveillance and entry quarantine for dengue infections following a fever screening program in Taiwan

Year 2007 2008 2009 2010
Total inbound passengers (sample size, n) 12,508,621 12,202,392 12,499,365 14,837,391
Inbound passengers from Southeast Asia 1,164,291 471,938 1,486,357 2,729,618
Confirmed febrile passengers1 11,118 12,158 12,286 12,553
Fever prevalence among total passengers % 0.09 0.10 0.10 0.08
Specimens taken for diagnostics2 5,654 4,946 3,706 3,956
Dengue importations detected in the airport fever screening program 3 72 100 108 126
Dengue importations detected in harbor screenings4 0 1 2 3
Dengue importations reported from communities 107 125 95 175
Sensitivity of the airport fever screening program % 40.22 44.44 53.20 41.86
Specificity of the airport fever screening program % 99.96 99.96 99.97 99.97
PPV5 of the airport fever screening program % 1.28 2.03 2.90 3.22
NPV6 of the airport fever screening program % >99.99 >99.99 >99.99 >99.99
  1. 1. Confirmed febrile passengers were detected by NCITs (37.5°C) followed by ear thermometers (more than 38°C) in 2 airports.
  2. 2. Confirmed febrile inbound passengers from dengue-endemic countries, mainly Southeast Asia and South Asia.
  3. 3. The cumulative results of the International Taoyuan Airport and the International Kaohsiung Airport.
  4. 4. Dengue importations reported from fever screening in 9 harbors with 10 NCITs were not enrolled as true positives in calculating the PPV and NPV of airport fever screening.
  5. 5. PPV: positive predictive value of the airport fever screening program.
  6. 6. NPV: negative predictive value of the airport fever screening program.