Table 1.

Sensitivity of dengue surveillance systems in American countries and corresponding expansion factors

Study	Country	Period	Type of dengue case	Method	Expansion factors
Duarte and Franca42	Brazil	1996–2002	Hospitalized dengue case	Sensitivity of the surveillance system using hospital records as the reference	Overall = 1.6 (1.4–1.8); DHF = 1.4 (1.3–1.5); DF = 2.1 (1.6–3.0)
Camacho and others63	Colombia	1995–1997	All types of dengue cases	Sensitivity of the surveillance system using emergency room medical records as the reference	Overall = 9
Standish and others44	Nicaragua	2004–2008	All types of dengue cases	Comparison of incidence obtained through active surveillance with reported incidence in the same area	Clinically diagnosed: 20.4 (2004–2008), 16 (2007–2008), 28 (2005–2006); lab-confirmed: 23.1 (2004–2008), 14 (2006–2007), 28 (2005–2006)
Dechant and Rigau-Perez41	Puerto Rico	1991–1995	Hospitalized dengue case	Capture–recapture method	1991–1995 = 2.4; 1991 = 2.3; 1993 = 3.4
Rigau-Perez43	Puerto Rico	1988–1997	Hospitalized dengue case	Sensitivity and specificity of the surveillance system compared with hospital records	Overall = 3

Figures in parentheses correspond to 95% confidence intervals assuming a binomial distribution for sensitivity analysis.