Table 2

Primary analysis for the performance* of the Widal test for typhoid fever diagnosis (n = 1680)

Widal titer

Sensitivity (95%CI)

Specificity (95%CI)

Positive Predictive Value

Negative Predictive Value


TH ≥1:80

12/16, 0.75

(0.51-0.90)

1630/1664, 0.98

(0.97-0.99)

12/46, 0.26

1630/1634, 1.00

TH ≥1:160

11/16, 0.69

(0.44-0.86)

1639/1664, 0.98

(0.98-0.99)

11/36, 0.31

1639/1644, 1.00

TH ≥1:320

6/16, 0.38

(0.18-0.61)

1646/1664, 0.99

(0.98-0.99)

6/24, 0.25

1646/1656, 0.99

TO ≥1:80

11/16, 0.69

(0.44-0.86)

1631/1664, 0.98

(0.97-0.99)

11/44, 0.25

1631/1636, 1.00

TO ≥1:160

10/16, 0.63

(0.39-0.82)

1640/1664, 0.99

(0.98-0.99)

10/34, 0.29

1640/1646, 1.00

TO ≥1:320

6/16, 0.38

(0.18-0.61)

1652/1664, 0.99

(0.99-1.00)

6/18, 0.33

1652/1662, 0.99


*The values were calculated using culture-confirmed typhoid fever cases (group 1; n = 16) as the true positives and those cases from which S. typhi were not isolated from blood culture (groups 2, 3, and 4; n = 1664) as the true negatives.

Ley et al. BMC Infectious Diseases 2010 10:180   doi:10.1186/1471-2334-10-180

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