Dengue Dual Infection Score (DDIS) of See et al

 

Patient selection: presence of dengue fever

 

Parameters:

(1) heart rate in beats per minute in ED

(2) total white blood cell count within 24 hours of admission

(3) hematocrit in percent within 24 hours of admission

(4) serum sodium in mmol/L within 24 hours of admission

(5) serum urea in mmol/L within 24 hours of admission

Parameter	Finding	Points
heart rate	< 90 beats per minute	0
	>= 90 beats per minute	1
total WBC count	< 6,000 per µL	0
	>= 6,000 per µL	1
hematocrit	>= 40%	0
	< 40%	1
serum sodium	>= 135 mmol/L	0
	< 135 mmol/L	1
serum urea	< 5 mmol/L	0
	>= 5 mmol/L	1

 

total score =

= SUM(points for all 5 parameters)

 

Interpretation:

• minimum score: 0

• maximum score: 5

• The higher the score the greater the risk of a concurrent bacterial infection.

 

Performance:

• A score >= 4 was 94% specific for a bacterial infection but 33% sensitive.

• The maximum Youden score was >= 3 with sensitivity of 61% and specificity of 83%.

• Hematocrit and serum urea could be abnormal due to common comorbid conditions.