Table 2. Comparison of results of screening for exposure to* and results of serologic testing for Nipah virus encephalitis among patients with encephalitis at 3 surveillance hospitals, Bangladesh, December 2012–March 2013.

Months	Prevalence (95% CI), %	Sensitivity (95% CI), %	Specificity (95% CI), %	Positive predictive value (95% CI), %	Negative predictive value (95% CI), %
Dec 2012–Mar 2013	5 (3–8)	82 (57–96)	86 (81–89)	24 (14–37)	99 (97–100)
Jan–Feb 2013	10 (6–16)	93 (68–100)	82 (74–88)	37 (22–54)	99 (95–100)

*Drinking raw or fermented date palm sap or having contact with encephalitis patients in month before illness onset.