Table 4.

Sensitivity, specificity, positive and negative predictive values of the WHO standard clinical case definition for ZIKV infection applied to the symptomatic pregnant women in the Jundiai Zika Cohort.

		Symptomatic Women with the ZIKV Infection
		ZIKV RT–PCR-Positive	ZIKV RT–PCR-Negative
Have symptoms that fulfill the WHO standard case definition	Yes	4 (TP)	28 (FP)	PPV = TP / (TP + FP) = 12.5%
	No	10 (FN)	157 (TN)	NPV = TN / (TN + FN) = 94.0%
		Sensitivity = TP / (TP + FN) = 28.6%	Specificity = TN / (FP + TN) = 84.9%

TP = true positive; TN = true negative; FP = false positive; FN = false negative; PPV = positive predictive value; NPV = negative predictive value.