Table 2. Sensitivity and specificity using CDC and WHO definitions of suspected Zika virus infection in study of clinical assessments to distinguish Zika and dengue virus infections, Singapore*.

Case definition			Characteristic
Source	Criteria		Patient meets criteria	Zika virus positive, n = 34	Zika virus negative, n = 57	Total, n = 91	Sensitivity, %	Specificity, %
CDC	Clinically compatible illness with >1 of the following not explained by another etiology: fever, rash, arthralgia, or conjunctivitis†		Yes	34	56	90	100	2
WHO	Fever and/or rash and any of the following: arthralgia, arthritis, nonpurulent conjunctivitis		Yes	24	19	43	71	67
			No	10	38	48

*CDC, Centers for Disease Control and Prevention; WHO, World Health Organization.
†We excluded 2 additional criteria, complications of pregnancy and neurologic manifestations, because they were not present in our study population.