Evaluation of Zika Virus Testing Through the Washington State Department of Health

Abstract

Objectives We used Washington State Department of Health (DOH) Zika surveillance data from January 1 to October 31, 2016 to (1) describe the population of individuals for whom Zika testing was requested, (2) determine whether health care provider (HCP) disciplines differ in appropriate referral practices for Zika testing, and (3) determine whether HCP disciplines differ in referral of positive Zika patients for testing. Methods Descriptive analysis with t-test and Chi-squared test was used to evaluate whether patient characteristics and HCP discipline differed by public health test approval status and laboratory results. Logistic regression was used to calculate odds ratios of approved test referral and referral of positive Zika patients by HCP discipline. Results Obstetrician/Gynecologist (OBGYN) and General Practice disciplines bore the greatest burden of Zika testing requests. Patient age, sex, pregnancy and symptom status, and discipline of HCP that made the request differed significantly by public health test approval status and laboratory results. Compared with OBGYNs, General Practice and “Other” disciplines had elevated odds of referring patients for whom testing was not approved by public health, whereas Emergency and Internal Medicine disciplines had elevated odds of requesting testing for laboratory positive patients. Conclusions Given the potentially severe consequences of Zika infection to pregnant women, testing guidance in place during this study appropriately fostered disproportionate testing of asymptomatic pregnant females. However, asymptomatic pregnant women rarely test positive. This supports the recent Center for Disease Control and Prevention recommendation to limit routine testing of asymptomatic pregnant females.