Surveillance of Pregnant Unaccompanied Children Who Migrated through Areas with Zika Virus Transmission to the US Border and Associated Challenges for Public Health, Maricopa County, Arizona, 2016

BACKGROUND:  Zika virus infection during pregnancy can cause severe birth defects. Historically high numbers of unaccompanied children (UC), including adolescents who are or become pregnant, migrate through areas with Zika virus transmission in Central America and Mexico to the US border. Once apprehended, UC are referred to Administration for Children and Families Office of Refugee Resettlement (ORR) custody. Federal law requires ORR to shelter and provide medical services to UC until reunification with sponsors, while awaiting immigration proceedings. Our objective is to describe this population temporarily residing in Maricopa County, Arizona and highlight challenges associated with providing Zika testing, counseling and monitoring.

METHODS: Maricopa County Department of Public Health (MCDPH) receives Zika testing requests from ORR-funded programs and associated medical providers. MCDPH tracks pregnant UC, collecting information on demographics, facility, gestational age (GA) and Zika testing status/results. MCDPH facilitates specimen collection and testing at the Arizona State Laboratory and CDC and ensures results are communicated to the provider and that patients are counseled. When a patient is reunified before test results are available, MCDPH works with state and federal partners to ensure results are communicated to the receiving health department, new provider and patient.

RESULTS: From 23 February to 27 November 2016, MCDPH investigated 81 pregnant UC from Mexico and Central America for Zika virus exposure; 57 (70%) were tested. Median age was 16 (range 14–17) years; median GA was 23 (range 2–39) weeks. One individual had confirmed Zika virus infection, one had an equivocal IgM result, five had results consistent with an unspecified flavivirus infection, and 50 tested negative for Zika virus by IgM antibody and/or polymerase chain reaction. Among 24 untested UC, 13 were reunified with an out-of-state sponsor prior to specimen collection, two did not meet testing requirements and one delivered before testing; eight await specimen collection. All seven (12.3%) with non-negative results were reported to the state health department for inclusion in the CDC Zika pregnancy registry. For UC reunified outside of Maricopa County prior to testing, no formal system exists to confirm healthcare access and follow up.

CONCLUSIONS: While infrastructure exists to ensure appropriate Zika virus testing, counseling, and access to indicated healthcare for pregnant UC arriving from Central America and Mexico, there is room for systems improvement. Robust communication between federal entities and state and local public health regarding surveillance of this at-risk population is needed to ensure appropriate follow up.