Zika Virus: Information for States and Territories

At a Glance – Zika in the U.S. (updated 2/7/18*) 

U.S. States
Total cases reported: 5,653
Travel-associated Zika virus disease cases reported: 5,372
Locally acquired vector-borne cases reported: 228
Sexually transmitted cases: 51
Laboratory acquired cases reported: 1
Pregnant women with any lab evidence of Zika virus infection: 2,395
Liveborn infants with birth defects: 106
Pregnancy losses with birth defects: 9

U.S. Territories
Total cases reported: 37,165
Travel-associated cases reported:147
Locally acquired cases reported: 37,018 
Pregnant women with any lab evidence of Zika virus infection: 4,711
Liveborn infants with birth defects: 141
Pregnancy losses with birth defects: 8

*Visit CDC.gov for the most up to date information.This webpage contains cumulative provisional data reported to ArboNET since 1/1/2015.


New from ASTHO: Top Questions on Zika: Simple Answers


Zika virus is a mosquito-borne flavivirus transmitted to humans primarily by the Aedes aegypti mosquitoes, the same mosquitoes that transmit dengue, yellow fever, and chikungunya viruses. CDC estimates that 80 percent of Zika cases are asymptomatic. Symptomatic cases usually result in mild illness and symptoms such as acute onset of fever, rash, joint pain, and conjunctivitis. Some evidence suggests severe outcomes such as Guillian-Barre syndrome and microcephaly in infants via maternal-fetal transmission of Zika virus. There is currently no vaccine to prevent or medicine to treat Zika virus. For more information on Zika virus in the United States see CDC's Zika Virus web page: www.cdc.gov/Zika.

What's New

Population-Based Surveillance of Birth Defects Potentially Related to Zika Virus Infection — 15 States and U.S. Territories, 2016 
This CDC Morbidity and Mortality Weekly Report (MMWR) provides the first comprehensive data on the prevalence of birth defects (3.0 per 1,000 live births) potentially related to Zika virus infection in a birth cohort of nearly 1 million births in 2016. A significant increase in birth defects strongly related to Zika virus during the second half of 2016 compared with the first half was observed in jurisdictions with local Zika virus transmission. Only a small percentage of birth defects potentially related to Zika had laboratory evidence of Zika virus infections, and most were tested for Zika virus.  

Birth Defects Potentially Related to Zika Virus Infection During Pregnancy in the United States
The journal of the American Medical Association released a ViewPoint article to accompany CDC’s MMWR report, highlighting how strong real-time public health surveillance systems are critical to infectious disease preparedness and response.

Defining Moments in MMWR History Podcast: Possible Association Between Zika Virus Infection and Microcephaly—Brazil, 2015
This podcast event featured an interview with Peggy Honein, co-lead for the Pregnancy and Birth Defects Task Force for CDC’s Zika response, on the Zika virus epidemic and the critical role of MMWR in disseminating information as it became available.


ASTHO staff have compiled the following links to selected resources and background materials that were created by state and territorial health departments and national and international sources for use by state health agency leaders. We'll add to these materials periodically.