From the Stanford Blood Center
January 30, 2019
TRACKING THE EPIDEMIC
In 2016, the world was in the midst of a Zika outbreak, with the largest occurring in 2016 in Brazil and Columbia. The graph below shows the distribution of Zika cases in Central America, the Caribbean, and South America from 2015–2017.
In the continental US, Zika cases also peaked in 2016, with the majority of cases occurring in people who had traveled to high-risk countries (although local mosquito transmission was reported in Florida and Texas). Overall, there have been 5,740 symptomatic Zika cases reported in the continental US from January 2015 to December 2018, of which:
- 5,454 cases were in travelers returning from affected areas
- 231 cases were from local mosquito transmission
- 55 cases through other routes including sexual transmission (52 cases), lab transmission (2 cases), and person-to-person through an unknown route (1 case)
The graph below shows confirmed symptomatic Zika cases in the US (reported to ArboNET) from 2016 to 2018 (data as of 12/4/2018).