2020 Case Counts in the US
2020 | 2019 | 2018 | 2017 | 2016 | 2015
Provisional Data as of January 7, 2021
Zika virus disease is a nationally notifiable condition. Cases are reported to CDC by state, territorial, and local health departments using standard case definitions. This webpage contains provisional data reported to ArboNET for 2020.
US States
- 2 Zika virus disease cases reported*
- 2 cases in travelers
- 0 cases acquired through presumed local mosquito-borne transmission
- 0 cases acquired through sexual transmission
- 0 case acquired through laboratory exposure
US Territories
- 47 Zika virus disease cases reported*
- 0 cases in travelers returning from an affected area
- 47 cases acquired through presumed local mosquito-borne transmission
- 0 cases acquired through other routes†
Presumed locally acquired cases of Zika in the U.S. territories were diagnosed using serologic testing, which detects antibodies against Zika. Since antibodies against Zika can persist for years after infection, serology cannot distinguish between a recent or past infection. Additionally, Zika and dengue virus antibodies cross-react, making it difficult to diagnose which virus is the cause of the current illness. None of these probable cases have tested positive using molecular testing, which detects the presence of the virus in the body and is the best indicator of a recent infection. In 2020, there have been no confirmed Zika virus disease cases reported from U.S. territories. Additionally, a large number of suspect Zika cases from the territories have been tested using molecular testing and none have been positive.
Zika virus disease cases** reported to ArboNET by states and territories – United States, 2020 (as of January 7, 2021)
Zika virus disease cases** and presumptive viremic blood donors reported to ArboNET—United States, 2020 (as of January 7, 2021)
| Travel-associated cases No. (%) |
Locally acquired cases No. (%) |
Presumptive viremic blood donors‡ No. (%) |
|
|---|---|---|---|
| States | (N=2) | (N=0) | (N=0) |
| North Carolina | 1 (50) | 0 (0) | 0 (0) |
| Virginia | 1 (50) | 0 (0) | 0 (0) |
| Territories | (N=0) | (N=47) | (N=0) |
| Puerto Rico | 0 (0) | 47 (100) | 0 (0) |
Footnotes
*Excludes congenital disease cases.
†Sexually transmitted cases are not reported for US territories because with local transmission of Zika virus it is not possible to determine whether infection occurred due to mosquito-borne or sexual transmission.
**Includes reported confirmed and probable Zika virus disease cases
‡Presumptive viremic blood donors are people who reported no symptoms at the time of donating blood, but whose blood tested positive when screened for the presence of Zika virus RNA by the blood collection agency. Some presumptive viremic blood donors develop symptoms after their donation or may have had symptoms in the past. These individuals may be reported as both Zika virus disease cases and presumptive viremic blood donors.
