Key points
- Chikungunya virus disease (chikungunya) is a nationally notifiable condition.
- Locally acquired chikungunya cases have not been reported from U.S. states or territories since 2019.
Chikungunya virus in the United States
- Before 2006, chikungunya was rarely identified in U.S. travelers.
- During 2006–2013, an average of 28 people per year in the United States tested positive for recent chikungunya virus infection. All were travelers visiting or returning to the United States from affected areas in Asia, Africa, or the Indian Ocean.
- In late 2013, the first local transmission of chikungunya virus in the Americas was identified in Caribbean countries and territories. Local transmission means that mosquitoes in the area have been infected with the virus and are spreading it to people.
- Beginning in 2014, chikungunya was reported among U.S. travelers returning from affected areas in the Americas, and local transmission was identified in Florida, Texas, Puerto Rico, and the U.S. Virgin Islands.
- Chikungunya became a nationally notifiable condition in 2015. Cases are reported to CDC by state and local health departments using standard case definitions.
- Locally acquired chikungunya cases have not been reported from U.S. states or territories since 2019.
| *Includes confirmed and probable disease cases **Locally acquired cases reported from Florida in 2014 and from Texas in 2015 †Includes cases acquired through other routes (e.g., laboratory transmission) |
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| Year | US States Locally acquired** |
US States Travel-associated† |
US Territories Locally acquired |
US Territories Travel-associated |
|---|---|---|---|---|
| 2014 | 12 | 2,799 | 4,659 | 51 |
| 2015 | 1 | 895 | 237 | 0 |
| 2016 | 0 | 248 | 180 | 1 |
| 2017 | 0 | 156 | 39 | 0 |
| 2018 | 0 | 116 | 8 | 0 |
| 2019 | 0 | 192 | 2 | 0 |
| 2020 | 0 | 33 | 0 | 0 |
| 2021 | 0 | 36 | 0 | 0 |
| 2022 | 0 | 81 | 0 | 0 |