Chikungunya in the US
Chikungunya virus in the United States
- Before 2006, chikungunya virus disease was rarely identified in U.S. travelers.
- During 2006‒2013, studies identified an average of 28 people per year in the United States with positive tests for recent chikungunya virus infection (range 5‒65 per year). 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 virus disease cases were 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 virus disease became a nationally notifiable condition in 2015. Cases are reported to CDC by state and local health departments using standard case definitions.
- County-level data from 2014 – present (provisional data) are located here.
| *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 |
Publications summarizing chikungunya virus disease cases reported to CDC from US states and territories:
Lindsey NP, Staples JE, Fischer M. Chikungunya virus disease among travelers — United States, 2014–2016. Am J Trop Med Hyg 2018;98(1):192–197.
Adams LE, Martin SW, Lindsey NP, Lehman JA, Rivera A, Kolsin J, Landry K, Staples JE, Sharp TM, Paz-Bailey P, Fischer M. Epidemiology of dengue, chikungunya, and Zika virus disease in the US States and Territories, 2017. Am J Trop Med Hyg 2019;101(4);884‒890.