Statistics & Maps

In the United States, an average of 17 Jamestown Canyon virus neuroinvasive disease cases are reported each year. There is significant under-diagnosis and under-reporting of less severe cases of Jamestown Canyon virus disease, therefore reported neuroinvasive disease cases are used to compare trends over time and place. Jamestown Canyon virus disease is a nationally notifiable condition. To ensure standardization of reporting across the country, CDC recommends that the national surveillance case definition (standardized reporting criteria) be consistently applied by all state health departments.

Most Jamestown Canyon virus infections occur from April through September. The virus is found throughout much of the United States, but Minnesota and Wisconsin have reported more than half of all cases. The recent increase in reported cases likely reflects increased awareness and testing, but also could be due to an increase in disease incidence.

Jamestown Canyon virus neuroinvasive disease cases reported to CDC by year, 2012–2021

Graph showing the number of Jamestown Canyon virus neuroinvasive disease cases reported each year from 2009 through 2018. See data table below.

Source: ArboNET, Arboviral Diseases Branch, Centers for Disease Control and Prevention

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Jamestown Canyon virus neuroinvasive disease cases reported to CDC by year, 2010–2019
Year Number of reported cases
2012 1
2013 15
2014 6
2015 6
2016 7
2017 58
2018 25
2019 25
2020 10
2021 21
Jamestown Canyon virus neuroinvasive disease cases reported to CDC by state of residence, 2012–2021

Map of the United States showing Jamestown Canyon virus neuroinvasive disease cases by state. See data table below.

Source: ArboNET, Arboviral Diseases Branch, Centers for Disease Control and Prevention

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Jamestown Canyon virus neuroinvasive disease cases reported to CDC by state of residence, 2010–2019
State of Residence Cases
Connecticut 1
Illinois 1
Indiana 1
Louisiana 1
Maine 3
Massachusetts 10
Michigan 10
Minnesota 41
New Hampshire 13
New Jersey 2
New York 4
North Carolina 1
Ohio 2
Oregon 1
Rhode Island 2
Tennessee 2
Wisconsin 79
Jamestown Canyon virus neuroinvasive disease average annual incidence by county of residence, 2012–2021

Map of the United States showing the distribution of Jamestown Canyon virus neuroinvasive disease. Cases are concentrated in the Great Lakes region.

Source: ArboNET, Arboviral Diseases Branch, Centers for Disease Control and Prevention

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Data table: This map shows the distribution of Jamestown Canyon virus neuroinvasive disease (encephalitis and/or meningitis) average annual incidence by county of residence from 2012 through 2021. Counties are shaded according to incidences ranging from less than 0.20, 0.20 to 0.49, and greater than 0.50 per 100,000 population. Shaded counties are primarily in northern states.

Additional Maps, Charts, and Tables

Jamestown Canyon virus disease cases and deaths reported to CDC by year and clinical presentation, 2012‒2021
Jamestown Canyon virus disease cases and deaths reported to CDC by year and clinical presentation, 2009‒2018
Neuroinvasive disease Non-neuroinvasive disease Total
Year Cases
No.
Deaths
No. (%)
Cases
No.
Deaths
No. (%)
Cases
No.
Deaths
No. (%)
2012  1 0  (0)  1  0  (0)  2 0  (0)
2013  15 0  (0)  7  0  (0)  22 0  (0)
2014  6 0  (0)  5  0  (0)  11 0  (0)
2015  6 0  (0)  5  0  (0)  11 0  (0)
2016  7 0  (0)  8  0  (0)  15 0  (0)
2017 58 2  (3) 17 0  (0) 75 2  (3)
2018 25 1  (4) 16 0  (0) 41 1  (2)
2019 25 2  (8) 20 0  (0) 45 2  (4)
2020 10 0  (0) 3 0  (0) 13 0  (0)
2021 21 2  (9) 11 0  (0) 32 2  (6)
Total  174 7  (4)   93  0  (0)  267 7  (3) 

Source: ArboNET, Arboviral Diseases Branch, Centers for Disease Control and Prevention

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Jamestown Canyon virus disease cases reported to CDC by state of residence, 2012–2021
Jamestown Canyon virus disease cases reported to CDC by state of residence, 2009–2018
State 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 Total
Alabama 0 0 0 0 0 0 0 0 0 0 0
Alaska 0 0 0 0 0 0 0 0 0 0 0
Arizona 0 0 0 0 0 0 0 0 0 0 0
Arkansas 0 0 0 0 0 0 0 0 0 0 0
California 0 0 0 0 0 0 0 0 0 0 0
Colorado 0 0 0 0 0 0 0 0 0 0 0
Connecticut 0 0 0 0 0 0 1 0 0 0 1
Delaware 0 0 0 0 0 0 0 0 0 0 0
Dist. of Columbia 0 0 0 0 0 0 0 0 0 0 0
Florida 0 0 0 0 0 0 0 0 0 0 0
Georgia 0 1 0 0 0 0 1 0 0 0 2
Hawaii 0 0 0 0 0 0 0 0 0 0 0
Idaho 0 1 0 0 0 0 0 0 0 0 1
Illinois 0 0 0 0 0 0 0 1 0 0 1
Indiana 0 0 0 0 0 0 0 0 0 1 1
Iowa 0 0 0 1 0 0 0 0 0 0 1
Kansas 0 0 0 0 0 0 0 0 0 0 0
Kentucky 0 0 0 0 0 0 0 0 0 0 0
Louisiana 0 0 0 0 0 1 0 0 0 0 1
Maine 0 0 0 0 0 2 1 0 0 1 4
Maryland 0 0 0 0 0 0 0 0 0 0 0
Massachusetts 0 1 1 1 2 2 1 4 0 0 12
Michigan 0 0 0 0 0 0 2 1 3 6 12
Minnesota 0 1 4 2 6 22 11 21 0 6 73
Mississippi 0 0 0 0 0 0 0 0 0 0 0
Missouri 0 0 0 0 0 0 0 0 0 0 0
Montana 0 0 0 0 0 0 0 0 0 0 0
Nebraska 0 0 0 0 0 0 0 0 0 0 0
Nevada 0 0 0 0 0 0 0 0 0 0 0
New Hampshire 0 1 0 0 0 3 0 3 5 5 17
New Jersey 0 0 0 1 0 0 0 0 0 2 3
New Mexico 0 0 0 0 0 0 0 0 0 0 0
New York 1 3 0 0 0 0 0 0 0 0 4
North Carolina 0 0 0 0 0 1 0 0 0 0 1
North Dakota 0 0 0 0 0 0 0 0 0 0 0
Ohio 0 0 0 1 0 1 0 0 0 0 2
Oklahoma 0 0 0 0 0 0 0 0 0 0 0
Oregon 0 1 0 0 0 0 0 0 0 0 1
Pennsylvania 0 1 0 0 0 0 0 0 0 0 1
Puerto Rico 0 0 0 0 0 0 0 0 0 0 0
Rhode Island 0 1 0 0 0 0 0 0 0 1 2
South Carolina 0 0 0 0 0 0 0 0 0 0 0
South Dakota 0 0 0 0 0 0 0 0 0 0 0
Tennessee 0 0 1 0 0 0 1 0 0 0 2
Texas 0 0 0 0 0 0 0 0 0 0 0
Utah 0 0 0 0 0 0 0 0 0 0 0
Vermont 0 0 0 0 0 0 0 0 0 0 0
Virginia 0 0 0 0 0 0 0 0 0 0 0
Washington 0 0 0 0 0 0 0 0 0 0 0
West Virginia 0 0 0 0 0 0 0 0 0 0 0
Wisconsin 1 11 5 4 7 43 23 15 5 10 124
Wyoming 0 0 0 1 0 0 0 0 0 0 1
Total 2 22 11 11 15 75 41 45 13 32 267

Source: ArboNET, Arboviral Diseases Branch, Centers for Disease Control and Prevention

To request data for previous years, please email dvbid2@cdc.gov.

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National & state maps (including county-level data) from 2003 – present