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Final Cumulative Maps & Data for 1999–2017

West Nile virus disease cases reported to CDC by state of residence, 1999-2017

West Nile virus disease cases reported to CDC by state of residence, 1999-2017
State 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 Total
Alabama 0 0 2 49 37 16 10 8 24 18 0 3 5 62 9 2 9 19 60 333
Alaska 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Arizona 0 0 0 0 13 391 113 150 97 114 20 167 69 133 62 107 103 78 111 1,728
Arkansas 0 0 0 43 25 28 28 29 20 9 6 7 1 64 18 11 18 9 18 334
California 0 0 0 1 3 779 880 278 380 445 112 111 158 479 379 801 783 442 553 6,584
Colorado 0 0 0 14 2,947 291 106 345 576 71 103 81 7 131 322 118 101 149 68 5,430
Connecticut 0 1 6 17 17 1 6 9 4 8 0 11 9 21 4 6 10 1 3 134
Delaware 0 0 0 1 17 0 2 0 1 1 0 0 1 9 3 0 6 0 1 42
Dist. of Columbia 0 0 0 34 3 2 5 2 0 8 2 6 15 10 1 3 5 1 4 101
Florida 0 0 12 28 94 41 21 3 3 3 3 12 24 73 7 17 13 8 5 367
Georgia 0 0 6 44 50 21 20 8 50 8 4 13 22 99 10 13 15 6 48 437
Hawaii 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 1
Idaho 0 0 0 0 1 3 13 996 132 39 38 1 3 17 40 19 13 9 25 1,349
Illinois 0 0 0 884 54 60 252 215 101 20 5 61 34 290 117 44 77 154 90 2,458
Indiana 0 0 0 293 47 13 23 80 24 4 4 13 9 77 23 10 21 18 26 685
Iowa 0 0 0 54 147 23 37 37 30 6 5 9 9 31 44 15 14 37 12 510
Kansas 0 0 0 22 91 43 25 30 40 31 13 19 4 56 91 54 34 37 27 617
Kentucky 0 0 0 75 14 7 5 6 4 3 3 3 5 23 3 1 2 8 10 172
Louisiana 0 0 1 329 124 109 171 180 40 49 21 27 10 335 54 125 5 59 53 1,692
Maine 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 1 0 0 2
Maryland 0 0 6 36 73 16 5 11 10 14 1 23 19 47 16 6 45 6 6 340
Massachusetts 0 0 3 23 17 0 6 3 6 1 0 7 6 33 8 6 10 17 6 152
Michigan 0 0 0 614 19 16 62 55 17 17 1 29 34 202 36 1 18 43 40 1,204
Minnesota 0 0 0 48 148 34 45 65 101 10 4 8 2 70 79 21 9 83 30 757
Mississippi 0 0 0 192 87 51 70 183 136 65 53 8 52 247 45 43 38 43 63 1,376
Missouri 0 0 0 168 64 36 30 62 77 15 5 3 10 20 29 13 29 11 19 591
Montana 0 0 0 2 222 6 25 34 202 5 5 0 1 6 38 5 3 6 11 571
Nebraska 0 0 0 152 1,942 53 188 264 163 47 52 39 29 193 226 142 68 95 68 3,721
Nevada 0 0 0 0 2 44 31 124 12 16 12 2 16 9 11 3 7 16 67 372
New Hampshire 0 0 0 0 3 0 0 0 0 0 0 1 0 1 1 0 0 0 1 7
New Jersey 0 6 12 24 34 1 6 5 1 10 3 30 7 48 12 8 26 11 8 252
New Mexico 0 0 0 0 209 88 33 8 60 8 8 25 4 47 38 24 14 6 33 605
New York 62 14 15 82 71 10 38 24 22 46 7 128 44 107 32 26 57 22 51 858
North Carolina 0 0 0 2 24 3 4 1 8 3 0 0 2 7 3 0 4 2 8 71
North Dakota 0 0 0 17 617 20 86 137 369 37 1 9 4 89 125 23 23 85 62 1,704
Ohio 0 0 0 441 108 12 61 48 23 15 2 5 21 121 24 11 35 17 34 978
Oklahoma 0 0 0 21 79 22 31 48 107 9 10 1 1 191 89 18 89 35 42 793
Oregon 0 0 0 0 0 3 7 69 26 16 11 0 0 11 16 8 1 4 6 178
Pennsylvania 0 0 3 62 237 15 25 9 10 14 0 28 6 60 11 13 30 16 20 559
Puerto Rico 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 1
Rhode Island 0 0 0 1 7 0 1 0 1 1 0 0 1 4 1 0 0 2 2 21
South Carolina 0 0 0 1 6 2 5 1 5 1 3 1 0 29 7 3 0 8 18 90
South Dakota 0 0 0 37 1,039 51 229 113 208 39 21 20 2 203 149 57 40 152 73 2,433
Tennessee 0 0 0 56 26 14 18 22 11 19 9 4 18 33 24 16 8 7 30 315
Texas 0 0 0 202 720 176 195 354 260 64 115 89 27 1,868 183 379 275 370 135 5,412
Utah 0 0 0 0 1 11 52 158 70 26 2 2 3 5 7 2 8 13 62 422
Vermont 0 0 0 1 3 0 0 0 0 0 0  0 1 3 2 0 0 2 3 15
Virginia 0 0 0 29 26 5 1 5 5 1 5 5 9 30 6 7  21 8 13 176
Washington 0 0 0 0 0 0 0 3 0 3 38 2 0 4 1 12 24 9 13 109
West Virginia 0 0 0 3 2 0 0 1 0 1 0 0 2 10 1 0 0 1 1 22
Wisconsin 0 0 0 52 17 12 17 21 13 8 1 2 3 57 21 6 9 13 51 303
Wyoming 0 0 0 2 375 10 12 65 181 8 12 6 3 7 41 5 8 11 7 753
Total 62 21 66 4,156 9,862 2,539 3,000 4,269 3,630 1,356 720 1,021 712 5,674 2,469 2,205 2,175 2,149 2,097 48,183

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West Nile virus neuroinvasive disease cases reported to CDC by state of residence, 1999-2017

West Nile virus neuroinvasive disease cases reported to CDC by state of residence, 1999-2017
State 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 Total
Alabama 0 0 2 34 25 15 6 8 17 11 0 1 5 38 3 0 5 13 40 223
Alaska 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Arizona 0 0 0 0 7 215 52 68 50 62 12 107 49 87 50 80 67 57 98 1,061
Arkansas 0 0 0 32 23 17 13 24 13 7 6 6 1 44 16 9 16 8 15 250
California 0 0 0 1 2 291 305 81 154 292 67 72 110 297 237 561 585 335 401 3,791
Colorado 0 0 0 6 621 41 21 66 99 17 36 26 2 62 90 46 57 59 29 1,278
Connecticut 0 0 6 10 12 0 4 7 2 5 0 7 8 12 1 3 8 1 2 88
Delaware 0 0 0 0 12 0 1 0 1 0 0 0 1 2 3 0 0 0 0 20
Dist. of Columbia 0 0 0 14 3 1 3 0 0 4 2 3 10 8 0 1 3 1 1 54
Florida 0 0 12 28 61 33 10 3 3 3 2 9 20 52 5 12 12 6 4 275
Georgia 0 0 6 28 27 14 9 2 23 4 4 4 14 46 4 11 13 4 44 257
Hawaii 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Idaho 0 0 0 0 0 1 3 139 11 4 9 0 1 5 14 6 5 3 16 217
Illinois 0 0 0 553 30 29 137 127 63 12 5 45 22 187 86 36 51 98 72 1,553
Indiana 0 0 0 180 15 8 11 27 14 3 2 6 7 46 19 9 16 15 18 396
Iowa 0 0 0 27 81 13 14 22 12 3 0 5 5 11 24 5 4 16 10 252
Kansas 0 0 0 22 89 18 17 17 14 14 4 4 4 20 34 18 12 18 12 317
Kentucky 0 0 0 53 11 1 5 5 4 3 3 2 4 13 1 0 1 5 9 120
Louisiana 0 0 1 204 101 85 117 91 27 18 10 20 6 155 34 61 41 38 38 1,047
Maine 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 1 0 0 2
Maryland 0 0 6 22 49 10 4 10 6 6 0 17 10 25 11 6 31 6 5 224
Massachusetts 0 0 3 19 12 0 4 2 3 1 0 6 5 25 7 5 7 10 5 114
Michigan 0 0 0 557 14 13 54 43 16 11 1 25 32 141 24 1 16 42 32 1,022
Minnesota 0 0 0 16 48 13 18 31 44 2 1 4 1 34 31 6 3 38 13 303
Mississippi 0 0 0 162 34 31 39 89 50 22 31 3 31 103 27 26 25 27 46 746
Missouri 0 0 0 126 39 27 17 51 61 12 4 3 6 17 24 10 23 9 17 446
Montana 0 0 0 2 75 2 8 12 37 0 2 0 1 1 10 2 3 3 3 161
Nebraska 0 0 0 84 194 7 55 45 21 7 11 10 14 42 54 41 19 35 19 658
Nevada 0 0 0 0 2 25 14 34 2 9 7 0 12 5 8 3 4 13 31 169
New Hampshire 0 0 0 0 2 0 0 0 0 0 0 1 0 1 1 0 0 0 0 5
New Jersey 0 5 12 16 21 1 3 2 1 6 3 15 2 22 10 6 23 11 6 165
New Mexico 0 0 0 0 74 32 20 3 39 5 6 21 4 24 24 19 12 6 23 312
New York 59 14 13 68 57 7 30 16 16 32 6 89 28 61 18 19 42 20 45 640
North Carolina 0 0 0 2 16 3 2 1 4 2 0 0 2 7 3 0 4 2 8 56
North Dakota 0 0 0 3 94 2 12 20 49 2 0 2 1 39 64 12 10 24 20 354
Ohio 0 0 0 310 84 11 46 36 13 14 0 4 10 76 21 10 23 12 23 693
Oklahoma 0 0 0 16 56 16 17 27 59 4 8 1 1 103 60 9 49 21 34 481
Oregon 0 0 0 0 0 0 1 7 7 3 1 0 0 0 7 7 0 2 3 38
Pennsylvania 0 0 3 42 145 10 14 8 5 12 0 19 5 33 6 11 17 12 15 357
Puerto Rico 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 1
Rhode Island 0 0 0 1 5 0 1 0 0 1 0 0 1 2 1 0 0 2 1 15
South Carolina 0 0 0 1 3 0 5 1 3 0 3 1 0 20 3 3 0 6 16 65
South Dakota 0 0 0 17 151 6 36 38 48 11 6 4 0 62 57 12 11 35 27 521
Tennessee 0 0 0 47 21 13 15 16 5 12 4 2 16 19 17 12 5 3 22 229
Texas 0 0 0 202 431 119 128 233 170 40 93 77 20 844 113 253 196 252 87 3,258
Utah 0 0 0 0 0 6 21 56 28 6 1 1 1 3 4 1 5 7 39 179
Vermont 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 0 0 2 2 7
Virginia 0 0 0 16 19 5 0 0 3 0 5 4 8 20 6 5 13 6 12 122
Washington 0 0 0 0 0 0 0 0 0 2 26 1 0 4 0 7 8 8 10 66
West Virginia 0 0 0 3 1 0 0 1 0 1 0 0 2 5 1 0 0 0 1 15
Wisconsin 0 0 0 22 7 5 11 11 7 4 1 0 2 44 17 3 6 10 47 197
Wyoming 0 0 0 0 92 2 6 15 23 0 4 2 1 3 16 0 3 8 4 179
Total 59 19 64 2,946 2,866 1,148 1,309 1,495 1,227 689 386 629 486 2,873 1,267 1,347 1,455 1,309 1,425 22,999

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West Nile virus disease cases and deaths reported to CDC by year and clinical presentation, 1999-2017

West Nile virus disease cases and deaths reported to CDC by year and clinical presentation, 1999-2017
Neuroinvasive disease Non-neuroinvasive disease Total
Year Cases
No.
Deaths
No. (%)
Cases
No.
Deaths
No. (%)
Cases
No.
Deaths
No. (%)
1999 59 7  (12) 3 0  (0) 62 7  (11)
2000 19 2  (11) 2 0  (0) 21 2  (10)
 2001  64  10  (16)  2  0  (0)  66  10  (15)
 2002  2,946 276  (9)  1,210  8  (1)  4,156  284  (7)
2003 2,866 232  (8) 6,996 32  (<1) 9,862 264  (3)
2004 1,148 94  (8) 1,391 6  (<1) 2,539 100  (4)
2005 1,309 104  (8) 1,691 15  (1) 3,000 119  (4)
2006 1,495 162  (11) 2,774 15  (1) 4,269 177 (4)
2007 1,227 117  (10) 2,403 7  (<1) 3,630 124  (3)
2008 689 41  (6) 667 3  (<1) 1,356 44  (3)
2009 386 32  (8) 334 0  (0) 720 32  (4)
2010 629 54  (9) 392 3  (1) 1,021 57  (6)
2011 486 42  (9) 226 1  (<1) 712 43  (6)
 2012  2,873 270  (9)  2,801  16  (1)  5,674 286  (5)
 2013  1,267 111  (9)  1,202  8  (<1)  2,469 119  (5)
 2014  1,347 87  (6)  858  10  (1)  2,205 97  (4)
 2015  1,455 142  (10)  720  4  (<1)  2,175 146  (7)
2016  1,309 105  (8)  840  1  (<1)  2,149 106  (5)
2017 1,425 146  (10) 672 0  (0) 2,097 146  (7)
Total  22,999 2,034  (9)   25,184  129  (<1)  48,183 2,163  (4) 

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

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Average annual incidence of West Nile virus neuroinvasive disease reported to CDC by age group, 1999-2017

Graph depicting Average annual incidence of West Nile virus neuroinvasive disease reported to CDC by age group, 1999-2016

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

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Average annual incidence of West Nile virus neuroinvasive disease reported to CDC by age group, 1999-2016 
 Age Group  Average Incidence
 <10  0.04
 10-19  0.09
 20-29  0.15
 30-39  0.27
 40-49  0.45
 50-59  0.55
 60-69  0.67
 ≥70  1.15

Average annual incidence of West Nile virus neuroinvasive disease reported to CDC by county, 1999-2017

This map shows the average annual incidence of human West Nile virus neuroinvasive disease (e.g., meningitis, encephalitis, or acute flaccid paralysis) by county from 1999-2017 with shading ranging from 0.01‐0.49, 0.50‐0.99, 1.00‐1.49, 1.50‐1.99, and greater than 2.00 per 100,000 population.  The heaviest concentration of incidents are found in the midwest region of the U.S. and the lightest concentration in the eastern half of the U.S.

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

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Average annual incidence of West Nile virus neuroinvasive disease reported to CDC by state, 1999-2017

Map of the United States showing average annual incidence of West Nile virus neuroinvasive disease reported to CDC by state, 1999-2017

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

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Average annual incidence of West Nile virus neuroinvasive disease reported to CDC by state, 1999-2017 
 State Average Incidence
Alaska 0.00
Alabama 0.25
Arizona 0.88
Arkansas 0.45
California 0.54
Colorado 1.35
Connecticut 0.13
Delaware 0.12
District of Columbia 0.48
Florida 0.08
Georgia 0.14
Hawaii 0.00
Idaho 0.73
Illinois 0.64
Indiana 0.32
Iowa 0.44
Kansas 0.59
Kentucky 0.15
Louisiana 1.23
Maine 0.01
Maryland 0.20
Massachusetts 0.10
Michigan 0.54
Minnesota 0.30
Mississippi 1.33
Missouri 0.40
Montana 0.86
Nebraska 1.91
Nevada 0.33
New Hampshire 0.02
New Jersey 0.10
New Mexico 0.81
New York 0.17
North Carolina 0.03
North Dakota 2.80
Ohio 0.32
Oklahoma 0.68
Oregon 0.05
Pennsylvania 0.15
Rhode Island 0.07
South Carolina 0.07
South Dakota 3.40
Tennessee 0.19
Texas 0.69
Utah 0.35
Vermont 0.06
Virginia 0.08
Washington 0.05
West Virginia 0.04
Wisconsin  0.18
Wyoming 1.68

West Nile virus neuroinvasive disease incidence reported to CDC by year, 1999-2017

Graph showing West Nile virus neuroinvasive disease incidence reported to CDC by year, 1999-2017

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

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West Nile virus neuroinvasive disease incidence reported to CDC by year, 1999-2017 
 Year  Incidence per 100,000 population
1999 0.02
2000 0.01
2001 0.02
2002 1.02
2003 0.99
2004 0.39
2005 0.44
2006 0.50
2007 0.41
2008 0.23
2009 0.13
2010 0.20
2011 0.16
2012 0.92
2013 0.40
2014 0.42
2015 0.45
2016 0.41
2017 0.44

West Nile virus disease cases reported to CDC by week of illness onset, 1999-2017

Graph showing West Nile virus disease cases reported to CDC by week of illness onset, 1999-2017

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

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West Nile virus disease cases reported to CDC by week of illness onset, 1999-2017 
Month Week of Onset Number of Cases
January 1 6
2 2
3 1
4 1
February 5 3
6 2
7 0
8 0
March 9 7
10 1
11 11
12 4
April 13 4
14 6
15 8
16 11
17 8
May 18 17
19 26
20 50
21 46
June 22 102
23 134
24 176
25 287
July 26 420
27 813
28 1,227
29 1,837
30 2,615
August 31 4,268
32 4,631
33 5,509
34 5,436
September 35 5,171
36 4,425
37 3,659
38 2,407
October 39 1,684
40 1,111
41 652
42 425
43 308
November 44 189
45 144
46 103
47 57
December 48 55
49 49
50 29
51 14
52 27
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