CDC continues to report cases of West Nile Virus, even this late in the season.  Forty-eight states have reported infection in birds, people and/or mosquitoes.  As of December 11, 2012, a  total of 5,387 cases of West Nile virus disease in people, including 243 deaths, have been reported to CDC.  About half the cases were classified as neuroinvasive disease (such as meningitis or encephalitis) and half were classified as non-neuroinvasive disease.

The 5,387 cases reported thus far in 2012 is the highest number of West Nile virus disease cases reported to CDC through the second week in December since 2003. Eighty percent of the cases have been reported from 13 states (Texas, California, Louisiana, Illinois, Mississippi, South Dakota, Michigan, Oklahoma, Nebraska, Colorado, Arizona, Ohio, and New York) and a third of all cases have been reported from Texas.

In addition to case numbers it is also important to look at Incidence Rate or cases per 100,000 people.  Note a number of the states listed above which contributed to 80% of the cases had a low incidence rate such as New York and Ohio and other states such as South and North Dakota, Texas, Louisiana, Arizona, and Illinois have high case numbers and high incidence rates.

WNV Neuroinvasive Disease as of 11 Dec 2012
2012 Population NID cases Incidence (cases per 100,000 population)
South Dakota 824,082 62 7.5
North Dakota 683,932 39 5.7
Mississippi 2,978,512 103 3.5
Louisiana 4,574,836 155 3.4
Texas 25,674,681 785 3.1
Oklahoma 3,791,508 101 2.7
Nebraska 1,842,641 40 2.2
Arkansas 2,937,979 44 1.5
Illinois 12,869,257 184 1.4
Michigan 9,876,187 138 1.4
Arizona 6,482,505 82 1.3
Colorado 5,116,796 62 1.2
New Mexico 2,082,224 24 1.2
District of Columbia 617,996 6 1.0
United States 311,591,917 2734 0.9
California 37,691,912 278 0.7
Indiana 6,516,922 45 0.7
Alabama 4,802,740 33 0.7
Wisconsin 5,711,767 39 0.7
Kansas 2,871,238 19 0.7
Ohio 11,544,951 76 0.7
Minnesota 5,344,861 34 0.6
Wyoming 568,158 3 0.5
Georgia 9,815,210 42 0.4
South Carolina 4,679,230 20 0.4
Maryland 5,828,289 24 0.4
Iowa 3,062,309 11 0.4
Massachusetts 6,587,536 23 0.3
Connecticut 3,580,709 12 0.3
Idaho 1,584,985 5 0.3
New York 19,465,197 60 0.3
Tennessee 6,403,353 18 0.3
West Virginia 1,855,364 5 0.3
Missouri 6,010,688 16 0.3
New Jersey 8,821,155 22 0.2
Virginia 8,096,604 20 0.2
Florida 19,057,542 46 0.2
Delaware 907,135 2 0.2
Pennsylvania 12,742,886 28 0.2
Rhode Island 1,051,302 2 0.2
Nevada 2,723,322 5 0.2
Vermont 626,431 1 0.2
Utah 2,817,222 3 0.1
Montana 998,199 1 0.1
Kentucky 4,369,356 4 0.1
New Hampshire 1,318,194 1 0.1
Maine 1,328,188 1 0.1
North Carolina 9,656,401 6 0.1
Washington 6,830,038 4 0.1
Alaska 722,718 0 0.0
Hawaii 1,374,810 0 0.0
Oregon 3,871,859 0 0.0

Table provided by SD DOH, Dr. Lon Kightlinger, State Epidemiologist

Kim Cassel