Table 1.

Total number of counties in CONUS, and their corresponding states, with at least one neuroinvasive WNV report by date.

Years	Counties/States; First Report	Counties/States; Last Report
1999–2004	Affected counties: 1223 ¶; AL, AZ, AR, CA, CO, CT, DE, DC, FL, GA, ID, IL, IN, IA, KS, KY, LA, MD, MA, MI, MN, MS, MO, MT, NE, NV, NH, NJ, NM, NY, NC, ND, OH, OK, PA, RI, SC, SD, TN, TX, UT, VA, WV, WI, WY.	Affect. CTYs: 246; AL, AR, CA, CO, CT, FL, GA, IL, IN, IA, KS, KY, LA, MD, MI, MN, MS, MO, MT, NE, NH, NM, NY, NC, ND, OH, OK, PA, RI, SD, TN, TX, VA, WV, WI, WY
2005–2009	Affect. CTYs: 347; AL, AZ, AR, CA, CO, FL, GA, ID, IL, IN, IA, KS, KY, LA, MI, MN, MS, MO, MT, NE, NV, NM, NY, NC, ND, OH, OK, OR, SC, SD, TN, TX, UT, VA, WA, WV, WI.	Affect. CTYs: 211; AL, AR, CA, CO, FL, GA, ID, IL, IN, IA, KS, KY, LA, MN, MS, MO, MT, NE, NV, NM, NY, NC, ND, OH, OK, OR, PA, SD, TN, TX, UT, VA, WA, WV, WI.
2010–2014	Affect. CTYs: 257; AL, AZ, AR, CA, CO, FL, GA, ID, IL, IN, IA, KS, KY, LA, ME, MD, MA, MI, MN, MS, MO, MT, NE, NH, NJ, NM, NY, NC, ND, OH, OK, OR, PA, RI, SC, SD, TN, TX, VT, VA, WA, WV, WI, WY, PR.	Affect. CTYs: 373; AL, AZ, AR, CA, CO, CT, DE, FL, GA, ID, IL, IN, IA, KS, KY, LA, MD, MI, MN, MS, MO, MT, NE, NH, NJ, NM, NY, NC, ND, OH, OK, OR, PA, RI, SC, SD, TN, TX, UT, VT, VA, WA, WV, WI, WY, PR.
2014–2019	Affect. CTYs: 209; AL, AK, AR, CA, CO, CT, FL, GA, IL, IN, IA, KS, KY, LA, MD, MA, MI, MN, MS, MO, MT, NE, NJ, NM, NY, NC, ND, OH, OK, OR, PA, SC, SD, TN, TX, UT, VT, VA, WA, WV, WI.	Affect. CTYs: 1206; AL, AK, AZ, AR, CA, CO, CT, DE, DC, FL, GA, ID, IL, IN, IA, KS, KY, LA, ME, MD, MA, MI, MN, MS, MO, MT, NE, NV, NJ, NM, NY, NC, ND, OH, OK, OR, PA, RI, SC, SD, TN, TX, UT, VT, VA, WA, WV, WI, WY

Data source: ArboNET; WNV: West Nile Virus; CONUS: Continuous Unites States; ^¶ In the 1999–2004 period, out of all counties with at least one neuroinvasive WNV case, 1223 counties had their first report (gray column), while only 246 counties had their last report in this period (white column).