Skip directly to search Skip directly to A to Z list Skip directly to site content
CDC Home

West Nile Virus Update --- United States, January 1--August 14, 2007

This report summarizes 2007 West Nile virus (WNV) surveillance data reported to CDC through ArboNET as of 3 a.m. Mountain Daylight Time, August 14, 2007. A total of 27 states have reported 444 cases of human WNV illness to CDC (Figure, Table). A total of 241 (54%) cases for which such data were available occurred in males; median age of patients was 48 years (range: 2--96 years). Dates of illness onset ranged from March 25 to August 5; 15 cases were fatal.

A total of 49 presumptive West Nile viremic blood donors (PVDs) have been reported to ArboNET during 2007. Of these, 19 were reported from California; seven from Texas; five each from Colorado and North Dakota; three each from Kentucky and South Dakota; two from Minnesota; and one each from Arizona, Iowa, New Mexico, North Carolina, and South Carolina. Of the 49 PVDs, 15 persons (median age: 49 years [range: 18--79 years]) subsequently had West Nile fever.

In addition, 539 dead corvids and 165 other dead birds with WNV infection have been reported in 24 states during 2007. WNV infections have been reported in horses in 17 states, in seven squirrels in California, and in two unidentified animal species in Idaho and Montana. WNV seroconversions have been reported in 189 sentinel chicken flocks in six states (Arizona, California, Florida, Iowa, North Dakota, and Utah) and Puerto Rico. A total of 1,845 WNV-positive mosquito pools have been reported from 31 states. Additional information about national WNV activity is available from CDC at and at


Return to top.

Return to top.

Use of trade names and commercial sources is for identification only and does not imply endorsement by the U.S. Department of Health and Human Services.

References to non-CDC sites on the Internet are provided as a service to MMWR readers and do not constitute or imply endorsement of these organizations or their programs by CDC or the U.S. Department of Health and Human Services. CDC is not responsible for the content of pages found at these sites. URL addresses listed in MMWR were current as of the date of publication.

All MMWR HTML versions of articles are electronic conversions from typeset documents. This conversion might result in character translation or format errors in the HTML version. Users are referred to the electronic PDF version ( and/or the original MMWR paper copy for printable versions of official text, figures, and tables. An original paper copy of this issue can be obtained from the Superintendent of Documents, U.S. Government Printing Office (GPO), Washington, DC 20402-9371; telephone: (202) 512-1800. Contact GPO for current prices.

**Questions or messages regarding errors in formatting should be addressed to The U.S. Government's Official Web PortalDepartment of Health and Human Services
Centers for Disease Control and Prevention   1600 Clifton Road Atlanta, GA 30329-4027, USA
800-CDC-INFO (800-232-4636) TTY: (888) 232-6348 - Contact CDC–INFO
A-Z Index
  1. A
  2. B
  3. C
  4. D
  5. E
  6. F
  7. G
  8. H
  9. I
  10. J
  11. K
  12. L
  13. M
  14. N
  15. O
  16. P
  17. Q
  18. R
  19. S
  20. T
  21. U
  22. V
  23. W
  24. X
  25. Y
  26. Z
  27. #