Myelitis

This report summarizes West Nile virus (WNV) surveillance data reported to CDC through ArboNET as of 3 a.m. Mountain Daylight Time, October 18, 2005.

Forty-two states have reported 2,316 cases of human WNV illness in 2005 (Figure and Table 1). By comparison, in 2004, a total of 2,151 WNV cases had been reported as of October 19, 2004 (Table 2). A total of 1,227 (57%) of the 2,163 cases for which such data were available in 2005 occurred in males; the median age of patients was 51 years (range: 3 months--98 years). Date of illness onset ranged from January 2 to October 11; a total of 66 cases were fatal.

A total of 364 presumptive West Nile viremic blood donors (PVDs) have been reported to ArboNET during 2005. Of these, 85 were reported from California; 54 from Texas; 52 from Nebraska; 22 from Louisiana; 20 from Arizona; 19 from Kansas; 17 from Iowa; 16 from South Dakota; 11 from Oklahoma; 10 from Minnesota; nine from Illinois; five each from Michigan, New Mexico, and North Dakota; four each from Alabama, Pennsylvania, and Utah; three each from Nevada and Wisconsin; two each from Colorado, Indiana, Mississippi, Montana, and Ohio; and one each from Idaho, Kentucky, Missouri, New York, North Carolina, and Oregon. Of the 364 PVDs, three persons aged 53, 56, and 72 years subsequently had neuroinvasive illness, seven persons (median age: 41 years; range: 17-64 years) subsequently had other illnesses, and 76 persons (median age: 46 years; range: 17-78 years) subsequently had West Nile fever.

In addition, 3,930 dead corvids and 831 other dead birds with WNV infection have been reported from 45 states. WNV infections have been reported in horses from 30 states; five dogs from Idaho, Minnesota, and Nebraska; four squirrels from Arizona; and five unidentified animal species in four states (Arizona, Illinois, North Carolina, and Texas). WNV seroconversions have been reported in 1,150 sentinel chicken flocks from 16 states. Eight seropositive sentinel birds have been reported from Michigan. One seropositive sentinel horse was reported from Minnesota. A total of 10,561 WNV-positive mosquito pools have been reported from 41 states and the District of Columbia.

Additional information about national WNV activity is available from CDC at http://www.cdc.govlncidod/dvbid/ westnile/index.htm and at http://wesmilemaps.usgs.gov.

COPYRIGHT 2005 U.S. Government Printing Office
COPYRIGHT 2005 Gale Group