Sorted By Test Name - Mayo Medical Laboratories

WNV
84186
WNVC
West Nile Virus (WNV) Antibody, IgG and IgM, Serum
Clinical Information: West Nile virus (WNV) is a mosquito-borne flavivirus (single-stranded RNA)
that primarily infects birds but occasionally infects horses and humans. WNV was first isolated in 1937
from an infected person in the West Nile district of Uganda. Until the viral infection was recognized in
1999 in birds in New York City, WNV was found only in the Eastern Hemisphere, with wide distribution
in Africa, Asia, the Middle East, and Europe.(1-3) In 2002, a total of 3,389 human cases of WNV
infection were reported from 37 states (794 cases in Illinois); 2,354 (69%) presented with
meningoencephalitis, 704 (21%) had West Nile fever, and 331 (10%) had an unspecified illness.(2)
Overall, the WNV epidemic in the United States was the largest arboviral meningoencephalitis outbreak
documented in the Western hemisphere. In addition, 33 cases of probable WNV infection occurred among
persons who had received blood components in the month before illness onset.(3) Most people who are
infected with WNV will not have any type of illness. It is estimated that about 20% of those who become
infected will develop West Nile fever with mild symptoms, including fever, headache, myalgia, and
occasionally a skin rash on the trunk of the body. About 1 of 150 WNV infections (