The normal values for west nile virus antibodies are <1.2, and this range is unisex for all age groups.
If IgM WNV and IgG WNV antibodies are detected in the initial sample, then it is likely that the person contracted the WNV infection at least 3 weeks prior to the test.
If the IgG WNV antibody is positive and the IgM WNV antibody level is low or not detectable, then it is most likely that the person was previously exposed to WNV but is not currently infected.
If the WNV IgG antibody levels have not changed or have decreased, this would indicate a past but not recent infection.
The presence of WNV antibodies may indicate an infection but cannot be used to predict the severity of an individual person’s symptoms or their prognosis.