Available Laboratory Testing
Commercial laboratories offer serology by enzyme-linked immunoassay (EIA or ELISA) or IFA to detect IgM and IgG antibodies that are produced in response to WNV exposure. Laboratory tests that are IgG positive and IgM negative indicate past infection or previous exposure and do not require further investigation. Commercial laboratory tests that are positive for IgM may be false positive, especially in the absence of neuroinvasive clinical symptoms, or may exhibit serologic cross-reactivity with other diseases or closely related arboviruses. As such, commercial laboratory tests that are positive for IgM must be retested at the NJDHSS Public Health and Environmental Laboratories (PHEL). Accurate information about date of collection, date of symptom onset, travel history, and clinical symptoms are essential for test interpretation.
The NJDHSS PHEL performs IgG and IgM ELISA tests for WNV on human serum and PCR on CSF specimens. All suspect cases must be approved by the Cape May County Department of Health and NJDHSS Infectious and Zoonotic Diseases Program (IZDP) prior to submission for testing at PHEL.
For any questions concerning surveillance of human West Nile Virus, please contact the County Epidemiologist at 609-463-6690 or by email.