Most West Nile Virus (WNV) infections are mild and often clinically unapparent. Approximately 20% of those infected develop a generally mild illness, WNV fever syndrome, characterized by fever, headache, malaise, nausea, body aches, and sometimes associated with a rash and swollen lymph glands. The incubation period is 5 to 15 days. The symptoms generally last 3 to 7 days; however, some patients have symptoms that persist for weeks to months.
Approximately 1 in 150 infections will result in severe neurological disease, neuroinvasive WNV, characterized by encephalitis, meningitis or acute flaccid paralysis. Clinical manifestations may include fever, headache, stiff neck, altered mental status (ranging from confusion to coma) and additional signs of brain dysfunction (e.g., weakness, paralysis, nerve palsies, abnormal reflexes, convulsions and abnormal movements).
Case fatality rates for neuroinvasive WNV range from 3% -15%, with advanced age the most significant risk factor for death. Patients older than 70 years of age are at particularly high risk for death.
Additional information can be found on CDC's website: Guidance for Clinicians.
Reporting the Disease
West Nile Virus is a reportable disease under N.J.A.C. section 8:57, and must be reported to the Cape May County Department of Health at 609-463-6690 or by fax 609-463-6580 or by email.
The New Jersey Department of Health and Human Services will approve testing at the Public Health and Environmental Laboratory (PHEL) only for neuroinvasive WNV. In addition, all commercial laboratory test results positive for WNV will also be submitted to the PHEL for testing. Only tests confirmed by the PHEL are considered confirmed for surveillance purposes.