Symptoms include fever and fatigue.
West Nile is transmitted by mosquitoes that feed on infected birds.
West Nile virus has been identified among birds and mosquitoes in every county except Atlantic, Cumberland or Salem county.
There were 30 cases of West Nile virus in New Jersey last year, including two deaths.
People are advised to apply insect repellant to their clothing and limit outdoor activities at dawn, dusk and during evening hours.