Number of mosquitoes carrying West Nile spikes in N.J. Here are the counties faring the worst.

Experts last month had predicted that mosquitoes testing positive for West Nile in the state would continue to increase. And, they were right.

Roughly three weeks ago, a total of 452 mosquito pools — a collection of mosquitoes trapped throughout the state — tested positive for the virus in all 21 counties.

As of Sept. 1 that number rose to 767 positive mosquito pools, a 40-percent spike in the total pools found during the same time last year, according to the New Jersey Department of Health’s most recent vector-borne surveillance report.

A few weeks ago, there were also only three people listed as having contracted West Nile in the state. But, that number rose to nine this week — the most recent being a man in Cape May County.

Here’s a break down of where people in the state have contracted West Nile virus:

• Bergen: 2
• Cape May: 1
• Essex: 1
• Hudson: 1
• Hunterdon: 2
• Ocean: 1
• Somerset: 1

As of last week,15 counties have seen an increase in West Nile virus activity this season compared with last year, according to the state Health Department.

And with West Nile activity continuing to rise throughout the state, here’s an updated breakdown of how New Jersey’s 21 counties are faring and which have had the highest concentration of mosquitoes to test positive for West Nile virus:

• Positive pools in 2018: 5
• Positive pools in 2017: 7
• Positive pools in 2016: 1