A 64-year-old Camden man and a 50-year-old Collingswood woman have been confirmed as the second and third cases of the mosquito-borne West Nile virus in Camden County this year, health officials reported Friday.

The county's first case - involving a 42-year-old Voorhees man - was confirmed Sept. 7 to the Camden County Department of Health and Human Services.

The three are among at least 22 with West Nile virus in New Jersey; one of the victims, a Burlington County man, died last week.

In Pennsylvania, 20 residents have tested positive for the virus. One, an elderly Luzerne County man, died, officials said.

The deaths and rising number of cases have prompted state and local agencies to increase efforts to monitor and combat the virus, through surveillance, testing, and spraying of pesticide.

Across the nation, 2,636 cases of the virus - the highest number ever recorded by the second week of September - have been reported this year to the Centers for Disease Control and Prevention. One hundred and eighteen people have died.

The Camden resident affected by the virus was treated at a hospital and released, The Collingswood resident was not hospitalized. Both believe they were exposed to mosquitoes were in their own yards, officials said.

The Voorhees resident, who also was not hospitalized, has recovered from the mosquito bite that he believes he received in Cape May County, according to officials.

As of Sept. 11, 48 states have reported West Nile virus infections in people, birds, or mosquitoes, the CDC said.

Two-thirds of the cases have been reported from six states - Texas, Louisiana, South Dakota, Mississippi, Michigan, and Oklahoma - and 40 percent of all cases have been recorded in Texas.

In the Philadelphia area, two cases have been reported in the city, three in Delaware County; one in Montgomery; one in Bucks, and one in Chester. In South Jersey, besides the three cases in Camden County and one in Burlington County, one case each has been reported from Atlantic, Gloucester, Cape May, and Salem Counties.

All three Camden County victims were exposed to the virus in early to mid-August, officials said. Their initial laboratory specimens tested positive for West Nile virus.

Those specimens were sent to the Public Health Environmental Laboratories in Trenton for further identification. To be considered a "confirmed" case, the specimen must be verified by PHEL.

The Camden County Mosquito Commission regularly checks several thousand suspected mosquito breeding sites across the county and sprays when needed.

"Our county mosquito commission works with the Public Health Environmental Laboratories in Trenton to verify the presence of West Nile virus in their samples," said Freeholder Jeffrey Nash, liaison to the Camden County Mosquito Commission.

"When a pool tests positive for West Nile virus, the Mosquito Commission returns within 24 hours to spray the area," he said.

Contact Edward Colimore at 856-779-3833 or ecolimore@phillynews.com.