MILWAUKEE (WTAQ) - Wisconsin health officials confirmed Thursday that two elderly women died, after they had probable cases of the West Nile virus.

The victims were a 78-year-old Greenfield woman from Milwaukee County, and a 71-year-old woman from Waukesha County.

More tests are needed before federal officials can confirm that West Nile caused the deaths. If that’s the case, they would be Wisconsin’s first deaths from the mosquito-borne West Nile virus since 2008.

As of Wednesday, the state had one confirmed case and 12 probable cases – the most since 2007. West Nile has also been known to kill birds and horses.

Nationally, 87 human deaths have been reported this summer – and almost 2,000 people have fallen ill.

The Centers for Disease Control says there is no licensed vaccine for West Nile. When the illness first surfaced a decade ago, common bug sprays advertised themselves as a good way to avoid the virus.

Less than one-percent of West Nile patients get seriously ill.

Paul Biedrzycki of the Milwaukee Health Department says he expects more cases in what he calls an “unusual year” for West Nile. He says residents should make sure they don’t have stagnant water near their homes, so they don’t create breeding grounds for the mosquitoes that carry the virus.