Maricopa and Pinal counties have recorded their first West Nile deaths of the season, bringing the total for the state this year to three. The first West Nile fatality of 2006 occurred in Pima County.
The deaths occurred as public health officials are reporting a late season peak in West Nile activity.
Humans contract West Nile virus through the bites of infected mosquitoes that have fed on sick birds, which are the carriers of the disease.
Most people infected with West Nile virus will experience no symptoms. About 20 percent will develop flulike symptoms. Only about 1 percent of victims will suffer the potentially fatal form of the disease.
Health officials say 45 people have become ill in the state so far this year, including the three who died.