Doctors for the county health department say the men in their 50s have the most serious symptoms which is a form of encephalitis.
State monitors report more mosquitoes are carrying the dangerous virus this year than during any previous summer since testing began 13 years ago.
August and September are typically the peak season, but experts say the mild winter and warm temperatures in spring allowed the mosquito population to bloom.
Even if you're bitten, most people don't get sick, but there is a slight risk for severe complications.
"Patients may have severe headaches, neck pain, higher fevers, lethargy, malaise, fatigue, and it can advance in coma and potentially be lethal," Dr. George Avetian, the Delaware County Senior Medical Advisor, said.
There is no vaccine and no specific treatment for West Nile.
So the advice is 'always be proactive.'
Drain anything with standing water including bird baths, kiddie pools, spare tires, empty flower pots, and even trash cans.
Wear insect repellant on exposed skin during dawn and dusk, when mosquitoes are most active.
The Montgomery County Health Department was taking offensive measures against the insects too on Monday night.
Crews were out spraying in Lower Merion, mostly in parts of Wynnewood and Ardmore.