Betty Best knew that something was wrong when her husband Howard slept through a NASCAR race on television.

They had been married 65 years, and she knew he never, ever slept through NASCAR.

"All that day, I sat there and watched him, and I knew something was wrong with my husband," she said.

When he woke, he had trouble moving his arms and legs, so they went to the hospital. Doctors diagnosed dehydration, gave him fluids, and sent him home.

But Howard Best wasn't himself anymore, his wife said. He lacked energy. He wasn't hungry. He got a fever.

A second trip to the hospital revealed that he had the West Nile virus.

"That's when I knew my husband was going to go," Betty Best told CNN affiliate WRAL in North Carolina.

He got weaker and weaker, finally losing the ability to speak, before he died August 9.

"Just as easy as it could be. No struggles, just gave it up," Betty Best said of the man she married when she was 17.

The United States is experiencing its biggest spike in the number of West Nile virus cases since 2004.

Howard Best is one of at least 26 Americans, by official federal count, to have died in the outbreak of the disease carried by infected mosquitoes. His widow thinks he was probably bitten as he worked on the tomatoes in the garden he loved.

She's grateful that he didn't suffer or have to spend time in a nursing home at the end of his life.

"If you got to go, just get out of here quickly," Betty Best said.

Suddenly, a widow after a lifetime with Howard, Betty is now ready to go, too, she says.

"I don't have a lot of desire to hang around here now," she said. "And I hope my children understand. You've been with someone 65 years and you go put them in the ground and a part of you goes in there, too."

Howard Best lived and died in North Carolina, but Texas is the state hardest hit by the current outbreak.

Dallas Mayor Mike Rawlings declared Wednesday that the city is facing an emergency as the West Nile virus spreads, killing at least 16 people in Texas.

The Dallas declaration clears the way for aerial spraying to kill the infected mosquitoes that carry the disease.

There were 26 deaths and 693 cases in 32 states nationwide as of Tuesday evening, according to the U.S. Centers for Disease Control and Prevention. Spokesman Tom Skinner told CNN the agency is updating case counts once a week after it has analyzed reports. The next report on its website is set for August 21.

Dallas County was already under a state of emergency declared last week.