The fever set in over the weekend.

Chills, then a shivering fit.

Rick Wilson figured it might be malaria.

Wilson, a theology professor at Mercer University, had traveled to the African nation of Liberia in June. It was the beginning of the rainy season there. Mosquitoes swarmed at night. Wilson was with a group of students for a three-week study-abroad course.

When he returned to the U.S. on June 18, he felt fine. He’d taken daily doses of antimalarial medicine before, during and after the trip.

Saturday morning, he mowed his lawn. Then, he said, “it hit me like a ton of bricks.”

That night he was in bed, trembling uncontrollably, buried in blankets.

“But blankets don’t do any good when you’ve got a chill like that,” Wilson, 59, said. “It scared my wife. She said, ‘We’re going to the emergency room.’ ”

His temperature hit 103 degrees.

Wilson told an emergency-room doctor at a Macon hospital that it might be malaria. Blood tests confirmed it.

According to the Centers for Disease Control and Prevention, there are about 1,500 cases of malaria diagnosed in the U.S. each year, mostly in people who’ve recently gone overseas. The incubation period is typically anywhere from a week to a month.

Wilson said because he’d taken antimalarial pills, which tourists are routinely advised to take, the illness was held in check longer.

Dr. Harold Katner, a local infectious disease expert, treats a couple of patients a year who suffer from malaria. One of them, a child who’d been to India, didn’t have symptoms for four months after returning.

In Wilson’s case, Katner said, the mosquito-borne sickness was apparently resistant to the antimalarial drug he took.

Wilson, who has been to Africa seven times in the past five years, said, “I got ahold of a mosquito, or you could say a mosquito got ahold of me.”

He is being treated with antibiotics and quinine.

“It’s great fun,” he joked from his hospital room Thursday.

Wilson hopes to go home by the weekend and return to work sometime next week.

“I’ve thought about looking up (a picture of) the malaria parasite online,” he said, “and having a framed photograph on my desk.”

To contact writer Joe Kovac Jr., call 744-4397.