MONTICELLO — With a growing number of Lyme disease cases in Minnesota, one family from Monticello has been hit particularly hard with three members diagnosed.

Joan Schuster and her two children, 14-year-old Alyssa and 13-year-old Jack, were diagnosed with Lyme disease in 2015. The infection spreads through the bite of a blacklegged tick, usually caused by the bacterium Borrelia burgdorferi.

An estimated 329,000 people in the U.S. are diagnosed with Lyme disease annually. Typical symptoms include fever, headache, fatigue and a rash at the site of a tick bite.

“I don’t wish this upon my worst enemy,” Schuster said. “It’s one of the cruelest diseases out there. It has no mercy on you.”

Minnesota Department of Health officials say the number of cases in the state has jumped 142 percent in the past twenty years. The blacklegged tick has expanded its territory north and west across the state, moving into areas that used to be considered to be lower risk.

Researchers at Mayo Clinic last year discovered Borrelia mayoni, a species of bacteria that also causes Lyme disease in humans.

Schuster said it is not known how her family contracted the disease, but they used to live in the deep woods near Becker, Minnesota.

“Ticks were very prevalent where we lived, we were constantly pulling ticks off of us, whether we had a bullseye rash, I can’t really recall,” Schuster said.

The Centers for Disease Control and Prevention reports that 70 to 80 percent of those included in its surveillance system reported having a rash.

The CDC doesn’t recognize the chronic form of the disease, saying accuracy of testing depends upon the disease’s stage. Schuster said her medical insurance no longer covers their medications for chronic treatment as a result.

The family spends $2,500 on prescriptions each month.

“I’ll do anything to feel better,” Schuster said. “Years ago, you told me I was going to put a pill down my throat, I never was a pill taker, but we have to if we want a life, and that is what we are looking for, is our future. Someday, it will come back.”