Sgt. Herold Davis and his wife Dottie aren’t joking when they ask visitors to sanitize their hands upon entering their Fort Hood, Texas, home.

After all, their youngest son can't risk an infection.

Zachary was born with congenital diaphragmatic hernia, which means his stomach, intestines, liver, spleen and kidneys were misplaced in his chest, leaving little room for his lungs to grow, reported the Killeen Daily Herald.

The cause of CDH is unknown and affects about one out of every 2,500 births, the newspaper reported.

Zachary, who was born prematurely last October, had to undergo corrective surgery to move his stomach and patch his diaphragm hole. He also underwent eight blood transfusions.

"They had to put his organs back,” Dottie Davis told the Killeen Daily Herald.

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The Davis family recently took Zachary home from the hospital.

His doctor, Cheryl Cipriani, a neonatologist at Scott & White Hospital in Temple, said she is hopeful the boy’s lungs will grow over time.

"There is a space of air in his chest where his intestines used to be where the lungs can grow into," she told the paper. However, in the meantime, the baby requires the use of oxygen from tanks, a nebulizer and other medical equipment.

"Hopefully, the worst is over," Dottie Davis said.

Click here to read the full story from the Killeen Daily Herald and to see the family’s photo.