BRYAN, Texas -

People living in Brazos County want to know where an E. coli strain came from that sickened five people, including two children.

The brothers -- 4-year-old Jack Melton and 17-month-old Noah Melton -- contracted E. coli strain 0157H7, which turned into hemolytic-uremic syndrome. The brothers were listed in fair condition at Texas Children's Hospital on Wednesday. Both boys underwent blood transfusions and dialysis.

The strand affects about 100,000 people in the U.S. each year. Hemolytic-uremic syndrome, or HUS, is a condition that results from the premature destruction of red blood cells, which can cause kidney failure.

"When kids get sick, parents often rush to give children antibiotics and it's been pretty well shown now that when people have this infection, antibiotics can actually make things worse instead of better," said Dr. Jeffrey Starke, the director of Infection Control at Texas Children's Hospital, "make it more likely that you will develop this severe complication."

Three adults have also been confirmed to have the same E. coli strain, said the Brazos County Health Department. The latest case was confirmed Monday.

Three more cases are under investigation.

"This bug is threatening our food supply," said Dr. Herbert DuPont with the University of Texas School of Public Health.

DuPont said the E. coli develops in the intestines of cattle and infects beef, fruits, and vegetables.

"The food that you bring in from the grocery, the lettuce and the spinach, should be thoroughly washed," he said.

It's unclear where the people were infected.

"It's a tricky puzzle that people are trying to piece together," said Dr. Eric Wilke with the Brazos County Health Department. "There's been a second survey where we contact all the local hospitals and say can we double check and make sure there's nothing, and so that's been done. I don't see any new cases on the horizon at this point."

"You wonder where it's coming from and how many people it's going to hit before they figure it out," said Cystal Emsoff. "I've got to worry about what kind of things I'm exposing her to and I'm certainly going to keep an eye out if she starts acting sick anytime soon."

It's very scary. You don't know what's going to happen," said

Kristie Mitchell.

Allen Duty, the pastor at New Life Baptist Church, the family's church, said the community is praying for the boys' recovery.

"They've said many times they would not be able to make it through the trials without the support and the Lord and the church coming around to support and help them in this trying time, and so it's been an amazing thing to see," he said.

You can offer well wishes to the family on this Facebook page.

According to the Center for Disease Control, symptoms include stomach cramps, diarrhea, and vomiting. The usual recovery time is about one week.

To avoid contracting E. coli, doctors recommend frequently washing your hands, avoiding unpasteurized dairy products, and cooking meats thoroughly.