Follow KDKA-TVFacebook | Twitter

ALTOONA, Pa. (KDKA) — A teenager from Altoona is among at least a dozen people in Pennsylvania who have been sickened by an E. coli outbreak linked to romaine lettuce.

More than 60 people from 16 states have been infected. Among those states, Pennsylvania has seen the most confirmed cases.

Due to privacy concerns, health officials have not released the locations of the cases. However, CBS News spoke with a teenager from Altoona who said she was sickened. Mia Zlupko said, at first, she thought it was just a stomach bug.  She was hospitalized, but has since recovered from her illness.

“All the doctors came in, like it was a big surprise. It’s E. coli,” Zlupko said.

Zlupko loves to dance and enjoys eating healthy foods like salads. However, after eating a romaine salad from a local store, she started throwing up and having abdominal issues. Initially, she had no idea what was wrong.

“It’s kind of hard to sit in a hospital and not know what’s wrong with you and you feel so drained and worn out,” Zlupko said.

When they found out what was wrong, her mom, Tina, could breathe again.

“We were all shocked. It was such a relief,” said Tina Zlupko.

Over the weekend, health officials expanded their warning about the romaine lettuce linked to the outbreak. They say if you have romaine lettuce in your home and don’t know where it’s from, you should throw it away.

The exact source of the E. coli outbreak hasn’t been identified, but the Centers for Disease Control and Prevention suspect it started in the area around Yuma, Arizona. That’s where 90 percent of the nation’s winter romaine lettuce is produced.

“It can be pretty frustrating for consumers when they heard since 2011 that new food safety standards are going to be in place,” said Director of Food Safety at the Pew Charitable Trusts Sandra Eskin.

E. coli is a bacteria that can cause severe illness, including bloody diarrhea and hemolytic uremic syndrome, which is a type of kidney failure. Symptoms of an E. coli infection include bloody diarrhea, abdominal cramping and vomiting.

If you have had any of these symptoms lately, you should consult with a medical professional. If you currently have any of these symptoms, you should seek medical attention. You can also call the department at 1-877-PA-HEALTH.

Some food safety experts say they expect that number of people infected by the outbreak to continue to rise.

Watch & Listen LIVE