(ABC 6 News)- Cases of E. coli have risen across the United States in 10 states since Tuesday, including the state of Iowa.

The outbreak has been linked to the popular fast food chain McDonald’s and their quarter pounder hamburger.

According to the CDC, there are currently 49 cases that have been opened since Tuesday along with 10 hospitalizations and one death.

One doctor at Mayo Clinic, Dr. Priya Sampathkumar, said handwashing is the number one key when preparing food in order to prevent the illness. And that it can come from any type of food in general. At a restaurant, she said it’s important to know what you’re ordering.

“Making sure that when you’re ordering at a restaurant, that you’re not very sure about the food safety standards, ordering the food that is fully cooked. This is what we tell our patients who are traveling oversees also,” said Sampathkumar.

Mayo also says that some people may be more at risk than other with complications to E. coli.

“Most people will recover without any complications at all, but people again who are very young, under the age of 5, people over the age of 70, are the ones who are more likely to get complications, so those are the ones that should seek care if they think they have an E. coli infection,” Sampathkumar said.

According to the CDC, there have been no recalls yet of quarter pounder burgers. McDonald’s is unsure what ingredient is leading people to get sick.

However, several locations have already stopped serving raw onions and beef patties in some states as the investigation continues.