Micaella Boer, 18, is one of four confirmed cases of E. coli O157:H7 in Fredericton. (Facebook)

Quick thinking by a Fredericton teen on Facebook who was hospitalized with E. coli may have made things a lot easier for a male friend who read her posting about her symptoms, and was later diagnosed with the illness.

Micaella Boer, 18, was first hospitalized in Fredericton last week. Micaella and her young male friend are two of the four confirmed cases of E. coli O157:H7 in the city, according to Micaella's mother, Victoria Boer.

Micaella's friend sought help for the illness after he saw her Facebook post describing her symptoms and realized his were similar.

Doctors sent him home with anitbiotics.

But Micaella and her father, Scott Boer, did some online research on the effects of E. coli and taking antibiotics.

They found that, in certain cases, antibiotics may make E. coli-related illness worse. Micaella also immediately messaged her friend, telling him not to take the medication.

"The boy that was admitted, he actually texted Micaella and said, 'What were your symptoms?' She told him what it was and he said, 'I have the same thing. I'm coming in,' and he got checked," Micaella's dad said.

"But if he would have gutted it out waiting for his diarrhea to pass, he'd be four or five days into the sickness before getting admitted. Information helps."

Tim Sly, an epidemiologist and professor of risk assessment at Ryerson University's school of occupational and public health, said physicians have to be on alert, particularly when it comes to children.

Illness dubbed 'hamburger disease'

Escherichia coli, its full name, is a bacteria commonly found in the intestines of animals and humans. There are hundreds of strains of the bacterium, but E. coli O157:H7 has been identified as dangerous to people. It was first recognized in the U.S. in 1982, when an outbreak of severe, bloody diarrhea was traced to contaminated hamburgers, leading the illness to be dubbed "hamburger disease."

E. coli O157:H7 secretes a powerful toxin that can destroy red blood cells leading to severe illness, high blood pressure and kidney damage. (CBC)

During the Walkerton, Ont., tainted water scandal more than a decade ago, doctors discovered giving antibiotics to children infected with E. coli O157:H7 appeared to increase the amount of toxin released and the chance of them developing hemolytic uremic syndrome (HUS), a fatal kidney disorder, Sly said.

Both Micaella and her friend are now being treated at Saint John Regional Hospital. Micaella's mother said it's a good thing her daughter was able to alert her friend.

"Micaella and Scott had done some research on not taking antibiotics because it makes the situation worse," Victoria said.

"[Doctors], at first, thought maybe he didn't have [E. coli] and they had sent him home with antibiotics, but Micaella and Scott texted him and said, 'Don't take them, just in case,' because everything was happening so fast. So, he didn't take them and it was really good that he hadn't."

The source of the outbreak of the infectious bacteria in Fredericton is unclear. Public health is investigating but it could be another week before lab results are available.