Mother Recounts How Healthy Teen Daughter Died From Simple Flu In New Documentary 'Unseen Enemy'

A mother who lost her healthy teen daughter to flu is speaking up and raising awareness about influenza in a new documentary. Gwen Zwanziger of Owatonna, Minnesota details her daughter's story in "Unseen Enemy," which will air on CNN on Friday, April 7 at 8 p.m.

Zwanziger told CNN she continues to cry over Shannon's death after all these years. She lost her daughter, who was 17-year-old, in 2014 following a flu complication.

Zwanziger said Shannon came home from school with fever one December afternoon. She spent the rest of that week in bed but when her fever spiked, the family took her to the hospital.

Doctors diagnosed her condition as the flu, which would eventually "run its course." Only, Shannon's health deteriorated and nobody realized her organs were failing. Five days after she developed the fever, Shannon died.

Zwanziger revealed it was her daughter's choice not to get vaccinated when flu season peaked during winter that year. "If I had pushed her into getting a flu shot, then I wouldn't have the guilt about "what if,'" the mom said.

Zwanziger became an advocate for flu awareness since her daughter's death. "Please take the flu seriously," the mom encouraged other parents. She also said parents should let loved ones stay home if they are sick so to prevent passing the disease to others.

Award-winning filmmaker Janet Tobias took interest in the Zwanziger family's story especially when diseases like Zika, Ebola and influenza continue to affect thousands of victims all over the world. Tobias, who made the documentary "Unseen Enemy" about viruses, said everyone can do something to help stop these diseases from spreading, as per Owatonna People's Press.

"It's going to take all of us, and what each of us decides to do, so that's not going to work sick, getting vaccines and washing our hands," Tobias said. "It all makes a difference." Lean more about "Unseen Enemy" in the video below.