Three days before Christmas, Elizabeth Widders was in her upstairs bathroom, putting bows in the hair of her daughter, Liviah. As Liviah stood in the morning light, her mother noticed that her eyes had turned yellow.

She asked her husband for a second opinion. He also saw the yellow tint.

Liviah and her two siblings all had jaundice as babies, and their parents were familiar with the telltale signs.

They took Liviah to the emergency room, where she was diagnosed with acute hepatitis. Less than two weeks later, doctors removed her failing organ and replaced it with a new one.

Over the past eight months, hundreds of other families have been caught in the same situation, as their otherwise healthy children developed a disease seemingly out of the blue. The World Health Organization says there have been hundreds of probable cases in 33 countries. At least nine children have died and 38 have required a transplant.

The cases have stumped experts, who are investigating a variety of possible causes. One hypothesis is that an adenoviruses, a family of common viruses that cause flu- or cold-like symptoms, may be responsible.

The revelation that Liviah's case might be part of a larger phenomenon has galvanized her parents, who have started sharing their story in hopes of educating others.

The chances of a case like this happening are very small, according to Jack Widders, Liviah's father.

It feels like lightning could hit any family.

ImageLiviah, rear, and her sister, Juliana, swinging outside their home in Mason, Ohio.
Liviah, rear, and her sister, Juliana, swinging outside their home in Mason, Ohio.Credit...Maddie McGarvey for The New York Times
Liviah, rear, and her sister, Juliana, swinging outside their home in Mason, Ohio.
ImageLiviah is not shy about showing off her transplant scar, which she calls her “princess mark.”
Liviah is not shy about showing off her transplant scar, which she calls her “princess mark.” Credit...Maddie McGarvey for The New York Times
Liviah is not shy about showing off her transplant scar, which she calls her “princess mark.”

On December 11, Liviah began throwing up. Liviah had spent the previous night with her grandmother, who was known to treat the children with treats.

Liviah bounced back quickly, but her brother also fell ill the next day. He was sick for a few days. Liviah went to a trampoline park and decorated cookies with her neighbors while she was back at school.

Her mother noticed her eyes a week and a half later. Liviah told her that her urine was orange.

The diagnosis was a shock. Exposure to toxins, heavy drinking and the hepatitis B and C viruses are some of the possible causes of the condition. Mrs. Widders looked at her husband and wondered where she had gotten the disease.

Mrs. Widders did not know that hepatitis can be caused by other viruses.

Liviah was admitted to the Cincinnati Children's Hospital Medical Center.

Liviah's condition deteriorated over the next few days.

Toxic substances such as ammonia can travel to the brain if the organ is not working properly, which is one of the primary roles of the liver. As Liviah's ammonia levels increased, she became angry and enraged.

Her natural clotting response was slowed because of the damage to her liver, and she was at high risk for bleeding problems.

Doctors gave Liviah steroids to reduce inflammation and a compound called lactulose to help flush out ammonia. She had a lot of tests, including a liver biopsy. Mr. and Mrs. Widders were at the hospital while relatives looked after their daughter.

Liviah woke up on Christmas Day and opened some gifts, including Hungry Hungry Hippos.

ImageLiviah getting a scan during her stay at Cincinnati Children’s Hospital in December, before her transplant.
Liviah getting a scan during her stay at Cincinnati Children’s Hospital in December, before her transplant.Credit...via Jack and Liz Widders
Liviah getting a scan during her stay at Cincinnati Children’s Hospital in December, before her transplant.
ImageLiviah returned briefly to the hospital after a liver rejection episode. She is taking medications to prevent another.
Liviah returned briefly to the hospital after a liver rejection episode. She is taking medications to prevent another.Credit...Maddie McGarvey for The New York Times
Liviah returned briefly to the hospital after a liver rejection episode. She is taking medications to prevent another.

Liviah's ammonia levels remained high despite the treatments. She was confused and agitated when she woke up. She asked if she could go for a walk. Where was her brother? She couldn't get through a game of Candyland with her grandmother.

Liviah was placed on the transplant list. The top priority is Status 1A.

Liviah's doctors decided to start her on the procedure to remove toxins from her blood while they waited for a match. Liviah's aunt was visiting when the call came. Mrs. Widders said that they had a transplant for Liviah.

The joy of Liviah's parents was offset by grief for the family of the deceased donor.

Mrs. Widders said that they were staring death in the face.

Her husband said that they knew that their joy came at the expense of others.

She said that someone else's tragedy was our miracle.

Liviah received a new organ. Doctors had her out of bed the next day to work on her strength.

Liviah was discharged from the hospital. The neighbors kept their decorations up for Liviah and the family celebrated Christmas again.

ImageThe Widders family shared Liviah’s story to raise awareness about the signs of liver problems and to encourage people to sign up to be organ donors.
The Widders family shared Liviah’s story to raise awareness about the signs of liver problems and to encourage people to sign up to be organ donors.Credit...Maddie McGarvey for The New York Times
The Widders family shared Liviah’s story to raise awareness about the signs of liver problems and to encourage people to sign up to be organ donors.
ImageMr. Widders put sunscreen on Liviah before heading outside. From the outset, doctors told Liviah’s parents that they might never know why her liver failed.
Mr. Widders put sunscreen on Liviah before heading outside. From the outset, doctors told Liviah’s parents that they might never know why her liver failed.Credit...Maddie McGarvey for The New York Times
Mr. Widders put sunscreen on Liviah before heading outside. From the outset, doctors told Liviah’s parents that they might never know why her liver failed.

Doctors warned Liviah's parents that they might never know why her liver had failed, even though they never found a cause.

In Liviah's case, doctors ruled out a lot of common causes, but blood tests showed an adenoviruses.

There was no sign of the adenoviruses in the liver, but an abnormal immune response could have caused the attack.

She admitted that it wasn't a very satisfying explanation. Liviah's adenoviruses levels were low, and they don't usually cause harm to healthy children.

The mystery did not bother Liviah's father. He said that she was alive.

When Liviah had a rejection episode, accepting the unknowns was harder for Mrs. Widders. After the setback, her mother wondered if Liviah might have a genetic or autoimmune disorder, but testing turned up no evidence of that. With Liviah home for good, her parents had peace of mind that they might never get answers.

A friend of Mr. Widders sent him a text about a group of children with the same disease. The Centers for Disease Control and Prevention was investigating a similar cluster in Alabama, where all nine children had tested positive for an adenoviruses.

ImageA rest after playing outside.
A rest after playing outside.Credit...Maddie McGarvey for The New York Times
A rest after playing outside.
ImageThe Widders family has been adjusting to a new normal, which includes administering immunosuppressive drugs to keep Liviah’s body from rejecting her new liver.
The Widders family has been adjusting to a new normal, which includes administering immunosuppressive drugs to keep Liviah’s body from rejecting her new liver. Credit...Maddie McGarvey for The New York Times
The Widders family has been adjusting to a new normal, which includes administering immunosuppressive drugs to keep Liviah’s body from rejecting her new liver.

The cases sounded familiar to Mr. and Mrs. Widders.

The C.D.C. says more than 200 children in the United States have been affected by the disease.

The virus has not been found in all of the affected children, and scientists don't know why a common childhood virus might cause damage to the liver. They are looking into whether the virus has changed or not.

It is possible that a prior coronaviruses infection or the lack of exposure to adenoviruses may have left children more vulnerable. It's possible that adenoviruses always caused hepatitis in a small subset of healthy children and that scientists weren't aware of the connection.

Is it a new disease? said Dr. William Balistreri, the director of the Cincinnati Children's Hospital. Is it a new virus with an old one?

Parents are confused by the absence of an obvious cause. A school nurse called Ms. Tenold in April to tell her that her daughter appeared to have jaundice. It was a typical week in the country.

Liviah's case was more severe than her daughter's, but it turned out to be milder. She was released from the hospital after a few days.

Ms. Tenold said that it would be nice for them to get to the bottom of it so that more children don't have to deal with it.

ImageLiviah and her mother have been making earrings to raise money for families of children with liver problems.
Liviah and her mother have been making earrings to raise money for families of children with liver problems.Credit...Maddie McGarvey for The New York Times
Liviah and her mother have been making earrings to raise money for families of children with liver problems.
Image“She’s not going to remember a lot of it, which is so great,” Liviah’s father said.
“She’s not going to remember a lot of it, which is so great,” Liviah’s father said.Credit...Maddie McGarvey for The New York Times
“She’s not going to remember a lot of it, which is so great,” Liviah’s father said.

In the months after Liviah's transplant, her parents encouraged friends and family members to register as organ donors, and held a blood drive in her name. Liviah is helping her mother make earrings to sell to raise money for the hospital's Helping Hands Fund, which provides assistance to the families of children who have been diagnosed with the disease.

Mrs. Widders said that they were stepping into the purpose that they had.

Liviah's parents have found themselves striking a delicate balance with parents worried that their own children might be next. They want people to be aware of the signs of a sick body, but also to know that Liviah is rare.

You can't react to every cold or vomit.

Liviah is in physical therapy and is doing well, her parents said. The entire family is in therapy to help them process what has happened. Liviah's old organ was sick and she was given a new one called Teddi.

Mr. and Mrs. Widders hope to make a book for Liviah that will chronicle exactly what happened to her, as well as how experts have been able to make sense of it.

She won't remember a lot of it, which is great, said her father, who has continued to record Liviah's levels in a spreadsheet.

The family is still adjusting to a new normal, which includes immunosuppressive drugs for Liviah to prevent her body from rejecting the new liver and a renewed focus on hygiene to protect her from other pathogens, to which she is now more vulnerable.

Liviah went back to preschool and soccer. She wore a bikini to show off her scar on the beach. She calls it her prince's mark.