The Imgur user shared two photos of his daughter and explained how a series of potentially fatal conditions left her fighting for her life.
"Three weeks ago she was admitted to the hospital with viral meningitis," he wrote. "She got over that in a few days since it was a light case.
"Now she is fighting RSV [Respiratory Syncytial Virus]. We almost lost her last Monday."
The dad continued: "Our local hospital told us if she got any worse there was nothing more they could do for her. We had to move her to a better facility.
"We chose LeBonheur [children's hospital] and as soon as the paediatric team arrived at the hospital to pick her up, she flatlined. They revived her and put her on a ventilator immediately.
"Since then, she had been diagnosed with of course RSV, a severe case of pneumonia, type H flu, bronchiolitis, and a partially collapsed right lung. Needless to say, it's been a rough week for my little one."
RSV is Respiratory Syncytial Virus, which causes infection of the lungs and breathing passages. It is a major cause of respiratory illness in young children.
According to the Centre for Disease Control and Prevention (CDC), RSV can be spread when an infected person coughs or sneezes into the air, creating virus-containing droplets that linger. Other people can become infected if the droplet particles contact their nose, mouth, or eye.
Children are often exposed to RSV outside the home, such as in school or childcare.
It can be prevented by people covering their coughs and sneezes, washing their hands frequently and correctly and avoiding sharing their cups and utensils.
The dad did not share details of how his daughter caught the illness.
He said his daughter is doing "much better" and is now only on oxygen for comfort.
"She has beaten so many odds this past week and made me even more proud to call her my daughter," he continued.
"I can not even begin to thank the staff for everything they have done for us. The nurses have been literal life savers.
"We might even be able to go home this weekend. RSV is no joke. I didn't know much about it until a week ago when it almost took my daughter from me.
"Please make sure to wash your hands before handling little ones. And make sure to wrap them up when heading outside into the cold."
For more information on RSV and the symptoms and treatments, visit cdc.gov/rsv.