The miracle baby that scientists declared was "functionally cured" of HIV after being born HIV positive is infected once again.

Four years ago, scientists were able to "cure" a Mississippi baby girl who was born with HIV by giving the infant a concoction of three strong dosages of antiretroviral medicine. The child also received treatment on a regular basis for the first 15 months of her life. However, the mother took the child off of antiretroviral drugs for 27 months, and now doctors say they found detectable levels of the virus in her blood.

"Certainly, this is a disappointing turn of events for this young child, the medical staff involved in the child's care, and the HIV/AIDS research community," NIAID Director Dr. Anthony Fauci said in a statement, according to NBC News. "Scientifically, this development reminds us that we still have much more to learn about the intricacies of HIV infection and where the virus hides in the body."

The little girl, now 4 years old, was once regularly tested for the AIDS virus. However, now the virus has not only returned, but researchers say it has the potential to damage her immune system.

The unnamed baby and her mom use to get regular care and treatment from doctors at University of Mississippi Medical Center until she was 15 months old. Then, she disappeared until the mother brought her back briefly at 18 months. Finally, the child stopped going for treatments for the last two years of her life.

"It felt very much like a punch to the gut," said Dr. Hannah Gay of the University of Mississippi, reports USA Today.

"The baby has now rebounded with clearly detectable HIV viremia," said Dr. Fauci.

"The fact that this child was able to remain off antiretroviral treatment for two years and maintain quiescent virus for that length of time is unprecedented," said Deborah Persaud, professor of infectious diseases at the John Hopkins Children's Center in Baltimore. "Typically, when treatment is stopped, HIV levels rebound within weeks, not years."