Two months after she was born, Eliana Nachem got a cough that wouldn’t go away. Three weeks later, she also started having runny stool, prompting a visit to her pediatrician.Eliana didn’t have allergies or a gastrointestinal condition; instead, tests pointed to a problem with her immune system. At 4 months old, Eliana received her diagnosis: severe combined immunodeficiency, or SCID.
Babies born with the extremely rare disease do not develop the cells required for a functioning immune system. Every germ becomes a potentially fatal threat and to stay healthy, children with the condition must live in a completely sterile environment. Without treatment, kids usually do not live past their second birthday.
https://www.nbcnews.com/health/kids-health/exposure-germs-ve-killed-11-years-later-s-living-normal-life-thanks-ge-rcna237621