 [ Symptoms ] what cause a two year old baby to have a yeast infection or urinary infection [ Disease ] yeast is an opportunistic fungal infection yeast loves warm dark moist areas typical of a two year old is diaper yeast is airborne can colonize in the colon and can just happen to anyone if the right conditions exist especially children with weaker less challenged immune systems children who recently used antibiotics for any reason are more likely to get diaper area yeast infections a urinary tract infection is very common in little girls especially those that are diapered utis can be misdiagnosed if the urine specimen is not taken by a catheter and properly cultured in the lab the most common pathogen causing a uti would be the various germs enteric bacteria present in stool that conveniently migrates into their tiny urethra a urinary tract infection in little boys is uncommon and needs a higher level of diagnostic investigation