Original sentence: Autism is a severely incapacitating, innate neurological condition.Most government health agencies appear to remain ambivalent as to whether or not it is known for certain if the incidence of autism is increasing.The advent of an autism epidemic was first suggested in the mid-1990s by a handful of healthcare professionals who noticed an alarming increase in the proportion of children exhibiting neurodevelopmental disorders
Edited sentence: Most authorities remain ambivalent as to whether or not the prevalence of autism is increasing  , and therefore whether the term "epidemic" is accurate.The advent of an autism epidemic was first claimed in the mid-1990s by a handful of healthcare professionals who noticed sharp increases in the numbers being diagnosed and reported to public health agencies