The reluctance of the American academic bureaucracy to admit to the prevalence of fraud in academic research is understandable, but there are many examples. Some of the recent notables are the serotonin hypothesis of depression, and aspects of the amyloid theory of Alzheimer's. Data falsification is not uncommon, and it's often done for obvious reasons - a graduate student may want that positive result that finishes off their PhD work and gets them a needed publication, a professor may want to support their past work with new data and results, an academic startup may want to prop up their latest drug development results to draw in investors and big corporations, etc.
The reason academic institutions don't want to talk about it is the same reason that religious institutions don't want to talk about child abuse - it makes a mockery of their whole enterprise. With the former, it's the search for truth via the scientific process, and with the later it's upholding moral standards and guiding society. Both institutions cover up such things in order to preserve their public image - which, of course, allows such behaviors to persist.
Note also that the corporatization of research, i.e. the focus on generating lucrative patents and the resulting emphasis on keeping raw data secret, tends to amplify opportunities for fraud.