Do public access fingerprint readers carry the risk of spreading diseases?

Yes, it can : The common cold is just one example, among many. The good news is that most of the diseases that are spread are not too serious and cause temp illness. Wash your hands with soap before eating and or contacting your hands to your face or mouth. Note that alcohol does not always destroy all viruses -- norwalk virus, which causes gastroenteritis, is not always destroyed by alcohol and requires soap.