This is the law in Michigan as well. It is based on preventative health care, as testing is not always accurate and can result in false negatives (rare, but it happens, as science is not yet perfect).
The repercussions of not applying the erythromycin ointment based on a false negative test would leave an infant blind. The law and its principle is based on safety and concern for the infant's health, and prevention. It is better to apply a preventative medication than to risk a lifetime of blindness.
The patient always has the right to refuse any medical procedure or medication. If you were told otherwise, you were incorrectly informed.
There IS a medical need for this. We aren't providing this to your child because we think it is fun; prevention is key to our country's health status and system. If everyone decided to reject all vaccines, immunizations, etc., because "they" weren't infected, we'd all be infected with diseases that were previously eradicated. Example: recent measles outbreak due to parents refusing to vaccinate their children with the MMR vaccine.
RN, BSN, MS (registered nurse)
Experience in L&D