Thank you for your question.  Although OSU does not list this plant or its diseases, it is related to the daphne, which has several viruses which cause this coloration:  https://pnwhandbooks.org/plantdisease/host-disease/daphne-viruses
The leaves contortions are consistent with a mosaic virus.  Although searching for aphids and controlling them is an option, removal and destruction of the plant is recommended at this advanced stage.  Good luck!

Thanks for getting back to me. I am so saddened to hear that the recommended so,union is removal and destruction of the l,ant. It is an otherwise healthy seven year old edgeworthia. 

Will the mosaic virus spread to other plants?

is it possible that if I remove the limbs on which the troubled leaves appear that I can save the rest of the bush?

As the PNW article indicates, there are several viruses, and, since we don't have an identification of the one your plant appears to have, we can't tell what other plants may be susceptible.  Since viruses are spread by vectors, in this case, aphids, control of that pest can reduce the risk.  The only advice given is to destroy the plant.  Once it is some plant tissue, it is throughout the plant.  If you want a more reliable diagnosis, you can submit plant tissue to the OSU Plant Diagnostic Clinic: https://bpp.oregonstate.edu/plant-clinic