Keep the leaves as dry as possible to help prevent this disease from spreading. Avoid overhead irrigation. Avoid working in the field when the plants are wet. A straw mulch will help prevent the fungus from splashing onto fruit from the soil. Plastic mulches promote disease spread, as they act as 'trampolines', causing raindrops full of spores to bounce higher into the plants.
Some varieties are less susceptible, but none are completely resistant.
See current recommendations for chemical control of this disease. By Pamela S. Mercure, IPM Program Assistant, University of Connecticut References. Cooley, D., D. Handley, S. Schloemann, and W. Wilcox. Disease Management and Physiological Disorders. Chapter 9 in Strawberry Production Guide for the Northeast, Midwest, and Eastern Canada.