The coronavirus has so diminished trust in the U.S. medical system that even people with obstructed bowels, chest pain and stroke symptoms are ignoring danger signs and staying out of the emergency room, with potentially mortal consequences. At Hoag Memorial Hospital Presbyterian in Newport Beach, mammograms have dropped as much as 90% during the pandemic. “When you see only 10% of possible patients, you’re not going to spot that woman with early-stage breast cancer who needs a follow-up biopsy,” said Dr. Burton Eisenberg, executive medical director of the Hoag Family Cancer Institute.