Major medical lab operator believes cyber breach exposed patient records

Quest Diagnostics said Thursday that it believes a cybersecurity breach led to unauthorized access to patient records. In a filing to shareholders, the major U.S. laboratory diagnostics company said it learned Wednesday that an intrusion affected a system used by doctors and other health care professionals to order tests and view results. The company did not immediately specify how many people or which records may have been impacted. Quest notified federal law enforcement and is working with outside cybersecurity experts to investigate and respond. It said the incident had not “materially” disrupted operations or its ability to serve patients. Quest says it serves one-third of adult Americans and half of physicians and hospitals annually, and has faced earlier breaches.