Robocalls are overwhelming hospitals and patients, threatening a new kind of health crisis

In the heart of Boston, Tufts Medical Center treats scores of health conditions, administering measles vaccines for children and pioneering next-generation tools that can eradicate the rarest of cancers. But doctors, administrators and other hospital staff struggled to contain a much different kind of epidemic one April morning last year: a wave of thousands of robocalls that spread like a virus from one phone line to the next, disrupting communications for hours.