Upgraded my Mac to Yosemite. Now Jest tests are failing

The first 50 of 149 test pass. Then I start to see the error below. My colleges can run these test in Mavricks OK. I've updated Xcode command line tools, reinstalled node and reinstall the npm packages. Still not working. Any ideas on how to fix this?

events.js:72
        throw er; // Unhandled 'error' event
              ^
Error: connect ECONNREFUSED
  at errnoException (net.js:905:11)
  at Object.afterConnect [as oncomplete] (net.js:896:19)

 FAIL  src/components/Routes/CampaignNew/__tests__/index-test.js
[Error: Worker process exited before responding! exit code: 8, exit signal: null
stderr:
  events.js:72
        throw er; // Unhandled 'error' event
              ^
Error: connect ECONNREFUSED
  at errnoException (net.js:905:11)
  at Object.afterConnect [as oncomplete] (net.js:896:19)