Nurses, physician assistants and other caregivers in the union representing 1,800 HealthPartners workers have voted overwhelmingly to strike if a contract agreement cannot be reached before Feb. 19.  Service Employees International Union represents 1,800 members at HealthPartners in Minnesota. The St. Paul Pioneer Press says 95% of members voted to begin a seven-day strike. The union announced results of Thursday’s vote on Friday outside the HealthPartners Neuroscience clinic. The nonprofit health care organization operates eight hospitals, 55 primary care clinics, 22 urgent care locations and numerous specialty practices in Minnesota and western Wisconsin.