The coronavirus positivity rate in Connecticut is down from this week’s high of more than 4 percent — but the overall trend line continues to rise. The City of New Haven is bracing for an increase in positive cases after researchers found a spike of the virus in wastewater — an early indication that the disease is spreading. Meanwhile, Bridgeport is temporarily closing its communicable disease clinic for two weeks after employees tested positive. Patient care will be transferred to nearby health departments and the state.