The University of Maine System is extending its planned COVID-19 testing to include a second round of screening for some students and staff, officials announced Tuesday. The Phase II follow-up screening will occur 7-10 days after arrival testing and is part of a three-phase surveillance strategy recommended by the UMS Scientific Advisory Board to lower the risk of disease transmission on campus from asymptomatic carriers, officials said in a statement released on Tuesday. “Our plans to bring students back to campus and limit the spread of COVID-19 will continue to evolve to reflect the best available science and safety practices,” Chancellor Dannel Malloy said in the statement.