Federal health officials may be about to get greatly enhanced powers to quarantine people, as part of an ongoing effort to stop outbreaks of dangerous contagious diseases.The new powers are outlined in a set of regulations the Centers for Disease Control and Prevention published late last month to update the agency's quarantine authority for the first time since the 1940s.The outlined changes are being welcomed by many health lawyers, bioethicists and public health specialists as providing important tools for protecting the public. But the CDC's increased authority is also raising fears that the rules could be misused in ways that violate civil liberties.The update was finalized at the end of the Obama administration and was scheduled to go into effect Feb. 21. But the Trump administration is reviewing the changes as part of its review of new regulations. So the soonest the changes could go into effect has been pushed to the end of March.Under the old rules, the CDC's authority was primarily limited to detaining people entering the country or crossing state lines. The agency was also limited to quarantining people who had one of about a dozen diseases, including cholera, diphtheria, tuberculosis, plague, smallpox and yellow fever.Yet even then, the CDC rarely exercised these powers and generally deferred to state and local health officials.With the new rules, the CDC would be able to detain people anywhere in the country without getting approval from state and local officials.The agency could also apprehend people to assess their health if they are exhibiting medical problems such as a high fever, headache, cramps and other symptoms that could be indicative of a dangerous infectious disease."Because of the breadth and scope of the definition of ill persons, CDC can target a much wider swath of persons to assess and screen," says James Hodge Jr., a professor of public health law and ethics at the Sandra Day O'Connor College of Law at Arizona State University.Hodge says the new rules are "really necessary," given the potential threat that infectious diseases pose. Some others who have studied the issue agree."The CDC has been operating its infectious disease powers under really antiquated regulations," says Lawrence Gostin, a professor of global health law at Georgetown University.But other attorneys say they fear the new rules give the CDC too much power — with insufficient safeguards to protect an individual's rights."It could represent a great danger to Americans' health and civil liberties," says Wendy Parmet, a health policy lawyer at Northeastern University.For example, she says, the rules would allow the CDC to hold someone in quarantine for 72 hours before their case is subject to review. And that review would be conducted by the CDC itself instead of an outside, objective entity."The concern," Parmet says, "is that unless these regulations are carried out with care, and by people who [base their actions] on science, they can be used to trammel the civil liberties of Americans."Parmet is especially concerned that the CDC's enhanced powers would take effect just as the Trump administration is assuming control over the agency."A lot of the signals we've received from President Trump suggests he may be inclined to not always listen to the science," Parmet says, "and to ground policy in what I guess we're now calling 'alternative facts,' instead of scientific facts. That's scary."When contacted by NPR, officials at the federal Department of Health and Human Services would only confirm that the new rules are under review; they declined further comment. NPR also contacted the CDC, but the agency has not made anyone available to discuss the new quarantine powers."My worst fear is we have a replay of Ebola and we have, say, President Trump assert the policy he thought we ought to have when he was citizen Trump," saysScott Burris, a professor of law at Temple University.During the 2014-2016 Ebola outbreakin West Africa, Burris points out, Trump tweeted that American health workers who got sick while treating victims should be prevented from returning to the United States for medical care.Some public health specialists fear the CDC's new powers could backfire on efforts to prevent disease. For example, some sick people might hide their symptoms for fear of being detained."The worst-case scenario is that people may try to evade these procedures by, say, taking medicines to reduce their fever, or be afraid to report it if they are feeling ill on a plane," says Jennifer Nuzzo, a research epidemiologist at the Johns Hopkins Center for Health Security."We don't want to drive cases underground by putting measures in place that seem as though they carry some penalties associated with them," Nuzzo says.Gostin agrees that the rules are imperfect and that quarantining anyone is a very serious step. "It's really a quite, I would say, draconian public health measure," he says. "The most draconian measure, because it allows you to literally imprison somebody who you don't know for sure is a danger to the public."But quarantines also can be key to stopping an outbreak, Gostin says. He believes the new rules give the CDC much-needed flexibility."We know that the United States is vulnerable to a whole range of infectious diseases that are circulating around the world," Gostin says. "But we don't know which one will be next. And so when something sweeps up on our shores, we don't want to have delay and have political debate."While he agrees the civil liberties protections in the new regulations should be even stronger, Gostin argues they're better than relying on the protections in the old rules. The new president is a self-described "germophobe," Gostin notes."If you're a germophobe, then you're going to overreact and the last thing we want in the face of a public health crisis is overreaction," he says. "And I think having rules in place that are modern at least will provide some buffer against the whims of an administration that may overreact." Copyright 2017 NPR. To see more, visit http://www.npr.org/.