The move to share the home addresses of people who have tested positive for the coronavirus is meant to protect police and emergency workers, but some say the disclosures could give them a false sense of security.

State and local governments are beginning to share the addresses of people who test positive for Covid-19 with police and other first responders in an effort to help protect emergency personnel from getting infected.

Health officials in at least three states—Alabama, Massachusetts and South Carolina—have all decided to share the information as a way to put first responders on high alert when they are called to a home where someone is known to be infected.

Federal health care privacy laws would typically limit disclosure of patients’ confidential health information, including their addresses, without their permission. But last month the U.S. Department of Health and Human Services issued guidance identifying specific circumstances under which usually protected personal  health information could be disclosed to law enforcement, foreseeably clearing the way for state and local governments to make such disclosures.

“Our nation needs our first responders like never before and we must do all we can to assure their safety while they assure the safety of others,” said Roger Severino, director of the agency’s office of civil rights. “This guidance helps ensure first responders will have greater access to real-time infection information to help keep them and the public safe.”

In Massachusetts, the Department of Health issued an order last month that obligates local boards of health to disclose to officials overseeing emergency response calls the addresses of all people known to have tested positive for Covid-19. Patients’ names would not be disclosed. Jurisdictions that receive the address information would be required “to ensure that the information is maintained confidentially, and is made available only to those who need to know in order to operate emergency response services.

An official with the state’s Executive Office of Public Safety and Security said the order would ensure that first responders called to the home of someone who had the virus would be on notice to wear personal protective equipment at all times at that location.

In South Carolina, the Department of Health and Environmental Control this week will launch a secure web-based system to allow first responders to query addresses while responding to calls to determine if a person living there has tested positive for the coronavirus. “We’ve heard the first response community loud and clear, that they want that information,” Nick Davidson, acting director of public health, told the Associated Press. “The simplest way would be to just hand them a list, but there’s complications with that.”

Addresses will not stay in the system forever, and will drop out of the database when health officials could “reasonably conclude” the person involved is no longer infected, Davidson said.

“I’m sure it’s not perfect, but it certainly is an attempt to try to provide them the information that they want in a timely manner, so that they could take actionable steps,” Davidson said.

In Alabama, the Department of Public Health has been disseminating address information to the state’s 911 board, which passes the data along to local 911 response districts, AL.com reported. The information is entered into the local district’s computer dispatch system and when emergency personnel are dispatched on a call, 911 call takers check the system and alert responders if they are headed to a coronavirus-positive address.

Some public health officials have objected to the disclosures, raising concerns about how the information is handled and also questioning if these notices could give first responders a false sense of security.

Keeping a database of known positive patients “definitely raises privacy concerns,” said Leslee Stein-Spencer, a program official with the National Association of State EMS Officials. But, on the other hand, she said she understands the desire to do everything possible to keep first responders safe.

“We don’t want EMS walking into a house where there is a Covid-19 patient and to not be prepared,” Stein-Spencer said.

That’s why she said it is imperative for first responders to have the necessary protective equipment and also for them to assume they will interact with someone who is infected with coronavirus on every call.

Because the virus is so widespread and many infected people remain either asymptomatic or have not been tested, others have said disclosing the addresses of known patients might not be that useful.

“Protecting the health of first responders is certainly an important priority, however, experts indicate that sharing this private information is not sound from a health perspective because so few people have been tested and a number of individuals are asymptomatic,” said Jennifer Granick, a surveillance and cybersecurity lawyer with the American Civil Liberties Union. “First responders should always be taking precautions when entering a home.”

Despite the HHS guidance, some state and local leaders have expressed caution over collecting and sharing such information.

In Ohio, Butler County Prosecutor Mike Gmoser told reporters that he feared that releasing address information would lead to the identification of individuals who have tested positive for coronavirus.

“I am not about to breach the privacy of sick people,” Gmoser told WXIX-TV. If their names get out, that would have a chilling effect if anybody knows they are sick, it would have a chilling effect on people reporting it and seeking treatment. They would become pariahs.”

But, later that week, after the county sheriff threatened to seek a court order to compel disclosure of the information, two local health departments altered their protocol and began sharing address data with the sheriff’s office.

Whatever decision state and local governments make about disclosing patient information, they should still warn first responders to take the necessary precautions on all calls, said Adriane Casalotti, the head of government and public affairs at the National Association of County and City Health Officials.

“For every case that has been diagnosed, there are multiple others that haven’t,” she said.