According to the U.S. Centers for Disease Control and Prevention (CDC), although there have been imported cases of Covid-19 detected in the United States, “at this time, the virus is NOT currently spreading in the community in the United States.” However, on Tuesday, February 25, 2020, Nancy Messonier, the CDC’s Director of National Center for Immunization and Respiratory Diseases, urged American businesses and families to start preparing for the possibility of a large outbreak, noting that the virus spread quickly once it appeared in other countries. Although the World Health Organization (WHO) still has not called Covid-19 a pandemic, Mike Ryan, head of WHO’s health emergencies program, suggests that countries need to be doing everything they can to contain the virus, at least in order to buy some time.
To that end, the CDC has been tapping some of its quarantine powers. CDC has authority to oversee quarantine and isolation of persons who carry communicable diseases, derived from the Commerce Clause of the Constitution, and codified in section 361 of the Public Health Service Act (42 U.S.C. § 264). The CDC’s authority, however, is limited to persons arriving in the United States or traveling between states. Each state has its own laws regarding quarantine powers, and the CDC also relies on state authorities to implement and enforce quarantine orders. There is some risk that state health authorities could act in a manner that is inconsistent with the intentions of the CDC (to be more or less restrictive). The CDC has not issued a large-scale isolation and quarantine since the Spanish influenza pandemic of 1918-1919.
The CDC asked thousands of Americans recently returning from China – even those who have shown no signs of having contracted the virus – to quarantine themselves for 14 days and to limit their contact with others. Those individuals appear to be voluntarily doing so. But further efforts to quarantine patients who tested positive for SARS-CoV-2 (the official name of the 2019 Novel Coronavirus) have been met with opposition. In California, a federal judge issued a temporary restraining order on February 21, 2020, blocking efforts to relocate to Costa Mesa, California up to 50 persons who may have tested positive for the virus. The California Health and Human Services Agency said it was working with federal authorities to find a place for people who had been evacuated to Travis Air Force Base after having been quarantined for 14 days on board the Diamond Princess cruise ship. City officials in Costa Mesa involved the court after learning that the patients would be moved to the Fairview Developmental Center in Costa Mesa, without obtaining city officials’ input and without giving any information about the suitability of the location or the safeguards in place.
Based on the Monday, February 24, 2020 hearing before U.S. District Judge Josephine Stanton, the injunction will remain in place until Monday, March 2, 2020 to allow officials from the CDC, the California Governor’s Office of Emergency Services, and other state and federal agencies to discuss plans and protocols with Costa Mesa officials.
While use of the Fairview Developmental Center as a quarantine facility may be stalled, use of quarantine powers may be on the rise in the near future. In light of her concerns about the inability to contain the virus, Messonier suggested that businesses should consider whether employees could telecommute, and recommended that hospitals look into expanding telehealth services. The CDC is evaluating other measures that could be used to curtail the spread of the virus, including school closures, voluntary home quarantines, and surface cleaning methods. The CDC is also discussing whether to lower the threshold on its definition that triggers a patient to be tested for the virus. Currently, officials recommend testing for people who have (1) respiratory symptoms and have recently traveled to China, or (2) been in close contact with an infected person. But based on reports of asymptomatic persons infecting others, those testing definitions could change. And we may be seeing potentially longer quarantine times, since the incubation period of the virus – currently considered to be 14 days, according to WHO guidelines – could be as long as 27 days, based on new reports from China.
 Centers for Disease Control and Prevention, “Coronavirus Disease 2019 (COVID-19) Situation Summary” (updated February 25, 2020)
 Megan Thielking and Helen Branswell, CDC expects ‘community spread’ of coronavirus, as top official warns disruptions could be ‘severe’,” STAT News (February 25, 2020), available at https://www.statnews.com/2020/02/25/cdc-expects-community-spread-of-coronavirus-as-top-official-warns-disruptions-could-be-severe/.
 Helen Branswell, “WHO tells countries to prepare for coronavirus pandemic, but insists it’s too soon to make that call,” STAT News (February 24, 2020), available at https://www.statnews.com/2020/02/24/who-tells-countries-prepare-coronavirus-pandemic-too-soon-to-make-call/. While encouraging countries to attempt to contain the spread of the virus as much as possible, Ryan also said that he thinks “we have to be very, very careful in trying to suggest that we could absolutely stop the virus from spreading from one country to the next. I don’t think that’s possible.”
 See also Centers for Disease Control and Prevention, Legal Authorities for Isolation and Quarantine, available at https://www.cdc.gov/quarantine/aboutlawsregulationsquarantineisolation.html.
 CDC, Legal Authorities for Isolation and Quarantine.
 Ryan Fahey, “THOUSANDS across America are in voluntary self-quarantine after returning from coronavirus-hit China, health officials reveal,” Daily Mail (February 21, 2020), available at https://www.dailymail.co.uk/news/article-8028457/Coronavirus-THOUSANDS-America-voluntary-self-quarantine.html.
 Associated Press, “Federal judge blocks coronavirus quarantine in California city,” Washington Times (February 23, 2020), available at https://www.washingtontimes.com/news/2020/feb/23/costa-mesa-california-coronavirus-quarantine-block/.
 Id.; Centers for Disease Control and Prevention Newsroom, “Update on the Diamond Princess Cruise Ship in Japan,” (February 18, 2020), available at https://www.cdc.gov/media/releases/2020/s0218-update-diamond-princess.html.
 Associated Press.
 Alicia Robinson, “Injunction stays in place on using Fairview Developmental Center in Costa Mesa to house coronavirus patients,” The Orange County Register (February 24, 2020), available at https://www.ocregister.com/2020/02/24/hed-goes-here-on-outcome-of-court-hearing/#.
 Thielking and Branswell.
 Reuters, “Study: Symptom-free Wuhan Woman Infects 5 Relatives with Coronavirus,” VOA News (February 22, 2020), available at https://www.voanews.com/science-health/coronavirus-outbreak/study-symptom-free-wuhan-woman-infects-5-relatives-coronavirus.
 See, e.g., id.; Pharmaceutical Technology, “Coronavirus incubation period could be 27 days, shows data” (February 23, 2020), available at https://www.pharmaceutical-technology.com/news/coronavirus-incubation-period-27-days/. A 70-year-old man in Hubei province had close contact with his infected sister on January 24, 2020, but did not exhibit any symptoms until February 20, 2020, receiving confirmation of the disease the next day.