Quarantine not likely to be best tool for halting bioterrorism-related disease, experts say

Dec 5, 2001 (CIDRAP News) – Large-scale quarantine of potentially exposed people is not likely to be the optimal strategy for containing a disease outbreak resulting from bioterrorism in most circumstances, according to public health experts writing in today's issue of the Journal of the American Medical Association.

"Imposition of large-scale quarantine—compulsory sequestration of groups of possibly exposed persons or human confinement within certain geographic areas to prevent spread of contagious disease—should not be considered a primary public health strategy in most imaginable circumstances," the report states. "In the majority of contexts, other less extreme public health actions are likely to be more effective and create fewer unintended adverse consequences than quarantine."

The article was written by Joseph Barbera, MD, of George Washington University and seven coauthors from there and Georgetown University, Johns Hopkins University, the US Department of Health and Human Services, and the New York City Health Department.

The authors say it is important to define "quarantine" carefully and to distinguish between quarantine and isolation. They define quarantine as the compulsory separation of groups of healthy people who may have been exposed to a disease. Isolation, in contrast, means the separation and confinement of people known or suspected to have a disease in order to prevent its spread.

No large-scale human quarantine has been imposed in the United States in the past 80 years, but authorities in some cases have quarantined large groups for several hours in response to bioterrorism hoaxes, the report says. In addition, health authorities have called for quarantine in some recent bioterrorism exercises. The federal and state governments have authority to impose quarantines in many situations, but quarantines would probably be challenged in the courts, the authors note.

Some quarantines earlier in US history proved harmful, the report says. For example, when a quarantine was used to contain smallpox in Muncie, Ind., in 1893, authorities had great difficulty convincing the citizenry that it was necessary. Violence broke out and culminated in the shooting of several public officials.

When considering using quarantine, the authors write, authorities must weigh carefully whether the action is medically warranted and practically feasible and whether the benefits would outweigh any possible resulting harm.

Authorities have invoked quarantines in some recent anthrax hoaxes, even though anthrax is not contagious (transmitted person-to-person), the report notes. And although many diseases are contagious, "only a limited number could pose a serious risk of widespread person-to-person transmission," and even fewer "confer a sufficient risk of serious illness or death" to justify large-scale quarantine.

Large-scale quarantine might be a reasonable consideration in the case of a major smallpox outbreak, the authors write. "But even in the setting of a bioterrorist attack with smallpox, the long incubation period (10-17 days) almost ensures that some persons who were infected in the attack will have traveled great distances from the site of exposure before the disease is recognized or quarantine could be implemented." The same would probably be true for other disease agents spread by bioterrorists. Authorities considering a quarantine would also have to consider whether they have the means to enforce it for as long as necessary, which could be several weeks, the report says.

The authors cite several possible harmful consequences of quarantines, including confinement of healthy and infected people together, civilian noncompliance that could compromise the quarantine and lead to violence, vigilantism to enforce the quarantine, and economic hardships.

Other, more limited steps for containing contagious disease outbreaks may be more effective than quarantine, in the authors' view. These include isolating people known to be infected; rapid vaccination or treatment programs; widespread use of disposable masks; short-term, voluntary home curfews; restricting the assembly of groups; and closure of mass transit systems.

The authors add that excellent communication with the public is essential to promote or ensure compliance with disease-containment measures. "In a bioterrorist attack, the media's appetite for information will be limitless and health authorities must be prepared to provide accurate and useful information on a nearly continuous basis," the article states.

Barbera J, Macintyre A, Gostin L, et al. Large-scale quarantine following biological terrorism in the United States: scientific examination, logistic and legal limits, and possible consequences. JAMA 2001;286(21):2711-7 [Abstract]

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