Many published reports say that state quarantines are ineffective or otherwise contrary to the best available scientific advice. A look at that scientific advice shows that it is policy-driven, not scientific. Exhibit A: the editors of the New England Journal of Medicine say that quarantines such as those enacted by multiple states and enforced by New Jersey are “not scientifically based.” But their argument is mostly about a disagreement on policy, not a dispute about science.
Quoting from their editorial:
The governors of a number of states, including New York and New Jersey, recently imposed 21-day quarantines on health care workers returning to the United States from regions of the world where they may have cared for patients with Ebola virus disease. We understand their motivation for this policy — to protect the citizens of their states from contracting this often-fatal illness. This approach, however, is not scientifically based, is unfair and unwise, and will impede essential efforts to stop these awful outbreaks of Ebola disease at their source, which is the only satisfactory goal. The governors’ action is like driving a carpet tack with a sledgehammer: it gets the job done but overall is more destructive than beneficial.
Let’s address each of these points.
ARE STATE QUARANTINES SCIENCE-BASED?
The science argument in the editorial is that health care workers who are not symptomatic are not contagious.
Furthermore, we now know that fever precedes the contagious stage, allowing workers who are unknowingly infected to identify themselves before they become a threat to their community.
There are three problems here. First, not all persons with Ebola Virus Disease display fever prior to case detection. According to a recently published original research paper:
The most common symptoms reported between symptom onset and case detection included fever (87.1%), fatigue (76.4%), loss of appetite (64.5%), vomiting (67.6%), diarrhea (65.6%), headache (53.4%), and abdominal pain (44.3%).
That is, fever was not a reported precursor symptom in about one-eighth of cases. Presumably, the editors of NEJM are familiar with this paper; it was published in the last two weeks — in their own journal.
Second, while health care workers knowledgeable about Ebola seem highly likely to seek medical care immediately, some might decide not to do so promptly if they are convinced that another cause is responsible. There are many potential causes of low-grade fever and the other indicator symptoms. Further, as the editorial notes, case confirmation may be delayed by days after symptoms appear:
[T]he sensitive blood polymerase-chain-reaction (PCR) test for Ebola is often negative on the day when fever or other symptoms begin and only becomes reliably positive 2 to 3 days after symptom onset.
The NEJM editors assert that this delay also means the risk of transmission is delayed. They assert that the risk of transmission to health care workers is until “the viral load in bodily fluids is high.” Even if this turns out to be true, no hospital treating a suspected Ebola case is going to wait until then before requiring patient isolation and the use of extraordinary precaution.
Third, the purpose of state quarantines is precautionary. Like those quarantined, State authorities also hope that Ebola is never confirmed. In the unlikely case that confirmation occurs, however, they want to be able to assure the public that it faces as close to zero risk as possible. The NEJM editors decry state officials’ desire for zero risk as cynical. That would be a fair accusation if state officials knew that those quarantined posed no risk to the public. They do not have such knowledge.
ARE STATE QUARANTINES ARE UNFAIR?
Clearly, this is not a science-based argument. Science has no objective tools by which unfairness can be even identified.
ARE STATE QUARANTINES UNWISE?
Like fairness, wisdom is not an attribute science can readily detect. Economists (and some others) often make the normative argument that a policy is unwise if its costs exceed its benefits. And this appears to be the argument the NEJM editors are making:
In the end, the calculus is simple, and we think the governors have it wrong. The health care workers returning from West Africa have been helping others and helping to end the epidemic that has killed thousands of people and scared millions. At this point the public does need assurances that returning workers will have their temperatures and health status monitored according to a set, documented protocol. In the unlikely event that they become febrile, they can follow the example of Craig Spencer, the physician from New York who alerted public health officials of his fever. As we continue to learn more about this virus, its transmission, and associated illness, we must continue to revisit our approach to its control and treatment.
But it is still a normative argument, not a positive one. It is interesting to note that the NEJM editors appear to believe that the costs of state quarantines exceed their benefits and the decision whether to quarantine should be based on normative benefit-cost analysis. And costs might exceed benefits, but neither the NEJM editors nor any other quarantine opponent has provided supporting evidence. What seems highly unlikely is that the costs exceed the benefits to a state government and its residents. That is the domain in which a governor must conduct his own admittedly qualitative benefit-cost analysis.
THE NEJM EDITORS’ OBJECTIONS ARE DRIVEN BY POLICY DIFFERENCES, NOT SCIENCE
The editorial is characteristic of appeals to science as a device for surreptitiously making policy decisions — that is, the scientization of policy. the usurpation by scientists of the authority to make policy decisions. The NEJM editors at least implicitly know this, for the core of their argument isn’t scientific at all — even if they say it is:
We should be guided by the science and not the tremendous fear that this virus evokes.
Guided by science is not the same thing as dictated by scientists, especially scientists who seem to consider public fear irrational and unworthy of much weight in decision-making.
Jeffrey M. Drazen, M.D., Rupa Kanapathipillai, M.B., B.S., M.P.H., D.T.M.& H., Edward W. Campion, M.D., Eric J. Rubin, M.D., Ph.D., Scott M. Hammer, M.D., Stephen Morrissey, Ph.D., and Lindsey R. Baden, M.D. Ebola and Quarantine, NEJM, October 27, 2014.
WHO Response Team, Ebola Virus Disease in West Africa — The First 9 Months of the Epidemic and Forward Projections, NEJM, October 16, 2014.