Friday, August 01, 2014

A Revision In the List Of Quarantinable Communicable Diseases


Photo Credit CDC PHIL


# 8902


Eighteen months ago, in EID Journal: A Brief History Of Quarantine, we looked at the long and successful use of quarantine in the United States, and around the world, to contain highly infectious diseases. 


Contrary to Hollywood’s draconian portrayal, quarantine usually consists of  having an exposed person stay home, and report to a healthcare worker by phone each day, during a disease’s incubation period.


Just so we are all on the same page, here is how the CDC differentiates between Quarantine and Isolation:

The CDC applies the term "quarantine" to more than just people. It also refers to any situation in which a building, conveyance, cargo, or animal might be thought to have been exposed to a dangerous contagious disease agent and is closed off or kept apart from others to prevent disease spread.

The Centers for Disease Control and Prevention (CDC) is the U.S. government agency responsible for identifying, tracking, and controlling the spread of disease. With the help of the CDC, state and local health departments have created emergency preparedness and response plans. In addition to early detection, rapid diagnosis, and treatment with antibiotics or antivirals, these plans use two main traditional strategies—quarantine and isolation—to contain the spread of illness. These are common health care practices to control the spread of a contagious disease by limiting people's exposure to it.

The difference between quarantine and isolation can be summed up like this:

  • Isolation applies to persons who are known to be ill with a contagious disease.
  • Quarantine applies to those who have been exposed to a contagious disease but who may or may not become ill.


During the SARS outbreak in 2003, then President George Bush via  Executive Order 13295: Revised List Of Quarantinable Communicable Diseases added SARS to the short list of quarantinable diseases.


(a) Cholera; Diphtheria; infectious Tuberculosis; Plague; Smallpox; Yellow Fever; and Viral Hemorrhagic Fevers (Lassa, Marburg, Ebola, Crimean-Congo, South American, and others not yet isolated or named).

(b) Severe Acute Respiratory Syndrome (SARS), which is a disease associated with fever and signs and symptoms of pneumonia or other respiratory illness, is transmitted from person to person predominantly by the aerosolized or droplet route, and, if spread in the population, would have severe public health consequences.


Two years later, when avian flu became a serious concern, Executive Order 13375  amended this list by adding :


‘‘(c) Influenza caused by novel or reemergent influenza viruses that are causing, or have the potential to cause, a pandemic.’’.

As emerging disease threats evolve, so to must the legalese enabling an adequate response.   Yesterday the White House issued the following executive order (h/t Sharon Sanders & Treyfish on FluTrackers) regarding a subtle change that broadens the scope of SARS and SARS-like diseases.


The White House

Office of the Press Secretary

For Immediate Release

July 31, 2014

Executive Order -- Revised List of Quarantinable Communicable Diseases

- - - - - - -

By the authority vested in me as President by the Constitution and the laws of the United States of America, including section 264(b) of title 42, United States Code, it is hereby ordered as follows:

Section 1.  Amendment to Executive Order 13295.  Based upon the recommendation of the Secretary of Health and Human Services, in consultation with the Acting Surgeon General, and for the purposes set forth in section 1 of Executive Order 13295 of April 4, 2003, as amended by Executive Order 13375 of April 1, 2005, section 1 of Executive Order 13295 shall be further amended by replacing subsection (b) with the following:

"(b)  Severe acute respiratory syndromes, which are diseases that are associated with fever and signs and symptoms of pneumonia or other respiratory illness, are capable of being transmitted from person to person, and that either are causing, or have the potential to cause, a pandemic, or, upon infection, are highly likely to cause mortality or serious morbidity if not properly controlled.  This subsection does not apply to influenza."

Sec. 2.  General Provisions.  (a)  Nothing in this order shall be construed to impair or otherwise affect:
(i) the authority granted by law to an executive department, agency, or the head thereof; or
(ii) the functions of the Director of the Office of Management and Budget relating to budgetary, administrative, or legislative proposals.

(b)  This order is not intended to, and does not, create any right or benefit, substantive or procedural, enforceable at law or in equity by any party against the United States, its departments, agencies, or entities, its officers, employees, or agents, or any other person.



The major change here is the removal of the requirement that the disease be transmitted  `predominantly by the aerosolized or droplet route’.   While not specifying why this change was needed, one could speculate that since we don’t have absolute answers regarding how MERS is transmitted, it falls outside of the older SARS definition. 

Quarantines are politically messy, difficult to administer, and lose their value quickly in an outbreak. Once a communicable disease is `in the community’, there is rarely a good  reason to pursue them. 


But implemented early in an outbreak – as was done with SARS in 2003 – they can literally turn the tide against an emerging epidemic.


During the 2003 SARS epidemic, Isolation was used in the United States for patients who were ill, but since transmission of the virus was very limited here, quarantine was not recommended for those exposed (cite).


In other countries, where transmission risks were greater, quarantines were used – quite successfully – in order to contain the virus. 

  • Singapore was one of the first countries to mandate quarantines when more than 800 family members of SARS patients were ordered to stay in their homes. 
  • Hong Kong sealed part of the Amoy Gardens Apartment complex after scores of cases erupted there, and later moved all remaining residents to two holiday camps where they were quarantined.
  • And Toronto, Canada closed schools and quarantined thousands in their bid to contain the virus (see The SARS Experience In Ontario, Canada).

The graph below shows two distinct phases of disease transmission in Canada, both apparently dampened by the implementation of quarantines.



While unlikely to be popular (particularly among those caught up in one) – quarantines are a necessary and often highly effective tool for public health – and likely stopped SARS from becoming a global pandemic in 2003.  

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