What’s in a name? Isolating the term “quarantine” from other contamination
While in practice both “quarantine” and (self)-“isolation” involves quite similar measures, the purpose and intent of both terms are quite different.
To quote from the World Health Organisation:
“The quarantine of persons is the restriction of activities of or the separation of persons who are not ill but who may been exposed to an infectious agent or disease, with the objective of monitoring their symptoms and ensuring the early detection of cases. Quarantine is different from isolation, which is the separation of ill or infected persons from others to prevent the spread of infection or contamination.” (Ref 1)
So why does it matter over a name, when the restrictions imposed both measures are similar?
In actual fact, they are not similar, since isolation involves symptomatic or infected (test positive) individuals while quarantine does not. Anyone who is in quarantine (and initially asymptomatic) and then subsequently developed symptoms, need to be moved to isolation away from other asymptomatic people in quarantine.
Furthermore, while the duration for quarantine and isolation may seem similar, they are likely to change as we understand COVID-19 pathophysiology more over time. There are increasing evidence that COVID-19 positive patients may shred viral RNA but not infective within 8-10 days of symptom onset (Ref 2), and may be considered safe for discharge when they are not symptomatic, often after 8 days of symptom onset. Hence some authorities may consider releasing asymptomatic COVID-19 positive individual as early as 10 days, although others mandate 21 days of isolation, “to be sure, to be sure”. Ironically the most likely period for infected individuals to deteriorate is also 8-10 days post symptom onset, so by 10 days after symptoms occur, either the person is on their way home or ICU.
On the other hand, it is likely that quarantine period of those who are exposed to contact with infected individuals but remain asymptomatic, will likely to stay around 14 days, despite some suggesting a shorter period (Ref 3) which I felt has serious flaws in their assumptions (Ref 4).
Currently the US (Ref 5) and Australia (Ref 6) differentiate between quarantine and isolation, but others including the UK (Ref 7) don’t. The latter may think their attempts at simplifying terms for the lay person is helpful, but they may run into trouble in the future if isolation period of infected persons increase (to 20 days) or decrease (to 10 days post symptoms onset and released if asymptomatic at 10th day), whereas it is very likely quarantine period for asymptomatic persons will remain at 14 days.
This will undoubtedly create confusion at a time when the UK confidence of government advice and intent is severely compromised and as a result, adherence to COVID-19 measures will be eroded.
I note that the title of this article is correct, but the text uses the term “self-isolate” which apparently stems from its use in various referenced NHS and UK government documents when the intent was to quarantine rather than isolate.
Perhaps Mr Johnson’s government subscribes to Humpty Dumpty’s outlook, but be careful not to fall off the wall while trying to be master.
“When I use a word,” Humpty Dumpty said, in rather a scornful tone, “it means just what I choose it to mean—neither more nor less.”
“The question is,” said Alice, “whether you can make words mean so many different things.”
“The question is,” said Humpty Dumpty, “which is to be master—that’s all.”
LEWIS CARROLL (Charles L. Dodgson), Through the Looking-Glass (1871)
Competing interests: No competing interests