We put our microscope on HK's inbound quarantine laws and find that the 21-day length of quarantine actually increases the risk to the community, Further, the ban on arrivals from 4 countries is irrational. Both fail to satisfy constitutional tests of proportionality.

HK's inbound quarantine laws: dangerous, irrational and unconstitutional
16 March 2021

Let's get a few things straight about HK's inbound quarantine rules for people arriving from outside China:

21 days is too long

Other places which have succeeded in reaching and maintaining zero local transmission have done so with only a 14-day border quarantine. These include New Zealand and Taiwan. If it were possible to still be incubating the virus and test negative after 12 or 14 days, then there would have been outbreaks in the communities linked to this. So the very few cases in HK that have tested negative in HK on day 12 and positive on day 19 are probably caused by one of two factors:

1. Infection during quarantine

First, hotels were not designed to be isolation facilities. They often share ventilation systems between rooms, including bathrooms, allowing droplet spread. They almost always share corridors. In the Park Royal Hotel in Melbourne, Australia, there was a known case of a woman who tested negative on days 3 and 11, but opened her hotel door to collect food and was infected by a family who had arrived 9 days after her and had opened their door for food around the same time as the woman. She left quarantine and was later tested positive. Genomic testing showed identical virus strains in the woman and the family.

This intra-quarantine risk means that the longer you stay in quarantine, the more likely you are to pick up an infection from an arriving guest. Consequently, there is an optimal period of quarantine which is long enough to cover incubation if you arrive with a latent infection, but anything longer than that increases the danger that you will become infected during quarantine and spread it into the community.

2. False positives

Second, a person who has recovered from the virus may still have some fragments of it in their system. The RT-PCR tests (the best we have) don't actually look for entire viruses - they match parts of the RNA genome, so it is possible to test positive with just fragments of the virus. This may make testing difficult with recovered persons testing negative on one test and positive on the next one.

Also, HK may be using excessive Cycle Threshold (CT) values in the tests. Each increment of 1 in the CT value corresponds to a round of amplification, doubling the amount of target in the specimen but also doubling the noise. So if you increase the CT value of the test from 35 to 40 then you make it 32 times more sensitive. In audio terms, turn up an amplifier loud enough and you might be able to hear a pin drop in the middle of a heavy rock concert, or what you think is a pin dropping might just be amplified noise. Click here for a more technical explanation from Public Health Ontario and here for an article from the New York Times on this.

The ban on arrivals from some countries is irrational

From 22-Dec-2020, HK has prohibited entry for anyone who has spent more than 2 hours in the UK in the previous 21 days (formerly 14 days), not counting the day of boarding their flight to HK. South Africa was added on 25-Dec-2020. Brazil and Ireland were added effective 23-Jan-2021 - perhaps the Government remembered that Ireland has an open land border with the UK (Northern Ireland).

The purported objective is to prevent new variants of the virus from entering the HK community. This has stranded HK residents overseas, or forced them to find another country to visit for 21 days before flying to HK, making it a very expensive 43-day trip when you include the 21-day inbound quarantine. Ironically there was much protest when certain politicians labeled SARS-CoV-2 the "WuFlu" or the "Chinese virus" but apparently no problem talking about the "British variant" (B.1.1.7 or 20I/501Y.V1), the "South African variant" (B.1.351 or 20H/501Y.V2) or the "Brazilian variant" (P.1 or 20J/501Y.V3) which were first found in those places.

The ban is irrational because:

  1. It implies that our inbound quarantine regime doesn't prevent new variants entering the community. Places with successful border quarantines including New Zealand and Taiwan have not imposed such bans.
  2. It ignores the fact that just because they are popularly called "UK/ South African/ Brazilian variant" doesn't mean they are limited to those countries - so it is a knee-jerk response to the names. The variants are all over the world. In mid-February, Italy estimated that 18% of new cases were the UK variant, and France 25%. One mutation that is common to the variants, known as N501Y, is showing up frequently in HK arrivals from the Philippines, India and Pakistan - but there are no outright bans on residents returning from those and other places.

The excessive length of quarantine and the ban on arrivals are unconstitutional

Basic Law Article 31 states in part:

"Hong Kong residents shall have freedom of movement within the Hong Kong Special Administrative Region... They shall have freedom to travel and to enter or leave the Region."

A law which restricts a Basic Law right, in this case, entry to, or movement within, the HKSAR, is constitutional only if it satisfies the legal tests of constitutional proportionality (see Leung Kwok Hung & Ors v HKSAR, FACC1/2005) - that is, it must be rationally connected to a legitimate objective and be no more than is necessary to achieve that objective. The objective must also be sufficiently important to justify limiting a fundamental right.

Given that we know from other places that 14 days' quarantine is sufficient to achieve the objective of border control, 21 days is plainly more than is necessary and is unconstitutional.

Similarly, given that inbound hotel quarantine works elsewhere to protect communities against variants of the virus, and given that we have been allowing entry of people with these variants arriving from other countries, the sledgehammer of an outright ban on arrivals is more than is necessary to crack this nut.

Accordingly, both of these measures fail the constitutionality test. Also, even if a tiny number of inbound cases escape detection (or arise from intra-quarantine infection), it has been demonstrated here and overseas that any leakage into the community can be contained with trace-test-isolate measures, so the risk is not sufficiently important to justify further limiting the fundamental rights - again, the regulations are unconstitutional.

This risk is encapsulated in Section 8 of the Prevention and Control of Disease Ordinance, which the Chief Executive uses to make the quarantine regulations. It requires that the disease "has a high probability of causing a large number of deaths in the population or a large number of serious disabilities". We have successfully contained 4 outbreaks in HK with only about 200 deaths. The annual death rate from all causes is about 50,000. At most, it can only be said that allowing people to return to HK and do 14 days' quarantine has a "small probability of a small number of deaths" - neither is enough to justify extending quarantine to 21 days or banning people from returning to HK.

Finally, for people arriving on non-stop flights from countries with almost zero infections, who have not been anywhere else in the last 14 days, the risk of adding to HK's infection load is so small that any quarantine requirement at all fails to satisfy the constitutionality test. It's no more risky than someone travelling from Kowloon to HK Island or vice versa. Those countries should be recognised and exempted from the quarantine regulations. It doesn't require complicated ministerial "travel bubble" negotiations or testing at both ends. Just do it, and give people back their Basic Law rights.

© Webb-site.com, 2021


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