How Hawaii Can Get Coronavirus Right in Twelve Steps
By: Darragh O'Carroll M.D.
Tags: Hawaii, Coronavirus, Health, Travel, Covid-19

How Hawaii Can Get Coronavirus Right In Twelve Steps

by Darragh C. O’Carroll M.D. — Board Certified Emergency Physician, CNN on-air contributor, and consultant to the NETFLIX Docuseries ‘Pandemic: How to Prevent an Outbreak’

*The Data from The Commonwealth of the Northern Marianas Islands was redacted on 11/30/2020, it is continually evolving and was requested to only be presented in their own Publications*

This paper has been peer reviewed and endorsed by

Paul S.Pottinger M.D. — Professor of Medicine, Division of Allergy & Infectious Diseases, University of Washington Michael W. Schwartz M.D. — Robert H. Williams Endowed Chair, Professor of Medicine, Division of Metabolism, Endocrinology and Nutrition, University of Washington Karl Kaiyala PhD — Research associate professor (emeritus), Department of Oral Health Sciences, School of Dentistry, University of Washington Lee Altenberg PhD — Adj Full Professor of Information and Computer Sciences and Mathematics, University of Hawai’i at Mānoa, Member of HiPAM D. Kapono Chong-Hanssen M.D. — Medical Director; Ho`ola Lahui Hawai`i/Kaua`i Community Health Center David Derauf M.D. MPH — Physician and Director of Kokua Kalihi Valley, Honolulu, Hawai’i Jonathan Dworkin M.D. — Board Certified in Internal Medicine and Infectious Disease, Waimea, Hawai’i Lee Evslin M.D. — Board Certified Pediatrician, Former CEO of Wilcox Medical Center, Kapaa, Hawai’i Brent Tatsuno M.D. — Board Certified in Pulmonology and Critical Care, Honolulu, Hawaii

Image courtesy of Luke McKeown @waikatospear

Nobody wanted to be suffering eight months into a global pandemic, but here we are. One silver lining about being this far along is that we know much more than when we began, and have the tools to outwit this coronavirus if deployed properly. We have learned on the international, national, and local scale that as soon as you disregard SARS-CoV-2, it will come roaring back. To keep Hawai’i afloat from both a public health and economic perspective, we must follow up-to-date scientific knowledge and research, because mass availability of vaccinations and hope of reprieve are still many months away. We can’t afford missteps — our lives and livelihoods depend upon it.

What this paper does is walk through, in twelve steps, how Hawaii’s current strategy to screen visitors and returning residents has gone starkly against international scientific consensus by

Overestimating the efficacy of a one test surveillance system

AND

2. Underestimating the amount of virus in the United States

This paper strongly recommends that Hawaii’s economic and public health leaders reconvene to honestly examine the efficacy of a one-test protocol. As the department of health has previously recommended, we also recommend reinstating some length of quarantine for visitors and returning residents culminating with a second test, as deemed acceptable by all parties. To continue with a one-test plan is putting workers in the visitor industry, and the entire state, at an unacceptably high risk.

Let’s start with some fundamental statistics, taken directly from the CDC’s website.

1. Why SARS-CoV-2 Is Unlike Prior Coronaviruses: Asymptomatic & Pre-Symptomatic Spread

The first row is the rate of asymptomatic persons, or persons who contract this disease but never develop symptoms. 40 percent of all persons infected with coronavirus are asymptomatic and will interact with people, travel, and spread this virus unknowingly. You would think these asymptomatic persons would be very inefficient at spreading disease, but if you look at the second row, they aren’t. Asymptomatic persons are 75 percent as infectious as those who do have symptoms.

Furthermore, those who eventually do have symptoms are infectious several days before these symptoms begin, collectively known as pre-symptomatic persons. Combining asymptomatic and pre-symptomatic spread leads to the last very important number…

Unlike the prior human coronaviruses MERS and SARS that were more easily contained, at least 50 percent of infections are transferred before there is any hint of infection.

2. CONTAINMENT STRATEGIES

Because at least 50 percent of infections are transferred before there is any hint of infection, there are two pillars of prevention in island nations and states like Hawaii (in addition to contact tracing [digital], public health messaging, and the availability of isolation/quarantine areas).

Mask use by all Containment of asymptomatic and pre-symptomatic persons

A fourteen day quarantine was Hawaii’s initial containment strategy, and a good one from a public health perspective, as after two weeks nearly everyone had passed their incubation period, or the number of days it takes to develop COVID-19 symptoms after exposure.

Below is an illustration of incubation periods, and it’s important to note that this period can be different for everyone. The length depends largely on the amount of virus encountered during exposure, but a commonly accepted average is 5–6 days, and rarely longer than fourteen.

adapted from L. Yang et al https://www.cambridge.org/core/journals/epidemiology-and-infection/article/estimation-of-incubation-period-and-serial-interval-of-covid19-analysis-of-178-cases-and-131-transmission-chains-in-hubei-province-china/C1B194C01268F005AAFBE8D50CB5F945/core-reader

Thus if a traveler has a negative test after fourteen days, it is 99% certain they will not be infectious to anyone else. Nations like New Zealand, Thailand, Hong Kong, Fiji, Australia, Taiwan and others continue to employ a fourteen day quarantine and release after a second negative test, especially if the traveler is from a high risk area.

Their residents and small businesses are enjoying lives and economic freedoms almost entirely unencumbered by this pandemic.

But for an economy like Hawaii’s that depends on high volume tourism, with an average length of stay dipping into the four day range during certain times of the year, continuing a fourteen day quarantine isn’t a tolerable option economically — we must strike a better public health and economic balance.

The solution to this dilemma, since May of 2020, has been one 72hr pre-arrival test.

3. HOW RELIABLE IS ONE TEST ?

The simple answer is that it depends on when the test is taken. Below is research from the Harvard School of Public Health released on June 27th. It depicts a concept called viral kinetics, or the amount of coronavirus inside a person over time — also called viral load. Focus on the viral load (black dotted line) and how it only appears on day 3, several days before symptoms begin.

adapted from DB Larremore et al https://www.medrxiv.org/content/10.1101/2020.06.22.20136309v2.full.pdf

Much as it takes weeks for a pregnancy test to result positive, it also takes several days for the virus to grow to detectable levels. You can see that during the first three days of incubation, it doesn’t matter what test is used (pink and brown horizontal lines), the viral load is too low to detect.

4. FALSE NEGATIVE RATE OF OUR MOST SENSITIVE TESTS

On August 18th, the Annals of Internal Medicine released a seminal study on the false negative rate of our most sensitive PCR tests.

A false negative is a result that incorrectly indicates that the coronavirus is absent.

The red line has been added to reflect viral load, and it’s very clear during the first three days of incubation the probability of a false negative (black dots) is close to 100 percent. It means for the average person, a test on days one to three from exposure is not useful at all.

adapted from LM Kucirka et al https://www.acpjournals.org/doi/10.7326/M20-1495

It’s only on day four of incubation that some notable efficacy is seen, where the false negative rate drops to about 65 percent. On Day five the false negative rate drops further to about 40 percent, and our tests peak in efficacy on day eight since exposure, with a 20 percent false negative rate.

5. GLOBAL CONSENSUS THAT ONE TEST IS NOT ENOUGH

What was just explained is a concept that is very widely accepted in the medical community, and why medical consultants to professional sporting organizations, the film industry, as well as nations who have controlled this virus use multiple tests AND a quarantine period to contain spread.

Below is a November 3rd release from CNN.

adapted from https://www.cnn.com/2020/11/03/health/covid-test-negative-contagious-wellness/index.html?fbclid=IwAR2UcIOa7HfjMd6J45whxXG3bUmGh0YtC4NwXNS-kHwAaL9F0g9Y_2iYofM

Next are a few paragraphs from a New York Times article released on September 14th, entitled “This is Why We Couldn’t Control the Pandemic”, by Tomas Pueyo.

adapted from https://www.nytimes.com/interactive/2020/09/14/opinion/politics/coronavirus-close-borders-travel-quarantine.html

On October 19th the Wall Street Journal published recommendations of Dr. Martin Cetron, the CDC’s Director of global migration and quarantine, on the UK-USA travel corridor.

adapted from https://www.wsj.com/articles/u-s-transportation-officials-airlines-spar-with-cdc-over-testing-vs-quarantines-for-international-flights-11603996361?fbclid=IwAR0MiPwz1cZjYs9ygJ67-f4iYkUhOUvX8J8DrraS4ZHbPBUa9g8vK3gbMyU

Lastly, on November 20th the Washington Post released this case study from New Zealand in which a traveler tested negative 48 hours prior to the flight, but became infectious and remained pre-symptomatic en route. The traveler eventually developed a fever 71 hours after arrival, but it led to a cluster of seven others, which would have continued to grow if not for New Zealand’s mandatory fourteen day quarantine.

adaped from https://www.washingtonpost.com/travel/2020/11/20/new-zealand-flight-covid/

6. SURVEILLANCE TESTING — It’s different than diagnostic testing.

So why are people recommending a second test? The New England Journal of Medicine published a letter on September 30th based on earlier work done by Harvard researchers, in which they advocate for increased testing frequency to control the spread of coronavirus.

Below in blue is another depiction of viral load over time. Also included is the performance two types of tests:

1. Low sensitivity cheaper rapid tests

And

2. High sensitivity expensive PCR tests

adapted from MJ Mina et al https://www.nejm.org/doi/full/10.1056/NEJMp2025631

The above picture demonstrates that because the viral load (in blue) increases so rapidly, using cheaper rapid tests more frequently will catch a greater number of infections than our expensive tests conducted sporadically.

This is called surveillance testing, and it’s very different from diagnostic testing.

The same Harvard researchers also published this in bar graph form, where they modeled several different surveillance strategies in a population of 10,000 people. The brown bars are cheaper lower sensitivity rapid tests, and the red bars are our expensive higher sensitivity PCR tests.

adapted from DB Larremore et al https://www.medrxiv.org/content/10.1101/2020.06.22.20136309v2.full.pdf

According to this Harvard model, if a surveillance test is conducted just once every fourteen days, which is similar to screening travelers with only one test, only 30 percent of asymptomatic and pre-symptomatic persons are caught. Just another 15 percent of persons will isolate themselves after developing symptoms (the dashed box on top).

United Healthcare group and Dr. Daniel Griffen of Columbia University Medical Center in New York released an interactive COVID-19 simulator in October that can calculate how effective any surveillance strategy is. Below is a screenshot after inputting a one test strategy, with the results highlighted in red.

adapted from https://calculator.unitedinresearch.com/complex_dashboard

This COVID-19 simulator also depicts one test will catch less than 40 percent of infections. You can try it for yourself at the link here.

7. WHAT ARE OTHER COUNTRIES & STATES DOING?

The countries that have successfully controlled the spread of COVID-19 have instituted much stricter guidelines than Hawaii.

New Zealand, Australia, Taiwan, Thailand, Vietnam, Hong Kong, South Korea, Fiji, and Japan all have grading systems for how long an international visitor must quarantine. Their systems are based on infectious rates of the country of origin, but all place three countries in the VERY HIGH RISK category: