Health officer discusses WA Notify app and new details about quarantines

Letter to the Community: December 9, 2020

Posted

Hello Thurston County!

As you’ve seen in local and national news, this past week has brought a lot of changes. Some of the most important developments are the COVID-19 vaccine, the contact tracing app WA Notify, and the new Centers for Disease Control (CDC) guidance for people in quarantine. Now, what does this all mean for Thurston County?

In Western Washington right now the effective reproductive number R0, or number of people the average person with COVID-19 infects, is 1.4. For the pandemic to end, this number must be less than 1. 

The majority of viral spread occurs through close contact with individuals who are asymptomatic (do not have symptoms) and presymptomatic (before the symptoms develop). People who are close contacts of someone with known infection, meaning they spent more than 15 minutes over a period of 24 hours within 6 feet of an infected person, are at significant risk for contracting COVID-19 themselves and public health instructs them to quarantine.

Currently, public health identifies contacts when performing case investigations. WA notify is a phone application created to help identify other close contacts who would otherwise be missed, like if a person was exposed at a store or on public transportation. WA notify works by using your Bluetooth to send random sets of numbers which change at set intervals to phones that have the app installed. When an app user tests positive for COVID-19 and are contacted by public health they are given a unique code to input into the app. The app then alerts people who are close contacts during the previous 14 days and directs them to a website where they can find information about testing and how to keep themselves and their loved ones safe. This app is anonymous and anyone can opt out at any time. For more information on WA Notify, please visit wanotify.org.

I receive a lot of questions about the length of quarantine for individuals who are close contacts (<6ft for longer than a cumulative 15 minutes over a 24-hour period) of individuals who have tested positive for COVID-19. On December 2, 2020, the CDC released several options for the14-day quarantine. While the incubation period for SARS-CoV-2, the virus that causes COVID-19, is 14 days, a  14-day home quarantine carries the least risk of inadvertently infecting another person.

Shortening at home quarantine means there is an increase in risk of transmission after quarantine. A ten-day quarantine carries a risk of post quarantine transmission of one in a hundred. The second option, is only recommended when there will be no impact on community diagnostic testing, is a sevenday at home quarantine with a negative test result on or after day five. The seven-day quarantine carries a post quarantine transmission risk of one in twenty. In each quarantine situation, individuals must wear masks in public at all times, maintain a distance of six feet or more from non-household members, and screen themselves for symptoms for the full 14 days of the incubation period. If symptoms develop during the quarantine period, the individual must isolate and contact the public health department for instructions.

To determine the length of at home quarantine, factoring in the risks associated with infection is critical. At this time, we are directing members of the public to quarantine at home for 10 days after exposure and continue to wear a mask, socially distance, and symptom screen for the remaining 4 days of the virus’ incubation period. I am looking at our Thurston County context and availability of testing to determine whether the seven day at home quarantine for people with no symptoms with a test on or after day five can be done safely, but for now, this is not standard in our county.

There are notable exceptions where the shortened at home quarantine regimen does not apply to congregate care facilities. Congregate care facilities include jails, long-term care facilities, day cares, schools, and other places where people are in close contact for prolonged periods of time. As we learn more about transmission risks, this guidance may change. I will continue to give guidance using the best available evidence and science.

While I am seeing high rates of community transmission within Thurston County, there is hope on the horizon. There are currently two vaccines which are due to be considered for Emergency Use Authorization (EUA) by the Food and Drug Administration (FDA) later this month. The vaccine made by Pfizer and BioNtech is scheduled to be reviewed December 10, 2020 and a vaccine created by Moderna is scheduled for review on December 17, 2020. If the EUA is approved the vaccine data will be vetted by the Scientific Safety Review Workgroup as part of the Western States Pact. There are several more vaccines in phase 3 trials.

Initially, there will be a limited number of doses of the vaccines available and will only be available to healthcare workers and first responders at high risk for contracting COVID-19 as well as staff and residents in long-term care facilities. Vaccination will take place in phases based on Advisory Committee on Immunization Practices and community conditions. You can find the current Washington State COVID-19 Vaccination Plan at: https://www.doh.wa.gov/Portals/1/Documents/1600/coronavirus/WACOVID-19-Vaccination-Plan.pdf 

Most of the vaccines in the pipeline are two dose vaccines given several weeks apart. It will then take an additional few weeks for the body to generate infection fighting cells in sufficient quantity to fend off a COVID-19 infection. For more information on how the COVID-19 vaccine work, visit:
https://www.cdc.gov/coronavirus/2019-ncov/vaccines/different-vaccines/how-they-work.html

Even after vaccination becomes more widely distributed, it will continue to be important for all of us to mask, maintain 6 feet of distance, avoid gatherings, and continue COVID-19 prevention measures until there is enough data showing it is safe to stop these countermeasures.

The COVID-19 situation in Thurston County is dynamic and changing quickly. While I am concerned about the increased transmission, I am hopeful through all of our efforts of masking, distancing, staying home when sick or instructed by public health, avoiding unnecessary travel and indoor gatherings, covering coughs and sneezes, and good hand hygiene will slow the spread.

Wishing you the best of health,
Dimyana Abdelmalek, MD, MPH, Thurston County Health Officer

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