Contact tracing, say public health officials, is key in stopping COVID-19 in its tracks. File photo

Contact tracing, say public health officials, is key in stopping COVID-19 in its tracks. File photo

Contact tracing is crucial, says north Island’s medical health officer

Dr. Charmaine Enns talks about the importance of case ID and follow-up

With all the discussions around the pandemic and responsive measures such as handwashing, masks and lockdowns, there is one strategy that could prove crucial to public health efforts.

In October, a doctor with the World Health Organization called contact tracing the “game-changer” needed for fighting the coronavirus in the near future.

It’s a sentiment echoed by the north Island’s medical health officer, Dr. Charmaine Enns. In an interview with the Record, she emphasized what contact tracing is, how it works and why it is so important in stopping the spread of COVID-19.

“This is the most important public health intervention we have,” she said. “We have only so many tools in our toolbox.”

Enns wants to see people live their lives, but do so in a manner that will protect them. To keep communities from having to go into lockdown, public health professionals and the public need to be vigilant in their efforts to trace the potential spread whenever a COVID-19 case crops up.

RELATED STORY: Pandemic response for parents starts with good info, says Enns

Case ID, then contact follow-up

The process is two-fold, starting with case identification, then contact follow-up. The aim is not to test everyone, only those with symptoms that could be COVID-19. When someone tests positive, public health staff respond quickly, with the positive lab result sent directly to the communicable disease (CD) nurses and the medical health officer in the area of the ‘case’ – in other words, the person who tests positive.

People are considered infectious for 10 days from the first day of their symptoms, though some symptoms can linger and repeat swab tests can remain positive for up to 100 days. However, the person is no longer infectious and not able to give COVID-19 to others else once they get to 10 days from the start of symptoms. (The exception concerns critically ill patients in hospital.)

The CD nurse interviews the case to determine when symptoms started, how they may have been exposed, their travel history and, importantly, any close contacts who may have been exposed to COVID-19 while the case is infectious. As a precaution, contact follow-up also includes any close contacts in the two days before the case showed symptoms in order to take into account potential transmission in the pre-symptomatic period.

Most close contacts don’t become cases

Time and space are key factors in defining a close contact. The general rule of thumb is that those who have been face to face without physical distancing for a cumulative 15 minutes or more is considered a close contact.

“Because this is COVID, a lot of people are keeping their social circles small,” Enns said. “This means the list of close contacts tends to also be small.”

If someone is considered a close contact, the person is supposed to self-isolate for a 14-day period from their last contact with the person who is positive. If anyone is going to develop COVID-19, it will occur within 14 days, known as the incubation period.

Public health staff follow up daily. Many people are choosing daily electronic follow-up but phone calls are also an option. If someone develops symptoms, they arrange for testing.

A negative test will not shorten a close contact’s 14-day self isolation period as the contact is still in the incubation period.

“The majority of close contacts do not go on to become cases,” Enns added.

On Vancouver Island, public health staff are testing about 1,000 people a day, and about “99.9 per cent” do not have COVID-19, meaning staff are testing too many people with symptoms not predictive of the disease.

The most important elements here are identifying the actual cases, followed by the close contacts who might have been exposed and ensuring they are isolated for the necessary time.

“This stops transmission,” Enns said. “It stops it in its tracks.”

If societies can do this, according to Enns, it can help avoid measures such as lockdowns.

Close versus casual contact

Another thing to consider is the difference between a casual and a close contact.

“If you are not named by public health as a close contact, it should not keep you from doing the things you should be doing,” Enns said.

Many people now are worried about being a contact of a contact, and needlessly staying home from work or keeping their kids out of school. Enns emphasizes someone is only considered a close contact through exposure to a person who not only shows symptoms but tests positive for COVID-19.

If the rising number of cases in B.C. is alarming, the relatively low incidence on the Island is more encouraging. Vancouver Island has kept case numbers low and has, for months, been able to have people isolate themselves, and if sick, recover at home rather than in hospital.

Definitions matter

Another challenge is terminology. All too often, Enns said, there is confusion in the media between “isolation” for those who become sick and test positive versus “quarantine” for close contacts of cases. If it seems like some game of semantics, it is because public health professionals want to be careful about asking people to stay home for 14 days because it is not an easy thing to do.

“Words matters, definitions matter,” Enns said, adding the term ‘self-isolation’ has evolved to cover both those in quarantine and isolation.

Role of businesses

There are other tools that can help with tracing contacts. Many businesses, especially ones such as restaurants or bars where customers might stay for an extended period, are following WorkSafe BC and using logbooks to get customer contact information. This can be helpful, Enns said, when regular channels to find out a case’s contacts are incomplete – in other words, when exposure comes through community transmission but they cannot pinpoint how a person contracted the disease.

“They have made our jobs so much easier for contact follow-up,” she said.

When the public gets a report about potential exposure at a particular business or on a flight, for example, this is how a notice is generated, but it’s not the first of line of defence. That remains with the public health working with those who test positive and their close contacts.

“Contact tracing let’s us have containment,” she said. “This is within our control.”

Evolution of knowledge

Enns also said shaming behaviour on social media toward people with the coronavirus or the insisting we hear about ‘every case in every place’ will only make it harder to get the right people to go for testing.

“We don’t need to police each other as citizens,” she said.

In the months since the pandemic was declared, the understanding of preventative measures, treatment and other factors has changed. Enns is concerned by the amount of misinformation circulating, and she reminds the public that the learning process for everyone, including people working in public health, is ongoing and the knowledge is evolving constantly.

“We’re in a pandemic where we know things are going to change,” she said. “We don’t have a playbook.”



mike.chouinard@comoxvalleyrecord.com

Like us on Facebook and follow us on Twitter.

Coronavirus

Get local stories you won't find anywhere else right to your inbox.
Sign up here

Just Posted

Rori Denness throws a javelin during BC Summer Games in 2016. (Black Press Media file photo)
Port Alberni ponders bidding for 2026 B.C. Summer Games

Port Alberni last hosted the BC Winter Games in 2004

Victoria artisan Tina Neurauter, right, used to shop at Pot Luck Ceramics with her daughter from Port Alberni. Now Neurauter is selling her handmade soaps and bath products at Bibi J’s, a new enterprise in the former Pot Luck Ceramics building on Gertrude Street in Port Alberni. (SUSAN QUINN/ Alberni Valley News)
Former Pot Luck Ceramics location reimagined as Bibi J’s

Owner Helma Swinkels revives social enterprise with new name, vision

The Rollin Art Centre’s Mistletoe Market begins on Dec. 1. (SUBMITTED PHOTO)
ARTS AROUND: Rollin Art Centre prepares for Mistletoe Market

Artisans and crafters are still needed for annual Christmas craft fair

‘Homelessness’ means many things to people with no permanent place to sleep. For some, the challenge to find safe shelter is greater than for others. (SUSAN QUINN/ Alberni Valley News)
Port Alberni mother battles to find housing for her son

Mary Elles fears her son will die on the street before he will find safe housing

A man wearing a face mask to help curb the spread of COVID-19 walks in downtown Vancouver, B.C., Sunday, Nov. 22, 2020. The use of masks is mandatory in indoor public and retail spaces in the province. THE CANADIAN PRESS/Darryl Dyck
B.C. records deadliest day of pandemic with 13 deaths, 738 new COVID-19 cases

Number of people in hospital is nearing 300, while total cases near 30,000

FILE - This May 4, 2020, file photo provided by the University of Maryland School of Medicine, shows the first patient enrolled in Pfizer's COVID-19 coronavirus vaccine clinical trial at the University of Maryland School of Medicine in Baltimore.  Pfizer announced Wednesday, Nov. 18, 2020, more results in its ongoing coronavirus vaccine study that suggest the shots are 95% effective a month after the first dose. (Courtesy of University of Maryland School of Medicine via AP, File)
VIDEO: B.C. planning for the rollout of COVID-19 vaccines in the first weeks of 2021

The question of who will get the vaccine first relies on Canada’s ethical framework

This undated photo issued by the University of Oxford shows of vial of coronavirus vaccine developed by AstraZeneca and Oxford University, in Oxford, England. (University of Oxford/John Cairns via AP)
Canada can make vaccines, just not the ones leading the COVID-19 race

Canada has spent more than $1 billion to pre-order seven different developing COVID-19 vaccines

British Columbia Premier John Horgan speaks during an announcement about a new regional cancer centre in Surrey, B.C., on Thursday, Aug. 6, 2020. Horgan is set to introduce his NDP government’s new cabinet Thursday. THE CANADIAN PRESS/Darryl Dyck
Horgan’s NDP cabinet built to tackle pandemic, economic recovery, says former premier

Seven former NDP cabinet ministers didn’t seek re-election, creating vacancies in several high-profile portfolios

Join Black Press Media and Do Some Good
Join Black Press Media and Do Some Good

Pay it Forward program supports local businesses in their community giving

Cannabis bought in British Columbia (Ashley Wadhwani/Black Press Media)
Is it time to start thinking about greener ways to package cannabis?

Packaging suppliers are still figuring eco-friendly and affordable packaging options that fit the mandates of Cannabis Regulations

The COVID-19 test centre at Peace Arch Hospital is located on the building’s south side. (Tracy Holmes photo)
B.C. woman calls for consistency in COVID-19 post-test messaging

‘Could we just get one thing straight?’ asks Surrey’s Deb Antifaev

(File photo)
Alberta woman charged after allegedly hitting boy with watermelon at Okanagan campsite

Police say a disagreement among friends at an Adams Lake campsite turned ugly

Most Read