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

Just Posted

The Co-op gas station at Whiskey Creek is burning after a camper van burst into flames just before 4 p.m. on Thursday, June 17, 2021. (FACEBOOK PHOTO)
Exploding camper van torches Highway 4 gas station between Qualicum Beach and Port Alberni

Highway traffic blocked after Whiskey Creek gas station erupts into flames

Timmy Masso smiles alongside his niece Huumiis and nephew Cinkwa. (Submitted photo)
Ucluelet Secondary School graduate earns TD Scholarship for Community Leadership

Timmy Masso’s passionate advocacy of the Nuu-chah-nulth language leads to $70K scholarship

Two ambulances and a medevac helicopter are on scene at Taylor River Flats rest area on Highway 4 due to a serious motor vehicle incident. (PHOTO COURTESY MAGGIE BROWN)
Highway 4 reopens after accident at Taylor River Flats

Multi-vehicle crash had closed highway to west coast

Grade 12 graduates Jada Touchie, Timothy Masso and Brendan Brown are all smiles after receiving their Goodies for the Grads gift packs thanks to a small neighbourhood grant from the Clayoquot Biosphere Trust. (Nora O’Malley photo)
Ucluelet Secondary School grads set to parade through town

Family and friends can cheer on the Class of 2021 this Saturday, June 19 at 4:30 p.m.

From left, Ahousaht First Nation Hereditary Chief Richard George presents a $10,000 cheque to Tofino Hatchery manager Doug Palfrey alongside Tyler Huebner of TCH Contracting The funds will go towards rebuilding Cypre river Chinook. (Carallyn Bowes photo)
Tofino Hatchery receives $10K donation

Tofino Salmon Enhancement Society tackling massive drop in Chinook salmon stocks

People line up to get their COVID-19 vaccine at a vaccination centre, Thursday, June 10, 2021 in Montreal. THE CANADIAN PRESS/Ryan Remiorz
Vaccines, low COVID case counts increase Father’s Day hope, but risk is still there

Expert says people will have to do their own risk calculus before popping in on Papa

Helen Austin performing with Trent Freeman at the 2018 Vancouver Island MusicFest. Austin is one of the many performers listed for the 2021 event.
Vancouver Island MusicFest goes virtual for 2021

Black Press to stream 25 hours of programming July 9-11

Greater father involvement in the home leads to improved childhood development and increased marital satisfaction, says expert. (Black Press Media file photo)
Vancouver Island researcher finds lack of father involvement a drag on gender equality

Working women still taking on most child and household duties in Canada: UVic professor

FILE – A science class at L.A. Matheson Secondary in Surrey, B.C. on March 12, 2021. (Lauren Collins/Surrey Now Leader)
Teachers’ union wants more COVID transmission data as B.C. prepares for back-to-school

BCTF says that details will be important as province works on plan for September

Provincial health officer Dr. Bonnie Henry outlines B.C.’s COVID-19 restart plan, May 25, 2021, including larger gatherings and a possible easing of mandatory masks on July 1. (B.C. government photo)
B.C. records 120 new COVID-19 cases, second vaccines accelerating

Lower Pfizer deliveries for early July, Moderna shipments up

A Heffley Creek peacock caught not one - but two - lifts on a logging truck this month. (Photo submitted)
Heffley Creek-area peacock hops logging trucks in search of love

Peacock hitched two lifts in the past month

The Calgary skyline is seen on Friday, Sept. 15, 2017. THE CANADIAN PRESS/Jeff McIntosh
2 deaths from COVID-19 Delta variant in Alberta, 1 patient was fully immunized

Kerry Williamson with Alberta Health Services says the patients likely acquired the virus in the hospital

The first suspension bridge is the tallest in Canada, with a second suspension bridge just below it. The two are connected by a trail that’s just over 1 km. (Claire Palmer photo)
PHOTOS: The highest suspension bridges in Canada just opened in B.C.

The Skybridge in Golden allows visitors to take in views standing at 130 and 80 metres

BC Green Party leader and Cowichan Valley MLA Sonia Furstenau introduced a petition to the provincial legislature on Thursday calling for the end of old-growth logging in the province. (File photo)
BC Green leader Furstenau introduces old-growth logging petition

Party calls for the end of old-growth logging as protests in Fairy Creek continue

Most Read