Contact Tracing 101
Contact Tracing 101
How to really #flattenthecurve
Johns Hopkins Bloomberg School of Health has opened a free introductory course on contact tracing COVID-19. According to Coursera it takes approximately seven hours to complete, with flexible deadlines you can adjust.
I recently took and passed this class, managing to finish within six hours. Following completion, participants can receive a certificate and join over 675,000 others that have enrolled.
But because people are busy, here’s a 6-minute rundown of what you should know.
What exactly is contact tracing?
Contact tracing is the process of identifying and notifying people who may have had contact with someone that’s been infected.
What is the history of contact tracing?
Contact tracing has been practiced for centuries for various diseases. In America, it was notably used to combat syphilis and AIDS outbreaks, and has been an effective measure of controlling infectious illnesses.
Why is contact tracing important?
Contact tracing is crucial to limiting the spread of the virus. When COVID-19 cases are found, it is important to immediately ask individuals to limit their contact with others to stop the transmission of the virus.
One way to help understand how fast this virus can spread is by examining its reproductive number – the number of people that one infectious person will go on to infect. The reproductive number of COVID-19 is two, meaning someone who is infected will (on average) go on to infect two other people. When you take that into account, it means the size of the outbreak will continue to double if nothing is done. Preventing one single infection, therefore, can have a big reduction in the total number of people infected.
How is contract tracing done?
Contact tracing begins with a positive test. A contact tracer then asks the person who tested positive about who else they may have been in contact with or what places they’ve been at since the beginning of a person’s infectious period.
Let’s say John tests positive for COVID-19. A contact tracer will ask him who he’s been in contact with since two days before he began to show symptoms. And let’s say John went to a book club the day before he began to feel ill. The contact tracer will then gather everyone’s contact information that was at the book club to tell them they may have been exposed to the virus, and they should quarantine for 14 days.
It is important to note that the contact tracer will not tell anyone at the book club it was John who had the virus – this detail is confidential. The contact tracer then repeats this process with everyone at the book club. The cycle continues.
What is the infectious period, and how long does it last?
The infectious period begins two days before an individual sees symptoms, and while every case varies, the infectious period ends 10 days after the first symptoms begin to show. The individual will need to isolate him or herself for that time period to limit the spread of the virus.
If, for example, John tells a contact tracer he began to feel ill on July 10, the contact tracer knows John has now been infectious for two days, beginning on July 8th. The contact tracer also now knows that John will be infectious for 10 days after he began to show symptoms, so he’ll be contagious at least through July 18.
The earliest possible time John stop isolating will be July 18.
Isolation vs. Quarantine
Both of these terms mean that someone will have to stop having contact with people for a period of time, but there is a meaningful difference.
Isolation means keeping someone who is sick away from healthy people. It can be done at home, but it means having no contact with anyone, including anyone who lives with them. Some people instead stay at a hotel or find a separate place where they can safely isolate. In general, someone can stop isolating 10 days after he or she show symptoms as long as the symptoms are improving and have been free of a fever for three days without medication.
Quarantine, however, means restricting the movement and contact of healthy people who may have been exposed to the virus since they may become infectious. They should quarantine for 14 days since the last time they had contact with the person who may have infected them.
In short, isolation is for the infected and quarantine is for the healthy.
Are there other effective measures to limit the spread of COVID-19?
Wearing a mask, washing your hands and keeping a distance of at least six feet can greatly limit the spread of COVID-19.
Infected people have the virus in their respiratory tract, mouth, noses and throats. When we talk, laugh, cough or sneeze, droplets that are so small we may not even see them come out – but they are there. If an infected individual happens to do any one of these things, those released droplets can have the virus in them and land on someone if close enough.
Those same droplets can also land on a surface that someone may unknowingly touch. This is why masks are an effective measure in reducing the spread. Lastly, the reason for keeping a distance of at least six feet? That is the farthest a droplet can land.
So for the sake of everyone in society: Protect yourself, protect those closest to you, and stay safe out there.