Contact tracing is a method of controlling an infectious disease. It involves identifying people who may have come into contact with a person who is sick. Public health officials can then recommend that at-risk individuals take precautions to prevent the spread of the disease.

Contact tracing is often part of a coordinated effort to contain an infectious illness. Although contact tracing is not a new practice, it has become more widespread since the start of the COVID-19 pandemic.

This article looks at how contact tracing works and the privacy concerns associated with it.

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Contact tracing can help slow the spread of infectious diseases.

According to the Centers for Disease Control and Prevention (CDC), contact tracing begins with a case investigation. This involves a contact tracer interviewing someone with a confirmed case of an infectious illness.

During this interview, tracers typically ask who the person has come into contact with and the places they have visited since they contracted the illness.

In the case of COVID-19, the World Health Organization (WHO) say that this includes anyone a sick person saw:

  • between 2 days before and 14 days after developing symptoms
  • at a distance of less than 1 meter (3 feet)
  • for more than 15 minutes

Contact tracers call at-risk individuals “contacts.” In addition to close friends and family, contacts also include people a sick person encountered:

  • on public transport
  • in a prison or shelter
  • in a school
  • at their workplace
  • at a social event
  • at a place of worship
  • in a hospital or other healthcare facility

Once contact tracers finish compiling a full list of contacts, they must call all of them as quickly as possible.

By alerting someone to the fact that they may have contracted an illness, contact tracers can recommend measures that prevent the spread of the disease.

These measures can include:

  • self-isolating
  • physical distancing
  • undergoing medical testing to confirm if a person is carrying the illness

The contact tracing team may also monitor contacts’ health, either through regular phone calls or self-reporting methods.

The advice that contact tracers provide will depend on the nature of the illness and how it spreads. It may also vary depending on the organization carrying out the contact tracing.

Contact tracers do not usually disclose the name of the person with a confirmed case of the illness. This protects their privacy and anonymity. However, they may provide educational resources that aim to help people understand their risk of infection.

No vaccine currently exists for SARS-CoV-2, which is the virus that causes COVID-19. Because of this, public health organizations have used contact tracing to reduce transmission.

According to an article in The Lancet Infectious Diseases, countries such as China, Germany, Iceland, Singapore, South Korea, and Taiwan have successfully kept transmission and mortality rates low by using a combination of contact tracing, testing, and physical distancing.

However, the success of manual contact tracing relies on large teams of trained contact tracers being able to quickly identify and locate at-risk individuals.

Many areas of the United States have expanded their contact tracing teams as a result of COVID-19. For example, the South Carolina Department of Health and Environmental Control report that they now have 400 contact tracers, whereas before the COVID-19 pandemic, they had 20.

However, one 2020 research article argues that manual tracing is too slow, and that contact tracing apps are more effective. In addition, any contact tracing effort relies on several important factors, including the availability of reliable medical testing to confirm cases and the ability and willingness of contacts to follow the advice to self-isolate.

Self-isolation is more difficult for people who live in crowded housing and those who are caregivers. Because of this, contact tracing is just one part of the effort to reduce the severity of the COVID-19 pandemic.

According to the CDC, people also need access to social services and suitable housing so that they can safely distance themselves from others.

Although contact tracing may help prevent the spread of diseases, some people worry that organizations may misuse their personal data or fail to store them securely.

Here are some of the privacy concerns surrounding contact tracing:

Collection of private health information

Some people express concerns about sharing information because they do not know how organizations might use this information in the future.

They worry that organizations might share their data with other companies, or that they will face stigma if people know aspects of their medical history.

Before a person shares information with a contact tracer, they can ask how the organization plans to access, protect, store, and use the data.

Location tracking

Contact tracing apps are a new way for organizations to see who may be at risk of developing an illness such as COVID-19.

Companies including Apple and Google have released contact tracing apps that track a person’s location. This allows public health organizations to easily see who has come into contact with a person who has COVID-19.

However, some people do not like the idea of companies being able to track their location via their phone, and for these apps to work effectively, a large number of people would need to download them.

Contact tracer security

Some people have reported scams wherein people call and pose as contact tracers. These scammers ask for highly personal information.

However, a contact tracer from a public health organization will never ask for a person’s

  • credit or debit card information
  • private financial information
  • Social Security number

Contact tracers also will not send emails or text messages asking people to click on a hyperlink. If someone receives a message that asks them to do this, they should not click on the link and instead block the contact.

Contact tracing is an important part of efforts to contain infectious illnesses. It allows health organizations to alert people to the possibility that they might develop the disease quickly, thereby reducing transmission.

Many countries have used contact tracing to try to reduce the number of COVID-19 cases. In the U.S., for example, numerous states have expanded their contact tracing teams.

However, some concerns about privacy still persist. If a person receives a call from a contact tracer, they can ask for more information on how the organization will store and use their personal data.

People should also be aware of phone scams and never reveal their financial information to someone who claims that they are a contact tracer.