Disease Investigation and Contact Tracing

What is disease investigation and contact tracing?

When there is an outbreak of illness, pubic health staff members and disease investigators work to identify possible sources, track the spread, and notify people who may be infected before the disease can spread. It’s a routine part of public health efforts to contain outbreaks and limit the spread of contagious diseases such as tuberculosis, sexually transmitted diseases, hepatitis, and other communicable diseases in our communities. This has been a part of daily public health operations for decades.

Step one

Case investigation: Disease investigators identify and interview positive cases of certain diseases. The investigator will ask for demographic information such as name, date of birth, address, gender at birth, race, and ethnicity. They will not ask for information such as your social security number, financial information, or immigration status. They will also ask questions that help to identify other people who may have been exposed, including information about workplace, travel history, the nature and timing of your illness if presenting symptoms, anyone you might have had close contact with, and other behavioral questions specific to a certain disease outbreak. 

 All of this information helps the investigator track the potential spread of the disease.

Step two

Contact tracing and notification:  Public health staff or trained volunteers call anyone identified as a close contacts to notify them of the possible exposure and provide guidance specific to that disease outbreak. This could include a vaccine or proven treatment, if it is available for that illness, education on how to prevent that spread of that illness, what symptoms to watch for, at what point someone should see a medical provider. Public health workers are trained and required by law to not reveal the identity of the person who may have exposed the contact, unless given permission. Just as they will protect the personal health information of the people they call.

The goal is to identify and notify other people who were potentially exposed, providing information and resources they need, and preventing or stopping any further spread of that disease. 


Our staff and volunteers are trained to protect patient privacy. We do not provide personally identifiable health information to the public, or those identified as close contacts when they are notified of an exposure to any disease. Sometimes we need to notify places you have been while infectious, such as a workplace. We will work with you to do this safely and privately.

When is Columbia County starting contact tracing?

Contact tracing for COVID-19 is not new. The Columbia County Public Health Department started contact tracing for COVID-19 with it's first identified case on March 27th.

Public health nurses and other county public health staff do contact tracing and notification for outbreaks of many diseases. Some examples in recent years include tuberculosis, hepatitis, and sexually transmitted diseases. There are disease investigators who work to identify, notify, and provide education on prevention resources to positive cases and those potentially exposed. 

So it’s important to remember that contact tracing is not a new effort, not for COVID-19 or for other diseases. It is a critical tool in preventing the spread of disease, and therefore is and always has been a part of the DNA of any public health department.

Why is COVID-19 different?

 The scale of this pandemic means that contact tracing is needed on a much larger scale all over the country and the world. 

The newness of this disease and the lack of both immunity in the population and pharmaceutical interventions, like a vaccine or a proven treatment, make this unique and challenging. Unlike measles, where high rates of vaccination can help slow or stop the spread in a community, we don’t have widespread immunity to COVID-19. Public health has a better understanding of the impact of some diseases, such as symptoms, understanding how the disease typically spreads, duration of a contagious stage, lifespan of a virus on surfaces, and who is most vulnerable. With COVID-19, these are things we continue to learn about.

The other thing that makes COVID-19 contact tracing different from other illnesses is measures like Stay Home, Save Lives→ and physical distancing that are in place to help curb its spread. The role of disease investigation and contact tracing in quick detection and containment of disease outbreaks is critical to keeping more businesses and activities open while avoiding a substantial increase in cases that would threaten hospitals’ capacity to provide acute inpatient care. 

So how many contact tracers are needed?

This is a long-term effort, and the exact number of staff and/or volunteers dedicated to contact tracing will likely fluctuate with the number of positive cases. 

The Columbia County Public Health Department has increased training and reassigned staff from other programs, hired new staff, and worked with volunteers through our Medical Reserve Corps to increase our contact tracing efforts. 

 If the number cases and contacts get beyond the capacity of the County Public Health Department, the Oregon State Public Health Department, Oregon Health Authority (OHA), will provide additional support.

What can I expect if I test positive?

If a person tests positive for COVID-19, that person will either be contacted by their medical provider, or a staff member of the Columbia County Public Health Department to notify them of their test results. If notified by their medical provider first, they can expect a phone call from a staff member of the Columbia County Public Health Department shortly after the first notification.

During a phone call with someone from public health, the disease investigator will ask for demographic information such as name, date of birth, address, gender at birth, race, and ethnicity, but will not ask for your social security number, financial information, or immigration status. They will also ask questions help to identify other people who may have been exposed, including information about workplace, travel history, the nature and timing of your illness if presenting symptoms, and anyone you might have had close contact (within 6ft for more than 15 minutes within a 24 hour period) in the few weeks prior to testing positive.  They will provide you and your household with recommendations and resources around self isolation, preventing the spread of illness, and answers to any other questions you might have. This phone call is followed by an email or information on theses recommendations and resources in the regular mail. Public health staff members will continue periodic follow-ups over the next few weeks via text or phone call to support any needs you might have to safely adhere to home isolation, answer questions, or make referrals for additional resources as necessary. Generally, the length of isolation is at least 10 days from the onset of symptoms and/or at least 24 hours after your fever is gone (without fever-reducing medication), and other symptoms such as cough are improving.

What contact information will show up when I am being contacted for my daily symptom check-in?

Email: noreply.arias@dhsoha.state.or.us

Phone: 503-397-7247

Text: 844-902-3260

What can I expect if I’m a close contact of a case?

If you've been identified as someone being in close contact with a confirmed case, you will receive a call from a member of our contact tracing team to notify you. Please keep in mind that due to confidentiality, they may not be allowed to disclose who the person that tested positive is. They will provide you with recommendations on how and why it's important to quarantine at this time, how to monitor your symptoms, and general disease prevention in the home. You will be asked to isolate yourself from other members of your household, and to monitor for the onset of  any COVID-19 related symptoms at home for 14 days. During the time period a member from the Public Health Department will do a daily symptoms check in by either email or text message through our state-wide contact tracing software, or a personal phone call based. You choose your preference of these three options. 

What number or email will show up when I am being contacted for my daily symptom check-in?

Email: noreply.arias@dhsoha.state.or.us

Phone: 503-397-7247

Text: 844-902-3260

If you do develop symptoms, we encourage you to contact your medical provider and to get tested for COVID-19. If you get tested and test positive, you will be asked to continue to stay home and away from others until 10 days have passed since the start of symptoms and/or at least 24 hours after your fever is gone (without fever-reducing medication), and other symptoms such as cough are improving.

For positive cases and those identified as close contacts, Columbia County Public Health Department:

  • Can help people come up with a plan to get groceries and other resources so they can stay home safely.

  • Asks contacts to stay home, but we do not punish or report them if they don’t stay home.

  • Wants to remind you that staying home the whole time is important because people can spread COVID-19 before they know they are contagious.

  • Will make sure people have a plan for seeking medical care if they develop symptoms.


Rumors and misinformation can cause of fear for many. Please help us stop the spread of misinformation and rumors. If you have a question about anything, please use credible resources such as the CDC, or Oregon Health Authority, or ask us at Columbia County Public Health. 

What you should know

Is public health staff conducting interviews in people's homes?

Case interviews and close contact notifications are almost always done by phone. Public Health staff will not be sent directly to homes to round people up. Our priority is reducing the spread of illness, which means we want you to stay home and avoid in-person contact with others, including Public Health Staff.

Are people being forced into isolation and quarantine facilities? 

You may have seen rumors about people being forced into isolation and quarantine facilities. If you have been identified as having positive lab results for COVID-19, and do not have a safe place to isolate yourself to protect others from the spread due to unstable housing or inability to maintain distance from vulnerable members of your household, Columbia County Public Health Department and Columbia Pacific Coordinated Care Organization (CPCCO) have the ability to provide alternative housing options to support isolation efforts. However, the preference is for people to isolate or quarantine at home→. We do ask that you maintain distance from household members during your illness You can do that by keeping to your own room, limiting contact in shared spaces such as bathrooms, and by increasing cleaning of high-touch areas such as handles and doorknobs. 

Will children of parents or guardians who test positive for COVID-19 be taken away?

There have been concerns about children being taken away from parents or guardians if the child or parent becomes ill with COVID-19. If there is a positive case of COVID-19 in a household where children are present, the same steps should be taken as in other households – stay home and away from others, practice good cleaning and hygiene, and call your doctor if either you or any children develop symptoms. It is a good idea to make a plan for who would care for your children if you were to become severely ill and needed to be hospitalized. We encourage you to talk to family, friends or neighbors you trust.

Citizenship status

  • People who seek health care or contact public health about COVID-19 symptoms will not be asked about their immigration or citizenship status.  No information will be shared with the federal government or immigration authorities (ICE).
  • Medical care for COVID-19 will not count against immigrants seeking permanent residency in the United States (also known as Public Charge).

 Help us protect your protect friends, family, and community members from future potential infections. We need your help to stop COVID-19.

Interested in helping with contact tracing? Please fill out this interest form→


NPR: Contact Tracing Helps Scientists To Study The Ways The Coronavirus Spreads

CDC: Case Investigation and Contact Tracing

Public Health Quick Links
General Information
Phone Numbers
503-397-7247 24-hour Reporting 503-397-7247
Fax: 888-204-8568
Emergencies: Dial 911
230 Strand St.
Columbia County Courthouse Annex
St. Helens,

Monday - Friday
8:30 a.m. to 4:30


Columbia County Public Health is committed to improving the quality of life and protecting the health and well-being of all residents by addressing social, economic, and environmental conditions. Our goal is to ensure that all people in Columbia County have the opportunity for a healthy life.