You may be reading that title and wondering what a disease investigator is and why the topic is being discussed in a public health blog post, so let’s start there!

In the state of Washington (and all states), there are certain health conditions that are considered “notifiable,” which means that anytime they are diagnosed (or suspected) by a healthcare provider, the information is forwarded to the local health department so they can learn more about who has the condition and how they got it. This is where a disease investigator comes in!

Disease investigators usually work within the communicable disease division of health departments, and you may have even talked to one before! When a community member gets sick with something like salmonella, E. coli, or hepatitis C, we reach out to ensure the patient is aware of their test results, discuss treatment, if necessary, and work to ensure the disease doesn’t continue to spread further. A day in the life of a disease investigator can be very exciting stuff.

An example of a typical (but busy) day can look like:

• A member of the public called to say they got sick with a stomach bug after eating at a birthday party.
• We received a call from the Washington State Department of Health letting us know they need our assistance reaching out to a local nursing home to test residents for a possible multidrug-resistant organism exposure.
• We received A new lab result in the state reporting system notifying us there is a new case of valley fever (coccidioidomycosis) to evaluate. It is important to call the patient to find out if they have recently traveled.
• A local veterinarian called asking for advice about whether or not a dog they are treating should be tested for rabies since it came in contact with a live bat.
• A fax from a hospital came in with a lab result for someone who tested positive for salmonella. Upon speaking with the patient, we discovered they ate at the same birthday party we received that call about earlier. Time to figure out if we have an outbreak on our hands!
• A school nurse called to inform us that one of their students is being evaluated for chickenpox. Even though it isn’t notifiable, we still have guidance and a notification letter we share just in case.

The possibilities are endless! The next steps we take depend on the needs of the case we are investigating.

Next steps might look like:

• Interviewing the patient to learn about their experience, including how they may have been exposed, their symptoms, and if they may have accidentally exposed others.
• Conducting contact tracing to inform contacts they may have been exposed and possible guidance if they need to seek healthcare.
• Consulting with healthcare providers to help them decide next steps for treatment.
• Conducting a foodborne illness outbreak investigation with the help of our environmental health team.
• Providing treatment if the person is unable to see a healthcare provider (for certain conditions, not all).
• Packaging specimens and shipping them to the public health lab for further testing. This can include things like stool specimens, nasal swabs, and even animals.
• Providing education on how to prevent the illness from spreading to others. Which usually always involves talking about good hand washing!

And at the end of the day, we take our on-call phone home with us in case of any urgent needs throughout the night. Though no day is the same, it usually contains a mix of these things, plus a few meetings. As disease investigators we often make interesting discoveries that make us feel like a detective. But no matter what the day brings, we’re here to help determine the cause of an outbreak, keep tabs on where and how disease spreads, connect people with the proper treatment when appropriate, and help prevent others from getting sick.