About the COVID-19 Serosurvey

From September 12-20, 2020 public health teams from the Maricopa County Department of Public Health and Arizona State University will visit randomly selected homes in Maricopa County to invite residents to participate in a serosurvey, which includes questions about their health and giving a sample for an antibody test. 

The blood samples will be analyzed by Mayo Clinic, and participants will be notified via phone about their antibody test results by Maricopa County Department of Public Health. Your participation will play an important role in helping public health know how many people in Maricopa County have been infected with COVID-19 and how many people need to get vaccinated so we can relax social distancing and mask requirements and get back to a more normal existence.

Participation is voluntary and everything in the program, including testing, is FREE. No personal or identifying information will be shared outside of public health and all samples and identifying information will be destroyed after the investigation is over.

Contact Us

If you would like to learn more about this important public health activity, please email us at covid19serosurvey@maricopa.gov or call 480-965-8384.

Organizations Involved

  • Maricopa County Department of Public Health is the third-largest public health jurisdiction in the country. MCDPH initiated the serosurvey as part of its response to COVID-19. Volunteers will be part of the field team going out to communities.
  • Arizona State University (ASU) is supporting the effort with coordination and volunteers who will also be part of the field teams.
  • Mayo Clinic is providing laboratory analysis of samples collected for the serosurvey.


Frequently Asked Questions


Antibody (also known as serology) tests are laboratory tests that look for the presence of antibodies, which are proteins made by the body in response to an infection. An antibody test is able to detect if you’ve had COVID-19 in the past, even if you didn’t have symptoms or know you were sick.

The COVID-19 antibody test used by the Maricopa County Department of Public Health is authorized by the U.S. Food and Drug Administration (FDA).



Most people who are infected by the virus make antibodies within days to weeks of infection. However, some individuals, such as those with depressed immune systems may not make antibodies after they are infected.



A positive test result indicates you likely have been infected with COVID-19 in the past.



A negative antibody test result indicates that antibodies to the virus were not detected in your blood sample. This could happen if:

  • You have not been infected with COVID-19 previously.
  • You had COVID-19 in the past, but you did not develop or have not yet developed detectable antibodies. It is unknown if all infected individuals will develop a detectable antibody response.


Antibodies likely provide some immunity to the COVID-19 virus; however, there's currently not enough information to know how long the immunity will last or whether past infection with the virus protects you from getting another infection. We also don't know if you could be infected by a different strain of COVID-19 In the future.

Whether your antibody test result is positive or negative, you should continue to protect yourself and others:

  • Keep physical distance from others—at least 6 feet apart.
  • Wear a cloth face covering when you go out in public.
  • Wash your hands often with soap and water, for at least 20 seconds.
  • Monitor yourself and your family for COVID-19 symptoms.
  • Stay home as much as possible, especially when you are sick.


If you agree to take part, you will be asked some questions about your general health status and possible exposures to the COVID-19 virus. After the interview, a public health professional will collect a small blood sample from you, similar to when blood is drawn at a laboratory or doctor’s office. The person who collects the sample will use full PPE and ensure safe protocols are implemented for specimen collection.



All household members older than six years of age living within the same household can participate. No ID is required, but for those household members younger than 18, consent of the parent or legal guardian is required. Participation is voluntary and testing is FREE.



In order to maintain safe social distancing practices, blood sample collection will take place outside the home, such as your front porch, in your yard under a tent that our team will set up, or by appointment in the Maricopa County Department of Public Health mobile clinic.



MCDPH will take a number of measures to protect both volunteers and participants:

  1. Our team will follow COVID-19 safety protocols.  
  2. All health information will be kept confidential, and participants will be notified about their results by Maricopa County Department of Public Health.  
  3. Maricopa County Department of Public Health will not share test results with anyone outside of public health.
  4. Participation will occur in a tent outside the person’s home or in a mobile clinic; volunteers will not ask to enter participants’ homes. 
  5. All blood samples will be held confidentially by public health and then destroyed after the test is run along with all identifying information.


The interview and blood draw will be completed in approximately 30 minutes. It may take more time for larger households, depending on the number of participants.



All antibody tests will be processed by the Mayo Clinic. Maricopa County Department of Public Health will contact you by phone with your results within 7-14 days of being tested. Once you verify your identity, they will provide you your results. You may also request a copy of your results by mail.



All interview answers, blood sample, and test results collected for this initiative will be kept private and confidential.



Maricopa County Department of Public Health will not share your test results with anyone outside of public health. Any information published from this serosurvey will aggregated (combined with others’ information) and de-identified.



Yes, individuals with COVID-19-like symptoms will be allowed to participate. However, the antibody test cannot determine if someone has an active COVID-19 infection.



Yes, we are interested in participation from all members of the community, even those who have not been ill. People can have COVID-19 without knowing they are infected or showing any symptoms.



No. If your home is randomly selected for participation when surveyors are in your area, our volunteers will come to your home and ask if you and others in your household are willing to participate. If your home is chosen and you are not home when the volunteers come to your neighborhood, a door hanger with information to schedule an appointment will be left.



MCDPH and ASU worked with the Centers for Disease Control and Prevention (CDC) to implement a method of sampling a smaller number of households in targeted communities that would result in a sample that represents all of Maricopa County. The CDC provided a list of 29 communities within the county.

The selected communities are within the following 29 ZIP codes. Any household within those ZIP codes that received a door hanger are part of the selected community.

ZIP CodeCity/Town
85009
Phoenix
85014
Phoenix
85017Phoenix
85019Phoenix
85022Phoenix
85027Phoenix
85027Phoenix
85031Phoenix
85037Phoenix
85041Phoenix
85054Phoenix
85086Phoenix
85120Mesa/Apache Junction
85203Mesa
85203Mesa
85207Mesa
85226Chandler
85249Chandler
85253Paradise Valley
85258Scottsdale
85260Scottsdale
85281Tempe
85304Glendale
85323Avondale
85339Phoenix
85375Sun City West
85382Peoria
85390Wickenburg
85390Wickenburg


To ensure we have a diverse sampling of our residents, participation in the serosurvey is only open to residents in randomly selected homes. For others seeking antibody testing, they can check with their healthcare provider or find community testing events at azdhs.gov/covid19testing.



You may email us at covid19serosurvey@maricopa.gov, or contact our hotline, 480-965-8384, should you have any questions.