Testing Data: DHHS receives positive and negative COVID-19 test results from healthcare providers, laboratories, and testing sites. At-home tests are generally not reported. Positive test results are reported immediately; negative test results may not be reported for 24-72 hours. Laboratory positives may not match confirmed cases due to ongoing investigations and confirmatory testing. When available, laboratory data is shown by the date a sample was tested. If unavailable, it is shown by the date reported to public health. Laboratory data definitions are as follows:
People Tested: One test per person is included by their earliest positive result, within a 90 day period. If there are no positive tests, their earliest negative result is used. Because this is deduplicated to a 90 day window, people may be counted more than once.
Total Tests: One test per person, per day (by collection date), per test type. For example, if a person was tested with a rapid antigen test and then gets a confirmatory PCR on the same day, both tests will be counted. This was updated on 4/14/21 from the previous definition of one test per person per day, regardless of test type. These definitions allow DHHS to report the total effort in testing statewide, while also not double counting any tests that may be reported more than once to DHHS. The Test/Test percent positivity calculation will continue to use the one test, per person, per day definition described below.
Test Types
PCR Tests: COVID-19 PCR tests detect viral genetic material and are used to diagnose active infections.
Antigen Tests: COVID-19 antigen tests are rapid diagnostic tests that detect specific fragments of the virus. Like PCR tests, they are very specific to the SARS-CoV2 virus and detect active infections. Antigen tests can often be performed at point-of-care facilities. As of 3/31/2022, DHHS will no longer report negative antigen tests due to changing federal reporting requirements and at-home testing. Positive antigen tests will continue reported.
Antibody Tests: COVID-19 antibody tests, also called serological tests, detect the presence of antibodies to the virus in blood samples. They are typically used to identify people with prior infections. There is a lag between infection and antibody production by the immune system, so antibody tests usually cannot be used to detect active infections.
Update: On March 14th, 2023 Utah implemented changes in its Communicable Disease Rule. This changed the reportability of COVID-19 testing, specifically removing negative reporting for a large portion of tests. Due to this change percent positivity will no longer be updated. Percent positivity data prior to 03/14 will still be available.
Percent Positivity Calculation: As of 3/31/2022, DHHS will be reporting percent from Nucleic Acid Amplification Tests (NAATs) because many rapid antigen tests are no longer being reported to public health due to changing federal reporting requirements and at-home testing. The historical percent positivity data has been updated to NAAT only so current data can be compared to past trends. DHHS calculates percent positivity using two methods: (1) the number of all positive tests over the number of all tests in a day and (2) the number of people tested positive over the number of people tested. For the first method, if a person was tested multiple times in a single day, DHHS will include positives first, and then negatives. For the second method, the first positive test result will be used for someone who has taken more than one test. Any future positive or negative results will not be used. If there is no positive result for that individual, then their first negative result is used. If a person is tested again, at least 90 days after their last test, DHHS will create a new record for the person and their most recent test result will also be included in the percent positivity calculations. If a person has two positive tests with at least 90 days between tests the case will be investigated as a possible reinfection.
As the COVID-19 virus circulates in the population, genetic mutations can occur that may change some virus characteristics. For example, the virus may become more easily passed from person to person and/or cause more severe disease. When these mutations occur and begin spreading, we call the virus with the changed genetic sequence a variant. Globally, there are several variants of concern (VOCs) that have been identified. The data are below are for VOCs as defined by CDC. Some VOCs may be under-reported if they were sequenced by national laboratories. Results labeled “Other Lineage” are either not a variant or, less frequently, a variant of interest (VOI). The Utah Public Health Laboratory (UPHL) and other laboratories in Utah are performing Whole Genome Sequencing (WGS) on a subset of PCR samples as a surveillance tool for these variants.
The following curve shows the turnaround time for COVID-19 laboratory tests in the state of Utah. Test turnaround time (TAT) is defined as the number of days between the date a test specimen was collected from the patient to the date the test was performed by the laboratory. The data reflect both positive and negative results from the current largest testing providers including ARUP Laboratories, Intermountain Central Laboratory, LabCorp and its subsidiaries, TestUtah, and the Utah Public Health Laboratory (UPHL). Other testing providers are not included.
Note: The last three days of data are not shown here, since tests performed in this time may not be reported yet.
Note: In an effort to reduce turnaround time, as of Dec. 30th, 2020, the lab contracted to process TestUtah results changed from Fulgent Genetics to ARUP. These updates are reflected on these graphs as of Jan. 13, 2021. TestUtah turnaround times are distinguished from ARUP turnaround times by using information about the ordering provider and facility.
Data for this report were accessed on November 02, 2023 10:14 AM.