In an email signed by Missoula County Board of Health and County Commissioner Chair Josh Slotnick, he and county commissioners Dave Strohmaier and Juanita Vero admitted that the county and the health department do not have information about the cycle threshold values of positive SARS-CoV-2 tests results accepted and reported by their agencies.

The cycle threshold value of SARS-CoV-2 PCR tests is sensitive and values that are too high can result in false positives. The problem of false positives has been prevalent, prompting the World Health Organization to publish a notice on January 20th.

The WHO notice informed test administrators, like Missoula County, and labs performing tests that high PCR cycle threshold values are resulting in false positive test results and to adjust accordingly. Florida Governor Ron DeSantis ordered last December that all labs must report their cycle threshold values with every test.

In a “corrected proof” for the Infections Diseases Society of America, testing data shows that positive test results found at a cycle threshold value of 35 have a 97% chance of being a false positive. A cycle threshold value of 25 results in only 30% false positives, indicating that the higher the cycle threshold value, the less accurate the SARS-CoV-2 tests become.

Since the WHO notice the day of the inauguration, daily new cases have dropped significantly indicating that health authorities and labs have heeded WHOs guidance on administering and performing tests.

Slotnick voted with other health board members last December to order that the local population mask their faces and to set limits on the time and place of Missoulians’ ability to congregate and conduct commerce.

The health board also ordered that positive SARS-CoV-2 test results would be the determining factor for lifting the mask mandate and other restrictions. To lift the county’s orders, they require that there be fewer than 25 positive cases per 100,000 people for two consecutive weeks. Currently, the county is only performing tests on people who have symptoms or that meet other specialized guidelines. The past two days have seen fewer than 25 positive cases, according to data on the county’s “Missoula County Numbers” page.

In a February 5th reply to a Montana Public Records Act request for the the PCR cycle threshold values, Strohmaier, Slotnick an Vero noted that, “It appears from your correspondence that [the Missoula City-County Health Department] advised you that they are not in possession of the information you requested,”

The health board representative and commissioners admitted, “Similar to that information, the Missoula County Commissioners do not have the information you are requesting.”

In a reply to our request on January 29th, health department Liaison Officer Stephen Robertson indicated that the county is not aware of the PCR cycle threshold values used in their own SARS-CoV-2 PCR tests and to check with the labs. Robertson did not provide information about the labs who are performing the tests.

We contacted University of Montana Genomics Core Laboratory, which processes up to 2000 tests a day for the health department. We asked lab manager, Dr. David Xing, the cycle threshold value that is used on SARS-CoV-2 PCR tests processed by the Missoula lab. We have not heard back, but will update readers when we do.

Despite the WHO notice, health administrators in Missoula appear to have not taken seriously possible issues with false positive test results. The WHO stated that to determine if a test is accurate, the PCR threshold cycle must be observed accurately. Local health authorities don’t seem to know standards related to their own tests, despite using these tests as a benchmark to remove their orders.