With such a large scope of reporting — at this point the state is at 25,634 cases and 1,095 deaths — it’s often difficult to tell when the numbers have been adjusted or corrected — something that happens on a semi-regular basis. An issue with the disease has always been working toward getting accurate and timely results, but because so many cases are asymptomatic or mild, people may not realize they’ve been infected.

A letter from Dr. Gary Voccio, health director for the Georgia DPH Northwest Health District, to the boards of health in the 10-county district outlined a recent change to their reporting guidelines. The change primarily has to do with the accuracy of a test intended to show if someone has had a previous COVID-19 infection.

There are two types of tests. A serologic-only test, obtained by a finger-prick blood sample, shows if a previous COVID-19 infection was present by looking for antibodies. The serologic test is also known as an antibody test. There is also the diagnostic test, which is obtained by a nasal swab, to test for an active infection.

Because of the unreliability of some of the serologic tests — many of which haven’t been approved by the Food and Drug Administration beyond emergency use — the state decided to stop counting the results of those test as of April 24.

“Some antibody tests have low sensitivity and specificity and may not produce reliable results, but because of the relative simplicity of the technology, the Food and Drug Administration decided to waive initial review of the tests as part of its emergency response to the coronavirus outbreak,” Voccio wrote in the letter.

At this point the DPH isn’t going to go back and adjust those numbers, citing a lack of resources.

“We simply do not have the resources right now to go back and remove the serology-only cases, some of which surely represent actual COVID-19 infections, from your total case count,” Voccio wrote.

Here is the letter that was sent to Public Health Departments in Northwest Georgia:

4/28/20

Dear Board of Health member:

I know you and others in your community have likely used the daily COVID-19 confirmed-case-and-death counts reported by the Georgia Department of Public Health (DPH) on its website (https://dph.georgia.gov/covid-19-daily-status-report) to follow the trajectory of the virus as it’s been transmitted and spread throughout our state, Northwest Georgia, and your county in particular.

We need to keep in mind these are not just numbers. Each case and every single death represent a living soul whose life may have been extinguished or irreparably altered. Our hearts go out to the family and friends of anyone touched by this virus we are all continuing to fight.

I want to tell you about a recent change to our reporting guidelines that might influence your understanding and trust of our data, particularly the confirmed case count. Effective Friday, April 24, we will no longer include so-called serology-only positive cases in our COVID-19 case counts.

What does this mean? There are presently two primary but very different ways to test for COVID-19 — diagnostic testing, which uses nasal swab samples to test for active infection, and serologic testing, which uses finger-prick blood samples to test for previous infection.

A positive diagnostic PCR (polymerase chain reaction) test tells us that the person tested presently has an active COVID-19 infection.

PCR tests for COVID-19 are both specific and sensitive, which means that people who test positive truly have the disease and that only a very small percent of the people carrying the virus slip through the test as a false negative.

Then there’s serologic antibody testing. A positive antibody test means that the person being tested was infected with COVID-19 in the past and that their immune system developed antibodies to try to fight it off. Some antibody tests have low sensitivity and specificity and may not produce reliable results, but because of the relative simplicity of the technology, the Food and Drug Administration (FDA) decided to waive initial review of the tests as part of its emergency response to the coronavirus outbreak.

Until Friday, April 24, Georgia DPH counted both PCR positives based on diagnostic testing and presumed antibody positives based on serologic testing as confirmed COVID-19 cases. Both have been reported in our COVID-19 Daily Status Report under COVID-19 Confirmed Cases By County.

However, based on guidance from the CDC and FDA, our state epidemiology staff determined that serology-only cases should no longer be reported as confirmed cases in data provided to the public at this time. We expect that this process may change again as revisions to the reporting criteria continue to be made to better suit the epidemiologic needs of responding to a new virus and as more information regarding the validity of these tests is available.

Listed below are our six counties who have serology-only cases included in their current cumulative case count. Our other four counties (Bartow, Haralson, Paulding, and Polk) do not.

County Serology (antibody) positives as of 4/24/20

Catoosa 23

Chattooga 2

Dade 11

Floyd 1

Gordon 2

Walker 44

Nearly all these serology-only cases were reported by a clinic in Walker County, and you can see the impact on Walker’s numbers and those of adjacent or nearby counties. Several other cases were reported by a Federally Qualified Health Center in Dade County.

Please understand that your county case count will not be reduced because of this reporting change. We simply do not have the resources right now to go back and remove the serology-only cases, some of which surely represent actual COVID-19 infections, from your total confirmed case count. This is just a change in the way we’re recording and reporting data going forward, for the moment anyway, to the public.

I’d also like to remind you that the confirmed case count, at best, represents only an incomplete snapshot of the spread of the virus in our communities. Because so many COVID-19 cases are asymptomatic or mild, never seek medical attention, and thus are not tested, we know there are many more people in our communities who have been infected with the virus than the confirmed case count indicates.

Also, please understand we expect to see county COVID-19 case counts continue to increase as testing increases. I hope this answers your questions and allays any concerns about the change in our reporting of confirmed COVID-19 cases.