Our COVID-19 prevalence is low in our county. We have run around 600 IgG with only 3 positive and they are low positive.. We are sending out +IgG to outside lab for confirmation. If the serology IgG is low positive on Abbott and neg
on Viracor we result the test as indeterminate.
Our lab team is doing IgG/IgM serology validations on our healthcare workers who have +PCR and were symptomatic and we are able to validate IgM and IgG levels in this population.
We are not sure how useful serology is at this point for asymptomatic HCWs since our area has such a low prevalence. We plan on continuing serology on all healthcare workers to hopefully get an idea of prevalence in our workforce and
to collect more data on serology testing in select populations.
Our esoteric lab manager has put together some useful information if anyone is interested. Please email and I’ll send it. JoAnn
JoAnn Shea, APRN, MS, COHN-S
Director, Team Member Health and Wellness
Tampa General Hospital
Office: 813-844-7692
Cell: 813-789-3441
jshea@tgh.org
From: MCOH-EH <mcoh-eh-bounces@mylist.net> On Behalf Of
Paul Winkel
Sent: Tuesday, April 28, 2020 11:41 AM
To: MCOH-EH <mcoh-eh@mylist.net>
Subject: Re: [MCOH-EH] Use COVID antibody results for return to work management?
WARNING: This email came from
an external source outside of Tampa General Hospital.
Hello JoAnn
I am in Springfield, MA. Our parent corporation is holding back on the serology testing due to high false positives when prevalence is fairly low. Do you know the prevalence of COVID in Tampa?
I would be interested in your results.
Thank you,
Paul Winkel, D.O., FACP
Trinity Health of New England
On Tue, Apr 28, 2020, 11:25 AM Shea, Joann via MCOH-EH <mcoh-eh@mylist.net> wrote:
We stopped using the test based strategy as all were PCR + for more than 3-4 weeks and infectivity at that point was not clear. We started IgM/IgG testing in-house last week and require IgG + in addition to 14 days OOW from onset of symptoms and 7 days symptom free to RTW. Since last week, we have been drawing serology on all PCR COVID+ healthcare workers to validate our testing and to assist with RTW decisions.
We also started drawing serology on HCW with classic COVID-19 symptoms in addition to the PCR. Yesterday we had a positive IgM on a nurse with classic COVID-19 symptoms ( cough, SOB, fever, loss of smell/taste) but had two previous negative PCR from our screening clinic.
Today, we opened up IgG testing to all HCWs in the organizations and offer 100 appts per day in our TMH clinic. We hope this testing will allow us to identify how many of our HCW may have had asymptomatic infection and how many are susceptible. We reiterate to our HCWs that a positive IgG does not indicate the amount or duration of immunity or if they are protected from reinfection.
Our Infectious Disease physicians plan to conduct a retrospective study on IgG testing of healthcare workers once we have a large enough sample. We have already scheduled over 2500 for IgG testing and are hoping for at least 5,000 by July. We included data points such as history of exposure, perform aerosolizing procedures, work in high risk unit, history of symptoms but never tested, and random selection of HCWs.
Will be happy to share results with this group.
JoAnn Shea, APRN, MS, COHN-S
Director, Team Member Health and Wellness
Tampa General Hospital
Office: 813-844-7692
Cell: 813-789-3441
William Scott, MD, MPH, FACOEM
Clinical Assistant Professor, Carle Illinois College of Medicine,
Clinical Assistant Professor, University of Illinois College of Medicine at Urbana-Champaign
Head, Occupational & Envionmental Medicine & Employee Health
Carle Foundation Hospital, Carle Physician Group.
_______________________________*****EXTERNAL EMAIL SOURCE*****Melanie Swift, MD, MPH
Medical Director, Mayo Clinic Physician Health CenterAssociate Medical Director, Occupational Health Service
Assistant Professor of Medicine
Division of Preventive, Occupational, and Aerospace Medicine
William Scott, MD, MPH, FACOEM
Clinical Assistant Professor, Carle Illinois College of Medicine,
Clinical Assistant Professor, University of Illinois College of Medicine at Urbana-Champaign
Head, Occupational & Envionmental Medicine & Employee Health
Carle Foundation Hospital, Carle Physician Group.
_______________________________*****EXTERNAL EMAIL SOURCE*****
- About 80% of COVID-infected individuals develop IgG by day 14, and almost 100% develop it by day 30.
- Some people with a new positive IgG still have detectable viral RNA by PCR in nasopharyngeal swabs.
- The PCR can’t tell whether that viral RNA represents viable, replication-competent virus; so we have to assume a person who is PCR-positive may be still communicable.
- We don’t yet know whether a positive IgG always represents neutralizing antibody and thus presumptive immunity.
So my personal take on this is:
- IgG is not helpful in determining safety to RTW.
- IgG may be helpful diagnostically, especially when an individual was not tested with PCR early in their illness course, and now appears to have late complications of COVID-19. The virus may be only replicating in the lower airway and nasal PCR could be negative. An IgM or IgG that was positive would help make the diagnosis.
- If we find evidence of neutralizing antibodies and durable immunity, and we have a vaccine that is in short supply, the test could help us develop a vaccine prioritization.
- If we find evidence of neutralizing antibodies and durable immunity, and we have another wave of hospitalized patients, IgG could help us identify HCP at lower risk, and this could be used in some sort of cohorting strategy.