New research suggests millions of people who tested negative for COVID-19 may have long COVID
Northwestern Medicine researchers suggest post-COVID clinics shouldn’t require a positive COVID-19 test to provide care for long-haulers
Chicago, IL – August 23, 2023 – Early in the COVID-19 pandemic, testing was limited, and many individuals couldn’t get a positive diagnosis during the window of viral shedding. This was especially important for COVID long-haulers, who were struggling with lingering symptoms such as brain fog, fatigue and cognitive impairment. Without a positive COVID-19 test, many were denied appointments at post-COVID clinics in the United States, but the Northwestern Medicine Neuro COVID-19 Clinic was an exception, evaluating new patients without a confirmed COVID-19 diagnosis.
According to new research published in Neurology® Neuroimmunology & Neuroinflammation, an official journal of the American Academy of Neurology, Northwestern Medicine researchers show 41% of long-haulers who initially tested negative for COVID-19 had antibody or T cell responses indicating they were exposed to the virus. This new research performed with very sensitive immunologic assays suggests post-COVID clinics shouldn’t require a positive COVID-19 test in order to provide care to long-haulers.
“It’s estimated that nearly 10 million Americans experienced neurologic manifestations of long COVID without an official COVID-19 diagnosis due to limited access to COVID testing in the first year of the pandemic or testing outside the window of detection,” said Igor Koralnik, MD, chief of neuroinfectious diseases and global neurology at Northwestern Medicine, who oversees the Neuro COVID-19 Clinic and is co-director of the Northwestern Medicine Comprehensive COVID-19 Center. “Millions of people in the United States have been rejected by the medical establishment and stigmatized because they didn’t carry a definite diagnosis of COVID-19 when they presented with their long COVID symptoms. We hope those people feel vindicated by our study.”
Millions of people in the United States have been rejected by the medical establishment and stigmatized because they didn’t carry a definite diagnosis of COVID-19 when they presented with their long COVID symptoms. We hope those people feel vindicated by our study.
- Researchers looked at 29 long-haulers who presented to the Neuro COVID-19 Clinic between June 2020 and April 2022 with a negative COVID-19 test.
- The median age was 43 and 93% of patients identified as female.
- Of the 29 tested, 41% had detectable antibody or T cell responses indicating they were exposed to the virus.
- The patients had striking similarities to long-haulers with positive COVID-19 tests in clinical presentation, quality of life measures and objective cognitive testing.
“We tested two types of immunity, both antibody and T cell responses, against two different proteins from the virus that causes COVID-19. Patients’ responses were mixed rather than all or nothing, suggesting that a comprehensive evaluation is necessary and that immunologic tests are not a one-size-fits-all for confirming prior exposure to the virus,” said Dr. Koralnik. “Post-COVID clinics shouldn’t require a positive test to provide care for long-haulers after suspected COVID-19. More research is needed to determine what causes long COVID and how to effectively treat its many symptoms.”
To date, the Neuro COVID-19 Clinic has treated more than 2,100 long-haulers from 44 states. For more information, visit nm.org and to schedule an appointment, please call 312.695.7950.