In the early phases of the COVID-19 pandemic, a considerable number of Americans were exposed to the virus SARS-CoV-2 but remained undiagnosed due to limitations in testing capabilities. Subsequent research has revealed that 41% of these individuals displayed an immune reaction indicative of exposure to SARS-CoV-2, implying they may have contracted COVID-19.
During the inception of the pandemic, a large number of Americans encountered the virus responsible for COVID-19, known as SARS-CoV-2. However, the inability to conduct widespread testing at that time resulted in many of them not receiving an official diagnosis. A significant portion of these individuals later showed symptoms that are characteristic of long COVID, a medical condition marked by prolonged symptoms extending beyond six weeks.
This latest research focused on a small subset of such individuals and discovered that 41% demonstrated evidence of past exposure to the virus. These results have been formally published in the journal Neurology Neuroimmunology & Neuroinflammation, an accredited publication of the American Academy of Neurology.
According to the principal researcher of the study, Igor J. Koralnik, MD, from Northwestern Medicine Comprehensive COVID-19 Center in Chicago and a Fellow of the American Academy of Neurology, “Most facilities specialized in treating long COVID currently admit only those patients who have a positive COVID-19 test result. This leaves a multitude of people with similar symptoms without specialized healthcare and ineligible for inclusion in research studies focused on long COVID.” He further emphasized that the data imply millions of Americans could have been exposed to SARS-CoV-2 during the early part of the pandemic, advocating that they should have equal access to specialized care and be included in pertinent research.
The study was restricted to a cohort of 29 individuals displaying symptoms of post-viral syndrome, including neurological issues such as cognitive impairments, headaches, and fatigue, but lacking a confirmed COVID-19 test result. These individuals were compared to 32 individuals of similar age who had been diagnosed with long COVID and had positive test results. The comparison also extended to 18 individuals who did not exhibit any of these symptoms and had no known exposure to COVID-19 or positive test results.
Blood tests were conducted on participants to detect antibodies against two specific proteins that signify an immune reaction indicative of a past COVID-19 infection—namely, the nucleocapsid and spike proteins. Among the 29 individuals with post-viral syndrome, 12 or 41% displayed immune responses consistent with past exposure to COVID-19 and paralleled the results seen in the long COVID group. A majority of these individuals had responses against the nucleocapsid protein, while half showed responses against the spike protein.
Moreover, the study found that these individuals exhibited symptoms and cognitive function test outcomes that were similar to those observed in the long COVID group. Dr. Koralnik highlighted the policy discrepancy, stating, “About 70% of specialized post-COVID healthcare facilities in the U.S. currently do not admit patients who display long COVID symptoms but do not possess a confirmed COVID-19 diagnosis.” According to the data, at least four million Americans could be suffering from a post-viral syndrome akin to long COVID and have detectable immune responses that warrant a diagnosis of COVID-19. Further research is needed to corroborate these findings.
One limitation of this research includes the relatively small sample size of individuals with post-viral syndrome. Additionally, it is possible that more participants might have shown positive immune responses if their blood samples had been collected closer to the onset of their symptoms.
Reference: “SARS-CoV-2–Specific Immune Responses in Patients With Postviral Syndrome After Suspected COVID-19” by Zachary S. Orban, Lavanya Visvabharathy, Gina S. Perez Giraldo, Millenia Jimenez and Igor J. Koralnik, 23 August 2023, Neurology: Neuroimmunology & Neuroinflammation. DOI: 10.1212/NXI.0000000000200159.
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Frequently Asked Questions (FAQs) about Undiagnosed COVID Cases
What is the main finding of the study?
The study reveals that a significant number of individuals with prolonged COVID-like symptoms, who were not diagnosed during the initial stages of the pandemic due to testing constraints, exhibited immune responses consistent with SARS-CoV-2 exposure, suggesting they might have had COVID-19.
What is long COVID?
Long COVID refers to a condition where individuals experience symptoms of COVID-19 that persist for an extended period, typically beyond six weeks after the initial infection.
How were the participants in the study selected?
The study included 29 individuals with post-viral syndrome and neurologic symptoms, matched with 32 individuals with confirmed long COVID symptoms and positive test results. A comparison was also made with 18 individuals without these symptoms and no known COVID exposure.
What were the key symptoms observed in the participants?
The participants exhibited symptoms such as memory and cognitive issues, headaches, and fatigue, similar to those associated with long COVID.
How were the immune responses measured?
Researchers conducted blood tests to detect antibodies against specific proteins, the nucleocapsid, and spike proteins, indicating prior exposure to SARS-CoV-2.
What percentage of individuals with post-viral syndrome showed immune responses?
Approximately 41% of individuals with post-viral syndrome demonstrated immune responses consistent with prior exposure to SARS-CoV-2.
Why is this study significant?
The study highlights the possibility of millions of Americans having been exposed to SARS-CoV-2 during the early stages of the pandemic, emphasizing the need for comprehensive healthcare and research inclusivity.
What is the implication for healthcare facilities?
The study underscores the importance of extending specialized care and research opportunities to individuals with post-viral syndrome, even in the absence of a confirmed COVID-19 diagnosis.
What are the study’s limitations?
The study’s limitations include a relatively small sample size of individuals with post-viral syndrome and the potential influence of timing on immune response detection.
What is the recommended future course of action?
Further research is required to validate and expand upon these findings, potentially leading to more inclusive healthcare policies and research initiatives for individuals with long-lasting COVID-like symptoms.
More about Undiagnosed COVID Cases
- Neurology Neuroimmunology & Neuroinflammation Journal
- Northwestern Medicine Comprehensive COVID-19 Center
5 comments
wow this study is super imporant coz it shows how many ppl coulda had covid but dint even kno it! crazy stuff tbh
this study mite hav big impact on covid research & treatment, hope more follow up is done. kudos to the researchers!
gr8 read! shows how testing probs early on affected lotsa ppl’s covid status. more reasons for bettr healthcare access!
the results r so interesting, i wonder if it cud change how clinics treat long covid patients? v informative article!
wait wut? covid related to cars now? lol jk, but seriously, good article, never thot bout covid like this before