A recent study conducted by researchers at Northwestern Medicine's Neuro COVID-19 clinic has found that a significant number of Americans who did not receive a Covid-19 diagnosis may have developed long Covid. The study, which included 29 participants with post-viral syndrome symptoms similar to long Covid, revealed that 41% of them had been exposed to the SARS-CoV-2 virus. While the study's sample size was small, the researchers believe that these findings could have important implications for a large number of people in the United States.
The researchers emphasized the need for improved Covid-19 diagnostic testing to increase sensitivity and provide clinical care to individuals experiencing post-viral syndrome after suspected Covid-19. They argued that these individuals deserve the same access to care and inclusion in research studies as patients with confirmed Covid-19 diagnoses. Currently, most post-Covid-19 clinics in the US only accept patients who have tested positive for the virus, leaving those with post-viral syndrome without specialized care and excluded from research participation.
The study enrolled outpatients who visited Northwestern Medicine's Neuro COVID-19 clinic between June 2020 and April 2022. Out of the 29 patients with post-viral syndrome, 23 were unvaccinated and six were vaccinated. None of them had been tested for the virus. They were compared to 32 patients diagnosed with long Covid and 18 healthy individuals who had not tested positive for Covid-19.
Among the patients with post-viral syndrome and long Covid, the most common co-morbidities were depression, anxiety, and hypertension. The researchers collected blood samples from all participants to detect potential exposures to the SARS-CoV-2 virus. They found that the post-viral syndrome group had visited the clinic at a median of 10.7 months after symptom onset, with 92% reporting at least four neurological symptoms.
The researchers concluded that a holistic approach combining clinical and multi-targeted immunologic measures would be most appropriate for diagnosing long Covid in patients with post-viral syndrome without a positive RT-PCR or antigen test for SARS-CoV-2. These findings highlight the importance of recognizing and providing care for individuals who may have developed long Covid without a confirmed Covid-19 diagnosis, particularly considering the limited testing availability during the early stages of the pandemic.