Understanding the Pathology
· Critical illness is associated with cerebral microbleeds for patients with severe COVID-19. A retrospective cohort study conducted at University Hospitals of Strasbourg, France compared 19 severe COVID-19 patients with MRI evidence of microhemorrhage to 18 COVID-19 patients with normal MRI and found more pronounced respiratory failure, higher D-dimer increases, and more frequent need for dialysis in the microhemorrhage group. The researchers hypothesize that blood-brain barrier dysfunction due to hypoxemia and levels of uremic toxins may be a key mechanism of COVID-19-related cerebral microhemorrhage, which clinicians should consider during severe COVID-19 patient management.
Transmission & Prevention
· A pooled surveillance testing program for asymptomatic SARS-CoV-2 infections was implemented on a college campus. This observational cohort study conducted by an interdisciplinary team at Duke University in North Carolina implemented mandatory masking, social distancing, and entry-and-surveillance SARS-CoV-2 testing with five-to-one pooled quantitative RT-PCR. Large-scale testing of 10,265 students (n=68,913 total tests) yielded 84 positive results (43 asymptomatic). Authors suggest pooled testing allows for high sensitivity and rapid results, while decreasing supply-chain disruptions by using fewer resources, which could be more successful in limiting transmission than testing only symptomatic individuals.
Adjusting Practice During COVID-19
· Decline in SARS-CoV-2 antibodies after mild infection was noted among frontline health care personnel. The CDC COVID-19 Response Team and IVY Network conducted an analysis of 3,284 frontline healthcare personnel, from 13 different hospitals across 12 states and found 194 had SARS-CoV-2 antibodies at initial baseline testing using ELISA assay (96% sensitivity and 99% specificity). About 60 days later, 156 returned for follow up testing, of which 93.6% had a decline in antibody response, and 108 reported COVID-19 symptoms. Additionally, among the cohort who initially tested positive, seroreversion was observed in 19.4% of those that reported symptoms, and 47.9% of those without symptoms. These results suggest antibodies to SARS-CoV-2 decline over time and negative serologic results do not exclude previous infection, highlighting there may be significant differences in interpretation on serological studies regarding COVID-19 epidemiology.