Universal Preprocedure COVID-19 Testing Reveals Hidden Infections

By Reuters Staff

July 01, 2021

NEW YORK (Reuters Health) - During times of high community transmission of SARS-CoV-2, universal screening for the virus before planned medical procedures "should be considered," say U.S. clinicians.

In a research letter in JAMA Network Open, Dr. Scott Roberts and colleagues at Yale University School of Medicine, in New Haven, Connecticut, note that about half of all SARS-CoV-2 infections occur through asymptomatic transmission and clinical screening may miss contagious patients.

This is a problem when aerosol-generating procedures are performed, potentially exposing healthcare teams to SARS-CoV-2 transmission. It's also known that patients with COVID-19 are at increased risk of developing complications from medical procedures.

Current guidelines suggest testing asymptomatic patients prior to preplanned procedures to help reduce the risk, they note.

From August 1 to November 30, 2020, Yale New Haven Health System tested more than 75,000 asymptomatic patients within three days of a planned ambulatory and inpatient procedure requiring moderate sedation or general anesthesia. The median test turnaround time was 7.8 hours.

A total of 318 patients (0.4%) tested positive. Thirty-two positive specimens from 31 patients were positive for the virus within one week of an initial negative preprocedure test result; 14 of these patients (45.2%) developed COVID-19 symptoms.

Three patients tested positive more than 100 days and one patient 63 days before the positive preprocedure test, "suggesting low-level persistent RNA positivity," the researchers say.

"With preprocedure testing, we detected asymptomatic patients with SARS-CoV-2 who were missed by clinical screening alone," Dr. Roberts and colleagues note in their article.

Mass SARS-CoV-2 testing before procedures "can reduce potential transmission events while providing an additional layer of health care personnel safety," they add.

"Postprocedural infectious complications of COVID-19 in this higher-risk population are also mitigated when COVID-19 status is known and procedural delay is possible. Additionally, the resource burden of performing procedures using COVID-19 precautions is reduced," they say.

The researchers acknowledge that the best timing for preprocedural SARS-CoV-2 testing is unclear.

"In rare circumstances, patients who initially tested negative later tested positive, reflecting either low viral burden early in the disease course, false-negative laboratory errors, suboptimal specimen collection, nosocomial transmission, or variable viral particle shedding in an individual long recovered from COVID-19. While the incidence of such conversions was low, occurrences were more common during higher community prevalence," they point out.

"While institutions should weigh the burden of preprocedure testing against managing patients with occult infections, universal preprocedure SARS-CoV-2 testing should be considered," they conclude.

The study had no commercial funding and the authors have indicated no relevant conflicts of interest.

SOURCE: https://bit.ly/3dlqnNx JAMA Network Open, online June 25, 2021.