Health care workers involved in aerosol-generating procedures for a patient with unknown COVID-19 were protected from infection with surgical masks and standard procedures, a case review suggests.
Surgical masks, hand hygiene and other standard procedures may be sufficient to protect health care workers from SARS-CoV-2 infection, according to a case report.
Published in the Annals of Internal Medicine, the case study reviewed a patient in Singapore with diabetes mellitus and hyperlipidemia who was hospitalized with pneumonia in February, requiring endotracheal intubation and mechanical ventilation.
The middle-aged man received treatment before his diagnosis of coronavirus disease 19 (COVID-19) was known. He had no known contact with anyone known to be infected with the novel coronavirus and hadn’t traveled recently to China.
The case involved 41 health care workers, who had exposure to aerosol-generating procedures for at least 10 minutes at less than 2 meters. Most of the health care workers exposed in the case (85%) wore surgical masks during aerosol-generating procedures. The remaining health care workers wore N95 masks.
“That none of the health care workers in this situation acquired infection suggests that surgical masks, hand hygiene, and other standard procedures protected them from being infected,” the report noted. “Our observation is consistent with previous studies that have been unable to show that N95 masks were superior to surgical masks for preventing influenza infection in health care workers.”
The patient had a difficult intubation, requiring video laryngoscope and an airway bougie, and improved after 3 days, at which time he was switched to non-invasive ventilation and received a nasopharyngeal swab, which tested positive for SARS-CoV-2.
Health care workers who were exposed to aerosol-generating procedures—including endotracheal intubation, extubation, noninvasive ventilation, and exposure to aerosols in an open circuit—were isolated and monitored at home for 14 days, with swabs tested for SARS-CoV-2 using a PCR assay on the first and last day of their isolation. None developed symptoms or tested positive for the virus.
The case study supports evidence that SARS-CoV-2 is primarily spread through aerosolized droplets and eases concerns that the virus may also spread by airborne transmission. However, the authors emphasized that experts recommend N95 masks be worn during aerosol-generating procedures and noted the limitation of the single case review and the need for further study.
Protecting health care workers from infection and burnout has been a concern amid the COVID-19 pandemic, as health systems worldwide have been stretched and shortages of personal protective equipment (PPE) have been reported.
Some fear rationing of PPE are putting health care workers at increased risk. The US Centers for Disease Control and Prevention issued recommendations for optimizing the supply of masks, ranging from reducing face-to-face encounters with patients, re-using masks and prioritizing equipment for select procedures to using homemade masks such as a bandana or scarf “as a last resort,” ideally in combination with a face shield.
As of early March, more than 3300 health care workers in China, where the pandemic started, had been infected, and 20% of health care workers responding to the disease in Italy have been infected, a recent report in The Lancet noted. Along with the need for proper PPE, the article noted that health care workers worldwide are under intense pressure and in need of support, including food, rest, family care and psychological support.