New study quantifies in-hospital COVID-19 risks

A new study published the Centers for Disease Control and Prevention suggests that aerosol-based transmission of COVID-19 can occur far beyond six feet, a range called for in social distancing guidelines. The study, carried out last month by researchers in Huoshenshan Hospital in Wuhan, China, identified numerous “hot spots” in both ICU and GW (General) areas of the hospital used to treat COVID-19 patients:

“The highest rates were for computer mice (ICU 6/8, 75%; GW 1/5, 20%), followed by trash cans (ICU 3/5, 60%; GW 0/8), sickbed handrails (ICU 6/14, 42.9%; GW 0/12), and doorknobs (GW 1/12, 8.3%). Sporadic positive results were obtained from sleeve cuffs and gloves of medical staff. These results suggest that medical staff should perform hand hygiene practices immediately after patient contact.”

The study also sought to evaluate the degree to which COVID-19 could be transmitted via aerosols. It found that COVID-19 “was widely distributed in the air and on object surfaces in both the ICU and GW, implying a potentially high infection risk for medical staff and other close contacts. Second, the environmental contamination was greater in the ICU than in the GW; thus, stricter protective measures should be taken by medical staff working in the ICU. Third, the SARS-CoV-2 aerosol distribution characteristics in the GW indicate that the transmission distance of SARS-CoV-2 might be 4 m.”

While the study found “wide contamination” in both ICU and General areas, the researchers acknowledged that their study had certain limits. “First, the results of the nucleic acid test do not indicate the amount of viable virus. Second, for the unknown minimal infectious dose, the aerosol transmission distance cannot be strictly determined.”

You can read the entire study here: https://wwwnc.cdc.gov/eid/article/26/7/20-0885_article