Previously, the CDC had defined a “close contact” as someone who was within 6 feet of someone who tested positive for COVID-19 for at least 15 minutes. This information is used for contact tracing purposes so that when someone tests positive anyone who was a close contact can be notified and quarantined to prevent the spread of COVID-19.
On July 28, a 20-year-old correctional facility employee had brief interactions with several inmates who were waiting for their COVID-19 test results. He was never within 6 feet of the inmates for very long, but he did interact with them multiple times throughout the day totaling about 17 minutes during his shift.
All 6 of the inmates who were tested for COVID-19 ended up testing positive. The employee was not considered a close contact since he hadn’t been around the inmates for very long at one time, and he continued to work.
On August 4, the employee started having symptoms of COVID-19 including a loss of taste and smell, a runny nose and shortness of breath. The only people he knew of that he had been around who had COVID-19 were the inmates who tested positive.
First of all, it’s important to understand why the CDC states that a close contact is someone who has been around someone with COVID-19 for at least 15 minutes. It’s not like something magical happens at the 15 minute mark, and poof, now you’re infected. Instead, it’s believed that a certain amount of the virus has to be transmitted from person to person in order for someone to get sick, and usually, you would have to be around someone for at least 15 minutes in order to get enough of those germs to actually contract the virus. This is referred to as an “infectious dose.”
It looks like may not be the case. Instead, in the case of the correctional facilities employee, it looks like being around people with COVID-19 for short interactions throughout the day that add up to at least 15 minutes might be enough to transmit the virus. That would redefine the term “close contact.”
It’s also important to note that during the interactions between the employee and the inmates, they were almost always wearing face masks. The employee was also wearing a gown and eye protection.
A CDC spokesperson commented on the study saying that it “adds to the scientific knowledge of the risk to contacts of those with Covid-19 and highlights again the importance of wearing face masks to prevent transmission.”
