I feel a bit like a broken wheel as the last several weeks have only focused about COVID-19. But we are watching history unfold. By that, I do not mean the number of infections, recoveries or deaths. I mean that each week, each day and even every hour we learn something new. Studies and data are being published all the time.
This week, I came across two studies looking at the impact of asymptomatic transmission. The rate of transmission seems to be what makes COVID-19 a more serious threat then outbreaks of coronavirus we have seen previously. As discussed in last week’s blog, the ability of SARS-CoV-2 to live on the surface was found to be the same as SARS-CoV-1 that caused the 2003 outbreak. This means that other factors are impacting its spread. Some additional factors could be higher viral loads in the upper respiratory tract which could account for spread, but also the potential for SARS-CoV-2 infected people to shed the virus even before they show symptoms.
With the COVID-19 pandemic we are seeing that most secondary transmission is occurring in the community as opposed to healthcare settings. In the first study, Japanese investigators looked at the 634 passengers from the Diamond Princess who tested positive for COVID-19. They found that 17.9% of the passengers were asymptomatic meaning they could presumably spread the virus. The second study published by Dutch researchers estimated a 48% occurrence for asymptomatic transmission for Singapore and a 62% for Tianjin, China.
This data raises concerns about the protocols being used for screening and the potential impact for further community transmission. It also highlights the potential for transmission to healthcare workers who would not be in PPE but could be exposed to infected patients who are not showing signs and symptoms of COVID-19.
The long and the short is while we are learning and sharing as much information as we can, and as quickly as we can, we must rely on some of the key tenets of infection prevention to minimize the spread of COVID-19. Hand hygiene is something that needs to be on the top of our minds. Wash your hands as frequently as possible and particularly before eating or touching your face. Keeping you and your hands to yourself via social distancing. Respiratory droplets can be projected quite some distance, hence the need to cover your mouth and nose when you cough or sneeze. This is the reason for the recommended six (6) feet space between people. Disinfection of high-touch surfaces and increasing the frequency of disinfection will help to limit the chance of secondary transmission from touching contaminated surfaces.
I’m sure next week more will be found, until then….