A new CDC study shows that isolating in separate rooms significantly reduces the likelihood of SARS-CoV-2 transmission between household members. Isolation in separate rooms proved to be the most effective mitigation measure against onward transmission of the SARS-CoV-2 virus, regardless of age, gender, vaccination status and other risk factors.
While vaccination has been found to reduce the risk of infection, it does not appear to reduce transmission within the household. It has been found that both vaccinated (first series of vaccinations) and unvaccinated adults and children with different demographic factors transmit the virus at similar rates. The study is a reminder that even as mandates are declining and much of the world suffers from fatigue, we should not ignore public health and non-medical interventions such as masking and isolating.
The study used data from 513 households with children under the age of 18 and 2,053 people. Data were collected from August 2020 to August 2021 in Utah, September 2020 to August 2021 in New York City, and November 2020 to October 2021 in Maryland. That means the study was conducted before the advent of the Omicron variant and the availability of vaccines for most children in the United States.
To assess how the SARS-CoV-2 virus was transmitted in households, the study participants took nasal swabs themselves weekly and during acute illness, which were sent to a laboratory for PCR testing. The study took participants through the alpha and delta waves. Through consistent PCR testing, researchers were able to capture both asymptomatic and symptomatic infections. Participants also completed weekly questionnaires about the symptoms they had experienced in the previous week and, if symptomatic, the preventive measures they took, e.g. B. Isolation or wearing a mask.
Primary cases were defined as participants with first onset of symptoms or positive SARS-CoV-2 test, whichever came first. However, since several household members were often infected at the same time, co-primary infections were excluded from the transmission analysis. Researchers found that 1 in 4 households experienced spread of SARS-CoV-2 among household contacts.
In addition to isolation in separate rooms, despite the current recommendation of 5 days, household members should also remain isolated until they test negative in a rapid antigen test. A recent study found that 62% of patients were still shedding infectious virus by day 5, and 23% were still shedding infectious virus by day 7. Those taking Paxlovid should also be aware of the possibility of reinfection and return to isolation if necessary.
By applying these mitigation strategies, we can ensure that we minimize the chance of Covid-19 being passed on to loved ones and housemates.