A combination of physical distancing, isolation and contact tracing could be the most effective way to control transmission of Covid-19, researchers in Britain reported Tuesday.
“Our findings reinforce the growing body of evidence which suggests that we can’t rely on one single public health measure to achieve epidemic control,” said Dr. Adam Kucharski of the Center for Mathematical Modelling of Infectious Disease at the London School of Hygiene and Tropical Medicine, who worked on the study.
Kucharski and colleagues estimated that when communities combine isolation of those with symptoms with household quarantines and testing of contacts, transmission rates could be cut by up to 64%.
“We estimated that if some level of physical distancing were maintained, it could supplement reductions in transmission from contact tracing,” they wrote in their report, published in the Lancet Infectious Diseases.
This can be compared to a situation where there is mass random testing done on 5% of the population each week. That, the team projected, would only lead to a 2% decrease in transmission. This is because substantially fewer infections would be detected and many of the newly diagnosed cases could have already transmitted the infection to others.
“For this mathematical modelling study, we used a model of individual-level transmission stratified by setting (household, work, school or other) based on BBC Pandemic data from 40,162 UK participants,” the researchers wrote.
They simulated how a range of different testing, isolation, tracing and physical distancing scenarios would work to reduce transmission.
The study did not consider the possibility of mass gatherings and assumed that any contacts made outside the home would be different each day.