The emergence of the delta variant and the continued reluctance of vaccines have caused many health and government officials to reconsider the need for non-pharmaceutical interventions (NPIs) such as social distancing policies, the wearing of masks, contact tracing and isolation of infected people to manage new outbreaks of COVID-19.
The one thing everyone wants to avoid is another lockdown, but what response measures work best without the need for strict social distancing? New research from the University of Georgia suggests authorities should prioritize contact tracing and quarantine.
“When social distancing in the general population is difficult to achieve, we can always count on contact tracing and isolation of cases if we do a good job,” said senior author Yang Ge, a doctoral student in the department of Epidemiology and Biostatistics of UGA’s College. of Public Health.
The study, recently published in Epidemics, modeled the impact of three interventions – social distancing, contact tracing and case isolation – on COVID-19 containment using both real patient data from China’s Zhejiang province and computer simulations.
The database included more than 1,200 symptomatic cases reported between January 7 and February 22, 2020, and the model took into account their daily contact activities with other people before, during and after the outbreak. As a result, the researchers were able to assess the contribution of each intervention, rather than just the combined effect of the three strategies.
They found that the outbreak in Zhejiang was suppressed by isolating cases within five days, with 36.5% of infected contacts being quarantined. This scenario was only realized when contact tracing was in place.
“Social distancing, case isolation and contact tracing are all essential to suppressing the epidemic, and they interact with each other in the sense that if you fail in one area, the other efforts need to be stepped up. In particular, we have noticed that contact tracing is very important although it is not part of the major conversation in current control efforts, ”said co-lead author Ye Shen, associate professor of epidemiology and of biostatistics at UGA.
In addition to testing the impact of each intervention, they also modeled scenarios in which some interventions were weaker than others, for example, if more or less time was needed to isolate a positive case.
“We have found that even with a low level of prevalence, gradual reopening is difficult without further strengthening the NPIs,” said Shen. Specifically, the curve was steeper when contact tracing was less effective.
These findings take on new meaning as parts of the United States and beyond experience peaks in major cases, while many low-income countries still await the arrival of vaccines and continue to rely on these interventions to help them. ensure the safety of their citizens.
“Slow research and delayed isolation could easily multiply the size of the epidemic by tens. We need to allocate sufficient resources to support such efforts, for example by funding contact tracing forces, allowing people to work or study from home when exposed to cases of COVID-19. , and at a minimum, encourage everyone to wear a face mask indoors, ”they said.
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Material provided by University of Georgia. Original written by Lauren Baggett. Note: Content can be changed for style and length.