26-06-2020 by Mirai
Models developed by ISGlobal researchers show that in this still current context of the COVID-19 epidemic, end of quarantine must be very gradual and that individual behavior is a key factor in limiting virus transmission and, therefore, occurrence. of a second wave. Scientists believe that gestures introduced during confinement, such as social distancing and wearing a mask, should continue.
At the moment of end of quarantines and in the absence of treatment, it is always necessary to respect the barrier gestures and physical distance, as well as to wear a mask when distance cannot be respected.
A study carried out by researchers from the Barcelona Institute for Global Health (ISGlobal) shows that keeping these interventions in place can help prevent a second wave of infections and the need for greater closure. In fact, several countries that initially imposed strict containment to limit the spread of SARS-CoV-2 are in the process of lifting their measures. But the question arises: how and when to relieve these restrictions without risk? A difficult decision given the delicate balance between the need to revive the economy and the risk of a second wave of infections that would overwhelm health systems.
Strict measures while questions persist
"The problem is that evaluating this risk is difficult, given the lack of reliable information on the actual number of people infected or the degree of immunity developed in the population," explains Xavier Rodó, who participated in the study. The latter consisted of making projections on how a second wave could be avoided based on a model that divides the population into seven groups: sensitive, quarantined, exposed, infectious, undetected, infectious and confined, cured, or dead. The researchers applied their model to countries affected differently by the coronavirus, including Spain, New Zealand, Japan, the United States, and Argentina.
The results, published in Nature Human Behavior, show that in countries that have not yet reached the peak of cases, the closure of public establishments must remain in place for at least 60 days and that the end of quarantine must be very gradual for reduce the risk of second wave. "Our model is different because it considers the return of confined people to the sensitive population to estimate the effect of the end of quarantine, and includes the behavior of people and the perception of risk as modulating factors," adds Professor Xavier Rodó. "It can be very useful for countries where the peak of cases has not yet been reached, such as those in the southern hemisphere."
Reduce transmission speed by 30% to avoid a second wave
The study also notes that a very gradual lifting of containment will also lead to a reduction in the number of infections and deaths, rather than suddenly "releasing" a large part of the population. For example, not all workers should return to work at the same time, and those who are most vulnerable to the virus should continue to work from home. Above all, the researchers emphasize that individual behavior remains essential to reduce or prevent a second wave. In fact, methods such as social distancing, hand hygiene, and the use of a mask could eliminate the need for further confinement.
Thus, the results show that even in countries that do not have the resources to test and track all "contact cases," complying with all of these instructions that researchers call "social empowerment" would be the key to stopping viral transmission. . "If we can reduce the transmission rate by 30% as a result, we can significantly reduce the size of the next wave." A 50% reduction in transmission speed could completely avoid this, "says Professor Xavier Rodó. However, the researcher specifies that his analysis did not take into account a possible effect of temperatures on virus transmission, a question that remains unanswered.
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