Covid: Why some countries have reduced isolation (and the doubts it generates among some scientists)

The authorities of those countries said that Reducing isolation is a way to maintain a certain degree of normalcy in the daily life of its citizens.

“If he’s asymptomatic, we want people to go back to work,” Dr. Anthony Fauci, the White House’s chief medical advisor, said in an interview with CNN on Wednesday.

However, some independent specialists have expressed reservations about these measures, especially when there is still a lack of data for omicron’s behavior.

So far, the United States is the country that has announced the largest quarantine reduction.

The US Centers for Disease Control and Prevention (CDC) released its new guide on Monday.

“People with covid-19 should be isolated for five days, and if they have no symptoms or if their symptoms improve (no fever for 24 hours), continue to wear a mask for 5 days when they are around other people, to reduce the risk,” he says. The Center for Disease Control on its website:

This measure comes at a time when the United States records infection records since the beginning of the epidemic.

On December 27, the CDC reported 441,278 cases, the highest number of daily cases the country has ever reported.

According to Fauci, cutting isolation is a way of avoiding “the exclusion of many people (from their activities)” given the large number of cases they encounter and still hope to obtain by omicron.

The CDC notes that this change is driven by science, which has shown that the largest transmission of SARS-CoV-2 occurs in the early stages of infection, usually 1 to 2 days before symptoms appear, and 2 or 3 days afterwards. . The development of symptoms.

The CDC’s announcement and Fauci’s explanations drew criticism.

One of them is Eric Topol, professor of molecular medicine and vice president of the Scripps Research Institute of Biosciences in California.

In an article titled “A Very Bad Day at the Centers for Disease Control and Prevention” published on their blog on December 28, Topol lists five reasons why he considers the scale “hollow.”

First, it acknowledges that while further disruption to the workforce and ordinary people must be avoided, There is no data or evidence to support this action..

Second, he criticizes that the CDC does not indicate that an isolated person should have an antigen or PCR test showing that they are no longer positive and therefore can turn.

Third, it states that there is not enough data on how long the spread lasts and how long the virus is eliminated in an omicron variant, something that is known for a delta variant, for example.

Fourth, the expert notes that the CDC’s evidence “doesn’t say a word” about an infected person’s vaccination status.

We know from previous studies that There is rapid elimination (the virus) among those who have been vaccinated Among those who have not been vaccinated, the CDC recommendation does not take this into account,” Topol writes.

Finally, he noted, the Centers for Disease Control and Prevention’s guidelines “assume that all people handle the virus in a similar way when there is actually great diversity.”

In other countries, the reduction was less severe.

In England, for example, infected people had to self-isolate for ten days, but since December 22 They can only be isolated for seven days if they test negative on the sixth and seventh days.

The same procedure applies to all people, regardless of their vaccination status.

In the UK, the omicron variant has caused staff shortages in companies, trains and the health services.

Richard Tedder, a member of the UK Clinical Virology Network, said the procedure was based on the assumption that a person with two negative tests was unlikely to transmit the virus.

“This is likely to be true given the balance of probabilities,” Tedder told Science Media Center.

But Tedder cautions he has two reservations.

The first relates to the fact that people in England can do the tests themselves which may be less sensitive than the PCR test.

And your other warning is the decrease in isolation time It should only apply to people who do not have any prerequisites Or who are undergoing treatment that affects their immune system, in which case the virus can behave differently.

In Spain, the Public Health Commission agreed that, from Thursday, people who test positive for coronavirus but do not have symptoms, will be able to reduce their quarantine from ten to seven days.

To leave isolation, neither antigen testing nor PCR will be necessary.

“It seems reasonable to me,” says Dr. Salvador Piero, a physician specializing in public health and pharmacoepidemiology at FISABIO, a biomedical research institution based on Generalitat Valenciana in Spain.

The expert says: “The ability to contagion decreases from the sixth or seventh day. Some certainly escape, but it is also true that they flee from us everywhere.”

“The social disruption that an Omicron can cause is massive, we’re talking about trains and planesPolice, firefighters and health.”

For the expert, reducing isolation allows attention to be focused on the most serious cases.

However, Piero cautions that this procedure has many operational challenges in practice.

“A challenge is to identify exactly what is asymptomatic,” the expert says. He wonders “what if what I have is a mild headache?”

In that sense, he says the key is for clinicians and patients to have clear standards on how to act.

Moreover, it indicates that A person who is asymptomatic today may not be asymptomatic tomorrow.

On Thursday, Spain recorded 161688 new infections, the highest number since the beginning of the epidemic, after more than a week with record numbers of daily injuries.

As for the United States, Piero insists he disagrees with Topol’s position.

“I differ a lot,” he says.

“I understand the part that says we don’t have enough evidence, but my question is what are the alternatives for each scale.”

“The alternative is millions of days of solitude for many people who may not need it.”

He concludes, “It does not seem to me madness that the United States decided on five days, (but) the British and the Spaniards seem much wiser by seven.”

Argentina agreed, on Wednesday, to reduce the quarantine of close contacts and to vaccinate the infected.

On Thursday, the country crossed 50,000 daily cases of coronavirus for the first time.

With the new measure, close contacts who are asymptomatic and who have had the full vaccination plan should be isolated for only five days and not ten, as before.

Confirmed cases with a full scheme should not be isolated for 10 days, but only for seven days.

“This makes sense, especially at a time when many cases and many people are isolated by close contact,” the doctor told BBC Mundo. Martin HogmanInfectious Diseases Physician, Member of the Argentine Society of Infectology.

“You have to do it with the utmost care, i.e. do the necessary activities but do not relax the procedures completely, continue to care, use the mask, avoid social gatherings, and avoid closed spaces without ventilation.”

Hojman explains that oomicrons are much more contagious than other types, but that doesn’t translate into more hospitalizations or deaths.

“As long as hospitalizations and deaths remain within the expected number and the health system is not in danger of collapsing, it seems to me that the restrictive measures have little application,” the doctor says.

“If household occupancy and deaths start to change, activity restriction measures will be necessary.”

When comparing Argentina’s actions with those of the United States, Hogman considers Argentine regulations to be “more prudent.”

The specialist concludes that “it seems to me that in the United States they have taken into account the economic issue more than the health issue, because with the pluses, especially in the unvaccinated, there are greater risks.”

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