Reduction of asymptomatic isolation to 5 days has no scientific basis

Faced with the decision of the Ministry of Health to reduce the minimum period of isolation for asymptomatic patients with Covid-19 from ten to five days, experts warn that there is not enough evidence that the new rule is safe.

A similar discussion occurs in the United States since the CDC (Centers for Disease Control and Prevention) also shortened the deadline to five days, with the condition of wearing a “well-fitting mask” for ten days, in addition to the need for up-to-date vaccinations.

A Japanese study published last week suggests that a 10-day quarantine would be better suited to prevent omicron transmissions. In the research, one of the few carried out with the new variant, half of the people evaluated had active virus between three and six days after infection. Between seven and nine days, 19% could still transmit it.

Infectologist Carlos Fortaleza, president of the São Paulo Society of Infectious Diseases, does not see any sense in reducing time from a sanitary point of view.

“Previous studies pointed to a peak of transmissibility on the 5th day and a gradual decline until the 10th day. The Japanese study shows that the omicron probably behaves like the other variants. The decision of the CDC and the Ministry of Health is only justified by the pressures economic.”

He finds it curious that Minister Marcelo Queiroga follows the CDC’s recommendation to reduce isolation time and, at the same time, does not take into account when the American center shows that 18 million children have already been vaccinated against Covid, without any serious side effect. “It’s a very selective thing to believe in what matters.”

For the infectologist, reducing isolation to five days is “precipitating chaos”. “The pragmatic argument of the specialists who defend the reduction is that the hospitals will be without people to attend. But I believe that if we send doctors, nurses to attend to people while they are transmitting, we will precipitate a problem that does not yet exist.”

In his assessment, despite the high rate of people on sick leave in many health services, the country is not yet in chaos. “Of course, if we reach a moment of absolute collapse, we’re going to need to send people with Covid to work to save lives. But we’re not at that moment yet.”

Evaldo Stanislau de Araújo, an infectious disease specialist at Hospital das Clínicas de São Paulo, also says that there is no consensus or a solid scientific basis to support the decision to reduce isolation to five days.

“The perception we have is that this is an economic and financial decision. It is even understandable, society has essential areas that need to work, but it is a decision taken in an untimely and reckless way, in the case of Brazil”, he says. .

Reckless given the difficulties of accessing tests for the detection of Covid. Many people are finding it very difficult to perform them and there is pressure for Anvisa (National Health Surveillance Agency) to release self-tests, widely used abroad.

“We have a data blackout and now a testing blackout. It is inhumane to make a recommendation like this. The decision is comfortable for the person who writes the standard, but absolutely insensitive for those at the end of the system, both professionals and patients. “

According to him, the greatest pressure fell on the weakest side, the workers. “The employer is not responsible, the laboratory has no way of doing it, people are thrown into a health service that is chaotic, the quality of many tests is poor.”

Araújo explains that in health services, especially private ones, there is a lot of rework – that is, people who received a diagnosis of Covid, went back to work, showed symptoms again and return to health units for retesting.

“It would be more prudent from a health point of view, given the scientific doubts that exist, for us to preserve the ten days and organize sector by sector, create a space in supplementary health to be able to finance and pay for the tests and where people can do them. them.”

Infectologist Alexandre Zavascki, a professor at the Federal University of Rio Grande do Sul, also has the same opinion. For him, ten days would be more prudent since, as the Japanese study shows, close to 20% of patients may have the virus capable of transmitting until the ninth day.

“After the five days, there are many people returning symptomatic to work and being able to transmit, even more with the Ômicron”, he says.

He argues, however, that five-day isolation could be a valid option in essential areas, but with all precautions. For example, being asymptomatic, with a negative test and with protective measures, such as a PFF2 type mask.

“The non-essential areas could continue for ten days because then you avoid these transmissions. Also because there is no way to evaluate everyone, test everyone, you have to use a cake recipe.”

With studies underway to validate isolation for seven days from the onset of symptoms, there are experts who advocate this period as the most viable. This is the case of infectious disease specialist Rosana Richtman, a doctor at the Emilio Ribas Institute of Infectious Diseases.

“No d6 [sexto dia de sintomas] or d7 [sétimo dia] does the antigen test and, if negative, releases from isolation, but still wearing a mask”, says she, who already adopts this rule with her work group at the maternity hospital where she also works.

If the person has not taken any test, he defends ten days of isolation. “Five days is a short time. Even in the US, they recognize that people are going to escape, but given the fact that there is already a shortage of people in healthcare, in commerce, in banks, they prefer that as most will no longer be transmitting on d5.”

For the doctor, the big problem of the ômicron variant is before the isolation exit. “People are taking a long time to get into isolation. While they don’t see the test result, they are spreading the virus 24 hours before the onset of symptoms, on d0, d1, d2, which is the main moment of spread. We are focusing a lot at the exit of isolation and not at the entrance. There you have a great viral load.”

In his opinion, although the virus is detected on the new day of infection, as the Japanese study shows, the amount of viral load is much lower and, in theory, a good mask used properly could hold the contagion.

“With the amount of cases that we are seeing, we are going to keep [os dez dias] it gets pretty complicated. There are companies practically closing, health services chaotic. We have to have common sense.”