“God strain”, “vaccine virus” and “early Christmas present” were some of the terms used to describe the Omicron variant of SARS-CoV-2 in late 2021, when it was identified in South Africa.
Studies have suggested that this strain of the new coronavirus is in fact less aggressive than the previous ones, among other factors, because it has a lower ability to invade lung tissue. On the other hand, the greater affinity with the cells of the upper airways seems to have given Ômicron a power of dissemination that has been compared to that of measles – one of the most contagious pathogens ever described.
According to the World Health Organization (WHO), Ômicron infects one hundred people every three seconds in the world.
In Brazil, this has been reflected in successive records of daily cases of Covid-19. Only on Friday (28), 269,968 new infections were recorded. The moving average of cases in the previous seven days was 25,034,806.
For experts interviewed by Agência Fapesp, the fact that the number of hospitalizations and deaths from Covid-19 is not growing at the same rate is due more to the population’s previous immunity – whether from vaccination or previous infections – than to the intrinsic characteristics of the disease. virus.
“In unvaccinated individuals, the disease is not so mild, and can cause death and important injuries. The point is that this virus has found a different host, which is no longer exposed to exposure”, says physician Paulo Saldiva, a professor at the Faculty of Medicine of the University of São Paulo (USP).
This is also the opinion of Elnara Negri, a pulmonologist at Hospital Sírio-Libanês, in São Paulo. “It is a variant very similar to the previous ones. The point is that in Brazil we are fortunate to have a population with good vaccination coverage. The only patient I had to intubate in this wave, so far, was not immunized. And he developed SARS-CoV-2 pneumonia with classic microcirculatory thrombosis. In the vast majority of those treated, the disease had a good course and I consider the vaccine to be largely responsible,” she says.
In partnership with colleagues from the Department of Pathology of the Faculty of Medicine of USP, among them Saldiva, Negri was one of the first people in the world to raise the hypothesis that blood clotting disorders would be the basis of the most serious symptoms of Covid-19 – including respiratory failure and pulmonary fibrosis. She points out that even among vaccinated people, especially the elderly and individuals with comorbidities, Ômicron can cause coagulopathy.
“If around the sixth day of symptoms, instead of improving, the patient starts to have fever, lower back pain and a worsening of tiredness or malaise, it is time to go to the doctor and get tests done to see if there is coagulopathy”, he warns. .
Infectologist Esper Kallás, from the USP School of Medicine, points out that in places where vaccination coverage is lower, the number of hospitalized for the disease has increased significantly.
One example is the Federal District, where the occupancy rate of beds in intensive care units (ICUs) reached 100% again. According to the DF State Health Department, 90% of those hospitalized for Covid-19 have not been vaccinated or have incomplete immunization.
In another six states – Espírito Santo, Goiás, Mato Grosso do Sul, Pernambuco, Piauí and Rio Grande do Norte – occupancy in ICUs is above 80%. In the case of pediatric ICUs, the situation is already critical in at least three states: Mato Grosso do Sul, Maranhão and Rio Grande do Norte.
The trend is also up in the number of deaths: there were 284 this Monday (31), totaling 627,138 deaths since the beginning of the pandemic. The moving average of deaths has also increased by more than 200% from two weeks ago.
blind flight
The experts consulted by the report say that the shortage of diagnostic tests and the blackout of data at the Ministry of Health – caused by a cyber attack on December 10 – have made it difficult to accurately assess how the wave of Ômicron is evolving in the country.
“We are a little lost in relation to the lethality rate, for example, which is very important information and can help convince people to get vaccinated”, says Saldiva.
According to the researcher, the problem is also a reflection of the low investment in epidemiological surveillance in the states. “At the height of the pandemic, the lack of human resources was supplied here in the state of São Paulo by the academic community, which worked on a voluntary basis. But the teams have now demobilized,” he says.
Last week, according to researchers at Imperial College London, UK, the transmission rate of SARS-CoV-2 in Brazil reached 1.78 – the highest rate since July 2020. This means that every 100 infected people are transmitting the virus to another 178. The British group had not calculated the index for Brazil since December 2021, due to the blackout of data at the Ministry of Health.
Estimates from the University of Washington, in the United States, point out that Brazil may reach a peak of 1.3 million infected per day by Covid-19 in mid-February. The projections include not only confirmed positive cases, but also estimates of who has become infected and never even tested.
What has changed
In the first wave of the pandemic, in 2020, the loss of smell and taste was considered one of the main indications of infection by SARS-CoV-2. Negri says that this symptom has no longer been observed and, on the other hand, sore throat has become something much more recurrent. “Fever and cough are still common. Some patients also experience diarrhea,” he reports.
Pediatrician Ana Escobar reports something similar among children, most of whom have not yet been vaccinated. “It usually starts with a sore throat, then fever – which can reach 39°C and last two or three days –, then headache and body ache. By the fourth day the child is well. Sometimes the cough persists until the tenth day,” she says.
Although the presentation of the disease in this population has not changed significantly, highlights the doctor, the number of children affected is proportionally much higher with Ômicron. “So it is normal that hospitalizations also increase, especially among those who have some underlying pathology, such as chronic lung diseases, rheumatology or cancer”.
Werther Brunow de Carvalho, coordinator of pediatric and neonatal ICUs at Instituto da Criança, linked to Hospital das Clínicas, Faculty of Medicine, USP, points out that Ômicron – like the previous strains – can cause pediatric multisystem inflammatory syndrome, a condition characterized by fever. persistent inflammation and inflammation in various organs, such as the heart, intestine and lung.
“The percentage of children who develop the syndrome is lower with Ômicron, but it can happen. And so there is no doubt that we should vaccinate”, says Carvalho.
The doctor says that at Hospital Santa Catarina, where he also works, the number of children treated with symptoms of respiratory infection doubled in January compared to the previous month. “In addition to SARS-CoV-2, there are cases of influenza, rhinovirus, parainfluenza and respiratory syncytial virus”, he says.
Pregnant women and postpartum women continue to be one of the populations at greatest risk for severe forms of Covid-19, informs obstetrician Rossana Pulcineli, a professor at USP and a member of the Brazilian Obstetric Observatory (OOBr). Data released by the group last year, before the arrival of Ômicron, indicate that the chance of death of an unvaccinated pregnant woman is 526% greater than that of a fully immunized one.
“Among those hospitalized without vaccine, 15% died. The number drops to 9% among those who received a dose of the immunizing agent and to 3% among those with the complete vaccination schedule”, he says.
According to the doctor, although Ômicron causes milder conditions, especially in immunized pregnant women, the number of hospitalizations due to flu syndrome has grown again in this population, from 147 in November to 1,643 in January, according to the most recent data from the Information System of the Epidemiological Surveillance of Influenza (Sivep-Gripe).
Among those hospitalized, 43.5% have a confirmed diagnosis of Covid-19, 4.8% of influenza (H3N2 influenza) and in 51.6% the cause has not been defined, which reflects the low availability of diagnostic tests.
“It is already known that pregnant women respond poorly to influenza and there was no monitoring when cases started to increase. We went weeks without updated data at a critical moment like this”, says Pulcineli, who also emphasizes the importance of pregnant women taking the third dose of the vaccine.
With regard to treatments with proven effectiveness, Kallás says that there are already two approved for use in the country: the antiviral remdesivir and the monoclonal antibodies. “But they are expensive drugs and no effort has been made by the government to make them accessible to the population”, he says.
Check out guidelines from the Ministry of Health in the face of the diagnosis of Covid-19
Source: CNN Brasil
