The lineage was found in several states and grew up in the country after years of dominance of types 1 and 2 of the virus
In recent months, Brazil has to face a significant increase in cases of dense relative to serotype 3 (DENV-3), especially in States of Saint PaulMinas Gerais, Amapá and Paraná. The records also begin to emerge in Rio de Janeiro.
According to the Sinan Notification Information System (Sinan) Ministry of HealthOf the cases of total Dengue whose samples were analyzed for the evaluation of the serotype in December 2024, 22.93% was positive for type 3, compared to 0.39% of the samples verified months before January.
This growth of Denv-3 after years of predominance of serotypes 1 and 2 in the national territory worries experts and health authorities. They warn that many people have never been exposed to type 3 and do not have an immunity dense to contract, the body develops specific antibodies against the soroty of the virus responsible for the infection (Denv1, Denv-2, Denv-3 or Denv-4 ), but not for the others, so the disease can be contracted up to four times.
“Since you have several co-sect serotypes in the population, increases the probability of these distinct serotype reinfection events”, explains Gonzalo Bentancor, a researcher at the Arbovirus laboratory of the Oswaldo Cruz Institute (IOC/ IOC/ IOC/ IOC/ IOC/ IOC/ IOC/Fiocruz).
Another problem is that Secondary infections tend to cause more serious paintings.
“It is known that the infection by the denty semotype 3, when it occurs after a previous infection by serotype 1, tends to cause more serious symptoms. And a significant part of the population without immunity for Dengue 3 was recently infected from 1, “he said that the virologist Maurício Lacerda Nogueira, professor at the Faculty of Medicine of São josé do rio preto (Famerp).
Why is serotype 3 on the rise?
Serotype 3 circulating today in Brazil is a different lineage from that of the 2000s, practically extinct. According to experts, it is likely that it comes from the Caribbean region, which, in turn, imported the serotype of the Asian continent. “The virus was imported. He was leaving Brazil and we brought it back,” says Nogueira.
It is likely that someone in the region contracted the disease, arriving in Brazil and here it was point from a Aedes Aegypti. “So the entire thing begins. And this explains how it reappeared,” he summarizes the infectologist. The variant was detected for the first time in Roraima in 2023 and has since spread in other states.
Since a new variant usually takes on the space of the previous ones, experts do not exclude that the DAV-3 becomes predominant at a certain point.
“It is a phenomenon of alternation,” says Fernando Spilki, virologist at the Feevale University and coordinator of the National Institute of Science and Technology in the genomic surveillance of the virus and unique health. “The immunity that is formed in one year can alter the spread of viruses that will appear the following year,” he adds.
Can we have an epidemic in 2025?
According to Nogueira, the arrival of a new lineage usually favors epidemics. On the other hand, it is not common to occur great Dengue epidemics in the following years – in 2024, Brazil had the greatest number of cases and deaths from the disease of its history. There were 6.6 million likely cases and 6,103 deaths.
Estimates that a more aggressive increase in cases can take place since March or only in the coming years. “For example, cities like Sao Paulo and Belo Horizonte, who recorded very high numbers last year, may not have such a large epidemic now. But this does not mean that it cannot happen in 2026 or 2027?
Julio Croda, infectoologist and professor of Fiocruz at the Federal University of Mato Grosso do Sul (UFMS), says that it is a “true concern” that an epidemic of Dengue can occur with that of 2024 due to the introduction of the new serotype. “It is natural, after so many years of low circulation of this serotype in Brazil, that it will become predominant again in this season or in the next.”
For Spilki, the dimension that the disease will be better understood by the coming months, when the peak of cases occurs historically.
Already Rivaldo Cunha, assistant secretary of the secretariat for the surveillance of health and the environment of the Ministry of Health, provides for a scenario of greater control. “In my personal opinion, we will have nothing similar to the proportions of last year,” he says.
According to him, such a perspective is due to the resumption of the work of endemic control agents, suspended during the pandemic and which was still restored until 2023 and the greater commitment of the population to eliminate the focus of Aedes Aegypti After the last outbreak.
What are the symptoms?
The symptoms caused by the Dengue 3 serotype are similar to those of others and the cases are no longer serious than those already known. “It is not possible to differentiate serum serotypes and it is necessary to perform molecular or serological tests,” says Bentancor.
Croda recalls, however, that Denv-3 can cause more serious paintings in people who have already been infected with other virus serotypes. “In a scenario in which much of the population was exposed to another serotype, as occurred last year, there is a greater risk of developing serious cases,” he says.
This concern is also present among the authorities, as indicated by the Secretary of Health of San PaoloEleuss Paiva, in an event that was held on Thursday 23.
https://www.youtube.com/watch?v=puhvel0u3pm
Caution must be of all
Experts point out that the control of the Dengue depends on the collective effort, which involves the entire society. “It serves nothing waiting for the state, at the municipal, state or federal level, taking care of what happens within our homes. Dengue is a disease that we contract at home, at work or in very close areas,” he says Nogueira.
Among the actions recommended by the Ministry of Health are:
- use of screens on windows and repellents in recognized transmission areas;
- Removal of containers in families who can become mosquito breeding sites;
- Sealing of water basins and water tanks;
- Not limitation of gutters, slabs and exhausts;
- Participation in the inspection of the preventive and control actions of the Dengue performed by Sus.
Vaccines
Another important measure of prevention is vaccination. The Dengue vaccine is available at Health Post for Children and Adolescenti from 10 to 14 years, residents of the pre -selected municipalities. The immunner, produced by the Japanese pharmacist, proved to be effective against the different virus serotypes, reducing the aggravation and risks of hospitalization by the disease.
The vaccine is also available on the private network, which applies doses to people aged 4 to 60. The dose values are about R $ 400 in the workshops and pharmacies consulted by the ratio and it takes two doses to complete the vaccination scheme.
Source: Terra
Ben Stock is a lifestyle journalist and author at Gossipify. He writes about topics such as health, wellness, travel, food and home decor. He provides practical advice and inspiration to improve well-being, keeps readers up to date with latest lifestyle news and trends, known for his engaging writing style, in-depth analysis and unique perspectives.
