The recent resurgence of serotype 3 of the dengue virus in Brazil – which has not caused epidemics in the country for over 15 years – has raised the alarm about the risk of a new epidemic of the disease caused by this viral serotype. A study by F.iocruz, coordinated by Fiocruz Amazônia and the Oswaldo Cruz Institute (IOC/Fiocruz), presents the genetic characterization of the viruses referring to four cases of the infection registered this year, in Roraima, in the North Region, and in Paraná, in the South of the country. The circulation of a long-absent serotype worries specialists.
"In this study, we carried out the genetic characterization of cases of infection by serotype 3 of the dengue virus. It is an indication that we may once again have, perhaps not now, but in the coming months or years, epidemics caused by this serotype", explains the virologist Felipe Naveca, head of the Emerging, Reemerging and Neglected Virus Surveillance Center at the Fiocruz Amazônia and researcher at the Laboratory of Arboviruses and Hemorrhagic Viruses of the IOC/Fiocruz, which acts as a regional reference for dengue, yellow fever, chikungunya, Zika and West Nile virus.
In order to quickly share information, the results of the analysis were published in a preprint article on the medRxiv platform, without the peer review process. The work was submitted for publication in a scientific journal. The research was carried out in partnership with the Central Public Health Laboratories (Lacens) in Roraima and Paraná, in addition to the participation of specialists from various research institutions.
According to Naveca, the analyzes indicate that the strain detected was introduced in the Americas from Asia, in the period between 2018 and 2020, probably in the Caribbean. "The serotype 3 lineage that we detected is not the same that already circulated in the Americas and caused epidemics in Brazil in the early 2000s. Our results showed that there was a new introduction of genotype III of serotype 3 of the dengue virus in the Americas, coming from from Asia. This lineage is circulating in Central America and recently it also infected people in the United States. Now, we identified that it arrived in Brazil", reports Naveca.
Of the four cases analyzed, three refer to indigenous cases in Roraima, that is, they correspond to patients who were infected in the state and had no travel history. The case in Paraná was imported, diagnosed in a person coming from Suriname.
The cases were initially identified by the Lacens of Roraima and Paraná, respectively. "Since it is serotype 3, it was important for us to carry out this analysis together with the Lacens and several other research institutions that signed this result, including the United States Center for Disease Control and Prevention (CDC), because they had identified cases coming from Cuba and the US. This is a valid alert not only for Brazil, but for the entire region of the Americas. Bearing in mind that we are experiencing a large number of cases of arboviruses this year in Brazil, the detection of a new serotype of dengue virus is not good news," he warned.
The dengue virus has four serotypes. Infection by one of them generates immunity against the same serotype, but it is possible to contract dengue again if there is contact with a different serotype. The risk of an epidemic with the return of serotype 3 occurs because of the low immunity of the population, since few people have contracted this virus since the last epidemics recorded in the early 2000s. There is also the danger of severe dengue, which occurs with more frequently in people who have already had the disease and are infected again, by another serotype.
The research was supported by the State of Amazonas Research Support Foundation (Fapeam), Genomic Health Surveillance Network; Innovate Fiocruz/Oswaldo Cruz Foundation (Amazon Innovation); Department of Science and Technology (Decit) of the Brazilian Ministry of Health; National Council for Scientific and Technological Development (CNPq) and Research Support Foundation of the State of Rio de Janeiro (Faperj).
The recent resurgence of serotype 3 of the dengue virus in Brazil – which has not caused epidemics in the country for over 15 years – has raised the alarm about the risk of a new epidemic of the disease caused by this viral serotype. A study by F.iocruz, coordinated by Fiocruz Amazônia and the Oswaldo Cruz Institute (IOC/Fiocruz), presents the genetic characterization of the viruses referring to four cases of the infection registered this year, in Roraima, in the North Region, and in Paraná, in the South of the country. The circulation of a long-absent serotype worries specialists.
"In this study, we carried out the genetic characterization of cases of infection by serotype 3 of the dengue virus. It is an indication that we may once again have, perhaps not now, but in the coming months or years, epidemics caused by this serotype", explains the virologist Felipe Naveca, head of the Emerging, Reemerging and Neglected Virus Surveillance Center at the Fiocruz Amazônia and researcher at the Laboratory of Arboviruses and Hemorrhagic Viruses of the IOC/Fiocruz, which acts as a regional reference for dengue, yellow fever, chikungunya, Zika and West Nile virus.
In order to quickly share information, the results of the analysis were published in a preprint article on the medRxiv platform, without the peer review process. The work was submitted for publication in a scientific journal. The research was carried out in partnership with the Central Public Health Laboratories (Lacens) in Roraima and Paraná, in addition to the participation of specialists from various research institutions.
According to Naveca, the analyzes indicate that the strain detected was introduced in the Americas from Asia, in the period between 2018 and 2020, probably in the Caribbean. "The serotype 3 lineage that we detected is not the same that already circulated in the Americas and caused epidemics in Brazil in the early 2000s. Our results showed that there was a new introduction of genotype III of serotype 3 of the dengue virus in the Americas, coming from from Asia. This lineage is circulating in Central America and recently it also infected people in the United States. Now, we identified that it arrived in Brazil", reports Naveca.
Of the four cases analyzed, three refer to indigenous cases in Roraima, that is, they correspond to patients who were infected in the state and had no travel history. The case in Paraná was imported, diagnosed in a person coming from Suriname.
The cases were initially identified by the Lacens of Roraima and Paraná, respectively. "Since it is serotype 3, it was important for us to carry out this analysis together with the Lacens and several other research institutions that signed this result, including the United States Center for Disease Control and Prevention (CDC), because they had identified cases coming from Cuba and the US. This is a valid alert not only for Brazil, but for the entire region of the Americas. Bearing in mind that we are experiencing a large number of cases of arboviruses this year in Brazil, the detection of a new serotype of dengue virus is not good news," he warned.
The dengue virus has four serotypes. Infection by one of them generates immunity against the same serotype, but it is possible to contract dengue again if there is contact with a different serotype. The risk of an epidemic with the return of serotype 3 occurs because of the low immunity of the population, since few people have contracted this virus since the last epidemics recorded in the early 2000s. There is also the danger of severe dengue, which occurs with more frequently in people who have already had the disease and are infected again, by another serotype.
The research was supported by the State of Amazonas Research Support Foundation (Fapeam), Genomic Health Surveillance Network; Innovate Fiocruz/Oswaldo Cruz Foundation (Amazon Innovation); Department of Science and Technology (Decit) of the Brazilian Ministry of Health; National Council for Scientific and Technological Development (CNPq) and Research Support Foundation of the State of Rio de Janeiro (Faperj).
*With information from Júlio Pedrosa (Fiocthrough Amazon)
The non-profit reproduction of the text is allowed as long as the source is cited (Comunicação / Instituto Oswaldo Cruz)
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