For the first time, the cosmopolitan genotype of dengue virus serotype 2 was detected in Brazil. Present in Asia, the Pacific, the Middle East and Africa, the lineage is the most widespread in the world, but it had never been found in Brazilian territory. The identification was carried out in February in a sample referring to a case that occurred at the end of November in Aparecida de Goiânia, in Goiás. The finding represents the second official record of this genotype in the Americas, after an outbreak in Peru in 2019.
The detection, led by the Oswaldo Cruz Institute (IOC/Fiocruz) in partnership with the Central Public Health Laboratory of Goiás (Lacen-GO), was immediately communicated to the municipal and state health departments and the Ministry of Health. For information to the scientific community, an article was published on the pre-print platform medRxiv, which allows rapid dissemination of results, prior to the peer review process. The work was also submitted for publication in a scientific journal and is currently under review.
In the Americas, a cosmopolitan strain of dengue virus serotype 2 has been detected in Goiás, Brazil, and Madre de Dios, Peru. Photo: playback/Giovanetti and collaborators
The dengue virus has four serotypes, named as 1, 2, 3 and 4, and each serotype can be subdivided into different genotypes (also called lineages), due to the presence of genetic variations. The cosmopolitan genotype is one of the six serotype 2 strains of the pathogen.
For the researchers, the arrival of this strain in Brazil is a cause for concern, because there is a possibility that it could spread more efficiently than the Asian-American lineage, also known as genotype 3 of serotype 2, which currently circulates in the country.
“We still don't know how the proliferation of the cosmopolitan genotype will be in Brazil. Worldwide, it is much more widely distributed and causes more cases than the Asian-American genotype, which has been circulating in Brazil for years. The global picture indicates that the cosmopolitan lineage has the capacity to spread easily”, says the research coordinator, Luiz Carlos Júnior Alcantara, researcher at the Flavivirus Laboratory of the IOC.
The possibility of an association between the cosmopolitan lineage and the increase in dengue cases in the state of Goiás in 2022 is, so far, discarded by scientists based on the genetic sequencing of samples carried out in the state. In all, around 60 genomes were decoded by the researchers in the first two weeks of February. These samples were randomly selected among samples of dengue cases confirmed by Lacen-GO in previous months. Approximately half belonged to serotype 1 and the other half to serotype 2. Among the serotype 2 samples, only one was of the cosmopolitan genotype and all the others had the Asian-American genotype, currently circulating in Brazil.
“The data show that the outbreak of dengue in Goiás is not caused by the cosmopolitan genotype”, states Alcantara, adding that dengue has a cyclical behavior in Brazil, which is related to several factors linked to the vector and the virus, as well as to climatic conditions and life of the population.
Considering the rapid identification of the cosmopolitan genotype, the researchers believe that it is possible to act to contain its spread. “Early detection makes it possible to reinforce control measures. We hope that this can help to limit the spread of this strain in Brazil and in the Americas, where we already have a complex epidemiological scenario, with multiple pathogens in circulation", evaluates the first author of the study, Marta Giovanetti, postdoctoral student at the Flavivirus Laboratory of the IOC.
Among the main actions to contain the spread of dengue is the elimination of stagnant water deposits, which can become breeding grounds for the mosquito. Aedes aegypti, transmitter of the disease. Click here and learn about the '10 minutes against Aedes' strategy.
In addition to actions to combat dengue, the researchers emphasize the importance of intensifying the genomic surveillance of the disease in order to map the possible circulation of the cosmopolitan lineage and better understand the routes of introduction of the virus in the country.
Phylogenetic tree, which indicates relationship between viral genomes in a similar way to a family tree, shows proximity between viruses isolated in the Americas and lineages from Bangladesh. Photo: playback/Giovanetti and collaborators
Initial analyzes carried out by the scientists show that the pathogen detected in Brazil is similar to two microorganisms isolated during the outbreak recorded in the province of Madre de Dios, Peru, in 2019. However, it is still not possible to say that the cosmopolitan genotype was introduced in Brazil from Peru.
“Considering the available genomes, we see that the viruses from Peru and Brazil are related to genomes from an outbreak recorded in Bangladesh. Everything indicates that the introduction in the Americas occurred from Asia, probably through intercontinental trips. However, in order to understand the dynamics of dispersion in the American continent, we need to have more sequenced samples”, clarifies Marta.
“The province of Madre de Dios borders the state of Acre, in Brazil. Active genomic surveillance in this region, with genetic sequencing of dengue 2 samples, would be important to understand this introduction and guide actions to contain viral spread”, adds the scientist.
The identification of the cosmopolitan dengue virus genotype was carried out based on a real-time arbovirus genomic surveillance project, led by the Flavivirus Laboratory of the IOC. In the initiative, the researchers travel to the Central Public Health Laboratories of the states (Lacens) and carry out the decoding of genomes with portable equipment for genetic sequencing. Since 2020, the work has also included the genomic surveillance of SARS-CoV-2, which causes Covid-19, receiving the name of VigECoV-2.
“In general, we spend a week at each Lacen and, in that period, we manage to generate more than 250 genomes. We carry out analyzes in real time and present the results to Lacen, the State Health Department and the Ministry of Health. The objective is for this data to serve as support for public health policies”, highlights Alcantara, noting that the project team also offers training for laboratory professionals.
The project is in collaboration with the Ministry of Health – through the General Coordination Office for Arboviruses (CGArb) and Public Health Laboratories (CGLab) –, the Pan American Health Organization (PAHO), the Center for Disease Control and Prevention (CDC, in acronym in English) and National Institutes of Health (NIH, in the acronym in English), both from the United States.
For the first time, the cosmopolitan genotype of dengue virus serotype 2 was detected in Brazil. Present in Asia, the Pacific, the Middle East and Africa, the lineage is the most widespread in the world, but it had never been found in Brazilian territory. The identification was carried out in February in a sample referring to a case that occurred at the end of November in Aparecida de Goiânia, in Goiás. The finding represents the second official record of this genotype in the Americas, after an outbreak in Peru in 2019.
The detection, led by the Oswaldo Cruz Institute (IOC/Fiocruz) in partnership with the Central Public Health Laboratory of Goiás (Lacen-GO), was immediately communicated to the municipal and state health departments and the Ministry of Health. For information to the scientific community, an article was published on the pre-print platform medRxiv, which allows rapid dissemination of results, prior to the peer review process. The work was also submitted for publication in a scientific journal and is currently under review.
In the Americas, a cosmopolitan strain of dengue virus serotype 2 has been detected in Goiás, Brazil, and Madre de Dios, Peru. Photo: playback/Giovanetti and collaborators
The dengue virus has four serotypes, named as 1, 2, 3 and 4, and each serotype can be subdivided into different genotypes (also called lineages), due to the presence of genetic variations. The cosmopolitan genotype is one of the six serotype 2 strains of the pathogen.
For the researchers, the arrival of this strain in Brazil is a cause for concern, because there is a possibility that it could spread more efficiently than the Asian-American lineage, also known as genotype 3 of serotype 2, which currently circulates in the country.
“We still don't know how the proliferation of the cosmopolitan genotype will be in Brazil. Worldwide, it is much more widely distributed and causes more cases than the Asian-American genotype, which has been circulating in Brazil for years. The global picture indicates that the cosmopolitan lineage has the capacity to spread easily”, says the research coordinator, Luiz Carlos Júnior Alcantara, researcher at the Flavivirus Laboratory of the IOC.
The possibility of an association between the cosmopolitan lineage and the increase in dengue cases in the state of Goiás in 2022 is, so far, discarded by scientists based on the genetic sequencing of samples carried out in the state. In all, around 60 genomes were decoded by the researchers in the first two weeks of February. These samples were randomly selected among samples of dengue cases confirmed by Lacen-GO in previous months. Approximately half belonged to serotype 1 and the other half to serotype 2. Among the serotype 2 samples, only one was of the cosmopolitan genotype and all the others had the Asian-American genotype, currently circulating in Brazil.
“The data show that the outbreak of dengue in Goiás is not caused by the cosmopolitan genotype”, states Alcantara, adding that dengue has a cyclical behavior in Brazil, which is related to several factors linked to the vector and the virus, as well as to climatic conditions and life of the population.
Considering the rapid identification of the cosmopolitan genotype, the researchers believe that it is possible to act to contain its spread. “Early detection makes it possible to reinforce control measures. We hope that this can help to limit the spread of this strain in Brazil and in the Americas, where we already have a complex epidemiological scenario, with multiple pathogens in circulation", evaluates the first author of the study, Marta Giovanetti, postdoctoral student at the Flavivirus Laboratory of the IOC.
Among the main actions to contain the spread of dengue is the elimination of stagnant water deposits, which can become breeding grounds for the mosquito. Aedes aegypti, transmitter of the disease. Click here and learn about the '10 minutes against Aedes' strategy.
In addition to actions to combat dengue, the researchers emphasize the importance of intensifying the genomic surveillance of the disease in order to map the possible circulation of the cosmopolitan lineage and better understand the routes of introduction of the virus in the country.
Phylogenetic tree, which indicates relationship between viral genomes in a similar way to a family tree, shows proximity between viruses isolated in the Americas and lineages from Bangladesh. Photo: playback/Giovanetti and collaborators
Initial analyzes carried out by the scientists show that the pathogen detected in Brazil is similar to two microorganisms isolated during the outbreak recorded in the province of Madre de Dios, Peru, in 2019. However, it is still not possible to say that the cosmopolitan genotype was introduced in Brazil from Peru.
“Considering the available genomes, we see that the viruses from Peru and Brazil are related to genomes from an outbreak recorded in Bangladesh. Everything indicates that the introduction in the Americas occurred from Asia, probably through intercontinental trips. However, in order to understand the dynamics of dispersion in the American continent, we need to have more sequenced samples”, clarifies Marta.
“The province of Madre de Dios borders the state of Acre, in Brazil. Active genomic surveillance in this region, with genetic sequencing of dengue 2 samples, would be important to understand this introduction and guide actions to contain viral spread”, adds the scientist.
The identification of the cosmopolitan dengue virus genotype was carried out based on a real-time arbovirus genomic surveillance project, led by the Flavivirus Laboratory of the IOC. In the initiative, the researchers travel to the Central Public Health Laboratories of the states (Lacens) and carry out the decoding of genomes with portable equipment for genetic sequencing. Since 2020, the work has also included the genomic surveillance of SARS-CoV-2, which causes Covid-19, receiving the name of VigECoV-2.
“In general, we spend a week at each Lacen and, in that period, we manage to generate more than 250 genomes. We carry out analyzes in real time and present the results to Lacen, the State Health Department and the Ministry of Health. The objective is for this data to serve as support for public health policies”, highlights Alcantara, noting that the project team also offers training for laboratory professionals.
The project is in collaboration with the Ministry of Health – through the General Coordination Office for Arboviruses (CGArb) and Public Health Laboratories (CGLab) –, the Pan American Health Organization (PAHO), the Center for Disease Control and Prevention (CDC, in acronym in English) and National Institutes of Health (NIH, in the acronym in English), both from the United States.
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