RESUMO
Highly anthropophilic and adapted to urban environments, Aedes aegypti mosquitoes are the main vectors of arboviruses that cause human diseases such as dengue, zika, and chikungunya fever, especially in countries with tropical and subtropical climates. Microorganisms with mosquitocidal and larvicidal activities have been suggested as environmentally safe alternatives to chemical or mechanical mosquito control methods. Here, we analyzed cultivable bacteria isolated from all stages of the mosquito life cycle for their larvicidal activity against Ae. aegypti. A total of 424 bacterial strains isolated from eggs, larvae, pupae, or adult Ae. aegypti were analyzed for the pathogenic potential of their crude cultures against larvae of this same mosquito species. Nine strains displayed larvicidal activity comparable to the strain AM65-52, reisolated from commercial BTi-based product VectoBac® WG. 16S rRNA gene sequencing revealed that the set of larvicidal strains contains two representatives of the genus Bacillus, five Enterobacter, and two Stenotrophomonas. This study demonstrates that some bacteria isolated from Ae. aegypti are pathogenic for the mosquito from which they were isolated. The data are promising for developing novel bioinsecticides for the control of these medically important mosquitoes.
Assuntos
Aedes , Larva , Controle de Mosquitos , Mosquitos Vetores , Aedes/microbiologia , Animais , Mosquitos Vetores/microbiologia , Controle de Mosquitos/métodos , Larva/microbiologia , Controle Biológico de Vetores/métodos , Bactérias/isolamento & purificação , Pupa/microbiologia , RNA Ribossômico 16S/análiseRESUMO
A new virus, named Mutum virus, related to members of the family Tymoviridae, was isolated from mosquitoes (Mansonia spp.) in clone C6/36 cells, and its complete genome was sequenced. Its genome is 6494 nt in size with an organization resembling that of tymovirids. The isolated virus is phylogenetically related to two viruses isolated from Culex spp. mosquitoes: Ek Balam virus, reported in Mexico, and Culex-originated Tymoviridae-like virus, isolated in China. The results of this study suggest that this virus is a new member of the family Tymoviridae.
Assuntos
Culex , Culicidae , Malvaceae , Tymoviridae , Animais , Brasil , Genoma Viral , Filogenia , Tymoviridae/genéticaRESUMO
BACKGROUND: Malaria remains a major public health problem in South America, mostly in the Amazon region. Among newly proposed ways of controlling malaria transmission to humans, paratransgenesis is a promising alternative. Paratransgenesis aims to inhibit the development of parasites within the vector through the action of genetically modified bacteria. The first step towards successful paratransgenesis in the Amazon is the identification of Anopheles darlingi symbiotic bacteria, which are transmitted vertically among mosquitoes, and are not pathogenic to humans. METHODS: Culturable bacteria associated with An. darlingi and their breeding sites were isolated by conventional microbiological techniques. Isolated strains were transformed with a GFP expressing plasmid, pSPT-1-GFP, and reintroduced in mosquitoes by feeding. Their survival and persistence in the next generation was assessed by the isolation of fluorescent bacteria from eggs, larvae, pupae and adult homogenates. RESULTS: A total of 179 bacterial strains were isolated from samples from two locations, Coari and Manaus. The predominant genera identified in this study were Acinetobacter, Enterobacter, Klebsiella, Serratia, Bacillus, Elizabethkingia, Stenotrophomonas and Pantoea. Two isolated strains, Serratia-Adu40 and Pantoea-Ovo3, were successfully transformed with the pSPT-1-GFP plasmid and expressed GFP. The fluorescent bacteria fed to adult females were transferred to their eggs, which persisted in larvae and throughout metamorphosis, and were detected in adult mosquitoes of the next generation. CONCLUSION: Serratia-Adu40 and Pantoea-Ovo3 are promising candidates for paratransgenesis in An. darlingi. Further research is needed to determine if these bacteria are vertically transferred in nature.
Assuntos
Anopheles/microbiologia , Bactérias/isolamento & purificação , Técnicas de Transferência de Genes , Simbiose , Animais , Bactérias/classificação , Fenômenos Fisiológicos Bacterianos , Brasil , Malária/transmissão , Mosquitos Vetores/microbiologiaRESUMO
The objective of this study was to evaluate the effectiveness of Aedes aegypti mass trapping using the sticky trap MosquiTRAP (MQT) by performing a cluster randomised controlled trial in Manaus, state of Amazonas, Brazil. After an initial questionnaire and baseline monitoring of adult Ae. aegypti abundance with BG-Sentinel (BGS) traps in six clusters, three clusters were randomly assigned to the intervention arm where each participating household received three MQTs for mass trapping during 17 months. The remaining three clusters (control arm) did not receive traps. The effect of mass trapping on adult Ae. aegypti abundance was monitored fortnightly with BGS traps. During the last two months of the study, a serological survey was conducted. After the study, a second questionnaire was applied in the intervention arm. Entomological monitoring indicated that MQT mass trapping did not reduce adult Ae. aegypti abundance. The serological survey indicated that recent dengue infections were equally frequent in the intervention and the control arm. Most participants responded positively to questions concerning user satisfaction. According to the results, there is no evidence that mass trapping with MQTs can be used as a part of dengue control programs. The use of this sticky trap is only recommendable for dengue vector monitoring.
Assuntos
Aedes , Dengue/prevenção & controle , Insetos Vetores , Controle de Mosquitos/instrumentação , Adulto , Animais , Brasil , Dengue/transmissão , Feminino , Humanos , Masculino , Densidade Demográfica , Inquéritos e QuestionáriosRESUMO
A longitudinal study was conducted in Manaus, Brazil, to monitor changes of adult Aedes aegypti (L.) abundance. The objectives were to compare mosquito collections of two trap types, to characterise temporal changes of the mosquito population, to investigate the influence of meteorological variables on mosquito collections and to analyse the association between mosquito collections and dengue incidence. Mosquito monitoring was performed fortnightly using MosquiTRAPs (MQT) and BG-Sentinel (BGS) traps between December 2008-June 2010. The two traps revealed opposing temporal infestation patterns, with highest mosquito collections of MQTs during the dry season and highest collections of BGS during the rainy seasons. Several meteorological variables were significant predictors of mosquito collections in the BGS. The best predictor was the relative humidity, lagged two weeks (in a positive relationship). For MQT, only the number of rainy days in the previous week was significant (in a negative relationship). The correlation between monthly dengue incidence and mosquito abundance in BGS and MQT was moderately positive and negative, respectively. Catches of BGS traps reflected better the dynamic of dengue incidence. The findings help to understand the effects of meteorological variables on mosquito infestation indices of two different traps for adult dengue vectors in Manaus.
Assuntos
Aedes , Dengue/epidemiologia , Umidade , Insetos Vetores , Estações do Ano , Animais , Brasil/epidemiologia , Dengue/transmissão , Feminino , Incidência , Estudos Longitudinais , Conceitos Meteorológicos , Controle de Mosquitos , Fatores de TempoRESUMO
The Mayaro virus (MAYV) is a significant reemerging arbovirus of public health concern, responsible for outbreaks in several countries including Brazil. In this study, 857 samples of patients with acute fever in the state of Rondônia, Brazil, were analyzed by reverse transcriptase qualitative polymerase chain reaction (RT-qPCR) to detect Zika, dengue, and chikungunya viruses. The mean age of the population was 38 years (SD = 17.46). Negative samples were subjected to duplex RT-qPCR to detect MAYV and Oropouche virus. One MAYV-positive sample with a negative result for all other viruses tested was identified and subsequently sequenced using the automated Sanger method and, through phylogenetic analysis, was characterized as belonging to genotype D, making it the first case of Mayaro in humans isolated in Rondônia. The symptoms reported by the positive patient were fever, vomiting, back pain, nausea, severe arthralgia, and retro-orbital pain. The study reinforces the need for differential diagnosis for Mayaro in the laboratory routine and the importance of genomic surveillance of this virus, mainly due to the similarity of symptoms with other arboviruses, which makes this screening difficult.
Assuntos
Arbovírus , Febre de Chikungunya , Vírus Chikungunya , Dengue , Infecção por Zika virus , Zika virus , Humanos , Adulto , Brasil/epidemiologia , Filogenia , Infecção por Zika virus/epidemiologia , Genótipo , Febre de Chikungunya/epidemiologia , Dengue/diagnóstico , Dengue/epidemiologiaRESUMO
According to the IPCC, by the year 2100, rises in global temperature could reach up to 5 °C above current averages. On a planet-wide scale, this is one of the effects of climate changes that could have repercussions on the biological cycle of Aedes aegypti, the main arbovirus vector in urban environments and a transmitter of the arboviruses that cause dengue, Zika, chikungunya and urban yellow fever. The objective of this study was to evaluate morphological changes in Ae. aegypti eggs and embryos maintained in a climate change simulator. For this, specimens obtained from an insectarium were kept in four chambers that simulated the range of environmental scenarios predicted by the IPCC for the year 2100. The eggs obtained from each room were collected and transported to the laboratory for morphometric and morphological analysis, using confocal and scanning microscopy. Aedes aegypti eggs (n=20) were used to obtain the following variables: total width, total length, length-width ratio and diameter of the micropylar disc. Additionally, 20 embryos were used to obtain the data on head capsule length, width and length-width ratio. The data were subjected to a normality test and the means of each variable were compared using ANOVA and Tukey's post-hoc test, considering (p ≤ 0.05). A significant reduction (p < 0.05) was observed mainly in the mean lengths under the current-extreme scenario (587.5 and 553.6 µm, respectively), as well as in the widths under the current-mild scenario (171 and 158.4 µm, respectively). The length of the cephalic capsule was also affected, showing significant differences in the means under the current-intermediate scenario (189.5 and 208.5 µm, respectively), as well as in the widths between the current-intermediate scenarios (173.7 and 194.9 µm, respectively). The results suggest significant changes in the morphometry of Ae. aegypti eggs and embryos as a result of the climatic influences to which the adults were subjected, which may have an impact on vector population density and, consequently, on arbovirus dynamics in urban environments.
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Oropouche virus (OROV) is characterized as a re-emerging arbovirus of great concern for public health, being responsible for several outbreaks of acute fever identified in Latin American countries, registering more than half a million reported cases. The incidence of reports of this virus is intrinsically favored by environmental conditions, in which such characteristics are related to the increase and distribution of the vector population to areas of human traffic. Moreover, there is a problem regarding the lack of diagnosis in Brazil that aggregates the success of the etiologic agent. Thus, by means of molecular techniques, we identified 27 positive cases of the OROV circulating in border locations in western Amazon, with 44.44% (12/27) of the cohort characterized as infected individuals with reported symptoms, mainly ranging from fever, myalgia, and back pain. Among the positive samples, it was possible to obtain a total of 48.14% (13/27) samples to analyze the S and M segments of Oropouche, which showed similarities among the Brazilian sequences. Thus, it was possible to verify the circulation of the OROV in Rondonia and border areas, in which the tracking of neglected arboviruses is necessary for the genomic surveillance of emerging and re-emerging viruses.IMPORTANCEThe western Amazon region is known for outbreaks of acute febrile illnesses, to which the lack of specific diagnostics for different pathogens hinders the management of patients in healthcare units. The Oropouche virus has already been recorded in the region in the 1990s. However, this is the first study, after this record, to perform the detection of individuals with acute febrile illness using a screening test to exclude Zika, dengue, and chikungunya, confirmed by sequencing the circulation of the virus in the state of Rondonia and border areas. We emphasize the importance of including diagnostics for viruses such as Oropouche, which suffers underreporting for years and is related to seasonal periods in Western Amazon locations, a factor that has a direct influence on public health in the region. In addition, we emphasize the importance of genomic surveillance in the elucidation of outbreaks that affect the resident population of these locations.
Assuntos
Orthobunyavirus , Infecção por Zika virus , Zika virus , Humanos , Orthobunyavirus/genética , Brasil/epidemiologia , Febre , Surtos de DoençasRESUMO
Background: Dengue virus (DENV) causes an important disease and directly affects public health, being the arbovirus that presents the highest number of infections and deaths in the Western Brazilian Amazon. This virus is divided into 4 serotypes that have already circulated in the region. Methodology: Molecular characterization of a cohort containing 841 samples collected from febrile patients between 2021 and 2023 was analyzed using a commercial kit to detect the main arboviruses circulating in Brazil: Zika, DENV-1, DENV-2, DENV-3, DENV-4 and, Chikungunya. Subsequently, Sanger sequencing was performed for positive samples. Results: The cohort detected 162 positive samples, 12 for DENV-1 and 150 identified as DENV-2, indicating co-circulation of serotypes. The samples were subjected to sequencing and the analysis of the sequences that obtained good quality revealed that 5 samples belonged to the V genotype of DENV-1 and 46 were characterized as DENV-2 Cosmopolitan genotype-lineage 5. Conclusion: The results allowed us to identify for the first time the Cosmopolitan genotype in Rondônia, Brazilian Western Amazon, and its fast spread dispersion.
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Carbon dioxide (CO2) is an important component for activating and attracting host-seeking mosquitoes. The BG-Sentinel® trap is a well-established monitoring tool for capturing Culicidae, but CO2 role for the trap effectiveness has not been evaluated in highly urbanised areas. The objective was to evaluate the effectiveness of BG-Sentinel traps baited with and without CO2 for capturing urban mosquitoes. Fifteen areas were selected within the city of Manaus, Brazil, where four BG-Sentinels were operated for 24 h, two of them with CO2 and two without CO2. Captured Aedes aegypti females were dissected for the determination of their parity status. A significantly higher proportion of traps (from 32-79%) were positive for female Ae. aegypti when using the BG-Sentinel with CO2 (χ2 = 11.0271, p ≤ 0.001). Catches of female Culex spp were six times higher in CO2 traps (Mann-Whitney U test = 190.5; p = 0.001). Parity rates were similar for both traps. This study showed that CO2 has primarily an enhancing effect on the efficacy of BG-Sentinel for capturing Culex spp in Manaus. For Ae. aegypti, the positivity rate of the trap was increased, when CO2 was added.
Assuntos
Aedes/fisiologia , Dióxido de Carbono , Culex/fisiologia , Insetos Vetores/fisiologia , Manejo de Espécimes/instrumentação , Aedes/anatomia & histologia , Animais , Brasil , Culex/anatomia & histologia , Entomologia/instrumentação , Entomologia/métodos , Feminino , Insetos Vetores/anatomia & histologia , Masculino , Ovário/anatomia & histologia , Oviposição/fisiologia , População UrbanaRESUMO
BACKGROUND: Mansonia mosquitoes transmit arboviruses to humans. This study describes the karyotypes and C-banding of Mansonia humeralis, Mansonia titillans, Mansonia pseudotitillans, and Mansonia indubitans. METHODS: From the 202 larvae, the brain ganglia were dissected (n=120) for the preparation of slides. Twenty slides with well-distended chromosomes for each species (10 for karyotyping and 10 for C-banding) were selected for further study. RESULTS: The haploid genome and the average lengths of the chromosomal arms differed in relation to the centromere between species, and intraspecific differences also occurred in the distribution of the C-bands. CONCLUSIONS: These results are useful for better understanding of the chromosomal variability of Mansonia mosquitoes.
Assuntos
Culicidae , Humanos , Animais , Culicidae/genética , Heterocromatina/genética , Brasil , Cariótipo , CariotipagemRESUMO
The objective of this study was to evaluate ecological aspects of Mansonia species before the construction of hydroelectric plants on the Madeira River, and thus enable the assessment of the impact of these projects on mosquitoes. A total of 199 samplings were carried out between November 2003 and August 2004, using the technique of attraction with protection. Temporal distribution was evaluated from monthly incidence values obtained from the bite index per man/hour. Relative abundance was subsequently calculated to evaluate the spatial distribution of species, according to land use and municipal districts; furthermore, the pattern of hematophagous activity was evaluated from 12-h and 4-h samplings. The data were analyzed according to the negative binomial distribution and generalized linear models to estimate the influence of environmental factors on the presence and abundance of Mansonia. A total of 1479 specimens were collected, distributed among four species-Mansonia titillans (87%), Mansonia humeralis (6.3%), Mansonia amazonensis (6%), and Mansonia indubitans (0.5%), and spatial distribution analysis showed Ma. titillans to be dominant. Hematophagous activity had peaks between 6:00 p.m. and 8:00 p.m. and species incidence was higher during the rainy season and in areas where domestic animals are raised. Therefore, the region studied presented characteristics favorable to the reproduction of Mansonia even before the construction of the hydroelectric plants and after construction, these conditions were enhanced, due to the increase in the availability of breeding sites for immatures and blood sources for females, as a consequence of changes in the environment.
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This work aimed to evaluate the spatial distribution of mosquitoes in different seasonal periods and the interaction between climatic factors and the abundance of mosquitoes, especially those belonging to the tribe Mansoniini in the area surrounding the Amazon hydroelectric production region (Jirau-HP) of Rondônia state, Brazil. Mosquito specimens were collected in May, July, October, and December 2018, and April, July, September, and November 2019, over periods of three alternating days during the hours of 6:00 p.m. to 8:00 p.m. Mosquito sampling was performed using automatic CDC and Shannon light traps. Canonical correspondence analysis (CCA), combined with Monte Carlo permutations, was used to evaluate the correlation between climatic variables and species distribution. In addition, non-metric multidimensional scaling (NMDS) was used to verify the similarity among the sampled communities from the different collections. After analyzing the total mosquito fauna at all sampling points, 46,564 specimens were identified, with Mansonia dyari showing the highest relative abundance in 2018 (35.9%). In contrast, Mansonia titillans had the highest relative abundance in 2019 (25.34%), followed by Mansonia iguassuensis (24.26%). The CCA showed that maximum temperature significantly influenced the distribution of mosquito populations in the study area (p = 0.0406). The NMDS showed that sampling carried out in the rainy and dry seasons formed two distinct groups. There was a significant correlation between species richness and cumulative precipitation 15 days before the sampling period (R2 = 58.39%; p = 0.0272). Thus, both temperature and precipitation affected mosquito population dynamics. The effect of rainfall on mosquito communities may be due to variations in habitat availability for immature forms.
Assuntos
Culicidae , Animais , Biodiversidade , Brasil , Ecossistema , Dinâmica Populacional , Estações do AnoRESUMO
Previous studies have linked the construction of hydroelectric dams with increases in the density of mosquitoes, especially Mansonia. In Brazil, Mansonia mosquitoes are still poorly studied at the taxonomic, biological, ecological and epidemiological levels, and nothing is known about the genetic diversity and the cryptic speciation of the group. The current study analyzed the molecular taxonomy of Mansonia species captured in the area surrounding the Jirau hydroelectric dam, Rondônia state, Brazil. Samples were collected from fifteen locations between 2018 and 2019. Genomic DNA of the specimens was extracted, and the DNA barcode region of the Cytochrome Oxidase, subunit I gene was amplified with PCR and both DNA strands were sequenced. The dataset was analyzed using MEGA, Mr. Bayes and DnaSP software. The results provided COI sequences for 100 specimens collected in the area surrounding from Jirau hydroelectric dam. These belonged to five species of the Mansonia subgenus, identified morphologically as Mansonia humeralis, Mansonia amazonensis, Mansonia titillans, Mansonia dyari and Mansonia indubitans. Findings showed that the COI gene is an effective and accessible DNA barcode that provides a high-resolution tool for delimiting species within the subgenus Mansonia, with the tree construction (Bayesian Inference) well supported and non-overlapping intraspecific and interspecific (K2-P) genetic distance values. These findings also indicate the occurrence of cryptic speciation within M. dyari and near of M. titillans. This is the first study to apply molecular tools to the taxonomy of Mansonia species from Brazil.
Assuntos
Culicidae , Malvaceae , Animais , Teorema de Bayes , Brasil , DNA , Código de Barras de DNA TaxonômicoRESUMO
BACKGROUND: Aedes aegypti is the primary vector of viruses, such as Zika, chikungunya, yellow fever, and dengue. In this context, a biomonitored chemical study was conducted to evaluate the activity of the crude extract of the endophytic fungus Phomopsis sp. against the larvae of Aedes aegypti. METHODS: Crude extract, fractions, and isolated substances were evaluated in in-vitro assays against third-stage larvae of Aedes aegypti. RESULTS: We isolated 3-nitropropionic acid with an LC50 of 15.172 ppm and LC90 of 18.178 ppm after 24 hours of larval exposure. CONCLUSIONS: The results indicated that 3-nitropropionic acid exerted larvicidal activity.
Assuntos
Aedes , Anopheles , Culex , Inseticidas , Infecção por Zika virus , Zika virus , Animais , Phomopsis , Inseticidas/farmacologia , Extratos Vegetais , Mosquitos Vetores , LarvaRESUMO
The control of arboviruses carried by Aedes aegypti (Linnaeus) and Aedes albopictus (Skuse) can be performed with tools that monitor and reduce the circulation of these vectors. Therefore, the efficiency of four types of traps in capturing A. aegypti and A. albopictus eggs and adults, with the biological product Vectobac WG, was evaluated in the field. For this, 20 traps were installed in two locations, which were in the South (Londrina, Paraná) and North (Manaus, Amazonas) Regions of Brazil, from March to April 2017 and January to February 2018, respectively. The UELtrap-E (standard trap) and UELtrap-EA traps captured A. aegypti and A. albopictus eggs: 1703/1866 eggs in Londrina, and 10268/2149 eggs in Manaus, respectively, and presented high ovitraps positivity index (OPI) values (averages: 100%/100% in Londrina, and 100%/96% in Manaus, respectively); and high egg density index (EDI) values (averages: 68/75 in Londrina, and 411/89 in Manaus, respectively), so they had statistically superior efficiency to that of the CRtrap-E and CRtrap-EA traps in both regions, that captured less eggs and adults: 96/69 eggs in Londrina, and 1091/510 eggs in Manaus, respectively. Also presented lower OPI values (averages: 28%/4% in Londrina, and 88%/60% in Manaus, respectively); and lower EDI values (averages: 10.5/9 in Londrina, and 47/30 in Manaus, respectively). The capture ratios of Aedes adults in the UELtrap-EA and CRtrap-EA traps in Londrina and Manaus were 53.3%/29.5% and 0%/9.8%, respectively. UELtrap-EA can be adopted as efficient tool for Aedes monitoring due to their high sensitivity, low cost and ease of use.
Assuntos
Aedes/fisiologia , Controle de Mosquitos/instrumentação , Óvulo , Animais , Brasil , Controle de Mosquitos/métodos , Densidade DemográficaRESUMO
Human actions intensify the greenhouse effect, aggravating climate changes in the Amazon and elsewhere in the world. The Intergovernmental Panel on Climate Change (IPCC) foresees a global increase of up to 4.5 °C and 850 ppm CO2 (above current levels) by 2100. This will impact the biology of the Aedes aegypti mosquito, vector of Dengue, Zika, urban Yellow Fever and Chikungunya. Heat shock proteins are associated with adaptations to anthropic environments and the interaction of some viruses with the vector. The transcription of the hsp26, hsp83 and hsc70 genes of an A. aegypti population, maintained for more than forty-eight generations, in the Current, Intermediate and Extreme climatic scenario predicted by the IPCC was evaluated with qPCR. In females, highest levels of hsp26, hsp83 and hsc70 expression occurred in the Intermediate scenario, while in males, levels were high only for hsp26 gene in Current and Extreme scenarios. Expression of hsp83 and hsc70 genes in males was low under all climatic scenarios, while in the Extreme scenario females had lower expression than in the Current scenario. The data suggest compensatory or adaptive processes acting on heat shock proteins, which can lead to changes in the mosquito's biology, altering vectorial competence.
Assuntos
Aedes/genética , Mudança Climática , Clima , Regulação da Expressão Gênica , Interação Gene-Ambiente , Proteínas de Choque Térmico/genética , Mosquitos Vetores/genética , Animais , Aquecimento Global , Transcrição GênicaRESUMO
ABSTRACT Background: Mansonia mosquitoes transmit arboviruses to humans. This study describes the karyotypes and C-banding of Mansonia humeralis, Mansonia titillans, Mansonia pseudotitillans, and Mansonia indubitans. Methods: From the 202 larvae, the brain ganglia were dissected (n=120) for the preparation of slides. Twenty slides with well-distended chromosomes for each species (10 for karyotyping and 10 for C-banding) were selected for further study. Results: The haploid genome and the average lengths of the chromosomal arms differed in relation to the centromere between species, and intraspecific differences also occurred in the distribution of the C-bands. Conclusions: These results are useful for better understanding of the chromosomal variability of Mansonia mosquitoes.
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BACKGROUND: Transovarial transmission of dengue virus in Aedes spp. mosquitoes is considered an important mechanism for the maintenance of the virus in nature and may be implicated in the occurrence of outbreaks and epidemics of the disease. However, there are few studies involving transovarial transmission and viral vector monitoring as a surveillance tool and control strategy. The present study evaluated transovarial transmission of dengue virus in Aedes aegypti populations as a xenomonitoring strategy in municipalities of the Amazonas state. RESULTS: Aedes sp. eggs (13.164) were collected, with 30% viability of third- and fourth-instar larvae. Transovarial transmission of DENV was detected in all municipalities. The transovarial infection rate (TOR) in the municipalities was 46% of the DENV positive samples. The minimum infection rate (MIR) was 17.7 in the state, varying from 11.4 to 24.1 per 1,000 larvae tested in the respective municipalities. Four DENV serotypes were identified, with DENV I and IV being present in all municipalities investigated. The number of reported dengue fever cases varied during this period. CONCLUSIONS: Our results suggest that transovarial transmission may be an important mechanism for the maintenance and spreading of the disease in Amazonas municipalities. Using qRT-PCR, it was possible to identify the four DENV serotypes in larval samples. The methodology used in the present study proved suitable as a DENV xenomonitoring model in immature mosquitoes, contributing to the development of systems for early detection of viral circulation and predictive models for the occurrence of outbreaks and epidemics of this disease. TRIAL REGISTRATION: CAAE34025414200005015 .