Central-West Brazil Research Articles

The relevance of biotic processes on modern tufa deposits, with an example from the Bonito region, Central-West Brazil

Abstract Tufas are freshwater carbonate rocks that form in continental environments through a combination of physical, chemical, and biological processes. This study investigates the role of microorganisms in the precipitation of Quaternary tufa deposits in the Serra da Bodoquena Formation, in the Bonito region. Two sites along the Mimoso River, named Taíka and Mimosa, characterized by the pool–barrage–cascade depositional subenvironment, were selected for this study. Four distinct facies were identified: stromatolitic boundstones, phytoherm boundstones of algae, phytoherm boundstones of bryophytes, and phytoclastic rudstones. These facies were observed in diverse hydrological settings, including fast-flowing waters, such as waterfalls and cascades, as well as slow-flowing areas, such as pools and dams. The δ18O depletion indicated a meteoric origin for the fluid involved in carbonate precipitation. The low δ13C values were attributed to photosynthetic processes and the contribution of light carbon-enriched groundwater. The presence of Oocardium stratum and calcified organic mucilage from extracellular polymeric substance (EPS) corroborates the significant role of microorganisms in tufa formation, particularly in stromatolitic boundstones and phytoherm boundstones of algae. Rapid CO2 degassing significantly contributes to mineralization in fast-flowing waters. Micro-CT results offer detailed insights into the relationship between mechanical processes and biological influences in shaping porosity characteristics. The findings of this study significantly enhance our understanding of the role of microorganisms in tufa formation, highlighting the complex interplay between biotic and abiotic processes in the development of different tufa facies. Moreover, the insights gained from this study provide valuable implications for interpreting tufa deposits worldwide.

Faeces of Capybara (Hydrochoerus hydrochaeris) as a Bioindicator of Contamination in Urban Environments in Central-West Brazil

Along with exposure to parasites and other biological disease vectors, animal faeces can also contain heavy metals and metalloids. We quantified metals, metalloids, and non-metals in the faeces of capybara (Hydrochoerus hydrochaeris) that live in parks in the city of Campo Grande (Brazil). Quantification of metalloids was obtained after acid digestion using an inductively coupled plasma optical emission spectrometer. Higher mean concentrations in mg/kg of aluminium (Al) (140.322), arsenic (As) (0.010), cadmium (Cd) (1.042), chromium (Cr) (26.866), cobalt (Co) (1.946), copper (Cu) (50.764), lead (Pb) (8.762), manganese (Mn) (291.469), molybdenum (Mo) (3.634), nickel (Ni) (5.475), and zinc (Zn) (100.027) were quantified in samples of faeces of capybara that live on the banks of a lagoon that receives input from streams that cross the city. According to the risk assessment, potential risks to the health of children and adults may occur due to the presence of Al, As, Cd, Co, Cu, and Mn through involuntary oral ingestion of faeces, via inhalation and dermal contact. The hazard index (HI) due to oral ingestion was greater than 1 for children and adults. Therefore, we believe that faeces of H. hydrochaeris can be considered as a bioindicator of environmental pollution in urban parks.

Molecular characterization and frequency of human pegivirus type 1 (HPgV-1) in kidney transplant recipients from Central-West Brazil.

Human Pegivirus Type 1 (HPgV-1), a ubiquitous commensal virus, has been recently suggested as a marker of immunologic function. There is scarce data for the presence, genotypes, and molecular characteristics of HPgV-1 among kidney transplant recipients. Therefore, the objective of this study was to examine the prevalence and the molecular characteristics (cycle threshold, genotypes) of this viral infection among kidney transplant recipients from the Brasília, Federal District of Brazil. HPgV-1 RNA detection in the plasma was assessed by RT-qPCR. Positive samples were submitted to sequencing and phylogenetic analysis of the 5´-UTR portion of the viral genome. The estimated HPgV-1 prevalence among renal-transplant recipients was 20%. The performed phylogenetic inference revealed that the most frequent genotype among these patients was HPgV-1 genotype 2 (78.9%) presented by its two subgenotypes (2A and 2B), followed by genotypes 1 and 3 (10.5% each). This study presents new data about the HPgV-1 circulation and molecular characteristics among kidney transplant recipients from the Federal District of Brazil. Further work is fundamental to examine the effect of HPgV-1 among patients with immunological suppression, including kidney transplant recipients.

Local Evapotranspiration Is the Only Relevant Source of Moisture at the Onset of the Rainy Season in South America

The South American Monsoon System, which transports moisture from Amazonia to Central-West Brazil, is an important moisture source for the summer rainy season in this region. While local evapotranspiration also contributes to the atmospheric moisture supply, the balance between local and remote sources during the onset of the rainy season remains uncertain. Our research aimed to quantify the role of local evapotranspiration in initiating the rainy season in Central-West Brazil. By utilizing data from various sources, such as remote sensing (MODIS), modern reanalysis (ECMWF’s ERA5), and composite products of rainfall (CHIRPS), and analyzing them in a comparative way, we conclusively found that local evapotranspiration is the only relevant source of moisture to the atmosphere during the dry-to-wet season transition, preceding the establishment of the monsoon system.

High silent prevalence of human herpesvirus 1 (HSV-1) infection affecting the indigenous reservation of the municipality of Dourados, Central-West Brazil

BackgroundThe indigenous population located in the central region of Brazil, is the second largest in terms of population size in the country. The Indigenous Reserve of Dourados has risk factors that increase the vulnerability of the indigenous population to infectious diseases, especially Human alphaherpesvirus (HSV-1), a neglected disease with high prevalence in priority populations in developing countries. The virus can also cause many more severe diseases, including widespread neonatal infections, herpetic keratitis, and herpes encephalitis, which can be fatal if left untreated. We estimated the prevalence of anti-HSV-1 antibodies and correlated it with the demographic and behavioral characteristics of the Indigenous population of the Jaguapirú and Bororó villages (Dourados, Mato Grosso do Sul (MS), Brazil).MethodsOur approach was cross-sectional. From March 2017 to November 2018. Using anti-HSV-1 (Gg1) IgM and anti-HSV-1 (gG1) IgG Euroimmun and the detection and quantification of HSV-1 viral load in plasma samples, through real-time PCR. The maps were constructed using QGIS and the statistical analyses using R Studio software.ResultsA total of 1138 individuals (> 18 years old) were enrolled. The prevalence of anti-HSV-1 IgM and IgG were 20% and 97.5%, respectively. The prevalence of anti-HSV-1 antibodies for IgG was higher in both sexes. Anti-HSV-1 IgM antibodies were present in 17.1%, 21.2%, 12.5%, and 22% of the participants with urinary problems, genital wounds, genital warts, and urethral discharge, respectively. Real-time PCR was used for confirmatory testing; HSV-1 DNA was detected in 25.6% (54/211) of anti-HSV1 IgM-positive samples. Viral loads ranged from 5.99E + 02 to 3.36E + 13.ConclusionsThe seroprevalence of HSV-1 IgM and detection of HSV-1 DNA in the Indigenous population confirmed high silent prevalence. Furthermore, the seroprevalence of HSV-1 in the Indigenous population was higher than that reported in the general adult Brazilian population. Various socioeconomic factors, drug use, and health and sexual behaviors could contribute to the facilitation of HSV-1 transmission in the Indigenous population. Our results may help develop culturally appropriate intervention programs that eliminate health access barriers and improve the implementation of public health policies aimed at promoting information regarding the prevention, treatment, and control of HSV-1 infection in Brazilian Indigenous populations.

Phylogenetic placement of Mimosa pabstiana reinforces a biogeographic pattern of the Pleistocene Arc Theory in Mimosa (Leguminosae, Caesalpinoideae)

New molecular evidence derived from the trnD-T region has unveiled an unexpected relationship for Mimosa pabstiana. Traditionally classified within M. sect. Batocaulon ser. Campicolae, our phylogenetic study reveals its new placement within M. sect. Batocaulon ser. Andinae. This discovery aligns with a biogeographic pattern consistent with the Pleistocene Arc Theory, encompassing inter-Andean valleys, the Chaco, Central-West Brazil, and Brazilian seasonally dry forests. Recent observations of M. pabstiana in Brazilian herbaria, along with newly collected field samples documented through photography and georeferencing, bring forth additional data about this poorly-known species. We further elucidate the phylogenetic placement of M. paraibana, previously hypothesized to have a close relationship with M. pabstiana.

Adaptability and stability of soybean [Glycine max (L.) Merrill] strains in Central-West Brazil

Adaptability and stability of soybean [Glycine max (L.) Merrill] strains in Central-West Brazil

Integrative approach revealing a species complex in the Neotropical freshwater crab Dilocarcinus septemdentatus (Herbst, 1783) (Decapoda: Trichodactylidae) with a description of a new species

The taxonomic status of the freshwater crab Dilocarcinus septemdentatus (Herbst, 1783) is still not well established. Currently, the main issue involves synonymization with D. spinifer H. Milne Edwards, 1853, based on a variation of the angulation of the gonopod apex. These species are distributed along rivers and lakes in northern South America, with disjunct occurrences in central-west Brazil and Argentina. Due to these inconsistencies, an integrative approach was performed to elucidate these questions, with morphological (including NanoCT-Scan) and molecular analysis (Maximum Likelihood Trees, Bayesian Inference, Genetics Distance Matrix, and Haplotype Network), based on mitochondrial markers COI and 16S rRNA. Both analysis revealed and supported the existence of a species complex under the name of D. septemdentatus. Based on the results obtained, we propose the revalidation of D. spinifer, the description of a new species, and the redescription of D. septemdentatus s. str., with a neotype designation for this species. The hypothesis that this species complex originated in the Pebas System, an extensive mega wetland system that existed along the lowlands of Western Amazonia from late Oligocene to late Miocene (c. 23–11 mya) is discussed.

First report of Calvatia fragilis Fr. (Basidiomycota) in Central-West Brazil

Calvatia fragilis, a species belonging to the Basidiomycota phylum, is noted for its presence in tropical and neotropical regions. However, this fungus has been scarcely documented in natural habitats in Brazil. The present study aims to enhance the understanding of the geographical distribution of Calvatia fragilis, reporting the first record of this species in a Cerrado ecosystem, specifically in the Brazilian Midwest, in the State of Goiás. The discovery site is an area dedicated to agricultural production, characterized by a red dystroferric clay soil. In December 2023, specimens of Calvatia fragilis were collected in this region. The gathered basidiomes were meticulously catalogued and identified using a specific identification key for the Calvatia genus. Prior to this study, records of the species were limited to the States of Rio de Janeiro, São Paulo, and Rio Grande do Sul. This research expands the knowledge on the distribution of Calvatia fragilis, now including the State of Goiás among the Brazilian areas where this fungus occurs.

First report of Laternea dringii, Phallales (Agaricomycetes) in the Central-West, State of Goiás, Brazil

Laternea dringii, a species of the phylum Basidiomycota, is notable for its distribution in tropical and neotropical regions. This study, conducted in the Cerrado area of Central-West Brazil, State of Goiás, reports the first record of L. dringii in this region. The study site, a farm with over 90 years of agricultural production, features moist soils rich in organic matter. In January 2024, specimens of L. dringii were collected, photographed, and identified using microscopic data and a key for the genus Laternea. This finding represents a significant expansion in the known distribution of L. dringii, previously documented only in Mexico and some Brazilian states. The discovery underscores the mycological diversity of the Brazilian Cerrado and contributes to a better understanding of the geographical distribution of fungi from the phylum Basidiomycota in Brazil.

Human T-lymphotropic virus 1/2 infection among prisoners of a major penitentiary complex of Goiás State, Central-West Brazil.

Studies on human T-lymphotropic virus 1/2 (HTLV-1/2) infection are scarce in incarcerated population. Therefore, this study estimated the prevalence of HTLV-1/2 infection among prisoners of the major penitentiary complex of Goiás State, Central-West Brazil, comparing it with available data from other Brazilian regions. A cross-sectional study was conducted with 910 prisoners of the major penitentiary complex in the State of Goiás, Central-West Brazil. All participants were interviewed, and their serum samples were tested for anti-HTLV-1/2 using an enzyme-linked immunosorbent assay (ELISA; Murex HTLV-I + II, DiaSorin, Dartford, UK). Seropositive samples were submitted for confirmation by a line immunoassay (INNO-LIA HTLV I/II, Fujirebio, Europe N.V., Belgium). The majority of participants were males (83.1%), between 25 and 39 years old (56.1%; mean age: 31.98 years), self-reported brown ethnicity (56.2%) and reported 9 years or less of formal education (41.4%). Most reported using non-injectable illicit drugs and various sexual behaviors that present risk for sexually transmitted infections (STIs). The prevalence of anti-HTLV-1/2 was 0.33% (95% CI: 0.07-0.96), HTLV-1 (0.22%) and HTLV-2 (0.11%). The two HTLV-1 seropositive prisoners reported high-risk sexual behaviors, and the HTLV-2 seropositive individual was breastfed during childhood (> 6 months) by her mother and three other women. These data revealed a relatively low seroprevalence of HTLV-1/2 in prisoners in Central-West Brazil, and evidence of HTLV-1 and HTLV-2 circulation in the major penitentiary complex of Goiás State. Given the prevalence of high-risk sexual behaviors, there is a crucial need to intensify education and health programs in prisons to effectively control and prevent HTLV-1/2 and other STIs.

Expandindo a distribuição de Tapanhuacanga campinorum (K.Krause) P.L.R.Moraes (Rubiaceae, Rubioideae) para o Centro-Oeste do Brasil: o primeiro registro para o Estado de Mato Grosso, no Parque Estadual do Cristalino

ABSTRACT We report the occurrence of Tapanhuacanga campinorum in the Parque Estadual do Cristalino, in the State of Mato Grosso, Central-West Brazil. This represents the first record of the genus in this State and the species in this region of the country, since T. campinorum was known only from the Amazonian campinas vegetation in the States of Amazonas and Pará, in the northern region of Brazil. We further comment on the distribution, conservation, and taxonomic aspects of this species.

Transition from an in-person to a telemedicine diabetic retinopathy screening program.

Timely screening and treatment are essential for preventing diabetic retinopathy blindness. Improving screening workflows can reduce waiting times for specialist evaluation and thus enhance patient outcomes. This study assessed different screening approaches in a Brazilian public healthcare setting. This retrospective study evaluated a telemedicine-based diabetic retinopathy screening implemented during the COVID-19 pandemic and compared it with in-person strategies. The evaluation was conducted from the perspective of a specialized referral center in an urban area of Central-West Brazil. In the telemedicine approach, a trained technician would capture retinal images by using a handheld camera. These images were sent to specialists for remote evaluation. Patient variables, including age, gender, duration of diabetes diagnosis, diabetes treatment, comorbidities, and waiting time, were analyzed and compared. In total, 437 patients with diabetes mellitus were included in the study (mean age: 62.5 ± 11.0 years, female: 61.7%, mean diabetes duration: 15.3 ± 9.7 years, insulin users: 67.8%). In the in-person assessment group, the average waiting time between primary care referral and specialist evaluation was 292.3 ± 213.9 days, and the referral rate was 73.29%. In the telemedicine group, the average waiting time was 158.8 ± 192.4 days, and the referral rate was 29.38%. The telemedicine approach significantly reduced the waiting time (p<0.001) and significantly lowered the referral rate (p<0.001). The telemedicine approach significantly reduced the waiting time for specialist evaluation in a real-world setting. Employing portable retinal cameras may address the burden of diabetic retinopathy, especially in resource-limited settings.

Inventory and ecological aspects of bioluminescent beetles in the Cerrado ecosystem and its decline around Emas National Park (Brazil)

Abstract Among the richest ecosystems in bioluminescent Coleoptera in Brazil, the Cerrado (savannas) is the most threatened one by agricultural expansion. The Emas (PNE) and Chapada dos Guimarães (PNCG) National parks are 2 of the last main remnants of the original Cerrado ecosystems in Central-west Brazil. During the past 3 decades, we have conducted several expeditions to collect, observe and study bioluminescent beetles occurring in the PNE and surrounding farms. More recently we also started to investigate the PNCG. We recorded a total of 51 bioluminescent species, including fireflies (n = 29), click beetles (n = 11), phengodids (n = 10), and staphylinids (n = 1). The PNE region was the richest one, especially for phengodids (n = 9). Among the habitats that compose the Cerrado physiognomy, the Cerrado and cerradão hosted most of the bioluminescent species, followed by forest, open fields and marshes. Most fireflies inhabiting the Cerrado ecosystem emit yellow-green light, whereas most click beetles emit predominantly green light, and among phengodid species, orange and red-light emission was found in 3 species. The spectacular click beetle Pyrearinus termitilluminans Costa-lodging luminous termite mounds were found in PNE and also reported for the first time at PNCG. In the farms around the PNE, however, a declining number of bioluminescent species was recorded in cerradão areas after the replacement of the surrounding cattle pastures by sugarcane plantations, especially adult phengodid males that were no longer attracted to light traps. Habitat reduction, use of agricultural pesticides and artificial night lighting are thought to be the major causes of such impact on bioluminescent beetle diversity.

Amphibian Diversity: Where everything starts to flood, Cáceres Municipality, North Pantanal, Central-West Brazil

Faunal inventories contribute to our understanding of regional diversity, and are fundamental for policy and decision-making regarding the management and conservation of large natural areas. This study aimed to inventory and compile information on amphibian species occurring in the North Pantanal region, in the municipal limits of Cáceres, Mato Grosso, Brazil. We used three methods to inventory amphibian species: (1) fieldwork, (2) analysis of specimens deposited in scientific collections, and (3) literature reviews. We registered 49 amphibian species in Cáceres. Of them, 48 species belonged to the Anura order and were distributed across eight families and 20 genera, and one species belonged to the Gymnophiona order (Siphonops paulensis). The families Leptodactylidae (20 spp.) and Hylidae (17 spp.) were dominant in terms of richness, accounting for 75.5% of all species found in Cáceres. The remaining families had between four and one species each. The municipality is strongly influenced by non-forested formations (e.g., the Cerrado and Pantanal) and presents a high species richness for a non-forested location in Brazil. Our findings highlight Cáceres as one of the richest areas in amphibian species in the North Pantanal region, expanding our knowledge regarding frog diversity. This study provides a foundation for future conservation strategies and additional assessments of amphibian species in light of potential population declines and other emerging threats.

Helminth community structure of the white-bellied woolly mouse opossum Marmosa constantiae Thomas, 1904 in Central-West Brazil.

Marmosa constantiae is a species of marsupial restricted to the central portion of South America. In Brazil, it occurs in the northwestern region including five states of the Amazon, Cerrado, and Pantanal biomes. However, there is no study of the helminth fauna or helminth community structure for this marsupial. The aims of this study were to describe the species composition and to analyse the structure of the helminthic community of M. constantiae in an area of the Amazon Arc in Sinop, north of the state of Mato Grosso, Brazil. Parasites were searched in 53 specimens of this marsupial, among which 44 were infected with at least one helminth species. Parasitic helminths were counted and identified. Nine species were collected: seven nematodes, one cestode, and one acanthocephalan. The most abundant species were Gracilioxyuris agilisis, Travassostrongylus scheibelorum, Pterygodermatites sinopiensis, and Subulura eliseae. These species were the only dominant ones in the component community. No significant differences were observed in the abundance and prevalence of helminths between male and female hosts. Host body size significantly influenced helminth abundance in males. The pattern of community structure considering the infracommunities in this locality indicated more species replacement than species loss along the environmental gradient. This is the first study to report the helminth fauna and the helminth community structure of M. constantiae.

Preliminary assessment of toxicity of aerosol samples from central-west Brazil using Artemia spp. bioassays

The present study reports the development of a bioassay using Artemia spp. to analyse the preliminary ecotoxicity of atmospheric aerosols (PM), which can affect the environment and human health. Herein, PM samples were collected in the city of Goiânia (Brazil) in 2016, extracted with ultrapure water and subsequently filtered through membranes with different pore sizes (100, 0.8, and 0.22 μm), and the extracts employed in the bioassays. The mortality rates (endpoint analysed) declined to membranes with smaller pore sizes (15 ± 4%, 47 ± 10% and 43 ± 9% for pore sizes of 100 μm, 0.8 μm and 0.22 μm, respectively). In general, the toxicity of the extract depended on its concentration, except for the sample with a higher negative particle surface charge, which presents a lower affinity for the negatively charged surfaces of cellular membranes. Moreover, although the PM concentration was higher for the sample collected during the dry season (September), the mortality rate was not significantly different to that determined for a sample with similar physical and chemical characteristics collected in the rainy season (December). This result demonstrates the importance of monitoring PM toxicities and their chemical and physical characteristics, in addition to their concentrations. Therefore, the new protocol to provide a preliminary analysis of the toxicity of the extracts of aerosol emerges as a useful, accessible, and fast tool for monitoring possible environmental hazards, and can simplify fieldwork.

Post-Harvest Eucalyptus Residue Removal Reduces Soil Aggregation and Biological Activities in Central-West Brazil

Tree residue removal from Eucalyptus plantations after timber harvest can reduce soil functioning by reducing the organic matter input. To assess the effects of residue management systems (RMS) on soil aggregation, carbon (C) and nitrogen (N) content, and biological activities, a field trial was conducted in a commercial Eucalyptus plantation (loamy sand soil) in Mato Grosso do Sul, Brazil. The study assessed three RMS: cut-to-length (CTL), tree-length (TL), and bare litter (BL), respectively. After 21 months, undisturbed soil samples were collected and physically isolated into three aggregate-size fractions: large macroaggregates (LM), medium macroaggregates (SM), and microaggregates (MI). Results showed that these soils are mostly composed of LM (54%), and that removing harvest residues from the growing site included total organic carbon (TOC) by 28%, microbial biomass-C by 20%, fluorescein diacetate hydrolysis by 17%, and β-glucosidase activity by 26%, when compared to CTL. TL outperformed CTL for the proportion of LM and LM-associated TOC. Across fractions, a higher microbial quotient was observed in SM and MI fractions, suggesting that the TOC has higher stability inside the LM. This study suggests that leaving harvest residues on the soil should be recommended for Eucalyptus plantations, especially in low-fertility sandy soils, as it helps in maintaining the soil structure and biological activities critical for soil health and ecosystem function.

Risk of adverse pregnancy and infant outcomes associated with prenatal Zika virus infection: a post-epidemic cohort in Central-West Brazil

This study aimed to estimate the risks of adverse infant outcomes in the first year of life related to prenatal Zika virus (ZIKV) exposure. A prospective cohort of pregnant women with rash was recruited in Central-West Brazil in a post-epidemic period (January 2017 to April 2019). We evaluated participants’ medical histories and performed ZIKV diagnostic testing using molecular (reverse transcription polymerase chain reaction [RT-PCR]) and serologic (immunoglobulin [Ig]M and plaque reduction neutralization tests [PRNT90]) assays. The ZIKV-positive group included both RT-PCR-confirmed cases as well as IgM and/or PRNT90-positive probable cases. Children were evaluated at birth and in the first 12 months of life. Transfontanellar ultrasound, central nervous system computed tomography, eye fundoscopy and retinography were performed. We estimated the absolute risk and 95% confidence interval (95% CI) of adverse infant outcomes among confirmed prenatally ZIKV-exposed children. Among 81 pregnant women with rash, 43 (53.1%) were ZIKV infected. The absolute risk of microcephaly among offspring of ZIKV-infected pregnant women was 7.0% (95% CI: 1.5–19.1), including the two cases of microcephaly detected prenatally and one detected postnatally. In total, 54.5% (95% CI: 39.8–68.7) of children in the ZIKV-exposed group had at least one ophthalmic abnormality, with the most frequent abnormalities being focal pigmentary mottling and chorioretinal atrophy or scarring. Our findings reinforce the importance of long-term monitoring of prenatally ZIKV-exposed children born apparently asymptomatic for Congenital Zika Syndrome.

Circulation of HDV Genotypes in Brazil: Identification of a Putative Novel HDV-8 Subgenotype.

Hepatitis D virus (HDV) is classified into 8 genotypes (1 to 8) and several subgenotypes. In Brazil, HDV-3 and HDV-1 predominate; however, most of the diagnosis efforts and molecular studies are directed to the area of endemicity of the Amazon Basin. Here, we determined the molecular epidemiological profile of circulating HDV in Brazilian HBsAg-positive patients between 2013 and 2015 in areas of endemicity and non-areas of endemicity. From 38 anti-HDV-positive individuals, 13 (34.2%) had detectable HDV-RNA and 11 (28.9%) were successfully sequenced. Partial HDAg (~320 nt) sequencing followed by phylogenetic analysis with reference sequences resulted in the identification of HDV-3 (9/11; 81.8%), HDV-5 (1/11; 9.1%), and HDV-8 (1/11; 9.1%). Most HDV-3 samples (8/9; 88.9%) were found in the endemic North region, while one was found in Central-West Brazil, a non-area of endemicity. HDV-5 and 8, genotypes native from African countries, were found in São Paulo, a cosmopolitan city from Southeast Brazil with a high circulation of immigrants. Phylogenetic analysis of HDV-8 strains indicated that the sample determined in our study, along with previously reported sequences from Brazil, formed a highly supported monophyletic clade, likely representing a putative novel HDV-8 subgenotype. IMPORTANCE Considered a neglected pathogen until the last 2 decades, an increase in the availability of genetic data of hepatitis D virus (HDV) strains around the world has been noticed recently, resulting in the proposition of different classifications. Our study aimed to determine the molecular epidemiological profile of HDV isolates circulating in areas of endemicity and non-areas of endemicity in Brazil. Based on the analyzed fragment, HDV-8 sequences clustered out of the clades formed by subgenotypes 8a and 8b might suggest the identification of a novel subgenotype, putatively designated subgenotype 8c. Our findings demonstrate the importance of continuous epidemiological surveillance to map HDV spread pathways and the introduction of imported variants. It also reinforces that as the amount of HDV genomes generated and reported increases, we will have changes in viral classification and, consequently, in our understanding of the dynamics of variability of this viral agent.