RESUMEN
In 2015, the Zika virus (ZIKV) emerged in Brazil, leading to widespread outbreaks in Latin America. Following this, many countries in these regions reported a significant drop in the circulation of dengue virus (DENV), which resurged in 2018-2019. We examine age-specific incidence data to investigate changes in DENV epidemiology before and after the emergence of ZIKV. We observe that incidence of DENV was concentrated in younger individuals during resurgence compared to 2013-2015. This trend was more pronounced in Brazilian states that had experienced larger ZIKV outbreaks. Using a mathematical model, we show that ZIKV-induced cross-protection alone, often invoked to explain DENV decline across Latin America, cannot explain the observed age-shift without also assuming some form of disease enhancement. Our results suggest that a sudden accumulation of population-level immunity to ZIKV could suppress DENV and reduce the mean age of DENV incidence via both protective and disease-enhancing interactions.
Asunto(s)
Virus del Dengue , Dengue , Infección por el Virus Zika , Virus Zika , Humanos , Brasil/epidemiología , Anticuerpos Antivirales , Reacciones CruzadasRESUMEN
The spread of Chikungunya virus is a major public health concern in the Americas. There were >120,000 cases and 51 deaths in 2023, of which 46 occurred in Paraguay. Using a suite of genomic, phylodynamic, and epidemiologic techniques, we characterized the ongoing large chikungunya epidemic in Paraguay.
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Fiebre Chikungunya , Virus Chikungunya , Epidemias , Humanos , Virus Chikungunya/genética , Paraguay/epidemiología , Sudáfrica , Fiebre Chikungunya/epidemiología , Filogenia , GenotipoRESUMEN
Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) is responsible for causing Coronavirus Disease-2019 (COVID-19), a heterogeneous clinical condition that manifests varying symptom severity according to the demographic profile of the studied population. While many studies have focused on the spread of COVID-19 in large urban centers in Brazil, few have evaluated medium or small cities in the Northeast region. The aims of this study were: (i) to identify risk factors for mortality from SARS-CoV-2 infection, (ii) to evaluate the gene expression patterns of key immune response pathways using nasopharyngeal swabs of COVID-19 patients, and (iii) to identify the circulating SARS-CoV-2 variants in the residents of a medium-sized city in Northeast Brazil. A total of 783 patients infected with SARS-CoV-2 between May 2020 and August 2021 were included in this study. Clinical-epidemiological data from patients who died and those who survived were compared. Patients were also retrospectively divided into three groups based on disease severity: asymptomatic, mild, and moderate/severe. Samples were added to a qPCR array for analyses of 84 genes involved with immune response pathways and sequenced using the Oxford Nanopore MinION technology. Having pre-existing comorbidity; being male; having cardiovascular disease, diabetes, and/or chronic obstructive pulmonary disease; and PCR cycle threshold (Ct) values under 22 were identified as risk factors for mortality. Analysis of the expression profiles of inflammatory pathway genes showed that the greater the infection severity, the greater the activation of inflammatory pathways, triggering the cytokine storm and downregulating anti-inflammatory pathways. Viral genome analysis revealed the circulation of multiple lineages, such as B.1, B.1.1.28, Alpha, and Gamma, suggesting that multiple introduction events had occurred over time. This study's findings help identify the specific strains and increase our understanding of the true state of local health. In addition, our data demonstrate that epidemiological and genomic surveillance together can help formulate public health strategies to guide governmental actions.
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COVID-19 , SARS-CoV-2 , Humanos , Masculino , Femenino , SARS-CoV-2/genética , COVID-19/epidemiología , Estudios Retrospectivos , Brasil/epidemiologíaRESUMEN
The Lambda variants of interest (VOI) (C37/GR/452Q.V1/21G) was initially reported in Lima, Peru but has gained rapid dissemination through other Latin American countries. Nevertheless, the dissemination and molecular epidemiology of the Lambda VOI in Brazil is unknown apart from a single case report. In this respect, we characterized the circulation of the SARS-CoV-2 Lambda VOI (C37/GR/452Q.V1/21G) in Sao Paulo State, Brazil. From March to June 2021, we identified seven Lambda isolates in a set of approximately 8000 newly sequenced genomes of the Network for Pandemic Alert of Emerging SARS-CoV-2 variants from Sao Paulo State. Interestingly, in three of the positive patients, the Lambda VOI infection was probably related to a contact transmission. These individuals were fully vaccinated to COVID-19 and presented mild symptoms. The remaining positive for Lambda VOI individuals showed different levels of COVID-19 symptoms and one of them needed hospitalization (score 5, WHO). In our study, we present a low level of Lambda VOI circulation in the Sao Paulo State. This reinforces the essential role of molecular surveillance for the effective SARS-CoV-2 pandemic response, especially in regard to circulating variants.
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COVID-19 , SARS-CoV-2 , Brasil/epidemiología , COVID-19/epidemiología , Humanos , SARS-CoV-2/genética , Organización Mundial de la SaludRESUMEN
Zika virus (ZIKV), an emerging virus belonging to the Flaviviridae family, causes severe neurological clinical complications and has been associated with Guillain-Barré syndrome, fetal abnormalities known collectively as congenital Zika syndrome, and microcephaly. Studies have shown that ZIKV infection can alter cellular metabolism, directly affecting neural development. Brain growth requires controlled cellular metabolism, which is essential for cell proliferation and maturation. However, little is known regarding the metabolic profile of ZIKV-infected newborns and possible associations related to microcephaly. Furthering the understanding surrounding underlying mechanisms is essential to developing personalized treatments for affected individuals. Thus, metabolomics, the study of the metabolites produced by or modified in an organism, constitutes a valuable approach in the study of complex diseases. Here, 26 serum samples from ZIKV-positive newborns with or without microcephaly, as well as controls, were analyzed using an untargeted metabolomics approach involving gas chromatography-mass spectrometry (GC-MS). Significant alterations in essential and non-essential amino acids, as well as carbohydrates (including aldohexoses, such as glucose or mannose) and their derivatives (urea and pyruvic acid), were observed in the metabolic profiles analyzed. Our results provide insight into relevant metabolic processes in patients with ZIKV and microcephaly.
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Autochthonous Zika virus (ZIKV) transmission in Brazil was first identified in April 2015 in Brazil, with the first ZIKV-associated microcephaly cases detected in October 2015. Despite efforts on understanding ZIKV transmission in Brazil, little is known about the virus epidemiology and genetic diversity in Minas Gerais (MG), the second most populous state in the country. We report molecular and genomic findings from the main public health laboratory in MG. Until January 2020, 26,817 ZIKV suspected infections and 86 congenital syndrome cases were reported in MG state. We tested 8552 ZIKV and microcephaly suspected cases. Ten genomes were generated on-site directly from clinical samples. A total of 1723 confirmed cases were detected in Minas Gerais, with two main epidemic waves; the first and larger epidemic wave peaked in March 2016, with the second smaller wave that peaked in March 2017. Dated molecular clock analysis revealed that multiple introductions occurred in Minas Gerais between 2014 and 2015, suggesting that the virus was circulating unnoticed for at least 16 months before the first confirmed laboratory case that we retrospectively identified in December 2015. Our findings highlight the importance of continued genomic surveillance strategies combined with traditional epidemiology to assist public health laboratories in monitoring and understanding the diversity of circulating arboviruses, which might help attenuate the public health impact of infectious diseases.
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Microcefalia/epidemiología , Infección por el Virus Zika/epidemiología , Virus Zika/genética , Adolescente , Adulto , Anciano , Brasil/epidemiología , Niño , Preescolar , Femenino , Humanos , Incidencia , Lactante , Recién Nacido , Masculino , Microcefalia/virología , Persona de Mediana Edad , Estudios Retrospectivos , Adulto Joven , Infección por el Virus Zika/virologíaRESUMEN
The Lambda variants of interest (VOI) (C37/GR/452Q.V1/21G) was initially reported in Lima, Peru but has gained rapid dissemination through other Latin American countries. Nevertheless, the dissemination and molecular epidemiology of the Lambda VOI in Brazil is unknown apart from a single case report. In this respect, we characterized the circulation of the SARS-CoV-2 Lambda VOI (C37/GR/452Q.V1/21G) in Sao Paulo State, Brazil. From March to June 2021, we identified seven Lambda isolates in a set of approximately 8000 newly sequenced genomes of the Network for Pandemic Alert of Emerging SARS-CoV-2 variants from Sao Paulo State. Interestingly, in three of the positive patients, the Lambda VOI infection was probably related to a contact transmission. These individuals were fully vaccinated to COVID-19 and presented mild symptoms. The remaining positive for Lambda VOI individuals showed different levels of COVID-19 symptoms and one of them needed hospitalization (score 5, WHO). In our study, we present a low level of Lambda VOI circulation in the Sao Paulo State. This reinforces the essential role of molecular surveillance for the effective SARS-CoV-2 pandemic response, especially in regard to circulating variants.
RESUMEN
São Paulo, a densely inhabited state in southeast Brazil that contains the fourth most populated city in the world, recently experienced its largest yellow fever virus (YFV) outbreak in decades. YFV does not normally circulate extensively in São Paulo, so most people were unvaccinated when the outbreak began. Surveillance in non-human primates (NHPs) is important for determining the magnitude and geographic extent of an epizootic, thereby helping to evaluate the risk of YFV spillover to humans. Data from infected NHPs can give more accurate insights into YFV spread than when using data from human cases alone. To contextualise human cases, identify epizootic foci and uncover the rate and direction of YFV spread in São Paulo, we generated and analysed virus genomic data and epizootic case data from NHPs in São Paulo. We report the occurrence of three spatiotemporally distinct phases of the outbreak in São Paulo prior to February 2018. We generated 51 new virus genomes from YFV positive cases identified in 23 different municipalities in São Paulo, mostly sampled from NHPs between October 2016 and January 2018. Although we observe substantial heterogeneity in lineage dispersal velocities between phylogenetic branches, continuous phylogeographic analyses of generated YFV genomes suggest that YFV lineages spread in São Paulo at a mean rate of approximately 1km per day during all phases of the outbreak. Viral lineages from the first epizootic phase in northern São Paulo subsequently dispersed towards the south of the state to cause the second and third epizootic phases there. This alters our understanding of how YFV was introduced into the densely populated south of São Paulo state. Our results shed light on the sylvatic transmission of YFV in highly fragmented forested regions in São Paulo state and highlight the importance of continued surveillance of zoonotic pathogens in sentinel species.
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Genoma Viral , Enfermedades de los Primates/virología , Fiebre Amarilla/veterinaria , Fiebre Amarilla/virología , Virus de la Fiebre Amarilla/genética , Zoonosis/virología , Animales , Brasil/epidemiología , Brotes de Enfermedades , Genómica , Humanos , Filogenia , Filogeografía , Enfermedades de los Primates/epidemiología , Enfermedades de los Primates/transmisión , Primates/virología , Fiebre Amarilla/epidemiología , Fiebre Amarilla/transmisión , Virus de la Fiebre Amarilla/clasificación , Virus de la Fiebre Amarilla/aislamiento & purificación , Zoonosis/epidemiología , Zoonosis/transmisiónRESUMEN
OBJECTIVE: To identify newborns with congenital Zika infection (CZI) at a maternity hospital in Salvador, Brazil, during the 2016 microcephaly outbreak. METHODS: A prospective study enrolled microcephalic and normocephalic newborns with suspected CZI between January and December 2016. Serology (immunoglobulins IgM and IgG) and quantitative reverse transcriptase polymerase chain reaction (RT-qPCR) for the Zika virus were performed. Demographic and clinical characteristics of newborns with and without microcephaly were compared. RESULTS: Of the 151 newborns enrolled, 32 (21.2%) were classified as microcephalic. The majority of these cases were born between January and May 2016. IgM and IgG Zika virus antibodies were detected in 5 (23.8%) and 17 (80.9%) microcephalic newborn blood samples, respectively. Six (24%) microcephalic newborns tested positive for Zika virus by RT-qPCR in urine or placenta samples. Thirteen (11.8%) normocephalic newborns also tested positive for Zika virus by PCR in urine, plasma, or placenta samples, while IgM antibodies against Zika were detected in 4 (4.2%) others. CONCLUSIONS: Identification of 17 normocephalic CZI cases, confirmed by IgM serology or RT-qPCR for Zika virus, provides evidence that CZI can present asymptomatically at birth. This finding highlights the need for prenatal and neonatal screening for Zika virus in endemic regions.
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Microcefalia/epidemiología , Complicaciones Infecciosas del Embarazo/etiología , Infección por el Virus Zika/etiología , Brasil/epidemiología , Estudios de Casos y Controles , Brotes de Enfermedades , Femenino , Humanos , Inmunoglobulina G/sangre , Inmunoglobulina M/sangre , Recién Nacido , Enfermedades del Recién Nacido/epidemiología , Transmisión Vertical de Enfermedad Infecciosa/estadística & datos numéricos , Masculino , Microcefalia/sangre , Microcefalia/virología , Tamizaje Neonatal/métodos , Embarazo , Complicaciones Infecciosas del Embarazo/sangre , Complicaciones Infecciosas del Embarazo/epidemiología , Estudios Prospectivos , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Virus Zika/aislamiento & purificación , Infección por el Virus Zika/sangre , Infección por el Virus Zika/epidemiologíaRESUMEN
In recent years, an increasing number of outbreaks of Dengue, Chikungunya and Zika viruses have been reported in Asia and the Americas. Monitoring virus genotype diversity is crucial to understand the emergence and spread of outbreaks, both aspects that are vital to develop effective prevention and treatment strategies. Hence, we developed an efficient method to classify virus sequences with respect to their species and sub-species (i.e. serotype and/or genotype). This tool provides an easy-to-use software implementation of this new method and was validated on a large dataset assessing the classification performance with respect to whole-genome sequences and partial-genome sequences. Available online: http://krisp.org.za/tools.php.
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Virus Chikungunya/aislamiento & purificación , Biología Computacional/métodos , Virus del Dengue/aislamiento & purificación , Virus Zika/aislamiento & purificación , Fiebre Chikungunya/virología , Virus Chikungunya/clasificación , Virus Chikungunya/genética , Dengue/virología , Virus del Dengue/clasificación , Virus del Dengue/genética , Genoma Viral , Genotipo , Filogenia , Virus Zika/clasificación , Virus Zika/genética , Infección por el Virus Zika/virologíaRESUMEN
This study tested the hypothesis that sickle red blood cell (SS-RBC) induce Toll-like receptors (TLR) and Nod-like receptor family, pyrin domain containing 3 (NLRP3)- inflammasome expression in peripheral blood mononuclear cells (PBMC). TLR and NLRP3 inflammasome could contribute to the maintenance of the inflammatory status in sickle cell anemia (SCA) patients, since SS-RBC act as danger signals activating these pathways. In this study, first, we evaluated TLR (2, 4, 5 and 9), NLRP3, Caspase-1, interleukin (IL)-1ß and IL-18 expression in PBMC freshly isolated from SCA patients (SS-PBMC) in comparison with PBMC from healthy individuals (AA-PBMC). In the second moment, we investigated whether SS-RBC could interfere with the expression of these molecules in PBMC from healthy donor, in the absence or presence of hydroxyurea (HU) in vitro. TLRs and NLRP3 inflammasome expression were investigated by qPCR. IL-1ß, Leukotriene-B4 (LTB4) and nitrite production were measured in PBMC (from healthy donor) culture supernatants. TLR2, TLR4, TLR5, NLRP3 and IL-1ß were highly expressed in SS-PBMC when compared to AA-PBMC. Additionally, SS-RBC induced TLR9, NLRP3, Caspase-1, IL-1ß and IL-18 expression and induced IL-1ß, LTB4 and nitrite production in PBMC cultures. HU did not prevent TLR and NLRP3 inflammasome expression, but increased TLR2 and IL-18 expression and reduced nitrite production. In conclusion, our data suggest that TLR and inflammasome complexes may be key inducers of inflammation in SCA patients, probably through SS-RBC; also, HU does not prevent NLRP3 inflammasome- and TLR-dependent inflammation, indicating the need to develop new therapeutic strategies to SCA patients that act with different mechanisms of those observed for HU.
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Anemia de Células Falciformes/metabolismo , Eritrocitos Anormales/metabolismo , Regulación de la Expresión Génica , Interleucina-1beta/biosíntesis , Leucocitos Mononucleares/metabolismo , Leucotrieno B4/biosíntesis , Adolescente , Anemia de Células Falciformes/patología , Niño , Preescolar , Eritrocitos Anormales/patología , Femenino , Humanos , Inflamación/metabolismo , Inflamación/patología , Interleucina-18/biosíntesis , Leucocitos Mononucleares/patología , Masculino , Proteína con Dominio Pirina 3 de la Familia NLR/biosíntesis , Nitritos/metabolismo , Receptores Toll-Like/biosíntesisRESUMEN
The purpose of this study was to investigate the balance between transfer ribonucleic acid (tRNA) supply and demand in retrovirus-infected cells, seeking the best targets for antiretroviral therapy based on the hypothetical tRNA Inhibition Therapy (TRIT). Codon usage and tRNA gene data were retrieved from public databases. Based on logistic principles, a therapeutic score (T-score) was calculated for all sense codons, in each retrovirus-host system. Codons that are critical for viral protein translation, but not as critical for the host, have the highest T-score values. Theoretically, inactivating the cognate tRNA species should imply a severe reduction of the elongation rate during viral mRNA translation. We developed a method to predict tRNA species critical for retroviral protein synthesis. Four of the best TRIT targets in HIV-1 and HIV-2 encode Large Hydrophobic Residues (LHR), which have a central role in protein folding. One of them, codon CUA, is also a TRIT target in both HTLV-1 and HTLV-2. Therefore, a drug designed for inactivating or reducing the cytoplasmatic concentration of tRNA species with anticodon TAG could attenuate significantly both HIV and HTLV protein synthesis rates. Inversely, replacing codons ending in UA by synonymous codons should increase the expression, which is relevant for DNA vaccine design.
RESUMEN
BACKGROUND: Human T-cell Leukemia Virus type 1 (HTLV-1) is the etiological agent of tropical spastic paraparesis/HTLV-associated myelopathy (HAM/TSP) that can be identified in around 0.25%-3.8% of the infected population. Disease progression can be monitored by the proviral load and may depend on genetic factors, however, it is not well understood why some HTLV-1 infected people develop the disease while others do not. The present study attempts to assess the molecular diversity of gp46 glycoprotein in HAM/TSP patients and Health Carrier (HC) individuals. METHODS: Blood samples were collected from 10 individuals, and DNA was extracted from PBMCs to measure the HTLV-1 proviral load. The gp46 coding sequences were amplified PCR, cloned and sequenced. The molecular characterization was performed using bioinformatics tools. RESULTS: The median HTLV-1 proviral load of HC (n = 5) and HAM/TSP (n = 5) patients was similar (average 316,227 copies/106 PBMCs). The gp46 molecular characterization of 146 clones (70 HC and 76 HAM/TSP) revealed an overall diversity, within HC and HAM/TSP clones, of 0.4% and 0.6%, respectively. Five frequent mutations were detected among groups (HAM/TSP and HC clone sequences). A single amino acid (aa) substitution (S35L) was exclusive for the HC group, and three gp46 substitutions (F14S, N42H, G72S) were exclusive for the HAM/TSP group. The remaining frequent mutation (V247I) was present in both groups (p = 0.0014). The in silico protein analysis revealed that the mutated alleles F14S and N42H represent more hydrophilic and flexible protein domains that are likely to be less antigenic. The Receptor Binding Domain is quite variable in the HAM/TSP group. Two other domains (aa 53-75 and 175-209) that contain multiple linear T-cell epitopes showed genetic diversity in both HAM/TSP and HC groups. Further analysis revealed 27 and 13 T-cell epitopes for class I HLA alleles and class II HLA alleles, when analyzing the entire gp46. CONCLUSIONS: The most common gp46 mutations were not associated clinical status because they were found in only one individual, except for the V247I mutation, that was found at viral clones from HAM/TSP ad HC individuals. Because of this, we cannot associate any of the gp46 found mutations with the clinical profile.
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Portador Sano/virología , Productos del Gen env/genética , Virus Linfotrópico T Tipo 1 Humano/genética , Paraparesia Espástica Tropical/virología , Proteínas Oncogénicas de Retroviridae/genética , Adulto , Anciano , Secuencia de Aminoácidos , Portador Sano/inmunología , Epítopos de Linfocito T/química , Epítopos de Linfocito T/genética , Epítopos de Linfocito T/inmunología , Femenino , Productos del Gen env/química , Productos del Gen env/inmunología , Virus Linfotrópico T Tipo 1 Humano/química , Virus Linfotrópico T Tipo 1 Humano/inmunología , Virus Linfotrópico T Tipo 1 Humano/aislamiento & purificación , Humanos , Masculino , Persona de Mediana Edad , Datos de Secuencia Molecular , Mutación , Paraparesia Espástica Tropical/inmunología , Estructura Terciaria de Proteína , Proteínas Oncogénicas de Retroviridae/química , Proteínas Oncogénicas de Retroviridae/inmunologíaRESUMEN
HIV-1 provirus activation is under control of the long terminal repeat (LTR)-5' viral promoter region, which presents remarkable genetic variation among HIV-1 subtypes. It is possible that molecular features of the LTR contribute to the unusual profile of the subtype C epidemic in the Brazilian Southern region. To characterize the LTR of Brazilian HIV isolates, we analyzed sequences from 21 infected individuals from Porto Alegre and Salvador cities. Sequences were compared with subtype B and C reference strains from different countries. Phylogenetic analysis showed that 17 (81%) samples were subtype B and four (19%) were subtype C. Common patterns of transcription factor binding sites (TFBS) in subtypes B and C sequences were confirmed and other potential TFBS specific for subtype C were found. Brazilian subtype C sequences contained an additional NF-κB biding site, as previously described for the majority of subtype C isolates. The high level of LTR polymorphisms identified in this study might be important for viral fitness.
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Infecciones por VIH/virología , Duplicado del Terminal Largo de VIH/genética , VIH-1/genética , Secuencia de Bases , Brasil/epidemiología , ADN Viral/genética , Infecciones por VIH/epidemiología , Humanos , Datos de Secuencia Molecular , Filogenia , Reacción en Cadena de la Polimerasa , Alineación de SecuenciaRESUMEN
Recent studies have demonstrated an increased prevalence of human immunodeficiency virus type 1 (HIV-1) subtype C in southern Brazil. Although Santa Catarina State (SC) is located in this area and presents one of the country's highest incidences of HIV/AIDS, knowledge on the molecular epidemiology of HIV-1 in such State is lacking. The aim of this study was to investigate the HIV-1 molecular diversity and epidemiological profile of HIV-1-infected patients from SC. DNA samples were PCR amplified and HIV-1 subtypes were determined using both env and gag genes by direct sequencing. Phylogenetic analyses revealed that 48% were subtype C and 23% were subtype B. Possible recombinant forms were observed for both B/C (23%) and B/F (6%) subtypes. Our results, for the first time, identifies HIV-1 subtype C as a major clade circulating in SC and contributes to the understanding of HIV epidemics in the country by confirming the epidemic spread of the HIV-1 subtype C in southern Brazil.
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Infecciones por VIH/epidemiología , VIH-1/genética , Epidemiología Molecular , Adulto , Brasil/epidemiología , Femenino , Genes env/genética , Genes gag/genética , Variación Genética , VIH-1/clasificación , Humanos , Masculino , Filogenia , Recombinación GenéticaRESUMEN
The molecular and biological properties of HIV-1 subtype C strains from South Brazil were investigated. We sequenced gag and env fragments of viruses from 22 HIV-1-infected individuals from Porto Alegre City, which has the highest frequency of subtype C in the country. The sequences were then compared with other subtype B, C, and F strains isolated in Brazil and other countries using phylogenetic methods. Amino acid signatures were identified and correlated with phenotypic characteristics. We identified six strains with subtype C (27.3%), eight subtype B (36.4%), one subtype F (4.5%), six C/B recombinants (27.3%), and one B/F recombinant (4.5%). The Brazilian subtype C sequences formed a unique phylogenetic group and presented 6 and 18 specific amino acid signatures in gag and env, respectively. Three distinct patterns of C/B recombinants presented characteristic Brazilian amino acid substitutions. Subtype C viruses were predominantly R5 and non-syncytium-inducing, while C/B recombinants were R5/X4 and syncytium-inducing viruses. These findings suggest that subtype C viruses circulating in Brazil are the result of a unique introduction into the country. Recombination events between subtypes B and C have been occurring frequently for more than 10 years in South Brazil. Biological characterization confirms the hypothesis that subtype C is distinct from the others in the evolution of coreceptor utilization.
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Infecciones por VIH/microbiología , VIH-1/genética , VIH-1/aislamiento & purificación , Secuencias de Aminoácidos , Secuencia de Aminoácidos , Secuencia de Bases , Brasil , Secuencia de Consenso , ADN Viral/análisis , Productos del Gen env/genética , Productos del Gen gag/genética , Genes env , Genes gag , VIH-1/clasificación , Humanos , Datos de Secuencia Molecular , Filogenia , Reacción en Cadena de la Polimerasa , Recombinación Genética , Análisis de Secuencia de ADN , Homología de Secuencia de Aminoácido , Especificidad de la EspecieRESUMEN
The first description of the human T-lymphotropic virus type 1 (HTLV-1) was made in 1980, followed closely by the discovery of HTLV-2, in 1982. Since then, the main characteristics of these viruses, commonly referred to as HTLV-1/2, have been thoroughly studied. Central and South America and the Caribbean are areas of high prevalence of HTLV-1 and HTVL-2 and have clusters of infected people. The major modes of transmission have been through sexual contact, blood, and mother to child via breast-feeding. HTLV-1 is associated with adult T-cell leukemia/lymphoma (ATL), HTLV-associated myelopathy/tropical spastic paraparesis (HAM/TSP), and HTLV-associated uveitis as well as infectious dermatitis of children. More clarification is needed in the possible role of HTLV in rheumatologic, psychiatric, and infectious diseases. Since cures for ATL and HAM/TSP are lacking and no vaccine is available to prevent HTLV-1 and HTLV-2 transmission, these illnesses impose enormous social and financial costs on infected individuals, their families, and health care systems. For this reason, public health interventions aimed at counseling and educating high-risk individuals and populations are of vital importance. In the Americas this is especially important in the areas of high prevalence.
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Infecciones por Deltaretrovirus/epidemiología , Adulto , Donantes de Sangre , Lactancia Materna , Región del Caribe/epidemiología , América Central/epidemiología , Niño , Estudios Transversales , Infecciones por Deltaretrovirus/prevención & control , Infecciones por Deltaretrovirus/transmisión , Femenino , Infecciones por HTLV-I/epidemiología , Infecciones por HTLV-I/prevención & control , Infecciones por HTLV-I/transmisión , Infecciones por HTLV-II/epidemiología , Infecciones por HTLV-II/prevención & control , Infecciones por HTLV-II/transmisión , Humanos , Recién Nacido , Leucemia de Células T/epidemiología , Leucemia-Linfoma de Células T del Adulto/epidemiología , Linfoma de Células T , Masculino , Persona de Mediana Edad , Paraparesia Espástica Tropical/epidemiología , Embarazo , Complicaciones Infecciosas del Embarazo/epidemiología , Factores de Riesgo , América del Sur/epidemiología , Estados Unidos/epidemiologíaRESUMEN
We compared the genetic diversity of the Brazilian human T-cell lymphotropic virus type 1 isolates with those found in KwaZulu-Natal (KZN), South Africa, and with the genetic background of the hosts. The seroprevalence rate in KZN was 1.7%. All sequences belonged to the A subgroup. The presence of South African sequences in two different clusters from Brazil, and the finding of the beta-globin haplotype in infected hosts are consistent with the transmission of this virus from southern Africa to Brazil.
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Evolución Molecular , Genes Virales , Infecciones por HTLV-I/genética , Virus Linfotrópico T Tipo 1 Humano/genética , Brasil/epidemiología , Variación Genética , Globinas/genética , Infecciones por HTLV-I/epidemiología , Haplotipos , Humanos , Epidemiología Molecular/métodos , Filogenia , Estudios Seroepidemiológicos , Sudáfrica , Secuencias Repetidas TerminalesRESUMEN
The first description of the human T-lymphotropic virus type 1 (HTLV-1) was made in 1980 followed closely by the discovery of HTLV-2, in 1982. Since then, the main characteristics of these viruses, commonly referred to as HTLV-1/2, have been thoroughly studied. Central and South America and the Caribbean are areas of high prevalence of HTLV-1 and HTLV-2 and have clusters of infected people. The major modes of transmission have been through sexual contact, blood, and mother to child via breast-feeding. HTLV-1 is associated with adult T-cell leukemia/lymphoma (ATL), HTLV-associated myelopathy/tropical spastic paraparesis (HAM/TSP), and HTLV-associated uveitis as well as infectious dermatitis of children. More clarification is needed in the possible role of HTLV in rheumatological, psychiatric and infectious diseases. Since cures for ATL and HAM/TSP are lacking and no vaccine is available to prevent HTLV-1 and HTLV-2 transmission, these illnesses impose enormous social and financial cost on infected individuals, their families, and health care systems. For this reason, public health interventions aimed at counseling and educating high-risk individuals and populations are of vital importance. In the Americas this is especially important in the areas of high prevalence(AU)
Asunto(s)
Humanos , Virus Linfotrópico T Tipo 1 Humano , Virus Linfotrópico T Tipo 2 Humano , Retroviridae , Donantes de Sangre , Medicina Preventiva , Región del Caribe/epidemiología , AméricasRESUMEN
La primera descripción del virus de la leucemia humana de células T tipo 1 (VLHT-1) se hizo en 1980, y al poco tiempo, en 1982, se descubrió el VLHT-2. Desde entonces las características principales de estos virus, a los que a menudo se les llama VLHT-1/2, se han estudiado exhaustivamente. Centroamérica, América del Sur y el Caribe son áreas con una alta prevalencia de VLHT-1 y VLHT-2 donde hay conglomerados de personas infectadas. Las principales vías de transmisión han sido el contacto sexual, la sangre y sus derivados, y la de madre a hijo por la leche materna. El VLHT-1 se asocia con la leucemia o el linfoma de células T maduras (LTM), la mielopatía o paraparesia tropical espástica ligada al VLHT (M/PTE), y la uveítis ligada al VLHT, así como con la dermatitis infecciosa de la infancia. Se necesita más información acerca del posible papel que desempeña el VLHT en la aparición de enfermedades reumáticas, psiquiátricas e infecciosas. En vista de que no se dispone de ninguna cura para la LTM ni la M/PTE, como tampoco de ninguna vacuna para prevenir la transmisión del VLHT-1 y VLHT-2, estas enfermedades acarrean enormes costos sociales y económicos para las personas infectadas, sus parientes y los sistemas de salud. Por este motivo, las intervenciones sanitarias orientadas a asesorar e instruir a personas y poblaciones en alto riesgo revisten una importancia crítica. En el continente americano esto cobra aun más importancia en zonas de alta prevalencia.
The first description of the human T-lymphotropic virus type 1 (HTLV-1) was made in 1980, followed closely by the discovery of HTLV-2, in 1982. Since then, the main characteristics of these viruses, commonly referred to as HTLV-1/2, have been thoroughly studied. Central and South America and the Caribbean are areas of high prevalence of HTLV-1 and HTVL-2 and have clusters of infected people. The major modes of transmission have been through sexual contact, blood, and mother to child via breast-feeding. HTLV-1 is associated with adult T-cell leukemia/lymphoma (ATL), HTLV-associated myelopathy/tropical spastic paraparesis (HAM/ TSP), and HTLV-associated uveitis as well as infectious dermatitis of children. More clarification is needed in the possible role of HTLV in rheumatologic, psychiatric, and infectious diseases. Since cures for ATL and HAM/TSP are lacking and no vaccine is available to prevent HTLV-1 and HTLV-2 transmission, these illnesses impose enormous social and financial costs on infected individuals, their families, and health care systems. For this reason, public health interventions aimed at counseling and educating high-risk individuals and populations are of vital importance. In the Americas this is especially important in the areas of high prevalence.