Clinical-epidemiological profile of COVID-19 patients during the first wave of the disease in the state of Pará, Brazil

December 2019 saw several cases of pneumonia of unknown origin reported in Wuhan, China; the cause of this unknown disease was later identified as the new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The purpose of the present study was to evaluate the epidemiological profile of coronavirus disease 2019 (COVID-19) in the North Region of Brazil to assess possible correlations between demographic, social and health factors as well as adherence to safety protocols and the epidemiological profile of COVID-19. Information was obtained via a socio epidemiological survey carried out using Google Forms shared on various social media platforms from May 13 to 20, 2020. 6,781 people, living in the State of Pará, participated in the study of which only 682 (10.1%) had been diagnosed with COVID-19. Of these, 43 (6.3%) required hospitalization. 155 (23.5%) tested positive by RT-PCR associated with computed tomography. The RT-PCR test, with no association with other methods, was performed in 77 (11.6%) cases and serology performed in 360 cases (54.6%). There was a higher prevalence of confirmed cases (457, 67.0%) in females than in males, and the predominant age group was 30 to 40 years of age (214 participants, 31.4%). Considering the relatively homogeneous demographic profile of the sample, continued research is vital, preferably multi-centric studies, to obtain relevant data regarding the epidemiological dynamics of COVID-19; this data will allow the development of pandemic-prevention strategies that consider the social, cultural and political aspects of specific locations

HTLV-2 infection in Manaus, Brazil: first description of HTLV-2c subtype in an urban area of the Western Amazon region

Abstract INTRODUCTION: We investigated the prevalence of human T-cell lymphotropic virus types 1 and 2 (HTLV-1/2) infection in patients with hematological diseases from the western Amazon region of Brazil. METHODS: Samples from 306 patients were submitted for the molecular diagnosis of HTLV-1/2 infection by real time PCR (qPCR), with amplification, sequencing, and phylogenetic analysis of the long terminal repeat (LTR) region. RESULTS: A 29-year-old male carrier of sickle cell anemia with a history of multiple blood transfusions was diagnosed with the HTLV-2c subtype. CONCLUSIONS: This study describes the first known occurrence of HTLV-2c in the urban area of Brazil's western Amazon region.

Boletim COVID-PA: relatos sobre projeções baseadas em inteligência artificial no enfrentamento da pandemia de COVID-19 no estado do Pará / Boletín COVID-PA: informes de proyecciones basadas en inteligencia artificial para enfrentar la pandemia COVID-19 en el estado de Pará, Brasil / COVID-PA Bulletin: reports on artificial intelligence-based forecasting in coping with COVID-19 pandemic in the state of Pará, Brazil

Objetivo: Relatar o produto de pesquisa e extensão universitária denominado Boletim COVID-PA, que apresentou projeções sobre o comportamento da pandemia no estado do Pará, Brasil. Métodos: Utilizou-se da técnica de inteligência artificial conhecida como 'redes neurais artificiais', para geração de 13 boletins com projeções de curto prazo baseadas nos dados históricos do sistema da Secretaria de Estado de Saúde Pública. Resultados: Após oito meses de projeções, a técnica gerou resultados confiáveis, com precisão média de 97% (147 dias observados) para casos confirmados, 96% (161 dias observados) para óbitos e 86% (72 dias observados) para ocupação de leitos de unidade de terapia intensiva. Conclusão: Esses boletins tornaram-se um instrumento útil para a tomada de decisão de gestores públicos, auxiliando na realocação de recursos hospitalares e otimização das estratégias de controle da COVID-19 nas diversas regiões do estado do Pará.

Objetivo: Reporte el resultado de la investigación y extensión universitaria denominada 'Boletim COVID-PA' que presentó proyecciones sobre el comportamiento de la pandemia en el estado de Pará, con un enfoque práctico y computacionalmente eficiente. Métodos: Fue utilizada una técnica de inteligencia artificial denominadas Redes Neurales para generar trece boletines con proyecciones basado en datos históricos del sistema de la Secretaría de Salud Pública. Resultados: Después de ocho meses de previsiones, la técnica genero resultados confiables con una precisión promedio de 97% (147 días observados) para casos confirmados, 96% (161 días observados) para los fallecimientos y 86% (72 días observados) para la ocupación de camas en las unidades de cuidados intensivos. Conclusión: Estos boletines se convirtieron en una herramienta para la toma de decisiones, auxiliando en la redistribución de recursos en los hospitales en el estado de Pará.

Objective: To report the university extension research result entitled 'The COVID-PA Bulletin', which presented forecasts on the behavior of the pandemic in the state of Pará, Brazil. Methods: The artificial intelligence technique also known as 'artificial neural networks' was used to generate 13 bulletins with short-term forecasts based on historical data from the State Department of Public Health information system. Results: After eight months of predictions, the technique generated reliable results, with an average accuracy of 97% (observed for147 days) for confirmed cases, 96% (observed for 161 days) for deaths and 86% (observed for 72 days) for Intensive Care Unit bed occupancy. Conclusion: These bulletins have become a useful decision-making tool for public managers, assisting in the reallocation of hospital resources and optimization of COVID-19 control strategies in various regions of the state of Pará.

Pathogenesis of HTLV-1 infection and progression biomarkers: An overview

ABSTRACT Infection by human T-cell lymphotropic virus type 1 (HTLV-1) occurs in lymphocytes, which travel throughout the body, thus affecting several target organs and causing varied clinical outcomes, particularly in populations that are underserved and do not have access to healthcare. However, the mechanism of pathogenesis is not yet fully understood. The TAX and HTLV-1 basic leucine zipper factor (HBZ) proteins maintain viral persistence and affect pathogenesis through cell proliferation and immune and inflammatory responses that accompany each clinical manifestation. TAX expression leads to inhibition of transcription error control, OX40 overexpression, and cell proliferation in adult T-cell leukemia (ATL). OX40 levels are elevated in the central nervous system (CNS), and the expression of TAX in the CNS causes neuronal damage and loss of immune reactivity among patients with HTLV-1-associated myelopathy (HAM). HBZ reduces viral replication and suppresses the immune response. Its cell compartmentalization has been associated with the pathogenesis of HAM (cytoplasmic localization) and ATL (nuclear localization). TAX and HBZ seem to act antagonistically in immune responses, affecting the pathogenesis of HTLV-1 infection. The progression from HTLV-1 infection to disease is a consequence of HTLV-1 replication in CD4+ T and CD8+ T lymphocytes and the imbalance between proinflammatory and anti-inflammatory cytokines. The compartmentalization of HBZ suggests that this protein may be an additional tool for assessing immune and inflammatory responses, in addition to those already recognized as potential biomarkers associated with progression from infection to disease (including human leukocyte antigen (HLA), killer immunoglobulin-like receptors (KIR), interleukin (IL)-6, IL-10, IL-28, Fas, Fas ligand, interferon (IFN)-γ, tumor necrosis factor (TNF)-α, and mannose-binding lectin).

Influence of exposure and vertical transmission of HIV-1 on the neuropsychomotor development in children

Abstract INTRODUCTION: Exposure to human immunodeficiency virus (HIV)-1 during pregnancy is a major risk factor for neurodevelopmental delay and deleterious effects in children. However, limited information about these conditions exists in poor geographical areas in Brazil. Prevention of vertical transmission of HIV-1 is dealt differently in different regions of the country and in poorer areas it is more difficult to evaluate the impact of the prevention methods. The outcomes of the exposure to HIV-1 and the impact of vertical HIV-1 transmission on neuropsychomotor development was evaluated for the first time in children born to HIV-infected mothers in the North region of Brazil, where the majority of the population has poor access to health services. METHODS: Sixty children born to HIV-1-infected mothers (case group) and 58 born to non-infected mothers (control group) were followed for the first 12 months of life in a prospective case-control study. Neuropsychomotor development was assessed using the Denver II test. RESULTS: Suspected neuropsychomotor developmental delays were more frequent in the case group (33.3%), namely in language (38.9%) and gross motor skills (27.8%). These delays were reversed in most children after 12 months of life due to therapeutic intervention. The delays were not reversed in three children, all of whom belonged to the case group. Only one of these was infected with HIV-1, and this child had the poorest neuropsychomotor outcomes. CONCLUSIONS: Maternal HIV-1 infection negatively affected the neuropsychomotor development in children, although other factors may have played a role.

Association of serum levels of C-reactive protein with CRP-717 T/C polymorphism and viremia in HCV and HBV carriers

Abstract INTRODUCTION: The present study investigated the association of the rs2794521 polymorphism in the CRP gene in individuals with chronic hepatitis B and C, correlating it with markers of hepatic inflammation, fibrosis scores, viral load, and plasma protein levels. METHODS: The study analyzed 185 blood samples obtained from patients with hepatitis B (n=74) and hepatitis C (n=111) and 300 samples from healthy donors. Genotyping was performed by real-time polymerase chain reaction, and protein levels were quantified using the automated immunoturbidimetric method. RESULTS: The TT genotype was the most frequent in all studied groups and was associated with higher plasma levels of the protein but not with the progression of liver disease. Low levels of C-reactive protein were associated with increased viremia and scores indicative of severe fibrosis and cirrhosis. CONCLUSIONS: The present results demonstrated a close relationship between the ability of the virus to replicate and cause liver damage and low serum concentrations of C-reactive protein. Future research may determine if these results can be interpreted as a possible form of escape for the virus by decreasing its action as an opsonin and decreasing phagocytosis, which are functions of C-reactive protein in the immune response.

Assessment of the sensory and physical limitations imposed by leprosy in a Brazilian Amazon Population

Abstract INTRODUCTION Leprosy often results in sensory and physical limitations. This study aimed to evaluate these limitations using a quantitative approach in leprosy patients in Belém (Pará, Brazil). METHODS This epidemiological, cross-sectional study measured the sensory impairment of smell and taste through the use of a questionnaire and evaluated activity limitations of daily life imposed by leprosy through the Screening of Activity Limitation and Safety Awareness (SALSA) Scale. Data were collected from 84 patients and associations between the degree of disability and clinical and epidemiological characteristics were assessed. RESULTS The majority of patients were men (64.3%), married (52.4%), age 31-40 years old (26.2%), had primary education (50%), and were independent laborers (36.9%). The multibacillary operational classification (81%), borderline clinical form (57.1%), and 0 degrees of physical disability (41.7%) were predominant. SALSA scores ranged from 17 to 59 points, and being without limitations was predominant (53.6%). The risk awareness score ranged from 0 to 8, with a score of 0 (no awareness of risk) being the most common (56%). Evaluation of smell and taste sensory sensitivities revealed that 70.2% did not experience these sensory changes. Patients with leprosy reactions were 7 times more likely to develop activity limitations, and those who had physical disabilities were approximately four times more likely to develop a clinical picture of activity limitations. CONCLUSIONS Most patients showed no sensory changes, but patients with leprosy reactions were significantly more likely to develop activity limitations. Finally, further studies should be performed, assessing a higher number of patients to confirm the present results.

JC virus/human immunodeficiency virus 1 co-infection in the Brazilian Amazonian region

Abstract JC virus (JCV) is a member of the Polyomaviridae family and is associated to a severe disease known as progressive multifocal leukoencephalopathy, PML, which is gradually increasing in incidence as an opportunistic infection among AIDS patients. The present study aimed to investigate the occurrence of JCV among HIV-1 carriers including their types and molecular subtypes and the possible association with disease. Urine samples from 66 HIV-1 infected subjects were investigated for the presence of the virus by amplifying VP1 (215 bp) and IG (610 bp) regions using the polymerase chain reaction. JCV was detected in 32% of the samples. The results confirmed the occurrence of type B (subtype Af2); in addition, another polyomavirus, BKV, was also detected in 1.5% of samples of the HIV-1 infected subjects. Apparently, there was no significant difference between mono- (HIV-1 only) and co-infected (HIV-1/JCV) subjects regarding their TCD4+/TCD8+ lymphocyte counts or HIV-1 plasma viral load. Self admitted seizures, hearing and visual loses were not significantly different between the two groups.

Toll-like receptor 3 gene polymorphisms are not associated with the risk of hepatitis B and hepatitis C virus infection

INTRODUCTION: The present study investigated the prevalence of two single-nucleotide polymorphisms (SNPs) in the Toll-like receptor 3 (TLR3) gene in patients infected with hepatitis B virus (HBV) and hepatitis C virus (HCV). METHODS: Samples collected from HCV (n = 74) and HBV (n = 35) carriers were subjected to quantitative real-time PCR (qPCR) to detect the presence of the SNPs rs5743305 and rs3775291 in TLR3 and to measure the following biomarkers: alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyl transpeptidase (GGT), and prothrombin time (PT). A healthy control group was investigated and consisted of 299 HCV- and HBV-seronegative individuals. RESULTS: No significant differences in allele, genotype and haplotype frequencies were observed between the investigated groups, and no association was observed between the polymorphisms and histopathological results. Nevertheless, genotypes TA/AA (rs5743305) and GG (rs3775291) appear to be associated with higher levels of ALT (p<0.01), AST (p<0.05) and PT (p<0.05). In addition, genotypes TT (rs5743305; p<0.05) and GG (rs3775291; p<0.05) were associated with higher GGT levels. CONCLUSIONS: This genetic analysis revealed the absence of an association between the polymorphisms investigated and susceptibility to HBV and HCV infection; however, these polymorphisms might be associated with a greater degree of biliary damage during the course of HCV infection. .

Chlamydia trachomatis serotype A infections in the Amazon region of Brazil: prevalence, entry and dissemination

INTRODUCTION: Chlamydia infection is associated with debilitating human diseases including trachoma, pneumonia, coronary heart disease and urogenital diseases. Serotypes of C. trachomatis show a fair correlation with the group of diseases they cause, and their distribution follows a well-described geographic pattern. Serotype A, a trachoma-associated strain, is known for its limited dissemination in the Middle East and Northern Africa. However, knowledge on the spread of bacteria from the genus Chlamydia as well as the distribution of serotypes in Brazil is quite limited. METHODS: Blood samples of 1,710 individuals from ten human population groups in the Amazon region of Brazil were examined for antibodies to Chlamydia using indirect immunofluorescence and microimmunofluorescence assays. RESULTS: The prevalence of antibodies to Chlamydia ranged from 23.9% (Wayana-Apalai) to 90.7% (Awa-Guaja) with a mean prevalence of 50.2%. Seroreactivity was detected to C. pneumoniae and to all serotypes of C. trachomatis tested; furthermore, we report clear evidence of the as-yet-undescribed occurrence of serotype A of C. trachomatis. CONCLUSIONS: Specific seroreactivity not only accounts for the large extent of dissemination of C. trachomatis in the Amazon region of Brazil but also shows an expanded area of occurrence of serotype A outside the epidemiological settings previously described. Furthermore, these data suggest possible routes of Chlamydia introduction into the Amazon region from the massive human migration that occurred during the 1,700s. .

Lack of evidence for human infection with Xenotropic murine leukemia virus-related virus in the Brazilian Amazon basin

Introduction This study confirmed the absence of natural infection with Xenotropic murine leukemia virus-related virus (XMRV) or XMRV-related disease in human populations of the Brazilian Amazon basin. We demonstrated that 803 individuals of both sexes, who were residents of Belem in the Brazilian State of Pará, were not infected with XMRV. Methods Individuals were divided into 4 subgroups: healthy individuals, individuals infected with human immunodeficiency virus, type 1 (HIV-1), individuals infected with human T-lymphotrophic virus, types 1 or 2 (HTLV-1/2), and individuals with prostate cancer. XMRV infection was investigated by nested PCR to detect the viral gag gene and by quantitative PCR to detect pol. Results There was no amplification of either gag or pol segments from XRMV in any of the samples examined. Conclusions This study supports the conclusions of the studies that eventually led to the retraction of the original study reporting the association between XMRV and human diseases. .

JC polyomavirus infection in candidates for kidney transplantation living in the Brazilian Amazon Region

This study evaluated the relative occurrences of BK virus (BKV) and JC virus (JCV) infections in patients with chronic kidney disease (CKD). Urine samples were analysed from CKD patients and from 99 patients without CKD as a control. A total of 100 urine samples were analysed from the experimental (CKD patients) group and 99 from the control group. Following DNA extraction, polymerase chain reaction (PCR) was used to amplify a 173 bp region of the gene encoding the T antigen of the BKV and JCV. JCV and BKV infections were differentiated based on the enzymatic digestion of the amplified products using BamHI endonuclease. The results indicated that none of the patients in either group was infected with the BKV, whereas 11.1% (11/99) of the control group subjects and 4% (4/100) of the kidney patients were infected with the JCV. High levels of urea in the excreted urine, low urinary cellularity, reduced bladder washout and a delay in analysing the samples may have contributed to the low prevalence of infection. The results indicate that there is a need to increase the sensitivity of assays used to detect viruses in patients with CDK, especially given that polyomavirus infections, especially BKV, can lead to a loss of kidney function following transplantation.

Lanfrediella amphicirrus gen. nov. sp. nov. Nematotaeniidae (Cestoda: Cyclophyllidea), a tapeworm parasite of Rhinella marina (Linnaeus, 1758) (Amphibia: Bufonidae)

The family Nematotaeniidae, tapeworms commonly found in the small intestines of amphibians and reptiles, includes 27 recognised species distributed among four genera: Bitegmen Jones, Cylindrotaenia Jewell, Distoichometra Dickey and Nematotaenia Lühe. The taxonomy of these cestodes is poorly defined, due in part to the difficulties of observing many anatomical traits. This study presents and describes a new genus and species of nematotaeniid parasite found in cane toads (Rhinella marina) from eastern Brazilian Amazonia. The cestodes were collected during the necropsy of 20 hosts captured in the urban area of Belém, Pará. The specimens were fixed and processed for light microscopy, scanning electron microscopy (SEM) and three-dimensional (3D) reconstruction. Samples were also collected for molecular analyses. The specimens presented a cylindrical body, two testes and paruterine organs. However, they could not be allocated to any of the four existing nematotaeniid genera due to the presence of two each of dorsal compact medullary testes, cirri, cirrus pouches, genital pores, ovaries and vitelline glands per mature segment. Lanfrediella amphicirrus gen. nov. sp. nov. is the first nematotaeniid studied using Historesin analysis, SEM and 3D reconstruction, and it is the second taxon for which molecular data have been deposited in GenBank.

Characterization of mannose-binding lectin plasma levels and genetic polymorphisms in HIV-1-infected individuals / Caracterização dos polimorfismos genéticos e dos níveis plasmáticos da lectina ligante de manose em indivíduos infectados pelo HIV-1

INTRODUCTION: The present study investigated the association between mannose-binding lectin (MBL) gene polymorphism and serum levels with infection by HIV-1. METHODS: Blood samples (5mL) were collected from 97 HIV-1-infected individuals resident in Belém, State of Pará, Brazil, who attended the Special Outpatient Unit for Infections and Parasitic Diseases (URE-DIPE). CD4+ T-lymphocyte count and plasma viral load were quantified. A 349bp fragment of exon 1 of the MBL was amplified via PCR, using genomic DNA extracted from controls and HIV-1-infected individuals, following established protocols. MBL plasma levels of the patients were quantified using an enzyme immunoassay kit. RESULTS: Two alleles were observed: MBL*O, with a frequency of 26.3 percent in HIV-1-infected individuals; and the wild allele MBL*A (73.7 percent). Similar frequencies were observed in the control group (p > 0.05). Genotype frequencies were distributed according to the Hardy-Weinberg equilibrium in both groups. Mean MBL plasma levels varied by genotype, with statistically significant differences between the AA and AO (p < 0.0001), and AA and OO (p < 0.001) genotypes, but not AO and OO (p = 0.17). Additionally, CD4+ T-lymphocytes and plasma viral load levels did not differ significantly by genotype (p > 0.05). CONCLUSIONS: The results of this study do not support the hypothesis that MBL gene polymorphism or low plasma MBL concentrations might have a direct influence on HIV-1 infection, although a broader study involving a large number of patients is needed.

INTRODUÇÃO: O presente estudo investigou a associação entre o polimorfismo no gene da lectina ligante de manose (MBL) e os níveis séricos da proteína com a infecção pelo HIV-1. MÉTODOS: As amostras de sangue (5mL) foram coletadas de 97 indivíduos infectados pelo HIV-1 residentes em Belém, Estado do Pará, Brasil, que frequentavam a Unidade de Referência Especial para Doenças Infecciosas e Parasitárias Especiais (URE-DIPE). Os níveis de linfócitos T CD4+ e da carga viral plasmática foram quantificados. Um fragmento de 349pb do exon 1 da MBL foi amplificado via PCR, utilizando DNA genômico extraído das amostras controles e dos indivíduos portadores do HIV-1, seguindo protocolos previamente estabelecidos. O nível plasmático de MBL nos pacientes foi quantificado usando kit de ensaio imunoenzimático. RESULTADOS: Dois alelos foram observados - MBL*O, com uma frequência de 26,3 por cento em indivíduos infectados e o alelo selvagem MBL*A (73,7 por cento). Frequências similares foram observadas no grupo controle (p > 0,05). As frequências genotípicas estavam em equilíbrio de Hardy-Weinberg em ambos os grupos. A média dos níveis plasmáticos MBL variou por genótipo, com diferenças significativas entre os genótipos AA e AO (p < 0,0001), e AA e OO (p < 0,001), mas não entre AO e OO (p=0,17). Além disso, os linfócitos T CD4+ e os níveis plasmáticos de carga viral não diferiram significativamente de acordo com o genótipo (p>0,05). CONCLUSÕES: Os resultados deste estudo não apoiam a hipótese de que o polimorfismo no gene MBL ou baixa concentração plasmática de MBL poderia ter uma influência direta sobre a infecção pelo HIV-1, embora um estudo com número maior de pacientes seja necessário.

Caracterização molecular do HTLV-1/2 em doadores de sangue em Belém, Estado do Pará: primeira descrição do subtipo HTLV-2b na região Amazônica / Molecular characterization of HTLV-1/2 among blood donors in Belém, State of Pará: first description of HTLV-2b subtype in the Amazon region

Este trabalho objetivou a caracterização molecular do vírus linfotrópico de células T humanas infectando doadores de sangue atendidos na Fundação Centro de Hemoterapia e Hematologia do Pará. Amostras de DNA de 79 indivíduos soropositivos para o vírus linfotrópico de células T humanas foram analisadas por meio da reação em cadeia da polimerase para as regiões genômicas pX, env e 5'LTR, de polimorfismos de comprimento de fragmentos de restrição e do seqüenciamento da região 5LTR, com posterior análise filogenética, definindo o tipo e o subtipo do HTLV circulante na população estudada. Observou-se uma maior prevalência de HTLV-1 (71 por cento) em relação ao HTLV-2 (29 por cento). As amostras de HTLV-1 sequenciadas foram classificadas como pertencentes ao subtipo Cosmopolita, subgrupo Transcontinental, sendo as de HTLV-2 identificadas como HTLV-2c. A análise de polimorfismos de comprimento de fragmentos de restrição da região env e do sequenciamento da região 5'LTR, identificou, pela primeira vez na Amazônia Brasileira, uma amostra de HTLV-2b, enfatizando a necessidade de estudos moleculares contínuos na região para melhor entendimento da epidemiologia de transmissão do HTLV na população e permitir a vigilância epidemiológica da emergência de novos tipos e subtipos.

This study aimed to perform molecular characterization on the human T-cell lymphotropic virus (HTLV) infecting blood donors attended at the Hematology and Hemotherapy Center-Foundation of Pará. DNA samples from 79 HTLV-seropositive individuals were analyzed by means of the polymerase chain reaction on the pX, env and 5'LTR genomic regions; restriction fragment length polymorphism analysis; and sequencing of the 5'LTR region with subsequent phylogenetic analysis. From this, the HTLV types and subtypes circulating in the study population were defined. There was higher prevalence of HTLV-1 (71 percent) than of HTLV-2 (29 percent). HTLV-1 samples were classified as belonging to the Cosmopolitan subtype, Transcontinental subgroup; and the HTLV-2 samples as HTLV-2c. Analysis on the restriction fragment length polymorphisms of the env region and sequencing of the 5'LTR region identified a sample of HTLV-2b, for the first time in the Brazilian Amazon region. This emphasizes the need for ongoing molecular studies in this region, in order to have better understanding of the epidemiology of HTLV transmission in the population, and to enable epidemiological surveillance of the emergence of new types and subtypes.

Frequencies of CCR5-D32, CCR2-64I and SDF1-3A mutations in Human Immunodeficiency Virus (HIV) seropositive subjects and seronegative individuals from the state of Pará in Brazilian Amazonia

The distribution of genetic polymorphisms of chemokine receptors CCR5-D32, CCR2-64I and chemokine (SDF1-3A) mutations were studied in 110 Human Immunodeficiency Virus type 1 (HIV-1) seropositive individuals (seropositive group) and 139 seronegative individuals (seronegative group) from the population of the northern Brazilian city of Belém which is the capital of the state of Pará in the Brazilian Amazon. The CCR5-D32 mutation was found in the two groups at similar frequencies, i.e. 2.2% for the seronegative group and 2.7% for the seropositive group. The frequencies of the SDF1-3A mutation were 21.0% for the seronegative group and 15.4% for the seropositive group, and the CCR2-64I allele was found at frequencies of 12.5% for the seronegative group and 5.4% for the seropositive group. Genotype distributions were consistent with Hardy-Weinberg expectations in both groups, suggesting that none of the three mutations has a detectable selective effect. Difference in the allelic and genotypic frequencies was statistically significant for the CCR2 locus, the frequency in the seronegative group being twice that found in the seropositive group. This finding may indicate a protective effect of the CCR2-64I mutation in relation to HIV transmission. However, considering that the CCR2-64I mutation has been more strongly associated with a decreased risk for progression for AIDS than to the resistance to the HIV infection, this could reflect an aspect of population structure or a Type I error

Epidemiological aspects of retrovirus (HTLV) infection among Indian populations in the Amazon Region of Brazil

HTLV was initially described in association with a form of leukemia in Japan and a neurological disease in the Caribbean. It was soon shown that HTLV-II was endemic among Amerindians and particularly among Brazilian Indians. The Amazon Region of Brazil is presently the largest endemic area for this virus and has allowed several studies concerning virus biology, the search for overt disease, epidemiological data including detailed demographic data on infected individuals, clear-cut geographic distribution, definition of modes of transmission and maintenance within small, epidemiologically-closed groups, and advances in laboratory diagnosis of the infection. A new molecular subtype named HTLV-IIc was further described on the basis of genome sequencing and phylogenetic analysis. This subtype is present in other areas of Brazil, indicating that the virus is additionally both a valuable marker for tracing past human migration routes in the Americas and a probable marker for social habits of the present human population. HIV, the other human retrovirus, is still not prevalent among indigenous communities in the Brazilian Amazon, but these groups are also easy targets for the virus

Allele frequency distributions of six hypervariable loci (D1S80, APOB, D4S43, vW1, F13A and DYS19) in two African-Brazilian communities from the Amazon region

The allele frequency distributions of three VNTR (D1S80, APOB and D4S43) and three STR (vW1, F13A1 and DYS19) loci were investigated in two Afro-Brazilian populations from the Amazon: Curiau and Pacoval. Exact tests for population differentiation revealed significant differences in allele frequency between populations only for the D1S80 and APOB loci. A statistically significant deviation from the Hardy-Weinberg equilibrium was observed only in the D1S80 locus of the Pacoval sample. A neighbor-joining tree was constructed based on DA genetic distances of allele frequencies in four Afro-Brazilian populations from the Amazon (Pacoval, Curiau, Trombetas, and Cametá), along with those from Congo, Cameroon, Brazilian Amerindians, and Europeans. This analysis revealed the usefulness of these Amp-FLPs for population studies - African and African-derived populations were closely grouped, and clearly separated from Amerindians and Europeans. Estimates of admixture components based on the gene identity method revealed the prevalence of the African component in both populations studied, amounting to 51 percent in Pacoval, and to 43 percent in Curiau. The Amerindian component was also important in both populations (37 percent in Pacoval, and 24 percent in Curiau). The European component reached 33 percent in Curiau

Genetical-demographic data from two amazonian populations composed of descendants of african slaves: Pacoval and Curiau

The Amazon region of Brazil includes communities founded by escaped slaves, some of which still remain relatively isolated. We studied two such Afro-Brazilian communities (Pacoval and Curiau), in the rural area of Alenquer, Pará, and in the metropolitan region of Macapá, Amapá, respectively. Among 12 blood loci, alleles considered as markers of African ancestry, such as HBB*S, HBB*C, TF*D1, HP*2M, ABO*B, RH*D-, and CA2*2 were found at frequencies that are expected for populations with a predominantly African origin. Estimates of interethnic admixture indicated that the degree of the African component in Curiau (74 per cent) is higher than that of Pacoval (44 per cent); an Amerindian contribution was not detected in Curiau. Estimated values of African ancestry fit well with the degree of isolation and mobility of the communities. Pacoval exhibited a high proportion of immigrants among the parents and grandparents of the individuals studied, whereas persons living in Curiau exhibited a low level of mobility, despite its location in the metropolitan area of Macapá city, suggesting a relatively strong barrier against the interethnic admixture in this population. In addition, analysis of genetic data in a sub-sample consisting of individuals whose parents and grandparents were born in the study site, and that probably represents the populations two generations ago, indicated that gene flow from non-black people is not a recent event in both populations.