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BACKGROUND: Syphilis remains a significant global public health issue, and female sex workers (FSWs) are highly vulnerable to the etiological agent of this disease. This study aimed to describe the prevalence of exposure to Treponema pallidum, as well as the vulnerability factors among FSWs in the state of Pará, Brazilian Amazon. METHODS: A cross-sectional, retrospective study involving 360 FSWs from five cities in Pará was conducted from 2005 to 2007. Blood samples were collected for treponemal and non-treponemal testing, and epidemiological information was obtained through interviews. RESULTS: The exposure rate to T. pallidum was 37.7% (136/360), and the majority of FSWs had serological results indicating past exposure (21.1%). Among the FSWs exposed to T. pallidum, most of them were single, aged 23 to 42 years old, had less than 8 years of schooling, and had a family income of between 1 and 3 minimum wages. They reported using condoms during sexual intercourse and had no history of sexually transmitted infection (STI). Furthermore, many of the FSWs exposed to T. pallidum reported having more than 20 sexual partners per month, and had partners from other Brazilian states, but not from other countries. An age over 42 years and a reduced level of education were factors associated with exposure to T. pallidum. Finally, a high rate of exposure to T. pallidum among FSWs in the Brazilian state of Pará (from 2005 to 2007) was detected. In later years, epidemiological studies conducted with FSWs recorded that this rate remained high. Measures to control, treat, and prevent syphilis among FSWs were necessary between 2005 and 2007, and they are still imperative today. Actions related to educational programs and STI control, treatment, and prevention measures contained in Brazilian policies aimed at women's health have not changed the vulnerability scenario of FSWs regarding their exposure to T. pallidum, even after 16 years, and must be reviewed and adapted to the conditions of the Brazilian Amazon.
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BACKGROUND: Syphilis is a chronic infectious disease, and its prevalence has been described since the 15th century. Because of the high prevalence of this infection in Brazil, this study aimed to evaluate the prevalence of syphilis and its associated factors among adolescent and young women living in the city of Boa Vista, Roraima, Brazil. METHODS: The present study was cross-sectional, descriptive, analytical and quantitative. It involved 200 young and adolescent women. Laboratory tests were performed to diagnose syphilis, and a sociodemographic and epidemiological questionnaire was employed. RESULTS: In the studied sample, 10 women had a positive result for syphilis, characterizing a prevalence of 5% for infection with Treponema pallidum. There was a statistically significant association between a monthly family income of less than 1 minimum wage and syphilis (p = 0.0449) and between illicit drug use and syphilis (p = 0.0234). CONCLUSIONS: These results indicate the need for public health interventions, action plans, and the implementation of risk reduction strategies focused on this population.
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People living with HIV (PLWH) continue to face stigma and discrimination during dental treatment in Brazil. This study aimed to describe the sociodemographic, educational and professional characteristics of dentists working in the Northern Brazilian region and to identify the level of knowledge of these health professionals in relation to the care and management of PLWH using a digital form. METHODS: This cross-sectional study was population-based among dentists and was conducted between July and December 2021. A total of 396 dentists were invited using the "snowball" sampling technique and received an anonymous digital form (Google® Forms platform) composed of four blocks of dichotomous and multiple-choice questions. After signing the informed consent form, dentists were divided into seven groups according to the amount of time that had passed (in years) since they had completed their bachelor's degree in dentistry. A total of 25 questions referring to sociodemographic, educational and professional factors and knowledge about the dental care of PLWH were asked, and all data were presented as descriptive percentages and then analyzed using the Kappa test. RESULTS: The average age was 31.9 years, and the states of Pará and Amazonas presented better knowledge about the dental care of PLWH. Dental prostheses (62/381-16.3%), orthodontics (57/381-15%) and periodontics (56/381-14.7%) were the most cited dental specialties, and demographic, professional and epidemiological characteristics showed a statistically significant difference regarding knowledge (<0.0001). CONCLUSIONS: The knowledge of dentists in Northern Brazil is partially high, although there is some lack of knowledge about the dental care of PLWH.
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Infecciones por VIH , Conocimientos, Actitudes y Práctica en Salud , Humanos , Adulto , Brasil/epidemiología , Estudios Transversales , Odontólogos , Encuestas y Cuestionarios , Infecciones por VIH/epidemiología , Infecciones por VIH/terapiaRESUMEN
Introduction: Human T-lymphotropic virus 2 (HTLV-2) has been described for more than 30 years as an endemic infection in Brazilian indigenous populations, with its occurrence varying by age and sex, maintained mainly by sexual intercourse and mother-to-child transmission, favoring intrafamilial aggregation. Methods: The epidemiological scenario of HTLV-2 infection has been described among communities of the Amazon region of Brazil (ARB), with the number of retrospective positive blood samples increasing for more than 50 years. Results: Five publications were selected that showed the presence of HTLV-2 in 24 of 41 communities; the prevalence of infection was described among 5,429 individuals at five points in time. Among the Kayapó villages, the prevalence rates were described according to age and sex and reached up to 41.2%. Three communities (Asurini, Araweté, and Kaapor) were kept virus free for 27 to 38 years of surveillance. Low, medium and high prevalence levels of infection were defined, and two pockets of high endemicity were shown in the state of Pará, pointing to the Kikretum and Kubenkokrê Kayapó villages as the epicenter of HTLV-2 in the ARB. Discussion: The prevalence rates over the years have shown a decline among the Kayapó (from 37.8 to 18.4%) and an apparent change to a higher prevalence among females, but not during the first decade of life, usually associated with transmission from mother to child. Sociocultural and behavioral aspects, as well as public health policies directed toward sexually transmitted infections, might have positively influenced the decline in HTLV-2 infections.
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BACKGROUND: The COVID-19 pandemic has had a great impact on pregnant women due to the broad clinical spectrum of the disease. The present study investigated the profile of three biomarkers during hospital admission of pregnant women-D-dimer, C-reactive protein (CRP), and ferritin-and their correlation with the severity and outcome of COVID-19. METHODS: The cross-sectional study included 226 pregnant women hospitalized in the city of Belém, Pará, Northern Brazil, from April 2020 to July 2021. Epidemiological and laboratory data were obtained from medical records, and all pregnant women underwent RT-PCR molecular testing for the detection of SARS-CoV-2. RESULTS: In total, 121 (53.5%) were positive and 105 (46.5%) were negative for SARS-CoV-2 using RT-PCR. Most pregnant women (49.5%) with COVID-19 were between 26 and 34 years old, were residing in the interior of the state of Pará (51.2%), and were in the third gestational trimester (71.9%). In addition, 71.1% of them were admitted to the ward and 28.9% were admitted to the intensive care unit (ICU), with 90.9% surviving COVID-19. The concentrations of D-dimer (p = 0.0122) and ferritin (p ≤ 0.0001) were significantly higher among pregnant women with COVID-19, especially among those hospitalized in the ICU. CONCLUSION: Ferritin and D-dimer seem to serve as important biomarkers for the prognosis of COVID-19 in pregnant women, which was not observed for CRP.
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COVID-19 , Humanos , Femenino , Embarazo , Adulto , COVID-19/diagnóstico , COVID-19/epidemiología , Mujeres Embarazadas , Proteína C-Reactiva/análisis , SARS-CoV-2 , Estudios Transversales , Ferritinas , Pandemias , Brasil/epidemiología , Biomarcadores , Estudios RetrospectivosRESUMEN
BACKGROUND: The gubernacular canal (GC) is an important dental structure that enables the alveolar bone ridge cohesion of permanent teeth, although GC absence may indicate a dental eruption that might be associated with certain syndromes such as Down's syndrome. This study aims to correlate the eruptive delay of permanent teeth in individuals with Down's syndrome (Ds) and the gubernacular canal (GC) through cone-beam computed tomography (CBCT). METHODS AND RESULTS: This cross-sectional study was conducted between January and July 2022 with a total of 31 individuals (G1 = 16 nonsyndromic and G2 = 15 Down's syndrome) who went through imaging evaluation using CBCT with the following acquisition parameters: tube voltage of 95 kVp, tube current of 7 mA, exposure time of 5.9 s and voxel sizes and field of view 0.15 mm and 0.30 mm, respectively. The imaging evaluation was to assess whether all teeth analyzed had the presence of GC and/or teeth eruption disturbance, with a descriptive statistical analysis of relative frequencies and quantitative variables as well as the p-value (p < 0.005) by G Test. RESULTS: A total of 618 teeth among 31 individuals were analyzed, 475 (76.8%) GC were detected by CBCT in 23/31 patients and of these, 6 belonged to G2. G2 had a decreased GC detection rate (n = 180-37.9%) and the most common tooth with GC detected was the mandibular 1st molar (21 GC/25 teeth-84%) and the absence of GC was most frequently observed in impacted and delayed/unerupted teeth of Ds individuals. CONCLUSION: We concluded that GC absence was higher among Ds individuals, explaining the increased rates of unerupted or impacted teeth in Ds individuals.
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CCR5Δ32 and SDF1-3'A polymorphisms were investigated in a cohort of viremia controllers, without the use of therapy, along with their influence on CD4+ T lymphocytes (TLs), CD8+ TLs, and plasma viral load (VL). The samples were analyzed from 32 HIV-1-infected individuals classified as viremia controllers 1 and 2 and viremia non-controllers, from both sexes, mostly heterosexuals, paired with 300 individuals from a control group. CCR5∆32 polymorphism was identified by PCR amplification of a fragment of 189 bp for the wild-type allele and 157 bp for the allele with the ∆32 deletion. SDF1-3'A polymorphism was identified by PCR, followed by enzymatic digestion (restriction fragment length polymorphism) with the Msp I enzyme. The relative quantification of gene expression was performed by real-time PCR. The distribution of allele and genotype frequencies did not show significant differences between the groups. The gene expression of CCR5 and SDF1 was not different between the profiles of AIDS progression. There was no significant correlation between the progression markers (CD4+ TL/CD8+ TL and VL) and the CCR5∆32 polymorphism carrier status. The 3'A allele variant was associated with a marked loss of CD4+ TLs and a higher plasma VL. Neither CCR5∆32 nor SDF1-3'A was associated with viremia control or the controlling phenotype.
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Síndrome de Inmunodeficiencia Adquirida , Quimiocina CXCL12 , Infecciones por VIH , Receptores CCR5 , Femenino , Humanos , Masculino , Síndrome de Inmunodeficiencia Adquirida/genética , Biomarcadores , Brasil , Quimiocina CXCL12/genética , Progresión de la Enfermedad , Frecuencia de los Genes , VIH-1 , Receptores CCR5/genética , ViremiaRESUMEN
Background: Throughout recent years, periodontal disease (PD) has been linked to innumerable medical systemic conditions, such as cardiovascular disease (CVD). This association could negatively impact oral health, so the knowledge of dentists who have graduated must follow modern dentistry in order to promote oral health, mainly in systemically compromised patients. Therefore, the present study aimed to determine and evaluate the knowledge level of dentistry undergraduate students (DUS) regarding the correct periodontal treatment and management of cardiac patients with PD. Methods: This cross-sectional and populational-based study was conducted between March and June 2022 in northern Brazil. A total of 153 DUS received an anonymous digital form (Google Forms Platform) using a non-probabilistic "snowball" sampling technique. The digital form was composed of four blocks of dichotomous and multiple-choice questions. After signing the informed consent term, DUS were divided into three groups according to their period/semester in dentistry graduation during the study time (G1: 1st period/semester; G2: 5th period/semester and G3: 10th period/semester). A total of 25 questions referring to demographic, educational and knowledge data about the dental and periodontal care of cardiac patients with PD were asked, and all data were presented as descriptive percentages and then analyzed using the Kappa test. Results: From a total of 153 (100%) DUS, the sample was mostly composed of 104 (68%) female participants, with an average age of 21.1 years. Regarding basic knowledge, the majority of answers were no, with G1 being higher than G2 and G3. Regarding clinical questions, 1247 (58.3%) answers were no. Additionally, regarding fundamental clinical questions 1, 2, 3, 7, 9, 11, 13 and 14, the majority of G1, G2 and G3 answered no, demonstrating a major lack of knowledge. Conclusions: In our study, DUS demonstrated a low knowledge level of the dental and periodontal care of cardiac patients with PD and its bi-directional link. Thus, according to our results, an improvement in dentistry educational programs regarding periodontal medicine must be implemented.
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Enfermedades Cardiovasculares , Enfermedades Periodontales , Humanos , Femenino , Adulto Joven , Adulto , Masculino , Enfermedades Cardiovasculares/complicaciones , Estudios Transversales , Enfermedades Periodontales/complicaciones , Enfermedades Periodontales/terapia , Estudiantes , OdontologíaRESUMEN
Hepatitis C virus (HCV) infection is an important public health problem, especially in areas with a low human development index such as the Amazon region. This study aimed to identify the prevalence and genotypes of HCV among people living with HIV (PLWH), both neglected chronic diseases in the Amazon region. From March 2016 to June 2017, 433 PWLH were attended to at two sexually transmitted infection referral centers in the city of Belém, in the Brazilian state of Pará in the Amazon region. All individuals were submitted to testing via the rapid immunochromatographic assay (RIA) for the qualitative detection of anti-HCV antibodies. Samples with anti-HCV antibodies were evaluated by reverse transcriptase polymerase chain reaction (RT-PCR), and samples with HCV RNA were subjected to nucleotide sequencing and phylogenetic analysis. Three (0.7%) PLWH had anti-HCV antibodies, and only one (0.2%) had HCV RNA (genotype 2); of these, 31 (7.1%) self-declared to have used drugs at least one time, and 12 (2.7%) regularly use injected drugs. One participant was elderly, single, heterosexual, with a history of unprotected sex and multiple sexual partners. This study detected a low prevalence of HCV infection and recorded the presence of HCV genotype 2 for the first time among PLWH in the Brazilian Amazon.
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We investigated an unusual report of localized necrotizing periodontitis coinfection in patients with mild COVID-19. Male patient, 30 years old, with previous medical history of hypovitaminosis, immunized with two doses of the Pfizer® vacci ne, attended in a dental college in northern Brazil with an acute dental emergency reporting itching, halitosis, intense gingival p ain and spontaneous bleeding, mild fever of 37.8ºC, dry cough, muscle pain and nausea. Metronidazole and chlorhexidine were prescribed to improve the necrotizing condition, to treat periodontitis scaling and root planing (SRP) were performed associated with chlo rhexidine irrigation and oral hygiene instructions, which treated the patients conditions. COVID-19 coinfections are possible, specially, oral bacterial infections which is demonstrated in this report, so correct treatment is necessary for both infections. This letter d escribes the first known occurrence of severe localized necrotizing periodontitis in the urban area of Brazil's Amazon region.
Investigamos un reporte inusual de coinfección de periodontitis necrotizante localizada en pacientes con COVID-19 con síntomas leves: Paciente masculino, de 30 años, con antecedentes médicos de hipovitaminosis, inmunizado con dos dosis de la vacuna Pfizer®, atendido en una facultad de odontología en el norte Brasil, con urgencia dental aguda reportando prurito, halitosis, dolor gingival intenso y sangrado espontáneo, fiebre leve de 37,8 ºC, tos seca, mialgias y náuseas. Se prescribió metronidazol y clorhexidina para mejorar el cuadro necrosante, para tratar la periodontitis se realizó raspado y alisado radicular (SRP) asociado a irrigación con clorhexidina e instrucciones de higiene oral. Las coinfecciones por COVID- 19 son posibles, especialmente las infecciones bacterianas orales, lo cual se demuestra en este reporte, por lo que es necesario un correcto tratamiento de ambas infecciones. Esta carta describe la primera aparición conocida de periodontitis necrotizante severa de un paciente del área urbana de la región amazónica de Brasil.
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Antiretroviral therapy (ART) improves the quality of life of people living with HIV-1 (PLHIV) and reduces the mortality rate, but some individuals may develop metabolic abnormalities. This study evaluated changes in the nutritional status and biochemistry of PLHIV on antiretroviral therapy in a cohort that had not previously received ART and to follow up these individuals for 24 months after starting treatment. The initial cohort consisted of 110 individuals and ended with 42 people, assessed by a physical examination. A biochemical assay was performed using the colorimetric enzyme reaction technique, the proviral load was detected by qPCR and the quantification of the CD4/CD8 T lymphocytes was conducted by flow cytometry. PLHIV had increased levels of total cholesterol, LDL, triglycerides, ALT, urea and creatinine after 24 months of ART use (p < 0.05). In the assessment of the nutritional status, PLHIV had increased measures of Triciptal Skinfold, body mass index and arm circumference after the use of ART (p < 0.05). The viral load levels decreased and the CD4 levels increased after 24 months of ART use (p < 0.05). The change in the nutritional status in PLHIV on antiretroviral therapy seems to be a slow process, occurring in the long term, therefore, there is the need for a constant evaluation of these people to identify patients who need a nutritional intervention.
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Infecciones por VIH , Seropositividad para VIH , VIH-1 , Humanos , Calidad de Vida , Infecciones por VIH/tratamiento farmacológico , Carga ViralRESUMEN
Highly oncogenic human papillomavirus (HPV) is well known to be associated with and a risk factor for various types of oral carcinomas such as oral squamous cell carcinoma (OSCC). The aim of this study was to evaluate and describe the HPV-induced OSCC prevalence and genotyping in the city of Belém, northern Brazil. This cross-sectional study features 101 participants who attended an oral pathology referral center in a dental college looking for diagnoses of oral lesions (OL). After signing the consent term and meeting the inclusion criteria, all participants went through a sociodemographic and epidemiological questionnaire. Then, OL were collected by excisional or incisional biopsy depending on OL size; after that, OL tissues were preserved in paraffin blocks to histopathological diagnoses. Afterwards, paraffin blocks were divided into benign and malignant/premalignant lesions based on the classification of potentially malignant disorders of the oral and oropharyngeal mucosa. Then, the paraffin blocks had DNA extraction performed by the ReliaPrep FFPE gDNA Miniprep method in order to identify HPV DNA of high oncogenic risk and low oncogenic risk. Then, the viral DNA was amplified and typed using the Inno-Lipa genotyping Extra II method, and the collected data were analyzed by Chi-square and G-tests. In total, 59/101 (58.4%) OL were malignant/premalignant lesions, of which OSCC was the most prevalent with 40/59 (67.7%) and 42/101 (41.6%) benign lesions. The most common area of OL incidence was upper gingiva 46/101 (45.5%). Regarding HPV DNA detection, approximately 27/101 (26.7%) had positive results; of these, 17/59 (28.8%) were malignant/premalignant lesions, and the most prevalent genotypes detected were 16, 18, 52 and 58, while among benign lesions, 10/42 (66.6%) had HPV-positive results, and the most prevalent genotypes detected were 6, 11 and 42. Age range was the only risk factor with a significant association between HPV and OSCC presence (p-value: 0.0004). A correlation between OSCC and oral HPV among analyzed samples could not be demonstrated in our small cohort.
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Chlamydia trachomatis is one of the most prevalent sexually transmitted bacteria worldwide and may increase the risk of other sexually transmitted infections (STIs) including the human immunodeficiency virus (HIV). This study describes the seroprevalence of C. trachomatis infection among antiretroviral-naïve patients who are newly diagnosed with HIV in the city of Belém, Pará, in the Amazon region of Brazil. A cross-sectional study was carried out between January 2018 and January 2019 in 141 people living with HIV/AIDS (PLHA) who were followed up in a specialized unit of the public health network of Pará. The investigation of IgG antibodies against C. trachomatis was performed by enzyme immunoassay. Sociodemographic and sexual behavior information were obtained through a questionnaire. The prevalence of IgG anti-C. trachomatis antibodies was 64.8% (92/141). The majority of individuals were young, heterosexual, single men who did not use condoms during sexual intercourse and had no history of STIs. No significant differences were found when comparing any clinical or demographic data between groups. Our results demonstrated a high rate of exposure to C. trachomatis in newly diagnosed HIV-infected individuals in the Amazon region of Brazil, and all PLHA should be screened for C. trachomatis to decrease transmission of the bacteria and prevent the clinical manifestations of chronic infection.
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BACKGROUND: Human papillomavirus (HPV) is the most common viral sexually transmitted infection of the reproductive tract, and cervical cancer is the most common HPV-related disease. This study estimated the prevalence, diversity of HPV genotypes, and associated risk factors in women screened for cervical cancer in northern Brazil. METHODS: The cross-sectional study was conducted in Belém, Pará, in the Amazon region of Brazil, and it included 162 women who were spontaneously undergoing a Pap-smear routine. Epidemiological, sexual, and health-related information was collected by interviews, and cervical samples were collected for cytological examination and HPV-DNA detection. HPV genotypes were classified as low risk (LR) and high risk (HR) by nucleotide sequencing. RESULTS: In total, 17.3% (28/162) of the participants had HPV-DNA, and LR-HPV was the most prevalent (71.4%). Among the 13 different types of HPV detected, HPV-11 was found most frequently (12/28; 42.9%), followed by HPV-31 (3/28; 10.7%). Of the participants with cytological alterations, HPV infection was detected in only four: two were diagnosed with low-grade squamous intraepithelial lesions (15.4%), one with atypical squamous cells of undetermined significance (7.7%), and one with atypical squamous cells, cannot exclude high-grade squamous intraepithelial lesions (7.7%). Of the 61 women who presented a normal cytology, 13 (21.3%) had positive tests for HPV infection, 4 (8.2%) of which were positive for a high-risk genotype. CONCLUSION: The prevalence of HPV was high in Belém, Pará, and especially in women who had normal cytology results, which suggests the need for greater screening for HPV infection in women's primary health care.
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Background: Chlamydia trachomatis infection is a major public health problem and the most common sexually transmitted infection in the world. Although highly prevalent, 70% to 80% of cases are asymptomatic and undiagnosed. Purpose: To overcome some limitations in terms of rapid diagnosis, phage display technology was used to bioprospect peptide mimetics of C. trachomatis immunoreactive and immunogenic antigens to be selected for the production of synthetic peptides. Methods: Initially, IgG from 22 individuals with C. trachomatis and 30 negative controls was coupled to G protein magnetic beads. The phage display technique consisted of biopanning, genetic sequencing, bioinformatics analysis and phage ELISA. Results: Clones G1, H5, C6 and H7 were selected for testing with individual samples positive and negative for C. trachomatis. Reactions were statistically significant (p < 0.05), with a sensitivity of 90.91, a specificity of 54.55, and AUC values >0.8. One-dimensional analysis with C. trachomatis components indicated that the G1 clone aligned with cell wall-associated hydrolase domain-containing protein, the H5 clone aligned with glycerol-3-phosphate acyltransferase PlsX protein, the C6 clone aligned with a transposase and inactivated derivatives, and the H7 clone aligned with GTP-binding protein. Molecular modeling and three-dimensional analysis indicated the best fit of the four clones with a protein known as chlamydial protease/proteasome-like activity factor (CPAF), an important virulence factor of the bacterium. Conclusion: The peptides produced by phage display are related to the metabolic pathways of C. trachomatis, indicating that they can be used to understand the pathogenesis of the infection. Because of their high sensitivity and AUC values, the peptides present considerable potential for use in platforms for screening C. trachomatis infections.
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The human T-lymphotropic virus 1 (HTLV-1) and 2 (HTLV-2) can be transmitted between humans by mechanisms associated with horizontal and vertical routes. Recently, high prevalence rates and levels of genetic diversity for HTLV-1 and HTLV-2 were detected among people who use illicit drugs (PWUDs) in the Brazilian state of Pará. None of the PWUDs with HTLV-1 or HTLV-2 were aware of their carrier condition of the retrovirus, and they ability to spread it to their family group, sexual partners, and other contacts. Thus, this study evaluated the presence of HTLV-1 and HTLV-2 in families of PWUDs in the state of Pará, in Northern Brazil. This descriptive study used convenience sampling and accessed 37 PWUDs and their respective families (n = 97) in 18 municipalities in the state of Pará, northern Brazil. All participants provided personal data and were tested for the presence of HTLV-1 and HTLV-2 using enzyme-linked immunosorbent assay and western blotting. HTLV positive samples were selected for Nested-PCR, and viral genotyping by nucleotide sequencing and phylogenetic analysis. HTLV-1 or HTLV-2 infections were detected in 15 families of PWUDs: 27 family members of PWUDs were infected with HTLV-1 (27.8%) and another 20 of them with HTLV-2 (20.6%). Subtypes 1a [subgroup A (54.5%)], 2b (20.5%), and 2c (25.0%) were detected. High horizontal (76.9%) and vertical (61.4%) transmission rates of HTLV were ascertained. Factors that facilitate the acquisition and transmission of HTLV-1 and HTLV-2 were reported by the participants, such as long-term relationships, unprotected sex, breastfeeding, and lack of knowledge about the condition of being a carrier of the retrovirus. Evidence indicates intrafamilial transmission of HTLV from PWUDs to members of their respective families. Key interventions should urgently be employed for the control and prevention of HTLV-1 and HTLV-2 to reduce the spread of this retrovirus in PWUDs and the general population in Northern Brazil and elsewhere.
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Human T-lymphotropic virus 1 (HTLV-1) is endemic worldwide and the infection results in severe diseases, including Adult T-cell Leukemia (ATL) and HTLV-1 associated myelopathy (HAM). There are some limitations of employing the present commercial serological assays for both diagnostic and epidemiological purposes in different geographical areas of the Brazil, such as the Amazon Region. Currently, methods for diagnosis are usually expensive to adapt for routine use. The aim of this work was to identify and characterize specific ligands to IgG that mimic HTLV-1 epitopes through the Phage Display technique, which could be used for diagnosis and as future vaccine candidates. Initially, IgG from 10 patients with HTLV-1 and 20 negative controls were covalently coupled to protein G-magnetic beads. After biopanning, genetic sequencing, bioinformatics analysis and Phage-ELISA were performed. The technique allowed the identification of 4 clones with HTLV-1 mimetic peptides, three aligned with gp46, A6 (SPYW), B6 (SQLP) and D7 (PLIL), and one with the protease and Tax, A8 (SPPR). Clones A6 and B6 showed higher values of accessibility, antigenicity and hydrophilicity. The reactivity of the clones evaluated by the Receiver Operating Characteristic (ROC) curve showed that the B6 clone had the highest Area Under Curve (0.83) and sensitivity and specificity values (both were 77.27 %; p < 0.001). The study showed that the Phage Display technique is effective for the identification of HTLV-1-related peptides. Clone B6 indicated to be a good marker for bioprospecting diagnostic test for HTLV-1 infection and could be used as a possible vaccine candidate for future studies.