Microsatellite allele sequencing in population analyses of the South American cactophilic species Drosophila antonietae (Diptera: Drosophilidae)

Drosophila antonietae belongs to the Drosophila buzzatii cluster, a cactophilic group of species naturally endemic to South America. Morphological and genetic analyses indicate that its populations are the most homogenous in the cluster and that the diversity observed is mainly a result of variation within populations. Seven polymorphic microsatellite loci were described for this species and used in the present study to investigate the genetic diversity of natural populations of D. antonietae by both length and sequence variation. The study aimed to understand how homoplasy and null alleles affect inferences about the population history of this species and to obtain an accurate interpretation of population inferences where these loci could be applied. The results provide useful information on the interpretation of genetic data derived from the microsatellite loci described for D. antonietae and on evolutionary aspects of cactophilic Drosophila. Importantly, the results indicate that size homoplasy and null alleles do not represent significant problems for the population genetics analyses because the large amount of variability at microsatellite loci compensate the low frequency of these problems in the populations. (C) 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 100, 573-584.

Effectiveness of the CAGE questionnaire, gamma-glutamyltransferase and mean corpuscular volume of red blood cells as markers for alcohol-related problems in the workplace

Objective: To evaluate the usefulness of gamma-glutamyltransferase (GGT) and mean corpuscular volume (MCV), as well as that of the CAGE questionnaire, in workplace screening for alcohol abuse/dependence. Methods: A total of 183 male employees were submitted to structured interviews (Structured Clinical Interview for DSM-IV 2.0 and CAGE questionnaire). Blood samples were collected. Diagnostic accuracy and odds ratio were determined for the CAGE, GGT and MCV. Results: The CAGE questionnaire presented the best sensitivity for alcohol dependence (91%; specificity, 87.8%) and for alcohol abuse (87.5%, specificity, 80.9%), which increased when the questionnaire was used in combination with GGT (sensitivity, 100% and 87.5%, respectively; specificity, 68% and 61.5, respectively). CAGE positive results and/or alterations in GGT were less likely to occur among employees not presenting alcohol abuse/ dependence than among those presenting such abuse (OR for CAGE = 13, p < 0.05; OR for CAGE-GGT = 11, p < 0.05) or dependence (OR for CAGE = 76, p < 0.0 1; OR for GGT = 5, p < 0.0 1). Employees not presenting alcohol abuse/dependence were also several times more likely to present negative CAGE or GGT results. Conclusions: The use short, simple questionnaires, combined with that of low-cost biochemical markers, such as GGT, can serve as an initial screening for alcohol-related problems, especially for employees in hazardous occupations. The data provided can serve to corroborate clinical findings. (C) 2008 Elsevier Ltd. All rights reserved.

Subjective memory impairment in a rural population with low education in the Amazon rainforest: an exploratory study

Background: The high prevalence of subjective memory impairment (SMI) in the elderly living in developed countries may be partly dependent on greater demand placed on them by new technologies. As part of a comprehensive study on cognitive impairment in a population living in the Amazon rainforest, we evaluated the prevalence of SMI and investigated the features associated with it. Methods: We evaluated 163 subjects (82 females) with a mean age of 62.3 years (50-94 years), 110 of whom were illiterate, using the answer to a single question ""Do you have memory problems?"" to classify them into groups with or without SMI. The assessment involved application of the Mini-mental State Examination (MMSE), delayed recall from the Brief Cognitive Battery designed for the evaluation of low educated and illiterate individuals, the Patient Questionnaire (PQ) of the Primary Care Evaluation of Mental Disorders (PRIME-MD), and the Happiness Analogical Scale. Results: A very high prevalence of SMI (70%) was observed, exceeding rates reported by similar studies conducted in developed countries. SMI was more frequent in women, whereas age and education did not impact on prevalence. Subjects with SMI had significantly more somatic and psychiatric symptoms on the PQ, as well as lower means on the MMSE, but not on the delayed recall test. Multiple logistic regressions showed that the most important factor associated with the presence of SMI was a high score on the PQ (OR: 3.84, p = 0.011). Conclusion: Psychological and somatic symptoms may be the principal cause of SMI in this population.

Risk of Potential Drug-Drug Interactions among Brazilian Elderly A Population-Based, Cross-Sectional Study

Background: Drug-drug interactions (DDIs) are one of the main causes of adverse reactions related to medications, being responsible for up to 23% of hospital admissions. However, only a few studies have evaluated this problem in elderly Brazilians. Objectives: To determine the prevalence of potential DDIs (PDDIs) in community-dwelling elderly people in Brazil, analyse these interactions with regard to severity and clinical implications, and identify associated factors. Methods: A population-based cross-sectional study was carried out involving 2143 elderly (aged 60 years) residents of the metropolitan area of Sao Paulo, Brazil. Data were obtained from the SABE (Saude, Bem estar e Envelhecimento [Health, Well-Being, and Aging]) survey, which is a multicentre study carried out in seven countries of Latin America and the Caribbean, coordinated by the Pan-American Health Organization. PDDIs were analysed using a computerized program and categorized according to level of severity, onset, mechanism and documentation in the literature. The STATA software statistical package was used for data analysis, and logistic regression was conducted to determine whether variables were associated with PDDIs. Results: Analysis revealed that 568 (26.5%) of the elderly population included in the study were taking medications that could lead to a DDI. Almost two-thirds (64.4%) of the elderly population exposed to PDDIs were women, 50.7% were aged >= 75 years, 71.7% reported having fair or poor health and 65.8% took 2-5 medications. A total of 125 different PDDIs were identified; the treatment combination of an ACE inhibitor with a thiazide or loop diuretic (associated with hypotension) was the most frequent cause of PDDIs (n=322 patients; 56.7% of individuals with PDDIs). Analysis of the PDDIs revealed that 70.4% were of moderate severity, 64.8% were supported by good quality evidence and 56.8% were considered of delayed onset. The multivariate analysis showed that the risk of a PDDI was significantly increased among elderly individuals using six or more medications (odds ratio [OR] 3.37) and in patients with hypertension (OR 2.56), diabetes mellitus (OR 1.73) or heart problems (OR 3.36). Conclusions: Approximately one-quarter of the elderly population living in Sao Paulo could be taking two or more potentially interacting medicines. Polypharmacy predisposes elderly individuals to PDDIs. More than half of these drug combinations (57.6%, n = 72) were part of commonly employed treatment regimens and may be responsible for adverse reactions that compromise the safety of elderly individuals, especially at home. Educational initiatives are needed to avoid unnecessary risks.

The impact of perinatal and socioeconomic factors on mental health problems of children from a poor Brazilian city: a longitudinal study

Low birth weight and preterm birth, and social disadvantage may negatively affect mental health of children, but findings have been inconsistent. To assess the influence of perinatal and social factors on mental health problems in children aged 7-9 years. A random sample of 805 births in So Luis, Brazil was studied in 1997/1998 and again in 2005/2006. Perinatal, socioeconomic and demographic variables were assessed within 24 h after delivery. The Strengths and Difficulties Questionnaire (SDQ) was used to assess mental health problems in the children. Simple and multiple Poisson regressions were used for statistical analysis. The overall prevalence of mental health problems in the total sample was 47.7%. The prevalences of emotional and conduct problems were 58.2 and 48.8%, respectively. Only paternal age (< 20 years) was associated with mental health problems as measured by the full SDQ scale (prevalence ratio PR = 1.27). Children born to single mothers (PR = 1.31) and those with birth weight from 1,500 to 2,499 g (PR = 1.18) and from 2,500 to 2,999 g (PR = 1.17) had a higher risk of emotional problems, but those from low income families had a lower risk (PR = 0.80). Children with a father of less than 20 years had a higher risk of having problems with their peers (PR = 1.75). A maternal education of 9 years or over was inversely associated with peer (PR = 0.70) and conduct problems (PR = 0.73). Girls had a lower risk of conduct (PR = 0.77) and hyperactivity problems (PR = 0.68). A maternal education of 4 years or less increased the risk of hyperactivity (PR = 1.48). Socioeconomic and demographic conditions were better predictors of mental health problems in children than birth weight or preterm birth. However, since most effect sizes were small most mental health problems were, unexplained by the variables in the study.

A new wavelet-based method for the solution of the population balance equation

A new wavelet-based method for solving population balance equations with simultaneous nucleation, growth and agglomeration is proposed, which uses wavelets to express the functions. The technique is very general, powerful and overcomes the crucial problems of numerical diffusion and stability that often characterize previous techniques in this area. It is also applicable to an arbitrary grid to control resolution and computational efficiency. The proposed technique has been tested for pure agglomeration, simultaneous nucleation and growth, and simultaneous growth and agglomeration. In all cases, the predicted and analytical particle size distributions are in excellent agreement. The presence of moving sharp fronts can be addressed without the prior investigation of the characteristics of the processes. (C) 2001 Published by Elsevier Science Ltd.

Tillering in grain sorghum over a wide range of population densities: Identification of a common hierarchy for tiller emergence, leaf area development and fertility

Most studies of tiller development have not related the physiological and morphological features of each calm to its subsequent fertility. This introduced problems when trying to account for the effects of tillering on yield in crop models. The objective of this study was to detect the most likely early determinants of tiller fertility in sorghum by identifying hierarchies for emergence, fertility and grain number of tillers over a wide range of assimilate availabilities. Emergence, phenology, leaf area development and dry weight partitioning were quantified weekly for individual tillers and main culms of tillering and uniculm plants grown at one of four densities, from two to 16 plants m(-2). For a given plant in any given density, the same tiller hierarchy applied for emergence of tillers, fertility of the emerged tillers and their subsequent grain number. These results were observed over a range of tiller fertility rates (from 7 to 91%), fertile tiller number per plant at maturity (from 0.2 to 4.7), and tiller contribution to grain yield (from 5 to 78%). Tiller emergence was most probably related to assimilate supply and light quality. Development, fertility and contribution to yield of a specific tiller were highly dependent on growing conditions at the time of tiller emergence, particularly via early leaf area development of the tiller, which affected its subsequent leaf area accumulation. Assimilate availability in the main culm at the time of tiller emergence was the most likely early determinant of subsequent tiller fertility in this study. (C) 2002 Annals of Botany Company.

Mortality problems in Brazil and in Germany: past-present-future. Learning from each other?

This article was written by a Swiss-German historical demographer after having visited different Brazilian Universities in 1984 as a guest-professor. It aims at promoting a real dialog between developed and developing countries, commencing the discussion with the question: Can we learn from each other? An affirmative answer is given, but not in the superficial manner in which the discussion partners simply want to give each other some "good advice" or in which the one declares his country's own development to be the solely valid standard. Three points are emphasized: 1. Using infant mortality in S. Paulo from 1908 to 1983 as an example, it is shown that Brazil has at its disposal excellent, highly varied research literature that is unjustifiably unknown to us (in Europe) for the most part. Brazil by no means needs our tutoring lessons as regards the causal relationships; rather, we could learn two things from Brazil about this. For one, it becomes clear that our almost exclusively medical-biological view is inappropriate for passing a judgment on the present-day problems in Brazil and that any conclusions so derived are thus only transferable to a limited extent. For another, we need to reinterpret the history of infant mortality in our own countries up to the past few decades in a much more encompassing "Brazilian" sense. 2. A fruitful dialog can only take place if both partners frankly present their problems. For this reason, the article refers with much emprasis to our present problems in dealing with death and dying - problems arising near the end of the demographic and epidemiologic transitions: the superanuation of the population, chronic-incurable illnesses as the main causes of death, the manifold dependencies of more and more elderly and really old people at the end of a long life. Brazil seems to be catching up to us in this and will be confronted with these problems sooner or later. A far-sighted discussion already at this time seems thus to be useful. 3. The article, however, does not want to conclude with the rather depressing state of affairs of problems alternatingly superseding each other. Despite the caution which definitely has a place when prognoses are being made on the basis of extrapolations from historical findings, the foreseeable development especially of the epidemiologic transition in the direction of a rectangular survival curve does nevertheless provide good reason for being rather optimistic towards the future: first in regards to the development in our own countries, but then - assuming that the present similar tendencies of development are stuck to - also in regard to Brazil.

Water quality issues in rivers, lakes and reservoirs in Asian countries: an approach to the problems and the methodologies

Water covers over 70% of the Earth's surface, and is vital for all known forms of life. But only 3% of the Earth's water is fresh water, and less than 0.3% of all freshwater is in rivers, lakes, reservoirs and the atmosphere. However, rivers and lakes are an important part of fresh surface water, amounting to about 89%. In this Master Thesis dissertation, the focus is on three types of water bodies – rivers, lakes and reservoirs, and their water quality issues in Asian countries. The surface water quality in a region is largely determined both by the natural processes such as climate or geographic conditions, and the anthropogenic influences such as industrial and agricultural activities or land use conversion. The quality of the water can be affected by pollutants discharge from a specific point through a sewer pipe and also by extensive drainage from agriculture/urban areas and within basin. Hence, water pollutant sources can be divided into two categories: Point source pollution and Non-point source (NPS) pollution. Seasonal variations in precipitation and surface run-off have a strong effect on river discharge and the concentration of pollutants in water bodies. For example, in the rainy season, heavy and persistent rain wash off the ground, the runoff flow increases and may contain various kinds of pollutants and, eventually, enters the water bodies. In some cases, especially in confined water bodies, the quality may be positive related with rainfall in the wet season, because this confined type of fresh water systems allows high dilution of pollutants, decreasing their possible impacts. During the dry season, the quality of water is largely related to industrialization and urbanization pollution. The aim of this study is to identify the most common water quality problems in Asian countries and to enumerate and analyze the methodologies used for assessment of water quality conditions of both rivers and confined water bodies (lakes and reservoirs). Based on the evaluation of a sample of 57 papers, dated between 2000 and 2012, it was found that over the past decade, the water quality of rivers, lakes, and reservoirs in developing countries is being degraded. Water pollution and destruction of aquatic ecosystems have caused massive damage to the functions and integrity of water resources. The most widespread NPS in Asian countries and those which have the greatest spatial impacts are urban runoff and agriculture. Locally, mine waste runoff and rice paddy are serious NPS problems. The most relevant point pollution sources are the effluents from factories, sewage treatment plant, and public or household facilities. It was found that the most used methodology was unquestionably the monitoring activity, used in 49 of analyzed studies, accounting for 86%. Sometimes, data from historical databases were used as well. It can be seen that taking samples from the water body and then carry on laboratory work (chemical analyses) is important because it can give an understanding of the water quality. 6 papers (11%) used a method that combined monitoring data and modeling. 6 papers (11%) just applied a model to estimate the quality of water. Modeling is a useful resource when there is limited budget since some models are of free download and use. In particular, several of used models come from the U.S.A, but they have their own purposes and features, meaning that a careful application of the models to other countries and a critical discussion of the results are crucial. 5 papers (9%) focus on a method combining monitoring data and statistical analysis. When there is a huge data matrix, the researchers need an efficient way of interpretation of the information which is provided by statistics. 3 papers (5%) used a method combining monitoring data, statistical analysis and modeling. These different methods are all valuable to evaluate the water quality. It was also found that the evaluation of water quality was made as well by using other types of sampling different than water itself, and they also provide useful information to understand the condition of the water body. These additional monitoring activities are: Air sampling, sediment sampling, phytoplankton sampling and aquatic animal tissues sampling. Despite considerable progress in developing and applying control regulations to point and NPS pollution, the pollution status of rivers, lakes, and reservoirs in Asian countries is not improving. In fact, this reflects the slow pace of investment in new infrastructure for pollution control and growing population pressures. Water laws or regulations and public involvement in enforcement can play a constructive and indispensable role in environmental protection. In the near future, in order to protect water from further contamination, rapid action is highly needed to control the various kinds of effluents in one region. Environmental remediation and treatment of industrial effluent and municipal wastewaters is essential. It is also important to prevent the direct input of agricultural and mine site runoff. Finally, stricter environmental regulation for water quality is required to support protection and management strategies. It would have been possible to get further information based in the 57 sample of papers. For instance, it would have been interesting to compare the level of concentrations of some pollutants in the diferente Asian countries. However the limit of three months duration for this study prevented further work to take place. In spite of this, the study objectives were achieved: the work provided an overview of the most relevant water quality problems in rivers, lakes and reservoirs in Asian countries, and also listed and analyzed the most common methodologies.

Lack of access and continuity of adult health care: a national population-based survey

OBJECTIVE To describe the lack of access and continuity of health care in adults.METHODS A cross-sectional population-based study was performed on a sample of 12,402 adults aged 20 to 59 years in urban areas of 100 municipalities of 23 states in the five Brazilian geopolitical regions. Barriers to the access and continuity of health care and were investigated based on receiving, needing and seeking health care (hospitalization and accident/emergency care in the last 12 months; care provided by a doctor, by other health professional or home care in the last three months). Based on the results obtained by the description of the sample, a projection is provided for adults living in Brazilian urban areas.RESULTS The highest prevalence of lack of access to health services and to provision of care by health professionals was for hospitalization (3.0%), whilst the lowest prevalence was for care provided by a doctor (1.1%). The lack of access to care provided by other health professionals was 2.0%; to accident and emergency services, 2.1%; and to home care, 2.9%. As for prevalences, the greatest absolute lack of access occurred in emergency care (more than 360,000 adults). The main reasons were structural and organizational problems, such as unavailability of hospital beds, of health professionals, of appointments for the type of care needed and charges made for care.CONCLUSIONS The universal right to health care in Brazil has not yet been achieved. These projections can help health care management in scaling the efforts needed to overcome this problem, such as expanding the infrastructure of health services and the workforce.

Population health diagnosis with an ecohealth approach

OBJECTIVE To analyze the characteristics of health diagnosis according to the ecohealth approach in rural and urban communities in Mexico.METHODS Health diagnosis were conducted in La Nopalera, from December 2007 to October 2008, and in Atlihuayan, from December 2010 to October 2011. The research was based on three principles of the ecohealth approach: transdisciplinarity, community participation, gender and equity. To collect information, a joint methodology and several techniques were used to stimulate the participation of inhabitants. The diagnostic exercise was carried out in five phases that went from collecting information to prioritization of problems.RESULTS The constitution of the transdisciplinary team, as well as the participation of the population and the principle of gender/equity were differentials between the communities. In the rural community, the active participation of inhabitants and authorities was achieved and the principles of transdisciplinarity and gender/equity were incorporated.CONCLUSIONS With all the difficulties that entails the boost in participation, the incorporation of gender/equity and transdisciplinarity in health diagnosis allowed a holistic public health approach closer to the needs of the population.

Performances of HTLV serological tests in diagnosing HTLV infection in high-risk population of São Paulo, Brazil

Testing problems in diagnosing human T-lymphotropic virus (HTLV) infection, mostly HTLV-II, have been documented in HIV/AIDS patients. Since December 1998, the Immunology Department of Instituto Adolfo Lutz (IAL) offers HTLV-I/II serology to Public Health Units that attend HTLV high-risk individuals. Two thousand, three hundred and twelve serum samples: 1,393 from AIDS Reference Centers (Group I), and 919 from HTLV out-patient clinics (Group II) were sent to IAL for HTLV-I/II antibodies detection. The majority of them were screened by two enzyme immunoassays (EIAs), and confirmed by Western Blot (WB 2.4, Genelabs). Seven different EIA kits were employed during the period, and according to WB results, the best performance was obtained by EIAs that contain HTLV-I and HTLV-II viral lysates and rgp21 as antigens. Neither 1st and 2nd, nor 3rd generation EIA kits were 100% sensitive in detecting truly HTLV-I/II reactive samples. HTLV-I and HTLV-II prevalence rates of 3.3% and 2.5% were detected in Group I, and of 9.6% and 3.6% in Group II, respectively. High percentages of HTLV-seroindeterminate WB sera were detected in both Groups. The algorithm testing to be employed in HTLV high-risk population from São Paulo, Brazil, needs the use of two EIA kits of different formats and compounds as screening, and because of high seroindeterminate WB, may be another confirmatory assay.

Structural change in the ruhr region: problems, potentials and developments

Due to the decline of the heavy industries in the Ruhr region, the area has to reinvent itself. The orientation towards service industries proves to be a difficult task for the district and its population. This paper examines the challenges, problems and potentials of the Ruhr region against the backdrop of its economical history out of a sociological perspective. Thereby the economical situation and its outcome towards the population stand in the foreground of the paper.

Development of population-specific function assessment intrument in Lebanon

RESUMO: Contexto: O funcionamento tem sido reconhecido como um dos principais indicadores de resultados para avaliar se as pessoas beneficiam das intervenções destinadas a melhorar a sua saúde mental. O funcionamento refere-se à forma como um indivíduo consegue responder às suas tarefas e solicitações, dos seus familiares e da sua comunidade, de acordo com os requisitos do local e a cultura em que vive (eg, tarefa de cozinhar e limpar para as mulheres em algumas culturas ). O funcionamento é altamente dependente da cultura - por isso, tem sido recomendado o desenvolvimento de medidas de funcionamento específicas de cada cultura. Desenvolver localmente os instrumentos de medida evita problemas de adequação, associados com a adaptação de instrumentos ocidentais. Embora os instrumentos criados desta forma sejam específicos de um meio cultural, eles são simultaneamente "transculturais", no sentido em que cada um se refere às tarefas mais importantes para a população local . Esta abordagem mostrou-se útil para investigadores e agências de ajuda (eg, ONGs) que trabalham em países não-ocidentais . Este estudo descreve o trabalho da agência International Medical Corps (IMC) na criação e validação de um questionário de funcionamento específico nas dimensões cultura e gênero, no Líbano, destinado a avaliar eventuais melhorias em pessoas que receberam intervenções de para problemas de saúde mental, a nível dos cuidados primários de saúde. Método: O instrumento foi desenvolvido usando um método que é uma alternativa à abordagem existente de adaptação de instrumentos ocidentais a outras culturas e situações; esta abordagem é rápida e exequível, tendo já demonstrado ser útil no desenvolvimento de instrumentos válidos e fidedignos. Inicialmente, foi solicitado que as pessoas identificassem, de uma lista livre, as tarefas mais importantes para cuidar de si próprias, da sua família e da sua comunidade; as tarefas identificadas foram posteriormente usadas como base para um instrumento de avaliação de funcionamento culturalmente válido. A partir daqui, foram desenvolvidos questionários específicos da comunidade em questão, posteriormente testados no terreno nas vertentes da validade (de conteúdo, facial e de constructo) e da fiabilidade (teste-reste e inter-entrevistadores). Resultados. O estudo resultou na criação e validação de um questionário de funcionamento específico de cultura e gênero capaz de medir efectivamente a capacidade de execução de tarefas importantes do quotidiano,como parte da avaliação de resultados levada a cabo por profissionais da CSP previamente treinados na identificação, suporte e encaminhamento de pessoas com problemas de saúde mental no Líbano. Conclusão. Neste trabalho descreve-se o desenvolvimento de um questionário de funcionamento específico de cultura e gênero, orientado para a avaliação de resultados, num contexto mais lato de um sistema abrangente de avaliação e monitorização de um serviço comunitário. --------------ABSTRACT: Background. Functioning has been recognized as one of the most important key outcomes to assess whether people benefit from interventions aimed to improve their mental health. Functioning refers to how well na individual can complete the tasks and demands for themselves, their family, and their community which are required by them depending on the setting and the culture they live in (e.g. task of cooking and cleaning for women in some cultures). Functioning is highly dependent on culture. Therefore, it has been recommended to develop culture-specific measures of function. Developing instruments locally avoids the problems of limited local relevance and appropriateness associate with adapting western instruments. Although each instrument created in this way is culturally bound, they are “cross cultural” in the sense that each refers to the tasks most important to local people. This approach proves useful for both researchers and aid agencies working in non-western countries. This study describes International Medical Corps’ (IMC) work in Lebanon to create and validate a culture and gender specific functioning questionnaire to assess improvements in people who received treatment interventions for mental health problems at the primary health care (PHC) level. Method. The measure was developed using a method that is an alternative to the existing approach of adapting western function instruments to other cultures and situations; an approach which has been demonstrated as rapid, feasible and which can yield valid and reliable instruments. Function was assessed by first asking local people what tasks are important to care for themselves, their family and their community using free listing, then using these tasks as the basis for a culturally valid function assessment instrument. Community specific function questionnaires based on these tasks were then created, and field-tested for validity using content, face and construct validity methods, and also field tested for reliability using inter-rater and test retest reliability methods. Results. The study resulted in the creation and validation of a culture and gender specific functioning questionnaire that would effectively measure the ability to do tasks important to daily existence, as part of assessing client level outcomes where PHC providers were trained in the identification, management and referral of people with mental health problems in Lebanon. Conclusion. The paper describes a successful pilot for developing culture and gender specific functioning questionnaires that evaluate client level outcomes as part of a more comprehensive system for monitoring and evaluation of community based case management supports and services.

Molecular epidemiology of hepatitis B virus among the indigenous population of the Curuçá and Itaquaí Rivers, Javari Valley, State of Amazonas, Brazil

INTRODUCTION: Hepatitis B virus (HBV) infection is one of the most serious public health problems in the world. In Brazil, HBV endemicity is heterogeneous, with the highest disease prevalence in the North region. METHODS: A total of 180 samples were analyzed and subjected to polymerase chain reaction (PCR) and semi-nested PCR of the HBV S-gene, with the aim of determining the prevalence of HBV-DNA (deoxyribonucleic acid) in indigenous groups inhabiting the areas near the Curuçá and Itaquaí Rivers in the Javari Valley, State of Amazonas, Brazil. RESULTS: The prevalence of the HBV-DNA S-gene was 51.1% (92/180). The analysis found 18 of 49 (36.7%) samples from the Marubo tribe, 68 of 125 (54.4%) from the Kanamary, and 6 of 6 (100%) from other ethnic groups to be PCR positive. There was no statistically significant difference in gender at 5% (p=0.889). Indigenous people with positive PCR for HBV-DNA had a lower median age (p<0.001) of 23 years. There was no statistical difference found in relation to sources of contamination or clinical aspects with the PCR results, except for fever (p<0.001). The high prevalence of HBV-DNA of 75% (15/20) in pregnant women (p=0.009) demonstrates an association with vertical transmission. CONCLUSIONS: The results confirm the high prevalence of HBV-DNA in the Javari Valley, making it important to devise strategies for control and more effective prevention in combating the spread of HBV.