Occlusal Loading Effect on Stress Distribution of Endodontically Treated Teeth: Finite Element Analysis Study

AIM

Evaluate the influence of occlusal loading on the stress distribution of endodontically treated teeth after root canal preparation with different file's sizes and tapers by means of finite element analysis.

METHODOLOGY

Seven three-dimensional models of a single-rooted, single-canal lower second premolar were established, one healthy control and six endodontically treated and restored models. The shape of root canal preparations followed file configurations 30/.05, 30/.09, 35/.04, 35/.06, 40/.04, and 40/.06. Von- Mises equivalent stresses were calculated by applying 30 N, 90 N and 270 N loads to the buccal cusp tip, each one at 90º, 45º and 20º angles from the occlusal plane simulating occlusion, dental interference and laterality, respectively.

RESULTS

45º loading was more prone to formation of higher stress values. The simulation of occlusion and laterality resulted in maximum stress areas located at the inner side of the root curvature, while under occlusal interference they were on the lingual surface over the tooth's long axis.

CONCLUSIONS

The angulation of occlusal loading and magnitude were determinants for stress distribution on dental structure. Both variations of size and taper were not determinants for the increase in the maximum stress areas.

The Xavante Longitudinal Health Study in Brazil: Objectives, design, and key results

OBJECTIVE

The Xavante Longitudinal Health Study was developed to permit granular tracking of contemporary health challenges faced by indigenous communities in Brazil, taking into consideration ongoing historical processes that may be associated with increases in child undernutrition, adult obesity, and cardiovascular disease risks.

METHODS

This was an open-cohort study with six semiannual data collection waves from 2009 to 2012. The study was undertaken in two Xavante villages, Pimentel Barbosa and Etênhiritipá, State of Mato Grosso, Central Brazil. No sampling technique was used. Data collection placed emphasis on growth and nutrition of children under five and nutrition status, blood pressure, and blood glucose levels of adolescents and adults.

RESULTS

Baseline data collection began in July/August 2009 with a population census (656 individuals). Between the first and final waves, the study population increased by 17%. At baseline, stunting and wasting was elevated for most age groups <10 years. Overweight, obesity, and increased risk of metabolic complications were expressive among individuals >17 years, disproportionately affecting females. Anemia was elevated in most age groups, especially among females. Mean systolic and diastolic blood pressure was moderate. The overall prevalence of high blood pressure was relatively low.

CONCLUSIONS

Our findings reveal marked health disparities relative to the Brazilian national population and a complex dietary health epidemiology involving the double burden of malnutrition, rapidly changing nutritional indicators, and elevated metabolic disease risk. The topically broad multidisciplinary focus permitted construction of the richest longitudinal data set of socio-epidemiological information for an indigenous population in Brazil.

Context-dependence of race self-classification: Results from a highly mixed and unequal middle-income country

Ethnic-racial classification criteria are widely recognized to vary according to historical, cultural and political contexts. In Brazil, the strong influence of individual socio-economic factors on race/colour self-classification is well known. With the expansion of genomic technologies, the use of genomic ancestry has been suggested as a substitute for classification procedures such as self-declaring race, as if they represented the same concept. We investigated the association between genomic ancestry, the racial composition of census tracts and individual socioeconomic factors and self-declared race/colour in a cohort of 15,105 Brazilians. Results show that the probability of self-declaring as black or brown increases according to the proportion of African ancestry and varies widely among cities. In Porto Alegre, where most of the population is white, with every 10% increase in the proportion of African ancestry, the odds of self-declaring as black increased 14 times (95%CI 6.08-32.81). In Salvador, where most of the population is black or brown, that increase was of 3.98 times (95%CI 2.96-5.35). The racial composition of the area of residence was also associated with the probability of self-declaring as black or brown. Every 10% increase in the proportion of black and brown inhabitants in the residential census tract increased the odds of self-declaring as black by 1.33 times (95%CI 1.24-1.42). Ancestry alone does not explain self-declared race/colour. An emphasis on multiple situational contexts (both individual and collective) provides a more comprehensive framework for the study of the predictors of self-declared race/colour, a highly relevant construct in many different scenarios, such as public policy, sociology and medicine.

Sleep quality and duration are associated with performance in maximal incremental test

BACKGROUND AND OBJECTIVE

Inadequate sleep patterns may be considered a trigger to development of several metabolic diseases. Additionally, sleep deprivation and poor sleep quality can negatively impact performance in exercise training. However, the impact of sleep duration and sleep quality on performance during incremental maximal test performed by healthy men is unclear. Therefore, the purpose of the study was to analyze the association between sleep pattern (duration and quality) and performance during maximal incremental test in healthy male individuals.

METHODS

A total of 28 healthy males volunteered to take part in the study. Sleep quality, sleep duration and physical activity were subjectively assessed by questionnaires. Sleep pattern was classified by sleep duration (>7h or <7h of sleep per night) and sleep quality according to the sum of measured points and/or scores by the Pittsburgh Sleep Quality Index (PSQI). Incremental exercise test was performed at 35 watts for untrained subjects, 70 watts for physically active subjects and 105 watts for well-trained subjects.

RESULTS

HR_max was correlated with sleep quality (r=0.411, p=0.030) and sleep duration (r=-0.430, p=0.022). Participants reporting good sleep quality presented higher values of W_max, VO_2max and lower values of HR_max when compared to participants with altered sleep. Regarding sleep duration, only W_max was influenced by the amount of sleeping hours per night and this association remained significant even after adjustment by VO_2max.

CONCLUSION

Sleep duration and quality are associated, at least in part, with performance during maximal incremental test among healthy men, with losses in W_max and HR_max. In addition, our results suggest that the relationship between sleep patterns and performance, mainly in W_max, is independent of fitness condition.

Indigenous and tribal peoples' health (The Lancet-Lowitja Institute Global Collaboration): a population study

BACKGROUND

International studies of the health of Indigenous and tribal peoples provide important public health insights. Reliable data are required for the development of policy and health services. Previous studies document poorer outcomes for Indigenous peoples compared with benchmark populations, but have been restricted in their coverage of countries or the range of health indicators. Our objective is to describe the health and social status of Indigenous and tribal peoples relative to benchmark populations from a sample of countries.

METHODS

Collaborators with expertise in Indigenous health data systems were identified for each country. Data were obtained for population, life expectancy at birth, infant mortality, low and high birthweight, maternal mortality, nutritional status, educational attainment, and economic status. Data sources consisted of governmental data, data from non-governmental organisations such as UNICEF, and other research. Absolute and relative differences were calculated.

FINDINGS

Our data (23 countries, 28 populations) provide evidence of poorer health and social outcomes for Indigenous peoples than for non-Indigenous populations. However, this is not uniformly the case, and the size of the rate difference varies. We document poorer outcomes for Indigenous populations for: life expectancy at birth for 16 of 18 populations with a difference greater than 1 year in 15 populations; infant mortality rate for 18 of 19 populations with a rate difference greater than one per 1000 livebirths in 16 populations; maternal mortality in ten populations; low birthweight with the rate difference greater than 2% in three populations; high birthweight with the rate difference greater than 2% in one population; child malnutrition for ten of 16 populations with a difference greater than 10% in five populations; child obesity for eight of 12 populations with a difference greater than 5% in four populations; adult obesity for seven of 13 populations with a difference greater than 10% in four populations; educational attainment for 26 of 27 populations with a difference greater than 1% in 24 populations; and economic status for 15 of 18 populations with a difference greater than 1% in 14 populations.

INTERPRETATION

We systematically collated data across a broader sample of countries and indicators than done in previous studies. Taking into account the UN Sustainable Development Goals, we recommend that national governments develop targeted policy responses to Indigenous health, improving access to health services, and Indigenous data within national surveillance systems.

FUNDING

The Lowitja Institute.

Indigenous and tribal peoples' health (The Lancet-Lowitja Institute Global Collaboration): a population study

BACKGROUND

International studies of the health of Indigenous and tribal peoples provide important public health insights. Reliable data are required for the development of policy and health services. Previous studies document poorer outcomes for Indigenous peoples compared with benchmark populations, but have been restricted in their coverage of countries or the range of health indicators. Our objective is to describe the health and social status of Indigenous and tribal peoples relative to benchmark populations from a sample of countries.

METHODS

Collaborators with expertise in Indigenous health data systems were identified for each country. Data were obtained for population, life expectancy at birth, infant mortality, low and high birthweight, maternal mortality, nutritional status, educational attainment, and economic status. Data sources consisted of governmental data, data from non-governmental organisations such as UNICEF, and other research. Absolute and relative differences were calculated.

FINDINGS

Our data (23 countries, 28 populations) provide evidence of poorer health and social outcomes for Indigenous peoples than for non-Indigenous populations. However, this is not uniformly the case, and the size of the rate difference varies. We document poorer outcomes for Indigenous populations for: life expectancy at birth for 16 of 18 populations with a difference greater than 1 year in 15 populations; infant mortality rate for 18 of 19 populations with a rate difference greater than one per 1000 livebirths in 16 populations; maternal mortality in ten populations; low birthweight with the rate difference greater than 2% in three populations; high birthweight with the rate difference greater than 2% in one population; child malnutrition for ten of 16 populations with a difference greater than 10% in five populations; child obesity for eight of 12 populations with a difference greater than 5% in four populations; adult obesity for seven of 13 populations with a difference greater than 10% in four populations; educational attainment for 26 of 27 populations with a difference greater than 1% in 24 populations; and economic status for 15 of 18 populations with a difference greater than 1% in 14 populations.

INTERPRETATION

We systematically collated data across a broader sample of countries and indicators than done in previous studies. Taking into account the UN Sustainable Development Goals, we recommend that national governments develop targeted policy responses to Indigenous health, improving access to health services, and Indigenous data within national surveillance systems.

FUNDING

The Lowitja Institute.

Anemia among indigenous women in Brazil: findings from the First National Survey of Indigenous People's Health and Nutrition

BACKGROUND

Anemia is recognized as a major public health problem that disproportionately affects vulnerable populations. Indigenous women of reproductive age in Brazil are thought to be at high risk, but lack of nationwide data limits knowledge about the burden of disease and its main determinants. This study aimed to assess the prevalence of anemia and associated factors in this population using data from The First National Survey of Indigenous People's Health and Nutrition in Brazil.

METHODS

Data were collected from Indigenous women between 15 and 49 years old based on a nationwide sample of villages. The outcomes of interest were hemoglobin levels (g/dL) and anemia (< 12 g/dL for nonpregnant and < 11 g/dL for pregnant women). Multilevel models were used to explore associations with contextual (village) and individual (household/woman) level variables.

RESULTS

Based on data for 6692 Indigenous women, the nationwide mean hemoglobin level was 12.39 g/dL (95% CI: 12.29-12.50). Anemia prevalence was high (33.0%; 95% CI: 30.40-35.61%) and showed pronounced regional disparities. No village-level characteristics were associated with anemia or hemoglobin levels in the multilevel model. Even after controlling for upper level variables, socioeconomic status, parity, body mass index, and having been treated for malaria were associated with anemia and hemoglobin levels.

CONCLUSION

The prevalence of anemia in Brazilian Indigenous women was 12% greater than the national estimates for women of reproductive age. Anemia prevalence and mean hemoglobin levels among Indigenous women appear to be partly explained by some previously recognized risk factors, such as socioeconomic status, body mass index, and malaria; however, part of the variability in these outcomes remains unexplained. Knowledge of health status and its potential determinants is essential to guide public policies aimed at controlling anemia burden in Indigenous communities.

Nutritional status and growth of indigenous Xavante children, Central Brazil

BACKGROUND

The aim of this study was to characterize the nutritional status of Xavante Indian children less than 10 years of age in Central Brazil and to evaluate the hypothesis of an association between child nutrition and socioeconomic differentiation in this population.

METHODS

A cross-sectional study was conducted in July 2006 that included all children under the age of 10 from the Xavante village Pimentel Barbosa in Mato Grosso, Brazil. The data collected included weight, height, and sociodemographic information. Sociodemographic data were used to generate two indices ("income" and "wealth") and to determine the proportion of adults in each household. Descriptive analyses were performed for weight-for-age (W/A), height-for-age (H/A), and weight-for-height (W/H) using the NCHS and the WHO growth references. Univariate and multivariate analyses were conducted using H/A and W/A as a response variables.

RESULTS

Of a total of 246 children under the age of ten residing in the village, 232 (94.3%) were evaluated. Following the NCHS reference, 5.6% of children under the age of ten presented low W/A and 14.7% presented low H/A. Among children under the age of five, deficit percentages for weight and height were 4.5% and 29.9%, respectively, following the WHO curves. Among children < 2 years of age, H/A index variability was found to be directly related to child's age and inversely related to the proportion of adults in the household. Maternal BMI was positively associated with growth for children from 2 to 4 years of age, explaining 11.5% of the z-score variability for the H/A index. For children 5 years of age and older, the wealth index and maternal height were positively associated with H/A. No significant associations were found using W/A as the dependent variable.

CONCLUSION

This study demonstrated that undernutrition, in particular linear growth deficit, is a notable health issue for Xavante children. These findings contrast with the nutritional profile observed among Brazilian children nationally, which is characterized by a sharp decline in child undernutrition in recent decades, even in the poorest regions of the country. This discrepancy calls attention to the persistent health disparities that exist between indigenous and non-indigenous people in Brazil.

Human mobility on the Brazilian coast: an analysis of strontium isotopes in archaeological human remains from Forte Marechal Luz Sambaqui

This study investigated strontium isotopes in the dental enamel of 32 human skeletons from Forte Marechal Luz sambaqui (shellmound), Santa Catarina, Brazil, aiming at identifying local and non-local individuals. The archeological site presents pot sherds in the uppermost archeological layers. Dental enamel was also examined from specimens of terrestrial fauna ((87)Sr/(86)Sr = 0.71046 to 0.71273) and marine fauna ((87)Sr/(86)Sr = 0.70917). The (87)Sr/(86)Sr isotope ratio for individuals classified as locals ranged from 0. 70905 to 0. 71064 and was closer to the isotope ratio of the seawater than to the ratio of the terrestrial fauna, indicating a strong influence of marine strontium on the inhabitants of this sambaqui. The results indicate the existence of three non-local individuals ((87)Sr/(86)Sr = 0.70761 to 0.70835), buried in both the level without pottery and the layer with pottery, possibly originated from the Santa Catarina Plateau, close to the municipality of Lages, or from the Curitiba Plateau. The occurrence of a slight difference between the isotope ratios of local individuals buried in the archeological layer without pottery, when compared to those in the layer with pottery, suggests a possible change in dietary patterns between these two moments in the site's occupation.

Cytokine genes are associated with tuberculin skin test response in a native Brazilian population

Tuberculosis was a major cause of population decline among Brazilian indigenous peoples and remains a leading cause of morbidity and mortality among them. Despite high BCG coverage, results of Tuberculin Skin Test (TST) reactivity have shown high rates of anergy in Amazonian Indians. Given the high prevalence of anergy in these populations and the fact that genetic host factors play an important role in susceptibility to Mycobacterium tuberculosis (MTB), the aim of this study was to evaluate the association of nineteen polymorphisms in fifteen genes related to immune response and anergy in the Xavante, an indigenous group from Brazil. A total of 481 individuals were investigated. TST anergy was observed in 69% of them. Polymorphisms in four genes showed absence or very low variability: SP110, PTPN22, IL12RB1 and IL6. IFNG +874 A/T heterozygotes and IL4-590 C/C homozygotes were more frequent in those individuals who presented a positive TST (prevalence ratios of 1.9 and 2.0 respectively). The risk of anergy was 1.5 in IL10-1082 G/G homozygotes when compared to carriers for the A allele. In indigenous groups such as the Xavante exposure to a variety of infections, associated with specific genetic factors, may disturb the T-helper 1 and T-helper 2 balance leading to increased immunological susceptibility.

Anthropometric evaluation of indigenous Brazilian children under 60 months of age using NCHS/1977 and WHO/2005 growth curves

OBJECTIVES

To perform a comparative analysis of anthropometric data from Suruí, Xavánte and Wari' indigenous children under 60 months of age using the NCHS/1977 and the WHO/2005 growth curves.

METHODS

Anthropometric measurements followed standard procedures and the data obtained were converted into z scores using the Epi-Info (Version 3.4) and WHO-Anthro (Version Beta) softwares. The indices height/age (H/A), weight/age (W/A) and weight/height (W/H) were descriptors of nutritional status for all children under 60 months of age, as well as the body mass index (BMI) for children 24-59 months old.

RESULTS

The frequencies of Suruí children < -2 z scores for H/A were 31.4 (NCHS/1977) and 38.6% (WHO/2005); Xavánte 30.9 and 42.3%; Wari' 61.7 and 68.3%. The frequencies of Suruí children < -2 z scores for W/A were 12.4 (NCHS/1977) and 8.5% (WHO/2005); Xavánte 16.5 and 11.6%; Wari' 51.7 and 45.0%. None of the Suruí children were < -2 z scores for W/H (NCHS/1977 and WHO/2005); the frequencies of Xavánte children were 1.7 and 3.3% and Wari' 1.7 and 0.0%. The frequencies of Suruí children > 2 z scores for W/H were 3.9 (NCHS/1977) and 3.9% (WHO/2005); Xavánte 0.0 and 0.8%; Wari' 0.0 and 0.0%. The frequency of Suruí children aged 24-59 months > 2 z scores for BMI was 5.4% (WHO/2005); Xavánte 9.5%; and Wari' 0.0%.

CONCLUSIONS

Our findings revealed important differences in the results from nutritional assessment, according to the set of growth curves used; however, the use of both growth curves revealed a high prevalence of malnutrition. Therefore, future studies with indigenous populations should present their results using two sets of growth curves to allow consistent comparison.

Risk of tuberculous infection in an indigenous population from Amazonia, Brazil

SETTING

Suruí Indians, Amazonia, Brazil.

OBJECTIVE

To estimate the prevalence and the annual risk of infection (ARI) of tuberculosis (TB) in an indigenous population in Brazil.

METHODS

We applied a method to estimate the prevalence of TB infection in populations with high bacille Calmette-Guérin (BCG) vaccine coverage. The method consisted of comparing levels of skin test reactivity in individuals tested with purified protein derivative (PPD) before and after stimulation with intradermal BCG. Fieldwork was carried out among the Suruí Indians (n = 993) in two phases, 3 months apart.

RESULTS

A total of 645 subjects were tested. In pre-BCG revaccination, tuberculin skin test (TST) indurations averaged 5.9 mm (33.5% > or =10 mm). In post-BCG revaccination TST, indurations averaged 9.4 mm (48.7% > or =10 mm). Conversion from non-reactor to reactor was 54.4%. The ARI ranged from 1.2% to 2.2%. In the logistic regression, age and history of TB were the strongest independent predictors of TB infection. BCG scar and the number of individuals per house were also associated with infection.

CONCLUSION

Tuberculous transmission is very high in the Suruí, surpassing the ARI reported for Brazil (0.6%). The epidemiology of TB in this indigenous population is related to unfavourable social and economic conditions, as well as to deficient health care services.

[Physical growth and nutritional status of Brazilian indian populations]

This paper reviews the literature on the physical growth of native populations from Brazil. Studies aiming at relating the physical growth patterns of these populations to their nutritional status are relatively recent and still do not provide a comprehensive picture of the situation. Compared to non-indigenous Brazilian children and international reference populations (NCHS), indigenous children are short and light for their age, although they maintain their body proportionality, as evaluated by weight for height. These findings could be interpreted as an indication of high rates of chronic protein-energy undernutrition. At least for some groups, data derived from health surveys provide further indication of the existence of marginal nutrition. It is pointed out, however, that international reference curves may not be appropriate for evaluating the physical growth of specific populations, which may be the case of Brazilian indigenous children. It is also pointed out that changes in subsistence practices and in health profiles due to the acculturation process may contribute to the deterioration of nutritional status of indigenous peoples.

Tuberculin reactivity and tuberculosis epidemiology in the Pakaanóva (Wari') Indians of Rondônia, south-western Brazilian Amazon

OBJECTIVE

To investigate the characteristics of tuberculin skin test reactivity in the Pakaanóva Indians, in Amazonia, Brazil, after revaccination of all study participants with bacille Calmette-Guerin (BCG).

METHODS

The investigation was designed as a post-BCG vaccination purified protein derivative (PPD) survey. Data included PPD readings, age, sex, nutritional status, place of residence, previous tuberculosis, physical examinations and BCG status. Bivariate and multivariate logistic regression analyses were conducted.

RESULTS

About 90% (n = 505) of the total population participated. One third (32.1%) of the subjects presented induration > or = 10 mm at 72 h. Induration sizes showed weak linear correlation with age; differences between sexes were not observed. Skin reaction was not associated with nutritional status. Individuals with a history of tuberculosis were six times more likely to test positive. History of tuberculosis, age, and previous BCG vaccination were significantly associated with PPD reactivity in the multivariate analyses.

CONCLUSION

The Pakaanóva showed a high proportion (58.4%) of non-reactors, even with a recent BCG booster. Sex differences in PPD reactivity were either not present or could not be demonstrated. The association between age and PPD reactivity resembles that observed in other Amazonian populations. The authors discuss the potential of PPD testing as a screening tool to enhance tuberculosis detection, especially in indigenous populations in Amazonia with limited access to health services.

Blood pressure levels in Xavánte adults from the Pimentel Barbosa Indian Reservation, Mato Grosso, Brazil

OBJECTIVE

To study blood pressure (BP) levels in the Xavánte Indians of Central Brazil.

METHODS

93 subjects > or = 15 years old were included. Systolic (SBP) and diastolic (DBP) blood pressure readings were taken to the nearest mm Hg at Korotkoff phases 1 and 5 using a mercury sphygmomanometer. Height and weight measurements were taken, as well as general information on demographic, dietary, and social factors, including use of tobacco and alcohol.

RESULTS

5.3% of the adult men and 7.7% of the adult women (> or = 18 years old) were classified as hypertensive (SBP > or = 140 mm Hg and/or DBP > or = 90 mm Hg). No patients were classified as stage 3 hypertensive (SBP > or = 180 mm Hg or DBP > or = 110 mm Hg). Men had higher mean body weight and height than women. There was no major difference in mean BMI (body mass index) for men and women. SBP showed a positive and statistically significant correlation with age in both men (P = .056) and women (P = .040). Among men, DBP showed a negative correlation with height (P = .032). Among women, weight and BMI showed a positive correlation with DBP (P = .013 and P = .005, respectively). Diastolic pressure did not show statistically significant correlation with age for either sex (P>.05).

CONCLUSION

The prevalence of hypertension has increased among the Xavánte over the years, which is probably related to behavioral, social, and economic alterations deriving from increased interaction with Brazilian national society.

[Human ecology and nutritional anthropometry of adult Xavánte Indians in Mato Grosso, Brazil]

This study compares anthropometric and ecological profiles of two Xavánte indigenous communities in Mato Grosso, Central Brazil. The research describes time allocation patterns and involves an anthropometric survey (including body mass, stature, and BMI) in adults over 20 years of age. Data from Etéñitépa (also known as Pimentel Barbosa) were collected in 1994. Field work at São José was conducted in 1998 and 1999. Compared with the São José group, Xavánte in Etéñitépa do more subsistence activities like farming, fishing, hunting, and gathering. The São José Xavánte do more paid work and generally engage in less physical activity. Average stature in the two communities is similar, but there are major differences in mean body mass and BMI. The São José group has average BMI values well over those of the Etéñitépa group in practically all age brackets. Obesity prevalence rates were high in both men (24.6%) and women (41.3%) in São José, while in Etéñitépa the rates were only 2.5% and 4.8%, respectively. The authors conclude that the different nutritional profiles in the two communities result from specific patterns of social, political, and economic interactions with Brazilian society.

[Oral health among the Xavánte Indians in Pimentel Barbosa, Mato Grosso, Brazil]

This study presents the results of an oral health epidemiological survey conducted in 1997, based on WHO criteria, in the Xavánte indigenous community of Pimentel Barbosa (or Etéñitépa), Mato Grosso State, Central Brazil. The study included 228 individuals (85% of the population) over two years of age. In about half the sample, the DMF index was less than 2, and in the 12-14-year age bracket it was 3.7. The low frequency of fillings in permanent and deciduous teeth suggests limited access to dental care services. Despite the number of sextants with bleeding and tartar, no cases of severe periodontal disease were detected (CPITN). In the community, comparison of the results of this survey with two previous surveys (1962 and 1991) showed a deterioration in oral health conditions over time and alterations in the occlusal pattern (increase in Angle class II and III). Dietary changes due to environmental and socioeconomic alterations resulting from interaction with the surrounding society, along with the lack of preventive programs, are among the causes of this deterioration in oral health among the Xavánte.

[Demographic profile of the Xavánte Indian population in Sangradouro-Volta Grande, Mato Grosso]

This paper analyzes the demographic profile of the Xavánte population at the Sangradouro-Volta Grande Indigenous Reserve in Mato Grosso, Brazil, from 1993 to 1997. The survey included annual censuses and vital statistics from 7 Xavánte villages. Permanent contact with Brazilian national society, established in the 1940s and 50s, caused a population drop due to epidemics and clashes. In 1995 there were 825 individuals in the community. The crude birth rate (57.7/1,000) and death rate (9.1/1,000) were higher than the national averages. The majority (56%) of the population is under 15 years of age (median: 13 years) and the infant mortality rate is high (87.1 per thousand live births), probably resulting from precarious sanitary conditions in the villages. Other results included the persistence of polygyny; low levels of migration; a dynamic of splits and formation of new villages; traditional housing patterns maintained in the old villages and abandoned in the new ones. The recent demographic recovery in the data from Sangradouro-Volta Grande is similar to that observed in the Pimentel Barbosa community. The study highlights the importance of systematically collecting and analyzing demographic data from indigenous populations.

[Physical growth of five to ten year old Xavante indian children in Mato Grosso]

OBJECTIVE: To investigate the physical growth of Xavante children aged 5-10 years and living at the Sangradouro and são Marcos reservations, state of Mato Grosso, central Brazil. METHODS: A cross-sectional survey was carried out in February 1997 in two native Brazilian Indian schools. Our sample included 233 children. The following data were collected: birth date, sex, weight, height, arm-muscle circumference, and triceps skinfold thickness. Data on height and weight were compared to National Center for Health Statistics (NCHS) growth charts following the recommendation of the World Health Organization. RESULTS: Our results show that 9% of our population sample had height-for-age Z scores <-2. For boys, statistically significant differences (P<0.05) in height-for-age and weight-for-age Z scores were observed between the two communities. Similar differences were not observed for girls. Xavante children are, in average, shorter in height than North-American children. However, for some age groups, the average values of height overlap with those of the Brazilian children investigated by the National Research on Health and Nutrition (PNSN). CONCLUSIONS: The physical growth profile of Xavante children presented important differences when compared to that of a number of other South American native Indian populations. Based on the information collected, we argue that North-American curves can be used to evaluate the nutritional status of Xavante children.

Haplotype and allele frequencies for three genes of the dopaminergic system in South American Indians

Haplotype and allele frequencies for the dopamine D2 receptor gene (DRD2), dopamine D4 receptor gene (DRD4), and dopamine transporter protein gene (SLC6A3) were determined in 135 individuals from five Brazilian Indian tribes, and the results integrated with those previously presented for this ethnic group. DRD2 and DRD4 were highly polymorphic. Haplotypes including TaqI A1 at DRD2, and the seven repeat allele at DRD4 were the most frequent variants, while the SLC6A3 locus was monomorphic for the 10 repeat allele in South American Indians. Genetic distances and the corresponding neighbor-joining tree indicated a geographic dichotomy between North + Central American and South American natives, with the exception of the Wai Wai, who live north of the Amazon river and are grouped in the northern cluster. G(ST) estimates from these genes vary between 0.05 and 0.11 for North and South America, respectively, indicating a higher degree of differentiation of the latter groups. These results are in accordance with previous genetic data on other systems, as well as with the history and biodemographical data of South American Indians. Am. J. Hum. Biol. 12:638-645, 2000. Copyright 2000 Wiley-Liss, Inc.

Association of the low-density lipoprotein receptor gene with obesity in Native American populations

Five low-density lipoprotein receptor gene (LDLR) restriction fragment length polymorphisms (RFLPs: TaqI, intron 4; HincII, exon 12; AvaII, exon 13; MspI and NcoI, exon 18) were investigated in 131 individuals from five Brazilian Indian tribes. All markers were polymorphic in this ethnic group. In the whole sample of Amerindians, 13 (41%) of the 32 expected haplotypes were identified, but only three were shared by all tribes. The Xavante, Suruí, Zoró, and Gavião tribes, who had been studied for anthropometry, were grouped according to their genotypes, and the corresponding mean values were examined. Significant associations were observed between HincII *H-, AvaII *A+, MspI *M-, and NcoI *N+ and the body mass index (BMI), triceps and subscapular skinfolds, and the arm fat index (AFI). Haplotypes were derived for these four RFLPs, and (*H-/*A+/*M-/*N+) haplotype carriers were compared with noncarriers of this haplotype with equally significant results for the three parameters (BMI, P=0.021; skinfold thickness, P<0.001; AFI, P=0.005). These results suggest that the LDLR gene has some influence over adipose tissue deposition.

High heterogeneity of apolipoprotein E gene frequencies in South American Indians

The apolipoprotein E (APOE) polymorphism was investigated in 186 individuals from six South American Indian tribes, and the results integrated with those previously presented for this ethnic group. The three APOE alleles commonly reported in other populations were also observed in South Amerindians with a highly heterogeneous distribution. As in other populations, APOE*3 was the most common allele (51-98%) followed by APOE*4 (2-47%). These two isoforms were identified in all tribes, but APOE*2 was observed among the Wai Wai (2%) and Mataco (4%) only. No previous indications of inter-ethnic admixture were observed among the Wai Wai, but the introduction of this allele among the Mataco through non-Indian sources cannot be excluded.

Hardships of contact: enamel hypoplasias in Tupí-Mondé Amerindians from the Brazilian Amazonia

This paper presents an assessment of enamel defects (hypoplasias) in the permanent anterior teeth of three Tupí-Mondé-speaking groups from the Brazilian Amazonia: the Gavião, Suruí, and Zoró. These are native societies that experienced the onset of permanent contact with Brazilian national society in different periods of the 20th century. Tupí-Mondé dentition is highly hypoplastic, which is possibly related to exposure to adverse health and nutritional conditions. Data for the Gavião, Suruí, and Zoró are in agreement with results from other populations that show that certain teeth, the maxillary central incisors and the mandibular canines in particular, tend to be more hypoplastic. Although all types of teeth show hypoplasia concentrations at some enamel zones, there is substantial intertooth variation in the age at which peaks occur. It is argued that hypoplasia concentrations at certain ages are unlikely to be related to postweaning stresses for the Tupí-Mondé. Statistically significant associations between presence of enamel defects and deficits in physical growth (height-for-age) were detected in children 7-11 years of age. Diachronic assessment of enamel defects, which rested upon the potential of enamel as "memory" of past periods of systemic physiological perturbation, allowed us to unravel aspects related to the dynamics of Tupí-Mondé life during the 20th century. Frequencies of enamel zones with defects peaked during the contact years of each of the Tupí-Mondé groups, attesting to the extreme social and biological hardships that characterized the contact experiences of these native societies with Brazilian national society.

Apolipoprotein B genetic variability in Brazilian Indians

Three apolipoprotein B restriction fragment length polymorphism (RFLPs) (XbaI, MspI, and EcoRI) and the signal peptide insertion-deletion polymorphism were investigated using the polymerase chain reaction in 140 individuals from 5 Brazilian Indian tribes. All studied markers were polymorphic in this ethnic group. The insertion allele 5' beta SP*29 at the signal peptide previously observed in Mexican Americans was detected in about 8% of the chromosomes of 2 tribes (Gavião and Zoró), therefore confirming the Amerindian origin of this allele. Negative linkage disequilibrium was observed between alleles at the signal peptide and the EcoRI polymorphism in all tribes. In 3 populations (Gavião, Suruí, and Zoró) a negative disequilibrium was also detected between the insertion-deletion signal peptide markers and the XbaI polymorphism. In the whole sample of Amerindians 14 of the 24 (58%) possible 4-marker extended haplotypes were identified, but only haplotype 2 (5' beta SP*24/*X+/*M+/*E+) and haplotype 5 (5' beta SP*27/*X-/*M+/*E+) were shared by all tribes. No associations between plasma lipid levels or body mass index and these polymorphisms were observed in this sample.

Faunal composition and behavior of anopheline mosquitoes in the Xavánte Indian reservation of Pimentel Barbosa, central Brazil

Faunal composition and behavior of anopheline mosquitoes were studied in a Xavánte Indian reservation of Central Brazil. Altogether 558 anophelines were collected in three environments (intra, peri, and extra-domiciliary). Anopheles darlingi (30.9%), An. triannulatus s.l. (24.6%) and An. oswaldoi (19.7%) were the most common species. Average capture rates were higher in the rainy season (8.03 per hour) than in the dry season (4.37 per hour). Anophelines exhibited exophilic behavior almost exclusively. It was observed that Xavánte cultural practices facilitate outdoor exposure during peak hours of mosquito activities (e.g., coming to the creek early in the morning for bathing or to draw water, fishing, etc.). The results of this study raise the question of whether or not applying to the Xavánte the more commonly recommended malaria control strategies (e.g., in-house spraying, screening windows, and impregnated bed nets) which aim at hampering human-mosquito contact inside human dwellings may be effective.

The Brazilian Xavante Indians revisited: new protein genetic studies

A total of 94 individuals from the Xavante village of Rio das Mortes were variously studied in relation to 28 protein genetic systems. No variation was observed for 15 of them, in accordance with previous studies. Of the remaining 13, four (Rh, Duffy, acid phosphatase, and GC) showed significant departures from the averages obtained in 32 other South American Indian populations. If studies performed in the 1960s are considered, there is indication that no significant changes in this village's gene pool has occurred in the last 30 years. Comparison with two other Xavante populations included nine systems with variation, and for three of them (MNSs, Rh, and Duffy) significant differences were found. Genetically the Rio das Mortes are closer to the São Marcos than to the Simões Lopes Xavantes. A dendrogram considering 25 genetic systems and 33 South American Indian populations was constructed. There the Xavante were grouped together, in two neighboring clusters, with three other tribes who speak Ge languages, But these clusters also present populations who speak other languages, and the reproducibility of the tree is low. South American Indians, at least with this set of markers, do not seem to be clearly classified into defined subgroups.

D1S80 locus variability in South American Indians

We have studied the hypervariable D1S80 locus in 185 individuals from five South American Indian tribes, integrating these results with previous investigations. Three alleles (*18, *24 and *30) were common to all tribes, but their frequencies varied between northern and southern populations. Brazilian tribes have a high frequency of *30 (average 35%) while in Argentinian and Chilean Indian populations this allele is present, on average, in 7% of the chromosomes only. Allele *24, the most common in other ethnic groups, was observed in 10% and 25% of northern and southern Amerindians respectively. Genetic distance and dendrogram analyses placed the Argentinian and Chilean tribes closer to Brazilian Caucasians, suggesting non-Indian admixture among them.

Hepatitis B epidemiology and cultural practices in Amerindian populations of Amazonia: the Tupí-Mondé and the Xavánte from Brazil

Hepatitis B infection and disease are highly endemic in South America. Prevalences of positivity are particularly high in Amazonia, and among Amerindian peoples in particular. This paper reports the results of a seroepidemiological survey for hepatitis B virus (HBV) carried out among four Amerindian populations from the Brazilian Amazon region: Gavião, Surui, Zoro and Navate. Rates of positivity to HBV serological markers (HBsAg, anti-HBs and or anti-HBc) are very high for the four groups, ranging from 62.8 to 95.7%. It is argued that the high rates of positivity in the Amerindian groups dealt with in this study, as well as for other Amazonian populations, are related to a complex of cultural practices which enhance the likelihood of HBV transmission (bloodletting, scarification, tattooing and orally processed food, among others). The authors suggest that, due to unique patterns of interaction between sociocultural and environmental factors. HBV infection assumes a specific profile in native Amazonian societies.

Cutaneous leishmaniasis in Tupí-Mondé Amerindians from the Brazilian Amazonia

This paper reports the results of a cross-sectional survey aimed at characterizing the epidemiology of American cutaneous leihsmaniasis (ACL) in 3 Tupí-Mondé-speaking Amerindian groups from the Brazilian Amazon region. Data include results of Montenegro skin tests (n = 550), serology (n = 233), and physical examinations (n = 676). Rates of skin test positivity were higher for males and differed between the groups (Gavião 43.0%, Suruí 52.8%, Zoró 68.1%), with a trend toward increase with age. Strong associations were also detected for the presence of suggestive ACL scars, on the one hand, and age, sex, and tribal affiliation, on the other. Although 14.7% of the subjects showed typical scars of past ACL disease, only 3 cases of active primary leishmanial ulcers were observed. The results did not indicate any clear association between seropositivity and positivity to the Montenegro intradermal test or presence of scars. The authors discuss the epidemiology of ACL in the Tupí-Mondé in the light of their ecology and recent history.

Mitochondrial DNA polymorphism in three Brazilian Indian tribes

The first 360 base pairs of the mitochondrial DNA (mtDNA) major noncoding region from 82 individuals affiliated with the Brazilian Xavante, Zoró and Gavião tribes were sequenced. A total of 14 different lineages were observed, the largest number (8) being found among the Zoró. The latter share five lineages with the Gavião (who are their neighbors and are culturally similar to them), but only one with the Xavante. The lineages can be grouped into four clusters, previously identified by other authors. The 9 base pair deletion characteristic of Asian and Pacific populations occurs in 32% of the individuals, whose mtDNA was classified in five lineages, all grouped in one of the four clusters. Nucleotide diversity, as evaluated by three indices, are not much different from those observed in Indians from Central and North America, despite the fact that the Xavante consistently show lower numbers. These results do not confirm previous generalizations about the genetic diversity of Amerindians, and the need for additional studies in this system is stressed. © 1996 Wiley-Liss, Inc.

Beta-globin gene cluster haplotype distribution in five Brazilian Indian tribes

Haplotypes derived from five polymorphic restriction sites in the beta-globin gene cluster were investigated in 139 individuals from five different Brazilian Indian tribes by the polymerase chain reaction (PCR). Eight haplotypes were identified. Haplotypes 2 ((+)----) and 6 (-)++(-)+) were the most frequent and were common to all tribes. Their prevalences ranged from 60% to 93% and from 3% to 18%, respectively. Average heterozygosity measured by the Gini-Simpson index is markedly reduced among these Brazilian Indians when compared with Europeans (56%), but much less (8%) in relation to Asiatics, suggesting the absence of an important bottleneck effect in the early colonization of South America. The coefficient of gene differentiation (GST') was estimated as 0.082 among six Brazilian Indian tribes, but when only three Tupi-Mondé-speaking tribes were considered, this estimate was reduced to 0.030.

Butyrylcholinesterase polymorphisms (BCHE and CHE2 loci) in Brazilian Indian and admixed populations

The genetic variability of butyrylcholinesterase, determined by the BCHE and CHE2 loci, was examined in nine Brazilian Indian groups. In addition, a search for the presence of the BCHE*F allele was also performed in eight other Brazilian Indian samples and in five admixed (black-Indian-white) rural Amazonian communities previously studied for the CHE2 locus and the BCHE*A allele. In the Indian populations the frequency of the BCHE*F allele varied from 0 to 7.1% +/- 3.4 and the frequency of the CHE2 C5+ phenotype ranged from 1.4% +/- 1.4 to 45.9% +/- 3.8. This study seems to be the first to report the presence of the BCHE*F allele in native Americans. The BCHE*A allele appeared in one Indian group (1.4% +/- 1.0), and we suggest that its existence in this tribe and in other native Americans can be explained by gene flow from white populations. Gene flow may also be the reason for the occurrence of the BCHE*F allele in Brazilian Indians, whereas the CHE2*C5+ allele may have been present in the paleo-Indians. The distributions of both the BCHE*F allele and the CHE2 C5+ phenotype in Brazilian Indians seem to be the result of the action of random genetic drift.

D1S80 locus variability in three Brazilian ethnic groups

We have studied the hypervariable locus D1S80 in 75 white and 53 black Brazilians from Porto Alegre, a southern Brazilian population, and in 50 Brazilian Indians from the Xavante and Zoró tribes. Allele frequencies were significantly different among the three ethnic groups, mainly because of the higher frequencies of alleles *21, *22, *28, and *34 and the lower frequency of allele *18 in individuals of African ancestry and the higher frequencies of alleles *18 and *30 in Brazilian Indians. In the Indian group a restriction in the number of alleles (7) and genotypes (15) was found. The data suggest that the D1S80 locus is a useful interpopulation marker. This is the first report of its allele frequencies in Amerindians.

Intestinal parasitism in the Xavánte Indians, central Brazil

This paper reports the findings of a survey for intestinal parasites among the Xavánte Indians from Central Brazil. A. lumbricoides (25.0%) and hookworms (33.6%) were the two most common helminths; E. histolytica complex (7.8%) and G. lamblia (8.6%) the most common protozoans. The majority (58.5%) of positive individuals hosted only one species of helminth. Egg counts for helminths, and for A. lumbricoides in particular, were found to be not dispersed at random, with a few individuals, all of whom young children, showing very high counts. The prevalence rates of intestinal parasites for the Xavánte are below those reported for other Amerindian populations from Brazil.

Paracoccidioidin and histoplasmin sensitivity in Tupí-Mondé Amerindian populations from Brazilian Amazonia

A cross-sectional epidemiological survey for paracoccidioidomycosis and histoplasmosis, including skin tests with paracoccidioidin and histoplasmin, physical examinations and X-rays, was conducted among three Tupí-Mondé Amerindian populations from Brazilian Amazonia. The study followed the diagnosis of an increasing number of cases of paracoccidioidomycosis among the Suruí in recent years. Positivity rates to paracoccidioidin and histoplasmin (> or = 5 mm of intradermal induration 24-48 h post-injection) were 43.8% and 78.7% for the Suruí, 6.4% and 5.8% for the Gavião and 14.9% and 80.5% for the Zoró, respectively. There was no significant difference in the results for males and females but marked differences were noted across age groups. The results of the univariate analysis were confirmed after adjustment for confounding variables by multiple logistic regression analysis: paracoccidioidin positivity was relatively high in the Suruí and histoplasmin positivity was relatively high in the Suruí and Zoró. The Suruí's greater exposure to Paracoccidioides brasiliensis, the causative agent of paracoccidioidomycosis, is probably associated with their adoption of new subsistence practices. The epidemiology of this mycosis among the Tupí-Mondé appears to be related to the environmental and socio-economic changes taking place in Amazonia.

Crescimento físico e estado nutricional de populações indígenas brasileiras

Este trabalho revisa a literatura sobre crescimento físico de populações indígenas do Brasil. Os estudos voltados para caracterização do estado nutricional através da antropometria são relativamente recentes e, ainda, não chegam a prover um quadro claro da situação. Quando comparadas com crianças brasileiras ou com populações-referência internacionais (NCHS), as indígenas são em média de menor estatura e peso, ainda que mantenham a proporcionalidade corporal, avaliada pelo indicador 'peso para estatura'. Estes resultados podem ser interpretados como evidência de altas freqüências de desnutrição energética-protéico crônica. Pelo menos para alguns grupos, dados oriundos de inquéritos de saúde provêem evidências favoráveis à existência de condições nutricionais marginais. É indicado, contudo, que curvas de referências internacionais talvez não sejam adequadas para avaliar o crescimento físico de populações específicas, incluindo as crianças indígenas brasileiras. Chama-se atenção, também, para o fato de que mudanças nas práticas tradicionais de subsistência e nas condições de saúde devido ao processo aculturativo podem contribuir para a deterioração do estado de nutrição das populações indígenas.

Pênfigo foliáceo endêmico (fogo-selvagem) no grupo indígena Xavánte, Mato Grosso, Brasil

Foi realizado inquérito soro-epidemiológico através de testes de imunofluorescência indireta e imunoprecipitação visando determinar a prevalência do pênfígo foliáceo endêmico (PFE) na população indígena Xavánte do Brasil Central. Do total de 163 amostras de soro testadas, 5 (3,1%) foram positivas à imunofluorescência. Todos os soros positivos procediam de indivíduos com sintomas clínicos da doença. Não foram observadas diferenças do PFE entre os Xavánte e a população em geral sob o ponto de vista imunológico, já que se verificou uma predominância da IgG4 entre os anticorpos nos pacientes indígenas.

Blood pressure levels of the Suruí and Zoró Indians of the Brazilian Amazon: group- and sex-specific effects resulting from body composition, health status, and age

Two related Tupí-Mondê-speaking tribes of the Aripuanã Indian Park of western Brazil are compared in terms of their recent contact with Western culture, subsistence patterns, general health, and blood pressure levels. Age, weight, height, sex, and tribal affiliation for Suruí and Zoró adults over age 18 are included in an analysis of covariance to test regression models of both diastolic and systolic blood pressure. Because of significant interaction effects between sex and other covariates, sex-specific models were developed. The relationship between body mass and blood pressure level in males conforms with Western data, but the direction and magnitude of effects for the age and body mass covariates in both sexes conflict with data from other modernizing societies. With age, weight/height ratio, and sex differences controlled for, Suruí males show a lower mean systolic blood pressure (SBP) level and diastolic blood pressure (DBP) level than Zoró males. Intertribal differences were smaller among females: Suruí females SBP and DBP differences were similar but did not reach significance. Other sex-specific differences include a greater inverse relationship between age and SBP level among the 104 male subjects than among the 98 female subjects (with similar trends in DBP) and a small but significant effect of the weight/height ratio on both SBP and DBP in males but not in females. Health status data for these groups suggest that hypothesized increases in mean blood pressure levels following the Suruí's acceptance of a Western diet and social stratification may be modified by their health status, particularly prevalent infectious disease.

Socioeconomic transition and physical growth of Tupí-Mondê Amerindian children of the Aripuanã Park, Brazilian Amazon

Anthropometric assessment of nutritional status is reported for three Tupí-Mondê-speaking groups from Rondônia and Mato Grosso, Brazil. This region of the Amazon basin is experiencing rapid development through government-oriented colonization. The Gavião, Suruí, and Zoró had their first contacts with Brazilian national society at different times, and the nature and degree of their participation in regional markets varies. Height, weight, sitting height, subischial leg length, upper arm circumference, triceps skin-fold thickness, and upper arm muscle and fat areas are reported for children 0-10.9 years of age. Like other Amazonian Amerindians, Tupí-Mondê children are short for their age but normal or above normal in weight for height with respect to the National Center for Health Statistics reference. Hence stunting levels are high (55.4%) and wasting levels are low (0.8%). There are also deficits in body composition parameters, especially in upper arm circumference and estimated muscle and fat areas. We interpret the results as evidence of suboptimal nutritional status, reflecting the interaction between poor diet and infectious and parasitic diseases. The Gavião, with the longest period of contact, present the lowest level of stunting. This finding is attributed to the use of cash income from rubber tapping and nut gathering to purchase of food items and health care. Differences in height between the three groups are mostly due to leg length, instead of sitting height, reinforcing the idea that environmental conditions can alter body proportions.

Avaliação do estado nutricional num contexto de mudança sócio-econômica: o grupo indígena Suruí do estado de Rondônia, Brasil

O presente trabalho discute os resultados de uma avaliação nutricional, realizada com 147 crianças de 0-8,9 anos da comunidade indígena Suruí, Parque Indígena Aripuanã, Rondônia. Os dados incluem antropometria, dosagem de níveis de hemoglobina e exame coproparasitológico. A reserva Suruí localiza-se em uma região de intensa colonização e fluxo migratório. O grupo foi contactado pela Funai em 1969 e, nos últimos anos, envolveu-se ativamente no mercado regional, o que resultou em parcial abandono das atividades de subsistência tradicionais. Comparados com a população-referência do NCHS, os resultados indicam elevadas prevalências de baixa altura para idade (46,3%), peso para idade (31,9%) e peso para altura (6,6%). São também altas as prevalências de anemia (71,2%) e parasitismo intestinal (>75%). Os autores argumentam que a precariedade do estado nutricional das crianças Suruí reflete carências alimentares, devido à redução da capacidade de produção de alimentos e inadequadas condições sanitárias presentes nas diversas aldeias.

[Epidemiological studies among Amerindians of Rondônia. IV. Serological survey for rotavirus among Suruí and Karitiána]

The authors present the results of a sero-epidemiological survey for rotavirus antibodies conducted among the Suruí and Karitiána, two amerindian groups of Rondônia, Brazilian Amazonia. The results indicate high percentages of seropositivity for both groups (67.8% among the Suruí and 77.4% among the Karitiána using ELISA and 45.5% for the Suruí and 56.7% for the Karitiána using indirect immunofluorescence). Chi square tests indicated no statistically significant association between group and seropositivity. The results are discussed in the light of other studies conducted among Brazilian amerindian groups.

Digital dermatoglyphics of three Amerindian populations of the Brazilian Amazonia: a further test of the field theory

Finger ridge counts of three Amerindian populations of the Brazilian Amazonia (Suruí-Paitér, Kayapó-Xikrín and Suruí-Mudjetíre) were subjected to principal component analysis in order to verify the concept of developmental field (field theory). For both sexes, a clear tripartite divisioning (digit I, digits II-III, and digits IV-V) was obtained, corroborating results previously published for other populations.

Black piedra among the Zoró Indians from Amazônia (Brazil)

A total of 130 Zoró Indians from the Brazilian Amazon were observed as part of an epidemiological survey. Black piedra was found in 74 (56.9%) individuals. Infection rates between the sexes were not significantly different. The age group least infected comprised the children, 0-10 years of age. The authors comment on the epidemiology of the infection among the Zoró.