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.

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.

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.

Alternative approaches in schistosomiasis control

Measures for the control of schistosomiasis were implemented in Egypt beginning 1922. This shows that developing endemic countries are facing this problem for near 70 years. However, results in the control of this infection have not been satisfactorily obtained in spite of the technologies and strategies recently developed. The idea that social and economic components are relevant in the control of schistosomiasis is not new although its extension and profundity have not usually been well understood. More recently, most of the workers have recognized that the focal distribution of the prevalence rates of schistosomiasis should not be neglected in the control of the infection. At present, field work projects on the control of schistosomiasis are being developed in rural areas of two Brazilian studies (Espírito Santo and Pernambuco). The adopted strategy aims to interfere in the complex relationships between man and his bio-social-cultural environment, without forgetting that the unequal distribution of the space is a consequence of the political and economic organization of the Society.

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.

[Paracoccidioidomycosis among the indian group Suruí of Rondonia, Amazonia, Brazil. A case report]

The Authors report a case of paracoccidioidomycosis in a Surui Indian patient from the state of Rondonia, Brazilian Amazon. The subject is an adult male, having been diagnosed on the basis of mycologic, serologic, and radiographic exams. The prescribed therapy was sulphamethoxazole 800 mg associated with trimethoprim 160 mg every 12 hours. A reevaluation of the patient conducted six months after the beginning of chemotherapy indicated overall improvement of his physical condition and of the radiologic picture, negativeness of the test of precipitin in capillary tube, and positiveness of the skin test with paracoccidioidin. The Authors also reviewed the cases of paracoccidioidomycosis described in the region, especially among the Surui Indian population.

[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.

Blood pressure studies among Amazonian native populations: a review from an epidemiological perspective

Nine publications are reviewed concerning blood pressure (BP) levels among Amerindian tribes of the Amazon Basin. The lifestyle of these lowland peoples includes most known protective factors against hypertension, and relative isolation from Western society. The latter, however, is rapidly changing. Sampling, data, and analysis problems make current blood pressure data difficult to interpret, and provide a questionable baseline from which to document pressure change during rapid culture change for these groups. Ethnographic and epidemiological perspectives are offered for future blood pressure and health studies among native Amazonians.

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.