Arawete and Asurini Indian tribes were revisited after a 36-year follow-up in search of HTLV infections. 46 persons (23 from each tribe) were tested for HTLV-1/2 antibodies and viral DNA. None were positive; this was probably because of their social/cultural isolation from neighboring tribes where HTLV-2c is hyperendemic.

HTLV-1/2 infection is endemic in Indigenous peoples of the Americas. Its origin is attributed to the migratory flow of Amerindian ancestral peoples. The present study aimed to investigate the seroprevalence of HTLV-1/2 infection in Indigenous peoples of the Brazilian Amazon. A total of 3350 Indigenous people belonging to 15 communities were investigated. The investigation was performed using serological (ELISA), molecular (qPCR) and confirmatory (Western blot and/or Inno-Lia) tests to detect and differentiate the infection. The seroprevalence was 8.3% for HTLV-1/2 infection, with 0.1% of individuals seropositive for HTLV-1 and 8.1% for HTLV-2. The prevalence of infection was statistically higher in women (10.1%) than in men (6.5%) (p = 0.0002). This female predominance was observed in all age groups; in females the prevalence was significant from 41 years old (p < 0.0001) and in males from 51 years old (p < 0.0001). Here, we present a prevalence of HTLV-1/2 among Indigenous peoples of the Brazilian Amazon. The endemic infection in these groups must reflect the different epidemiological profiles observed in these peoples, such as sexual transmission through rejection of condom use, breastfeeding, especially in cases of cross-breastfeeding, and the high rate of pregnancy in the villages.

Shifts in subsistence strategy among Native American people of the Amazon may be the cause of typically western diseases previously linked to modifications of gut microbial communities. Here, we used 16S ribosomal RNA sequencing to characterise the gut microbiome of 114 rural individuals, namely Xikrin, Suruí and Tupaiú, and urban individuals from Belém city, in the Brazilian Amazon. Our findings show the degree of potential urbanisation occurring in the gut microbiome of rural Amazonian communities characterised by the gradual loss and substitution of taxa associated with rural lifestyles, such as Treponema. Comparisons to worldwide populations indicated that Native American groups are similar to South American agricultural societies and urban groups are comparable to African urban and semi-urban populations. The transitioning profile observed among traditional populations is concerning in light of increasingly urban lifestyles. Lastly, we propose the term “tropical urban” to classify the microbiome of urban populations living in tropical zones.

This study was carried out to investigate the frequency of genetic variants related to body mass index (BMI) and type 2 diabetes (T2D) and evaluating the potential impact of risk alleles on susceptibility to these disorders in six indigenous peoples from Brazilian Amazon region. The majority of Fst values for pairwise population comparisons among the indigenous groups are low or moderate. The indigenous people show high values of differentiation with Africans, Europeans and Southeast Asians and moderate values with East Asian and American populations, as expected. The allelic frequencies among indigenous indicate that the majority of associations observed with T2D in continental populations can be replicated in native Amazonians. The genetic risk scores calculated for T2D in indigenous are high and similar to those calculated for Americans and East Asians, while the estimates obtained for obesity are low, probably due to the low frequencies of the risk allele of the FTO gene found in our samples. ADRB3 -rs4994 and ABCC8 -rs1799854 genes showed a significant association with BMI and waist circumference, and the KCNJ11 -rs5219 gene with hyperglycemia. These results emphasize the importance of knowing the genetic variability underlying complex genetic diseases in indigenous peoples and the search for particular or rare variants.

Introdução/Objetivo A pandemia ocasionada pelo SARS-CoV-2, agente causal da COVID-19, desencadeou uma série de consequências de saúde global, chamando a atenção das organizações de saúde principalmente para o impacto nas populações mais vulneráveis. Com a chegada do novo coronavírus na Amazônia, os povos indígenas do estado do Pará foram os grupos populacionais que mais necessitaram uma atenção específica, pois são mais vulneráveis do ponto de vista social, econômico e biológico. O objetivo deste trabalho foi investigar a prevalência de anticorpos IgG anti-SARS-CoV-2 (S1 e S2), em populações indígenas do Estado do Pará. Métodos Foram analisados um total de 532 indígenas das etnias Kayapó (401), Tembé (56), e Amanayé (75), sendo 235 homens (44.17%), 273 mulheres (51.32%) e 24 (4.51%) sem informação de gênero, com idade média de 30 anos. Amostra de sangue (5 mL) foi obtida de cada indivíduo e o plasma foi submetido a pesquisa de anticorpo IgG anti-SARS-CoV-2 utilizando-se o imunoenzimático ELISA (Euroimmun, USA). Resultados 433 indivíduos foram reagentes (81.39%), 75 não reagentes (14.10%) e 24 indeterminados (4.51%). A prevalência por etnia foi de: 87.78% nos Kayapó, 51.79% nos Tembé e 69.33% nos Amanayé. A prevalência entre os sexos foi de 35.53 % nos homens e 42.11% nas mulheres. Conclusão Os resultados indicam, que as etnias Tembé, Amanayé e Kayapó tem alta prevalência de anticorpos IgG anti-SARS-CoV-2 que podem ser decorrentes de infecção natural ou fruto da campanha de imunização. Esses resultados reforçam a necessidade da manutenção da vigilância imunológica dessas populações como forma de prevenção de novas ondas epidêmicas de COVID-19 nas aldeias. Financiamento CNPQ/MS/MCTI-401235/2020-3.

The presence of lymphocytic alterations in the blood of indigenous people infected with human T-lymphotropic virus 2 (HTLV-2) was investigated in peripheral blood smears from 25 indigenous people of the Xikrin do Bacajá ethnicity (11 men and 14 women) diagnosed with HTLV-2 infection by Western blot and qPCR. Smears were stained using the Leishman method and examined for lymphocyte morphology under an optical microscope. A group of 25 individuals seronegative for HTLV-1/2 infection were used as controls. Among the HTLV-2-infected group, six slides (24%) showed atypical lymphocytes (05 with atypical lymphocytes and 01 with petal-shaped nuclei usually referred to as flower cells). The finding was significantly different from that observed among the noninfected group, in which no lymphocytic alteration was observed (p=0.0223). This unique finding is reported for the first time among indigenous peoples and suggests that HTLV-2 infection may be associated with lymphocytic alterations, reinforcing the need for a larger and more detailed clinical study of people living with HTLV-2, particularly the indigenous populations of the Amazon in which the infection is hyperendemic.

No abstract

No abstract