Prevalence of HTLV-I antibody among two distinct ethnic groups inhabiting the Amazon region of Brazil

Abstract

HTLV-I seroprevalences of 3.63% (02/55), 12.19% (10/82) and 13.88% (10/72) were demonstrated among Tiryio, Mekranoiti and Xicrin Amazonian Indians, respectively, by the Western blotting enzyme assay (WBEI). By indirect immuno electron microscopy (IIEM), 2 Tiriyo, 9 Mekranoiti and 6 Xicrin Amerindians were reactive. Of 44 serum samples from Japanese immigrants, none reacted by any of the techniques before mentioned. One, 8 and 6 serum samples from Tiryio, Mekranoiti and Xicrin Indians, respectively, were both WBEI and IIEM positive. Our results strongly suggest that HTLV-I and/or an HTLV-I antigenic variant circulate (s) among populations living in the Amazon region of Brazil.

The challenge of describing the epidemiology of HTLV in the Amazon region of Brazil

“…In the Amazon region of Brazil, HTLV-1 and HTLV-2 infections were primarily described [63,[84][85][86], and soon their geographical dissemination expanded [6]. In 1998, HTLV-2 was detected for the first time outside native Indian communities, and both viruses were found in blood donors [82] and HIV-1 carriers [50].…”

“…The State of Para has been the site of the majority of epidemiological studies intending to define prevalence rates of antibodies against HTLV-1/2 with a variety of different populations, and several conflicting results have been obtained. The initial figures indicated that the prevalence rates measured by immunoenzymatic assays ranged from 3.6% to more than 30% for HTLV-1, mostly among Indians populations [84,85], that the rate was 0.91% among those undergoing blood donation screening [100]. A large distribution of HTLV-2 was shown among Indians communities not only in the State of Para but also in the Amazon area of Brazil, reaching confirmed prevalence rates of more than 40% [6,51,56,63] among some Indian communities and the detection of a new molecular subtype (HTLV-2c) that was soon also described in urban areas outside of the ARB [6,33,50,51,116].…”

“…The initial approach of Japanese immigrants did not result in HTLV reactivity [85], but later, the prevalence of 1.78% of HTLV-1 was found in immigrants from Kyushu residing in the ARB [88]. The Marajo Archipelago also showed different figures according to the population group investigated.…”

Endocrine and metabolic disorders in HTLV-1 infected patients

“…[1][2][3] The HTLV-1 infection is endemic in Japan and several countries in South America, Caribbean and Africa. 2,[4][5][6][7] The transmission pathways of HTLV-1 infection include vertical, parenteral and sexual transmission. 2,7 Risk factors associated with HTLV-1 infection include: hemotransfusion, low socioeconomic status, low education level, high-risk sexual behavior, anal sex, fi rst sexual relationship before 18 year-old and having more than 3 sexual partners in life.…”

No Relationship between HTLV‐1 Infection and Filariasis—Serological Study on Patients with Filariasis in Recife, Brazil

“…Positive reactivity to HTLV-1-associated antigen in sera was commonly observed among people in endemic areas such as southern Japan, Caribbean islands and parts of Africa and South America (2, 3, 5, 10) but was rarely seen in non-endemic areas including some areas studied in Brazil, except in some high-risk infection groups (1,4,9,11).…”