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Origin and prevalence of human T-lymphotropic virus type 1 (HTLV-1) and type 2 (HTLV-2) among indigenous populations in the Americas.

Paiva A, Casseb J - Rev. Inst. Med. Trop. Sao Paulo (2015 Jan-Feb)

Bottom Line: In the Americas, HTLV-1 has more than one origin, being brought by immigrants in the Paleolithic period through the Bering Strait, through slave trade during the colonial period, and through Japanese immigration from the early 20th century, whereas HTLV-2 was only brought by immigrants through the Bering Strait.The endemicity of HTLV-2 among the indigenous people of Brazil makes the Brazilian Amazon the largest endemic area in the world for its occurrence.A review of HTLV-1 in all Brazilian tribes supports the African origin of HTLV-1 in Brazil.

View Article: PubMed Central - PubMed

Affiliation: Universidade Federal de Alagoas, Hospital Universitário, Maceió, Alagoas, Brazil.

ABSTRACT
Human T-lymphotropic virus type 1 (HTLV-1) is found in indigenous peoples of the Pacific Islands and the Americas, whereas type 2 (HTLV-2) is widely distributed among the indigenous peoples of the Americas, where it appears to be more prevalent than HTLV-1, and in some tribes of Central Africa. HTLV-2 is considered ancestral in the Americas and is transmitted to the general population and injection drug users from the indigenous population. In the Americas, HTLV-1 has more than one origin, being brought by immigrants in the Paleolithic period through the Bering Strait, through slave trade during the colonial period, and through Japanese immigration from the early 20th century, whereas HTLV-2 was only brought by immigrants through the Bering Strait. The endemicity of HTLV-2 among the indigenous people of Brazil makes the Brazilian Amazon the largest endemic area in the world for its occurrence. A review of HTLV-1 in all Brazilian tribes supports the African origin of HTLV-1 in Brazil. The risk of hyperendemicity in these epidemiologically closed populations and transmission to other populations reinforces the importance of public health interventions for HTLV control, including the recognition of the infection among reportable diseases and events.

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HTLV-1 and HTLV-2 among indigenous populations of South America. Based onthe references from Table 2.
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f03: HTLV-1 and HTLV-2 among indigenous populations of South America. Based onthe references from Table 2.

Mentions: In South America, HTLV-2 predominates among indigenous groups (Table 1), with subtype 2b clearly prevailing inAmerindian populations121, except in Brazil, where it is characterized by subtype 2c23,43,69,72,119,126 (Fig. 1). HTLV-1 and HTLV-2 also differ intheir geographical distribution among the various indigenous groups (Fig. 3). FUJIYOSHI et al. (1999)51 conducted a seroepidemiological study on indigenous peoples of the Andes ofColombia, Peru, Bolivia, Argentina, and Chile; Chiloé Island (Chilean coast); EasterIsland (Chilean province of Polynesia); and the plains along the Atlantic coast fromColombia to the Orinoco, Amazon, and Patagonia, demonstrating an ethnic andgeographically independent distribution between HTLV-1 and HTLV-2, with foci of HTLV-1prevalent mainly in the Andean highlands and that of HTLV-2 in the coastal plains.FUJIYOSHI et al. (1995)50 also observed that HLA haplotypes in indigenous Andean groups with HTLV-1 andindigenous groups with HTLV-2 of the lower Orinoco (Venezuelan Amazon) were mutuallyexclusive. HLA haplotypes associated with HTLV-1 are commonly found in the known HTLV-1endemic Indian and Japanese populations, whereas the haplotypes associated with HTLV-2are specifically found among indigenous Orinoco and North American groups, suggestingthat ethnic HLA haplotypes are separate from those native to South America and may beinvolved in the susceptibility to infection by HTLV-1 or HTLV-2. In southern Colombia,for example, HTLV-1 was first detected among natives belonging to the Paez people of the Andes136. Subsequently, HTLV-2 has been identified among the Wayuu, Guahibo, and Tunebogroups in the Guajira Peninsula in extreme northeastern Colombia (Caribbean Sea), withprevalence rates between 4.1% and 31.5%39,50,121,136. Other foci of HTLV-1 are found in various isolated indigenous populations(Wayuu, Waunana/Noanama, Inga, Kamsa, Embera), with prevalence rates from 1.0% to 8.5%7,39,40,137. Both viruses have been detected within some of these groups7,39, although in most, HTLV-1 and HTLV-2 appear to be mutually exclusive40,41,49,136,137, including a 31.5% HTLV-2 rate among Guahibo natives49 (Table 1). These observations suggestthat the natives of South America could be divided into two major ethnic groups by anHTLV-1 and HTLV-2 carrier state that evolved among mongoloid populations and transmittedindependently as two different strains among the indigenous peoples of the Andeshighlands and coastal Atlantic plains41,50,51,137.


Origin and prevalence of human T-lymphotropic virus type 1 (HTLV-1) and type 2 (HTLV-2) among indigenous populations in the Americas.

Paiva A, Casseb J - Rev. Inst. Med. Trop. Sao Paulo (2015 Jan-Feb)

HTLV-1 and HTLV-2 among indigenous populations of South America. Based onthe references from Table 2.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4325517&req=5

f03: HTLV-1 and HTLV-2 among indigenous populations of South America. Based onthe references from Table 2.
Mentions: In South America, HTLV-2 predominates among indigenous groups (Table 1), with subtype 2b clearly prevailing inAmerindian populations121, except in Brazil, where it is characterized by subtype 2c23,43,69,72,119,126 (Fig. 1). HTLV-1 and HTLV-2 also differ intheir geographical distribution among the various indigenous groups (Fig. 3). FUJIYOSHI et al. (1999)51 conducted a seroepidemiological study on indigenous peoples of the Andes ofColombia, Peru, Bolivia, Argentina, and Chile; Chiloé Island (Chilean coast); EasterIsland (Chilean province of Polynesia); and the plains along the Atlantic coast fromColombia to the Orinoco, Amazon, and Patagonia, demonstrating an ethnic andgeographically independent distribution between HTLV-1 and HTLV-2, with foci of HTLV-1prevalent mainly in the Andean highlands and that of HTLV-2 in the coastal plains.FUJIYOSHI et al. (1995)50 also observed that HLA haplotypes in indigenous Andean groups with HTLV-1 andindigenous groups with HTLV-2 of the lower Orinoco (Venezuelan Amazon) were mutuallyexclusive. HLA haplotypes associated with HTLV-1 are commonly found in the known HTLV-1endemic Indian and Japanese populations, whereas the haplotypes associated with HTLV-2are specifically found among indigenous Orinoco and North American groups, suggestingthat ethnic HLA haplotypes are separate from those native to South America and may beinvolved in the susceptibility to infection by HTLV-1 or HTLV-2. In southern Colombia,for example, HTLV-1 was first detected among natives belonging to the Paez people of the Andes136. Subsequently, HTLV-2 has been identified among the Wayuu, Guahibo, and Tunebogroups in the Guajira Peninsula in extreme northeastern Colombia (Caribbean Sea), withprevalence rates between 4.1% and 31.5%39,50,121,136. Other foci of HTLV-1 are found in various isolated indigenous populations(Wayuu, Waunana/Noanama, Inga, Kamsa, Embera), with prevalence rates from 1.0% to 8.5%7,39,40,137. Both viruses have been detected within some of these groups7,39, although in most, HTLV-1 and HTLV-2 appear to be mutually exclusive40,41,49,136,137, including a 31.5% HTLV-2 rate among Guahibo natives49 (Table 1). These observations suggestthat the natives of South America could be divided into two major ethnic groups by anHTLV-1 and HTLV-2 carrier state that evolved among mongoloid populations and transmittedindependently as two different strains among the indigenous peoples of the Andeshighlands and coastal Atlantic plains41,50,51,137.

Bottom Line: In the Americas, HTLV-1 has more than one origin, being brought by immigrants in the Paleolithic period through the Bering Strait, through slave trade during the colonial period, and through Japanese immigration from the early 20th century, whereas HTLV-2 was only brought by immigrants through the Bering Strait.The endemicity of HTLV-2 among the indigenous people of Brazil makes the Brazilian Amazon the largest endemic area in the world for its occurrence.A review of HTLV-1 in all Brazilian tribes supports the African origin of HTLV-1 in Brazil.

View Article: PubMed Central - PubMed

Affiliation: Universidade Federal de Alagoas, Hospital Universitário, Maceió, Alagoas, Brazil.

ABSTRACT
Human T-lymphotropic virus type 1 (HTLV-1) is found in indigenous peoples of the Pacific Islands and the Americas, whereas type 2 (HTLV-2) is widely distributed among the indigenous peoples of the Americas, where it appears to be more prevalent than HTLV-1, and in some tribes of Central Africa. HTLV-2 is considered ancestral in the Americas and is transmitted to the general population and injection drug users from the indigenous population. In the Americas, HTLV-1 has more than one origin, being brought by immigrants in the Paleolithic period through the Bering Strait, through slave trade during the colonial period, and through Japanese immigration from the early 20th century, whereas HTLV-2 was only brought by immigrants through the Bering Strait. The endemicity of HTLV-2 among the indigenous people of Brazil makes the Brazilian Amazon the largest endemic area in the world for its occurrence. A review of HTLV-1 in all Brazilian tribes supports the African origin of HTLV-1 in Brazil. The risk of hyperendemicity in these epidemiologically closed populations and transmission to other populations reinforces the importance of public health interventions for HTLV control, including the recognition of the infection among reportable diseases and events.

Show MeSH
Related in: MedlinePlus