Ethnic/geographic analysis of Human T-lymphotropic virus type 1 (HTLV-1) infection among Buenos Aires residents in Argentina

EIRIN ME, BRAVI C, JONES L, BERINI C, DELFINO C, BIGLIONE MM

Leuven

Conferencia; 15th International Conference on Human Retrovirology: HTLV and related viruses; 2011

The International Retrovirology Association

Introduction: HTLV-1 is endemic in the Northwest among Kollanatives while Buenos Aires city (BA) is considered asnon-endemic. In the last decades, migrations to BA havechanged from Europeans to Latin-Americans fromcountries with endemic focus for HTLV-1 infection(Bolivia, Paraguay, Peru, Brazil, and Chile) and also fromdifferent African countries.Objective: To determine the phylogeographic origin of HTLV-1strains and the ethnic background of HTLV-1 positiveresidents of Buenos Aires.Materials and methods63 HTLV-1 positive BA residents were retrospectivelystudied. Phylogeny of LTR region was performed byPAUP 4.0 and tree topology was visualized by TreeView.The ethnic origin of individuals was inferred by thestudy of mitochondrial DNA haplogroups (completecontrol region).Results: All LTR sequences were classified as Cosmopolitan subtype/Transcontinental subgroup. Twenty-five of them,belonging to individuals of Amerindian and 3 of Africanancestry, were included in the Big Latin American clusterwith HTLV-1 references from Amerindians. On theother hand, 9 LTR sequences belonging to individuals ofAmerindian ancestry, grouped with references from peopleof black ethnic component of Africa, French Guiana and Suriname (Small Latin American and South Africanclusters).Conclusions: This study confirms the presence HTLV-1 cosmopolitansubtype/ Transcontinental subgroup in BA residents andshows HTLV-1 strains from individuals of Amerindianancestry closely related to references from Africa andLatin-American countries with an important afro-amerindianethnic component. Finally, these results highlightthe importance of ethnic origin of HTLV-1infected peopleand the retroviral phylogeny to understand the influenceof migration waves in the dynamics of the infectionin a specific geographic area.