High Prevalence of HTLV-1 Infection among Japanese Immigrants in Non-endemic Area of Brazil

Abstract

BackgroundHuman T-lymphotropic virus type 1 (HTLV-1) has worldwide distribution and is considered endemic in many world regions, including southwestern Japan and Brazil. Japanese immigrants and their descendants have a high risk of acquiring this infection due to intense population exchange between Brazil and Japan.ObjectiveThis cross-sectional study aimed to estimate the prevalence of HTLV, analyze the main risk factors associated with this infection, identify the main circulating types and subtypes of HTLV in Japanese immigrants and descendants living in Campo Grande-MS (Middle-West Brazil), as well as analyze the phylogenetic relationship among isolates of HTLV.Study DesignA total of 219 individuals were interviewed and submitted to blood collection. All collected blood samples were submitted for detection of anti-HTLV-1/2 using the immunoassay ELISA and confirmed by immunoblot method. The proviral DNA of the 14 samples HTLV- 1 positive were genotyped by nucleotide sequencing.ResultsThe overall prevalence of HTLV-1 was 6.8% (IC 95%: 3,5-10,2). Descriptive analysis of behavioral risk factors showed statistical association between HTLV-1 and age greater than or equal to 45 years. The proviral DNA of HTLV-1 was detected in all HTLV-1 positive samples. Of these, 14 were sequenced and classified as Cosmopolitan subtype, and 50% (7/14) belonged to subgroup A (transcontinental) and 50% (7/14) to the subgroup B (Japanese).ConclusionThe high prevalence of HTLV-1 found evidence of the importance of early diagnosis and counseling of individuals infected with HTLV-1 for the control and prevention of the spread of this infection among Japanese immigrants and their descendants in Central Brazil.

HTLV‐1 intrafamilial transmission among Japanese immigrants in Brazil

“…Proviral DNA was extracted from whole blood samples using the Wizard Genomic DNA Purification Kit (Promega, Madison, WI), according to the manufacturer's instructions. Polymerase chain reaction targeting the HTLV‐1 5′ long terminal repeat (LTR), agarose gel electrophoresis, and DNA visualization were performed as previously described and the obtained amplicons were purified using illustra™ PCR DNA and Gel Band Purification Kit (GE Healthcare) according to the manufacturer's instructions. Then, purified amplicons (635 nucleotides) were directly sequenced using the BigDye Terminator v3.1 Cycle Sequencing kit (Applied Biosystems, Foster City, CA).…”

“…In a recent paper, we calculated a 6.8% prevalence among Okinawan immigrants and their descendants aged 11‐101 (mean 54.4) years in Campo Grande. The existence of two HTLV‐1 subgroups, namely transcontinental and Japanese, was reported.…”

Oral and cutaneous lymphomas other than mycosis fungoides and sézary syndrome in a mexican cohort: Recategorization and evaluation of international geographical disparities

“…[50515253] This contrasts with the higher frequency of HTLV-I/II seropositivity and the prevalence of ATCLL reported among Asians and South Americans (namely Brazil). [545556]…”

Evaluation of human T-lymphotropic virus prevalence/co-infection rates for a four-year period in a non-metropolitan blood center in Southeast Brazil

“…A large community of Japanese descendants lives in Araçatuba, which could be responsible for the slightly higher HTLV prevalence. Similarly, a high HTLV-1 prevalence (6.8%) was observed in Japanese descendants from a non-endemic area in Brazil (City of Campo Grande, mid-west Brazil) (6) . However, we could not confirm this because the ethnicity of the HTLV-positive blood donors from this locality was not collected.…”