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Human T-lymphotropic viruses (HTLV) are Deltaretroviruses that infect millions of individuals worldwide via the same transmission routes as HIV. With the aim of exposing the possible re-emergence of HTLV in West Africa since discovery, a systematic review was carried out, focusing on the distribution of the virus types and significance of frequent indeterminate reports, while highlighting the need for mandatory routine blood screening. Capturing relevant data from discovery till date, sources searched were Google Scholar, CrossRef, NCBI (PubMed), MEDLINE, Research Gate, Mendeley, abstracts of Conferences and Proceedings, organization websites and reference lists of selected papers. A total of 2626 references were initially retrieved using search terms: Worldwide prevalence of HTLV, HTLV in Africa, HTLV in West Africa, HTLV subtypes, HTLV 3 and 4 in Africa, HTLV of African origin, HTLV seroindeterminate results, Spread of HTLV. These references were rigorously trimmed down to 76. Although evidence shows that HTLV is still endemic in the region, West Africa lacks recent epidemiological prevalence data. Thorough investigations are needed to ascertain the true cause of indeterminate Western Blot results. It is imperative that routine screening for HTLVs be mandated in West African health care facilities. Keywords: HTLV in West Africa, Worldwide distribution, Epidemiology, HAM/TSP, Seroindeterminate individuals, Blood transfusion, ATLL

Human T-lymphotropic virus (HTLV) infection has been under enhanced surveillance in England and Wales since 2002, however, little is known about testing patterns. Using data from two surveillance systems held at Public Health England, we described HTLV antibody testing patterns between 2008 and 2013 and the demographic and clinical characteristics of persons diagnosed with HTLV in England and Wales between 2004 and 2013. An increase in HTLV testing was observed in England between 2008 and 2013 (3,581 to 7,130). Most tests (82%; 7,597/9,302) occurred within secondary care, 0.5% (48/9,302) of persons were reactive for HTLV antibodies and 0.3% (27/9,302) were confirmed positive. Increasing age and female sex were predictors of a reactive HTLV screen and confirmed diagnosis. Testing in primary care including sexual health and antenatal services was infrequent. Between 2004 and 2013, 858 people were diagnosed with HTLV, most of whom were female (65%; 549/851), of black Caribbean ethnicity (60%), not born in the United Kingdom (72%; 369/514) and asymptomatic at diagnosis (45%; 267/595). Despite increased testing, the epidemiology and clinical features of those diagnosed with HTLV have remained consistent. Apart from donor screening, testing for HTLV infection remains uncommon, except to diagnose associated disease.

Marina Lobato Martins1,3, Rafaela Gomes Andrade2,3, Bernardo Hinkelmann Nedir2,3 and Edel Figueiredo Barbosa-Stancioli2,3 1Gerencia de Desenvolvimento Tecnico Cientifico, Centro de Hematologia e Hemoterapia de Minas Gerais (Fundacao HEMOMINAS), 2Laboratorio de Virologia Basica e Aplicada, Departamento de Microbiologia, Universidade Federal de Minas Gerais, 3Interdisciplinary HTLV Research Group (GIPH) Brazil

Human T-lymphotropic virus type 1 (HTLV-1) and HTLV-2 were among the first human retroviruses discovered in the early 1980's. The International Retrovirology Association is an organized effort that fostered the efforts of scientists and clinicians to form interdisciplinary groups to study this group of retroviruses and their related diseases. The Association promotes excellent science, patient education, and fosters the training of young scientists to promote "bench-to-bedside" research. The International Conference on Human Retrovirology: HTLV and Related Viruses sponsored by the Association supports clinicians and researchers in the exchange of research findings and stimulation of new research directions. This years conference will be held from June 22 to 25, in Montego Bay, Jamaica http://www.htlvconference.org.jm/. Since its inception in 1988, these conferences have provided a highly interactive forum for the global community of HTLV scientists. This is of particular importance as HTLV research enters its third decade and a new generation of scientists takes over this important work. Many of the scientists attending the meeting will be from developing countries where HTLV is endemic, consistent with the history of international collaborations that have characterized HTLV research. The International Conference on Human Retrovirology provides a unique opportunity for researchers of all disciplines interested in HTLV infections to meet their peers and to address the questions facing clinicians and scientists who study retroviruses, like HTLV.

Human T lymphotropic viruses (HTLVs) have a limited spread in the general populations of Western countries. Consequently, the transfusional risk for HTLV is consider to be low in Italy and the screening for anti-HTLV-I/II antibodies has not yet been introduced. In 1992, 1087 blood donors attending a transfusional center in northern Italy underwent anti-HTLV-I/II screening carried out by means of two different ELISA tests. Eleven individuals who were negative at the first test were borderline at the second, eight of them showing reactivity to Western blot (WB). Polymerase chain reaction (PCR) for the detection of HTLV DNA, subsequently performed on the peripheral blood mononuclear cells of these 11 subjects, was positive in the same 8 WB-reactive donors. Five of them were infected by HTLV-II, and three by HTLV-1. Our results confirm that the sensitivity of the ELISA tests actually used for the detection of HTLV-I/II antibodies is low, and that HTLV-infected blood donors may be frequently undetected. Moreover, in our study population, the prevalence of HTLV infection (0.73%) was greater than that which might be expected from the existing seroepidemiological data in Italy.

Sera of 65 hemophiliacs, 85 hemodialysis patients and 304 healthy volunteer blood donors in Japan were tested for antibodies against both HTLV-I and -III by an indirect immunofluorescence and radioimmunoprecipitation assay. The results showed that 10 (15.4%) of the hemophiliacs were anti-HTLV-III positive, while all other subjects were anti-HTLV-III negative. All groups contained subjects positive for anti-HTLV-I. The prevalence of the antibody in the hemophiliacs (17.4%) and hemodialysis patients (9.4%) was significantly high as compared to that of healthy controls (1%).

Human T-lymphotropic viruses (HTLV) type I and II were first described more than a decade ago. HTLV-I epidemiology and etiopathology are more defined than those of HTLV-II, but conflicting results have been obtained in seroepidemiologic surveys, mainly for difficulties in the discrimination between the two infections. The introduction of advanced serologic and molecular assays has recently provided sensitive and specific tools for diagnosis, and the epidemiologic and etiopathologic patterns linked to these retroviruses are being more precisely defined. Moreover, extensive nucleotide sequence analyses performed so far have mainly focused on HTLV-I isolates. The recent discovery of new HTLV-II endemic areas and the isolation of HTLV-II strains from intravenous drug users have finally provided the material for the molecular characterization of HTLV-II isolates, which is now a rapidly envolving field. We review the diagnostic strategies available and the etiologic associations reported so far for both viruses and also discuss the occurrence and significance of indeterminate serologic reactivities observed in both endemic and non-endemic areas.