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To assess the prevalence of human T cell leukemia virus type I (HTLV-I) and 2 (HTLV-II) infection and the associated risk factors among immigrants living in Northern Italy, we surveyed 3017 open-population subjects from three geographical areas and 371 prisoners. In the open population, the overall prevalence was 0.3% for HTLV-I and 0.1% for HTLV-II, while among prisoners, HTLV-I and HTLV-II infection were detected in 1.4 and 0.8% of subjects, respectively. HTLV-I prevalence was higher in subjects with multiple sexual partners or sexually transmitted diseases. This association was significant in the open-population group and close to significance in prisoners. Multivariate analysis showed that human immunodeficiency virus (HIV) seropositivity remained significantly associated with HTLV-I infection in both targeted populations (OR: 11.2 in the open population; OR: 9.9 among prisoners), whereas sexual exposure was associated with HTLV-I seropositivity only for prisoners (OR: 14.3). No independent variable was related to HTLV-II infection.

PURPOSE: A literature review was performed of the three principal subpopulations most commonly associated with human T-cell lymphotropic virus type II (HTLV-II) with the view of identifying the prevalence and transmission routes of HTLV-II. These included blood donors (BDs), intravenous drug users (IVDUs), and Amerindians (Indian populations from the Americas). We used the major criterion of serological and molecular distinction between human T-cell lymphotropic virus types I (HTLV-I) and II (HTLV-II). Three questions were formulated in addressing the possibility that HTLV-II might be responsible for the reported prevalence and transmission of this virus in these groups. Question One: Which population groups have the highest HTLV-II seroprevalence rates? Question Two: Are worldwide HTLV infection rates among the three sub-populations associated predominantly with the HTLV-II retrovirus type? Question three: What are the principal modes of transmission of HTLV-II? METHODS: Since earlier epidemiologic studies did not routinely use assays capable of distinguishing between HTLV-I and HTLV-II antibodies, their findings are necessarily inaccurate. However, with the more recent development of enhanced serologic assays, using recombinant antigens that are capable of accurately making this differentiation, it is now possible to more precisely define the epidemiology of HTLV-II. We reviewed only those studies where serological and molecular methods of accurately distinguishing between the two retroviruses were utilized. Initially, we located 36 studies, which met this particular review criterion. Of the five different assays we identified, the most prevalent were the polymerase chain reaction (PCR) ( n = 14) and the synthetic peptide-based enzyme-linked immunoassay (Synth EIA) ( n = 13). Our BD, IVDU, and Amerindian groups were also evaluated according to this differentiation schema. We were able to locate over 100 prevalence studies where focus was on some aspect of analysis of at least one or more of these three groups. By using many search terms — such as HTLV-II endemic population, seroepidemiological, as well as case control and cohort studies — we were able to create a comprehensive bibliographic database. RESULTS: The two groups identified with high HTLV-II prevalence rates are the IVDUs and Amerindian population. The importance of breast-feeding, IVDU, and contaminated blood products in the HTLV-II transmission process is confirmed. Sexual intercourse, however, as a mode of HTLV-II transmission remains problematic. CONCLUSIONS: By confining our evaluation to only those studies that used serological and/or molecular methods capable of distinguishing between the two retroviruses , we have been able to establish with confidence that there are consistent emerging patterns of HTLV-II infection in these populations.

A infecção pelos vírus HTLV-I/II encontra-se presente em todas as regiões brasileiras, mas as prevalências variam de um estado para outro, sendo mais elevadas na Bahia, Pernambuco e Pará. As estimativas indicam que o Brasil possui o maior número absoluto de indivíduos infectados no mundo. Testes de triagem de doadores e estudos conduzidos em grupos especiais (populações indígenas, usuários de drogas intravenosas e gestantes) constituem as principais fontes de informação sobre essas viroses em nosso país. O HTLV-I causa a leucemia/linfoma de células T do adulto (LLTA), a paraparesia espástica tropical/mielopatia associada ao HTLV (TSP/HAM), uveíte associada ao HTLV (HAU) e anormalidades dermatológicas e imunológicas. O HTLV-II não se mostrou associado a nenhuma doença até o momento. O diagnóstico é feito com testes de triagem (ELISA, aglutinação) e confirmatórios (Western Blot, PCR). Estes vírus são transmitidos pelo sangue e agulhas contaminadas, através de relações sexuais e de mãe para filho, especialmente através do aleitamento materno. Medidas de prevenção devem focalizar a orientação de doadores soropositivos, mães infectadas e usuários de drogas intravenosas.

Background Universal HTLV antenatal screening is currently not mandatory in European countries. However, the large number of immigrants coming from HTLV-I endemic areas might force to change this recommendation in the near future. Objectives To determine the prevalence of HTLV infections in immigrant pregnant women attended in a general Hospital in the Mediterranean coast of Spain. Study design From February 2006 to December 2009, a cross-sectional study was carried out on all immigrant pregnant women attended at a reference obstetric unit in Elche, Spain. An enzyme immunoassay (EIA) was used for testing HTLV-I/II antibodies in serum, being reactive samples further confirmed by Western blot. Results A total of 1439 immigrant pregnant women were examined. Overall, 520 (36.1%) came from Central and South America and 90 (6.2%) from Sub-Saharan Africa, where HTLV infection is endemic. Three samples were EIA-seroreactive for HTLV-1/2. One of them was a woman infected with HTLV-I coming from Brazil and the other two were women infected with HTLV-II coming from Bolivia and Colombia, respectively. Thus, the overall HTLV seroprevalence in the study population was 2.1 per 1000 (95% CI: 0.5–6.6/1000), although it reached to 0.58% in the subset of women from Central and South America. Conclusions HTLV antenatal screening should be considered in pregnant women coming from Central and South America, in whom the prevalence of infection is relatively high and avoidance of breastfeeding may effectively prevent vertical HTLV transmission.

To determine the seroprevalence of Human T-cell Lymphotropic Virus-1/2 (HTLV-1/2) in blood donors in Northern Pakistan.Descriptive study.Armed Forces Institute of Transfusion, Rawalpindi, from July to August 2013.A total of 2100 blood donors were screened for anti-HTLV-1/2 antibodies during the study period, in a pool of six, on a highly sensitive, Chemiluminiscent Microparticle Immunoassay (CMIA) based system. The screening test-reactive donors were recalled, counseled and interviewed, and a fresh sample was obtained for confirmatory testing. Confirmation was performed using additional immunoassays including Line Immunoassay (LIA); with additional testing for HTLV-1 pvDNAPCR. Frequency and percentages were determined.Four donors (0.19%) were repeatedly screening test-reactive and were subsequently confirmed to be HTLV-1 infected by line immunoassay and HTLV-1 pvDNAPCR. All four donors were male with mean age of 27 ± 6.27 years. Two (50%) of the positive donors gave history of Multiple Sexual Partners (MSP).HTLV-1 seroprevalence in Northern Pakistan blood donors was determined to be 0.19%. Large scale studies, including the cost effectiveness of screening blood donations for anti-HTLV-1/2 in Pakistan, are recommended.

Background HTLV-1/2 infection can cause severe and disabling diseases in children and adults. The aim of the study was to estimate the prevalence of HTLV-1/2 infection in pregnant women living in the metropolitan area of Rio de Janeiro. Methodology/Principal Findings 1,204 pregnant women were tested upon hospital admission for delivery in two public hospitals in the cities of Rio de Janeiro and Mesquita, between November, 2012 and April, 2013. The samples were screened by chemiluminescent microparticle immunoassay (CMIA) and reactive ones were confirmed by Western blot (WB). Epi-info software was used for building the database and performing the statistical analysis. Eight patients had confirmed HTLV-1/2 infection (7 HTLV-1, one HTLV-2), equivalent to a prevalence rate of 0.66%. Two further reactive screening tests had negative Western blot results and therefore were considered negative in the statistical analysis. All HTLV-1/2-positive patients were born in Rio de Janeiro, most were non-Caucasian (87.5%), in a stable relationship (62.5%), had at least ten years of formal education (62.5%) and a monthly family income of up to US$600.00 (87.5%). There was only one case of coinfection with syphilis and none with HIV. The mean age of the infected women was 28.4 (SD = 6.3) years and of the seronegative ones was 24.8 (SD = 6.5) (p = 0.10). The median number of pregnancies were 3.0 and 1.0 (p = 0.06) and the median number of sexual partners were 3.5 and 3.0 (p = 0.33) in the seropositive and negative groups, respectively. There were no statistically significant differences between the groups. Conclusions/Significance A significant prevalence of HTLV-1/2 was found in our population. The socio-epidemiological profile of carrier mothers was similar to the controls. Such findings expose the need for a public health policy of routine HTLV-1/2 screening in antenatal care, since counselling and preventive measures are the only strategies currently available to interrupt the chain of transmission and the future development of HTLV-1/2-related diseases., Author Summary HTLV-1/2 are retroviruses transmitted by blood products, sexual contact and from mother to child, mainly through breastfeeding. The infection has a characteristic geographical distribution with endemic areas often neighbouring very low prevalence areas. Infection is life long and although asymptomatic in most cases, it can cause severe and disabling diseases in children and adults. There is currently no cure, vaccine or effective treatment for HTLV-1/2 infections. Our research is the first to study the prevalence of HTLV-1/2 in pregnant women living in the metropolitan area of Rio de Janeiro, the second largest in Brazil. 1,204 pregnant women were tested upon hospital admission for delivery in two public hospitals in the cities of Rio de Janeiro and Mesquita, between November, 2012 and April, 2013 and a significant prevalence of HTLV-1/2 was found (0.66%). The socio-epidemiological profile of carrier mothers was similar to the controls'. Epidemiological knowledge is fundamental for the elaboration of public health policies such as routine HTLV-1/2 screening in antenatal care, since counselling and preventive measures, mainly avoidance of breastfeeding, are the only strategies currently available to interrupt the chain of transmission and the future development of HTLV-1/2-related diseases.

The human T-cell lymphotropic virus type 1 (HTLV-1) and HTLV-2 are common copathogens among Human Immunodeficiency Virus (HIV)-infected individuals. HTLV-2 may confer a survival benefit among patients with HIV-1/HTLV-2 coinfections, along with lower plasma HIV-1 levels and delayed rates of CD4(+) T-cell decline. These effects have been attributed to the ability of the HTLV-2 viral transactivating Tax2 protein to induce the production of high levels of antiviral CC-chemokines and to downregulate expression of the CCR5 receptor, resulting in impaired entry of HIV-1 into CD4(+) T-cells. This study investigated the innate immunity of coinfected HIV/HTLV individuals by testing the ability of patient PBMCs to produce CC-chemokines in association CCR5 receptor modulation. The cellular proliferative responses of HIV/HTLV coinfected versus HIV monoinfected individuals were also evaluated. Higher levels of MIP-1α, MIP-1β, and RANTES (P 0.05) were found in HIV-1/HTLV-2 coinfected group compared to HIV-1 monoinfected population. Upregulated levels of RANTES were shown in HIV-1/HTLV-1 after 1 and 3 days of culture (P 0.05). Lymphocytes from HIV-1/HTLV-2 coinfected individuals showed significant CCR5 downregulation after 1 and 3 days of culture compared to lymphocytes from HIV-1 and uninfected groups (P 0.05). Lower percentages of CCR5-positive cells were found in HIV-1/HTLV-1 coinfected after 3 days of incubation (P 0.05). Levels of proliferation were significantly higher in the HIV-1/HTLV-1 group compared to HIV-1 alone (P 0.05). HTLV-2 and HTLV-1 infections may induce the involvement of innate immunity against HIV-1 via stimulation of CC-chemokines and receptors, potentially modifying CCR5/HIV-1 binding and HIV-1 progression in coinfected individuals.

There are many viruses that are not cleared from the body after they infect an individual. These include the herpes simplex viruses, hepatitis B, and five other viruses that are discussed in this chapter. The viruses are presented in chronologic fashion based on discovery, focusing on the possible sequelae that chronic infection with these viruses can cause. Adult T-cell lymphoma/leukemia (ATLL), an aggressive leukemia/lymphoma, remains a difficult disease to treat. A section reviews the natural course of human immunodeficiency virus (HIV) in the infected individual and follows it with an in-depth review of the major sequelae, listed by organ system. The immune system takes the brunt of the effects of HIV since these cells are the target of the virus. As an individual becomes infected, HIV quickly decimates the immune system. The chapter focuses first on the effect of HIV itself and only briefly mentions the infections that can affect the nervous system. Peripheral neuropathies have become the most common neurologic complication in the highly active antiretroviral therapy (HAART) era. They have been classified as inflammatory demyelination polyradiculoneuropathy, mononeuropathy multiplex or radiculopathy, distal symmetric polyneuropathy (DSP), and toxic neuropathy from antiretroviral therapy. Although pulmonary hypertension (PAH) may be associated with human herpesvirus 8 (HHV-8), HIV has been associated with pulmonary hypertension when no other organisms have been identified.

Introduction : Transmission of human T-lymphotropic viruses (HTLV) occurs from mother to child, by sexual contact and blood transfusion. Presently, in most centres in Nigeria, there is no routine pre-transfusion screening for HTLV. The study aims to determine the prevalence of HTLV- 1 and HTLV-2 among healthy blood donors at a tertiary centre in Lagos. Methods : A cross-sectional study was carried out at the blood donor clinic of the Lagos State University Teaching Hospital (LASUTH), Ikeja. About 5mls of venous blood was collected from each subject into a sterile plain bottle after obtaining subject's consent. The serum separated and stored at -200C. Sera were assayed for HTLV by an enzyme-linked immunoassay (ELISA) for the determination of antibodies to HTLV 1 and HTLV -2. Western blot confirmatory testing was done on reactive samples. All donors were also screened for HIV, HBsAg and HCV by rapid kits. Results : The seroprevalence of HTLV -1 by ELISA was 1.0% and 0.5% by Western Blot among blood donors. A total of 210 healthy blood donors were enrolled. Only 2 (1.0%) blood donors were repeatedly reactive with ELISA test. On confirmatory testing with Western Blot, 1 (0.5%) blood donor was positive for HTLV. All the healthy blood donors were negative for HIV, HbsAg and HCV. None of the 210 blood donors had been previously transfused; as such no association could be established between transfusion history and HTLV positivity among the blood donors. Conclusion: The seroprevalence of HTLV in this environment is low among healthy blood donors. Key words : Seroprevalence, HTLV, healthy blood donors, Nigeria

The identification of blood-borne viral infections is important in transfusion medicine. The aim of this study was to evaluate the prevalence of human herpesvirus (HHV) [cytomegalovirus (CMV), HHV-6, HHV-7 HHV-8] and human retrovirus (HRV) (human T-cell lymphotropic virus (HTLV)-I/II, HRV-5) infections among apparently healthy Latvian blood donors. DNA extracted from peripheral blood leukocytes (PBL) of 150 individuals was tested for herpesviruses by sensitive polymerase chain reaction (PCR) technique. None of the blood donors was positive for HHV-8 infection, while the incidence of latent beta-herpesvirus infections was high: single infection by CMV, HHV-6, and HHV-7 was detected in 2.6%, 8.0%, and 43.3% of blood donors, respectively. Simultaneous dual and triple infections of these viruses were observed in 28.0% and 4.7% of individuals, respectively. Active infection by CMV and HHV-6 was not found, but HHV-7 DNA was present in plasma of 10.6% of the blood donors. While all blood donors were HTLV-II and HRV-5 negative, 4.6% of HTLV-I seronegative blood donors were positive for the HTLV-I tax gene, although none of them harbored sequences for structural genes of the provirus. Based on our results, we conclude that monitoring of beta-herpesvirus infections in blood donors can be important in cases of transfusions to immunocompromised persons. HHV-8, as well as the retroviruses HTLV-II and HRV-5, were not found in blood of Latvian blood donors. More investigations are required to explain the presence of the HTLV-I tax sequence in seronegative blood donors.

Phenotypic change and broader coreceptor usage by HIV-1 have been associated with disease progression. HIV-1 coreceptor usage by primary isolates obtained from HIV-1-infected and HIV-1/HTLV-II-coinfected individuals was determined. HIV-1 was isolated from 15 of 20 HIV-1-infected and 17 of 24 HIV-1/HTLV-II-coinfected individuals. None of the isolates from either the HIV-1-infected or the coinfected group infected CCR5delta32 PBMCs, suggesting that they all were R5-tropic. Further, both spontaneous and PHA-stimulated production of MIP-1beta and RANTES were similar in HIV-1-infected and coinfected individuals. These data indicate that coinfection with HTLV-II has no effect on HIV-1 coreceptor usage or ex vivo beta-chemokine production.

Extensive studies have been carried out on native Amerindian populations living in French Guiana in an attempt to detect human T cell leukemia virus type 2 (HTLV-2). However, the first strain of this virus identified in this region was not detected in these populations, but in a Brazilian woman of Amerindian origin. Comparative analyses of the nucleotide sequences of 589 bp of the gp21 env gene and of 625 bp of the long terminal repeat (LTR) showed that this new HTLV-2 strain (HTLV-2 GUY) was of subtype A. Sequence comparison and phylogenetic analyses demonstrated that HTLV-2 GUY was closely related to a group of distinct variants of HTLV-2 subtype A strains originating mostly from Brazilian inhabitants and formerly called HTLV-2 subtype C. As there is a high level of immigration from Brazil in French Guiana, we carried out a seroepidemiological study of 175 Brazilians, mostly women (obtained from a serum databank) and 72 female Brazilian prostitutes living in French Guiana to determine whether HTLV-2 is likely to become an emerging infection in this area. No HTLV-2 infection was detected, indicating that this virus is unlikely to become prevalent in the near future.

Because HTLV-I, HTLV-2, and HIV share identical modes of transmission, simultaneous or subsequent infections with these retroviruses are to be expected. The population of Santos, the largest port in Latin America, includes large numbers of female commercial sex workers and intravenous drug users, presumably having been exposed to retroviral infection. To evaluate the seroprevalence of HTLV infection and their associated risk factors, a cross-sectional survey was carried out in 499 HIV-infected individuals from Santos, Brazil. HTLV testing consisted of enzyme immunoassays for serologic screening and confirmatory Western blot testing. Overall HTLV-I and HTLV-2 seroprevalences were 6.0% (95% confidence interval [CI], 3.9-8.1) and 7.4% (95% CI, 5.1-9.7), respectively. Multivariate logistic regression for statistical analysis revealed HTLV-I infection to be independently associated with: intravenous drug use (IDU) (odds ratio [OR]. 2.99; 95% CI, 1.09-8.20), seropositivity to hepatitis C virus (HCV) (OR, 3.03; 95% CI, 1.02-9.01) and < 3 years of education (OR, 4.73; 95% CI, 1.56-14.41). HTLV-2 infection was associated with: IDU (OR, 3.22; 95% CI, 1.33-7.84), HCV seropositivity (OR, 5.40; 95% CI, 1.86-15.66) and nonwhite race (OR, 3.32; 95% CI, 1.58-7.00). Results indicate that HIV-infected individuals living in Santos are at similarly high risk of being exposed to HTLV- 1 and HTLV-2. IDU constitutes the main risk factor for HTLV acquisition in this population, and there is no significant risk associated with sexual practice.

The prevalence of human T-cell lymphotropic viruses types 1 and 2 (HTLV-1/2) in Mozambique is not known. The present study examined blood samples from 208, 226, and 318 individuals from Northern, Central, and Southern Mozambique, respectively, of all socioeconomic and demographic strata attending public health centers in Mozambique for HTLV-1/2-specific antibodies. Serum samples were assessed for HIV- and HTLV-1/2-specific antibodies by using enzyme immunoassays, and infections with HTLV-1 and -2 were confirmed by using Western blot. An overall HTLV-1/2 prevalence of 2.3% (2.9% in female and 1.1% in male subjects) was observed, and the prevalence of infection increased with age. Regional variation in the prevalence of HIV and HTLV-1/2 was observed; 32.2%, 65.5%, and 44% of individuals tested HIV positive in Northern, Central, and Southern Mozambique, respectively, and 2.4%, 3.9%, and 0.9% tested HTLV-1/2 positive in the same regions. HTLV-1 infection was confirmed in these individuals. No association between HTLV-1 infection and sociodemographic variables or HIV status was detected, although the low number of HTLV-1-positive cases did not allow robust statistical analyses. The results obtained suggest different risk factors and epidemiologic correlates of HIV and HTLV-1 transmission in Mozambique. Furthermore, our results suggested that North and Central Mozambique should be considered endemic regions for HTLV-1 infection. As no cases of HTLV-2 were detected, HTLV-2 appears to have not been introduced into Mozambique.

To gain insight on the significance of human T-cell lymphotropic virus type 1 (HTLV-1) indeterminate serological reactivities, we studied villagers of South Cameroon, focusing on a frequent and specific HTLV-1 Gag indeterminate profile (HGIP) pattern ( gag p19, p26, p28, and p30 without p24 or Env gp21 and gp46). Among the 102 sera studied, 29 from all age groups had a stable HGIP pattern over a period of 4 years. There was no epidemiological evidence for sexual or vertical transmission of HGIP. Seventy-five percent of HGIP sera reacted positively on MT2 HTLV-1-infected cells by immunofluorescence assay. However, we could not isolate any HTLV-1 virus or detect the presence of p19 Gag protein in cultures of peripheral blood mononuclear cells obtained from individuals with strong HGIP reactivity. PCR experiments conducted with primers for HTLV-1 and HTLV-2 (HTLV-1/2 primers) encompassing different regions of the virus did not yield HTLV-1/2 proviral sequences from individuals with HGIP. Using 11 peptides corresponding to HTLV-1 or HTLV-2 immunodominant B epitopes in an enzyme-linked immunosorbent assay, one epitope corresponding to the Gag p19 carboxyl terminus was identified in 75% of HGIP sera, while it was recognized by only 41% of confirmed HTLV-1-positive sera. A positive correlation between HTLV-1 optical density values and titers of antibody to Plasmodium falciparum was also demonstrated. Finally, passage of sera through a P. falciparum -infected erythrocyte-coupled column was shown to specifically abrogate HGIP reactivity but not the HTLV-1 pattern, suggesting the existence of cross-reactivity between HTLV-1 Gag proteins and malaria-derived antigens. These data suggest that in Central Africa, this frequent and specific Western blot is not caused by HTLV-1 infection but could instead be associated with P. falciparum infection.

The aim was to assess the prevalence and modes of transmission of human T-lymphotropic virus type 1 (HTLV-1) infection in an adult population in Bissau and to evaluate possible interactions between the pattern of spread of HTLV-1 and HIV-1/HIV-2. Univariate and multivariate analyses were used to evaluate gender- and age-specific HTLV-1 prevalences as well as associated risk determinants in an adult population based on a serosurvey comprising 2127 individuals from 304 randomly selected houses in Bissau. Using stringent Western blot criteria the overall seroprevalence of HTLV-1 was 3.6% 2.2% among men and 4.7% among women respectively. One individual was seropositive to HTLV-2. The prevalence of HTLV-1 which increased with age in both genders however more markedly among women was >4 times higher (9.4%) among older individuals (>44 years of age) than among younger individuals (2.4%). Blood transfusion and HIV-2 seropositivity were independently associated with HTLV-1 seropositivity in men. Among women both HIV-2 seropositivity and HIV-1 seropositivity were significant risk determinants. Having had sexual partners was associated with a five-fold increased risk among women but did not reach significance. The adult population of Guinea-Bissau has a higher prevalence of HTLV-1 than reported from most other countries in West Africa. The gender- and age-specific pattern of spread of HTLV-1 closely resembles that observed for HIV-2 another retrovirus prevalent to the region. The close correlation between HTLV-1 and HIV-2 most likely reflects the shared risk factors related to sexual behavior. The implication of the high percentage of double infections in this population needs to be determined. (authors)

To investigate the immunological features of human T lymphotropic virus type II (HTLV-II) infection and specific mechanisms whereby HTLV-II might influence the progression of HIV-1 disease in coinfected individuals, we have analyzed the production of the C-C chemokines RANTES and macrophage inflammatory proteins 1α and 1β (MIP-1α and MIP-1β) by PBMCs from HTLV-II-infected and HTLV-II/HIV-1-coinfected individuals. We observed spontaneous production of significant levels of MIP-1α and -1β and, to a lesser extent, RANTES, from individuals infected with HTLV-II alone or with concomitant HIV-1 infection. Spontaneous C-C chemokine production was not observed in PBMCs from uninfected or HIV-1-infected individuals. Although HTLV-II is known to preferentially infect CD8+ lymphocytes in vivo, we observed that whereas RANTES was produced exclusively by the CD8+-enriched fraction, MIP-1α and -1β were produced by both the CD8+-enriched and CD8+-depleted fractions of HTLV-II-infected PBMCs. RT-PCR demonstrated active expression of the HTLV-II regulatory protein Tax in the infected CD8+ T lymphocyte population, and it was further shown that Tax transactivates the promoters of MIP-1β and RANTES. Therefore, it appears that HTLV-II stimulates the production of C-C chemokines both directly at a transcriptional level via the viral transactivator Tax and also indirectly. Although the HTLV-II-infected individuals in this study are all virtually asymptomatic, they certainly display an abnormal immune phenotype. Moreover, our findings suggest that HTLV-II, via chemokine production, would be expected to alter the progression of HIV-1 infection in coinfected individuals.

It has been established that the human T cell lymphotropic viruses type I and II (HTLV-I and HTLV-II) are both present in some indigenous peoples of the Americas. While HTLV-I has been identified in coastal British Columbia Indians (BCIs), HTLV-II has not been previously reported in the BCIs or other Canadian Amerindians. The prevalence of HTLV-I and HTLV-II in these populations has not been extensively studied. In this article, we examine a group of BCIs from Vancouver Island who belong to the Nuu-Chah-Nulth and are known to have an increased incidence of rheumatic disease. In 494 serum samples from this tribe, the levels of prevalence of HTLV-I and HTLV-II were 2.8 and 1.6%, respectively. No association could be made between arthropathy and HTLV-I infection. In addition, we characterized an HTLV-II isolate of a BCI from the coastal mainland of British Columbia and with a history of intravenous drug abuse. This case represents the first molecular characterization of a Canadian Amerindian HTLV-II isolate: a subtype IIa virus with phylogenetic affinity for intravenous drug user isolates and containing an extended form of the Tax protein. These results are consistent either with this strain having been sampled from a polymorphic ancestral pool of HTLV-II that gave rise to the current epidemic spread of this virus by intravenous drug use and sexual transmission, or with its being "back-transmitted" into the BC Amerindian population in association with intravenous drug use.

HTLV-I and HTLV-II infect T lymphocytes. A high HTLV-I proviral load in peripheral blood mononuclear cells (PBMCs) has been associated with a higher risk of neurologic disease. For HTLV-II, large numbers of infected lymphocytes might contribute to accelerate the immunodeficiency and increase the risk of neuropathy in HTLV-II/HIV-1 coinfected people. We have examined the impact of antiretroviral drugs on HTLV proviral load, testing longitudinal samples collected from 1 HTLV-I infected patient suffering HTLV-I-associated myelopathy (HAM), and two HTLV-II/ HIV-1 coinfected subjects. The HAM patient showed a reduction greater than 2 log in the peripheral proviral load after being treated with zidovudine and lamivudine. In contrast, potent antiretroviral treatment in HIV-1/HTLV-II coinfected carriers produced an initial increase in the HTLV proviral load, which was followed by a reduction greater than 1 log thereafter. In conclusion, antiretroviral drugs seem to reduce HTLV proviral load, although in HIV-1 coinfected persons a transient increase in HTLV proviral load could reflect the rapid blocking of HIV-1 replication occurring in response to therapy, thus causing an increase in the number of circulating T lymphocytes carrying HTLV proviral DNA.

Data obtained during routine diagnosis of human T-cell lymphotropic virus type 1 (HTLV-1) and 2 (HTLV-2) in "at-risk" individuals from São Paulo, Brazil using signal-to-cutoff (S/C) values obtained by first, second, and third generation enzyme immunoassay (EIA) kits, were compared. The highest S/C values were obtained with third generation EIA kits, but no correlation was detected between these values and specific antibody reactivity to HTLV-1, HTLV-2, or untyped HTLV (p=0.302). In addition, use of these third generation kits resulted in HTLV-1/2 false-positive samples. In contrast, first and second generation EIA kits showed high specificity, and the second generation EIA kits showed the highest efficiency, despite lower S/C values. Using first and second generation EIA kits, significant differences in specific antibody detection of HTLV-1, relative to HTLV-2 (p=0.019 for first generation and p0.001 for second generation EIA kits) and relative to untyped HTLV (p=0.025 for first generation EIA kits), were observed. These results were explained by the composition and format of the assays. In addition, using receiver operating characteristics (ROC) analysis, a slight adjustment in cutoff values for third generation EIA kits improved their specificities and should be used when HTLV "at-risk" populations from this geographic area are to be evaluated.

The phylogeny of human T cell lymphotropic virus type II (HTLV-II) was investigated by using strains isolated from Amerindian and Pygmy tribes, in which the virus is maintained primarily through mother-to-child transmission via breast-feeding, and strains from intravenous drug users (IDUs), in which spread is mainly blood-borne via needle sharing. Molecular clock analysis showed that HTLV-II has two different evolutionary rates with the molecular clock for the virus in IDUs ticking 150–350 times faster than the one in endemically infected tribes: 2.7 × 10 −4 compared with 1.71/7.31 × 10 −7 nucleotide substitutions per site per year in the long terminal repeat region. This dramatic acceleration of the evolutionary rate seems to be related with the mode of transmission. Mathematical models showed the correlation of these two molecular clocks with an endemic spread of HTLV-II in infected tribes compared with the epidemic spread in IDUs. We also noted a sharp increase in the population size of the virus among IDUs during the last decades probably caused by the worldwide increase in intravenous drug use.

Several studies have reported an association between HTLV-II and a neurological condition which has come to be called HTLV-II-associated myelopathy and is similar, in some cases, to HTLV-I-associated myelopathy. To further explore the establishment of an etiological link between this virus and neurological disease, we determined the HTLV status of three individuals, one of which presented with symptoms of progressive ataxia. Since the patient with neurological disease and her husband were HTLV-II positive, we had the potential to study one of few cases of an HTLV-II-associated neurological disorder, and the first case in Canada. However, although the individual with the neurological disease was HTLV-II positive, we discovered that her brother, who displays the same clinical symptoms, was not positive for either HTLV-II or HTLV-I. Thus, disease association with HTLV-II became unsupportable. We present here, nevertheless, the first sequence and phylogenetic analysis of an HTLV-II isolate in Canada. This study suggests that cases of HTLV-II and neurological disease must be carefully investigated before any etiological conclusions can be made.

To examine risk factors for human T cell lymphotropic virus type II (HTLV-II) infection, a case-control study was conducted among the Guaymi Indians of Panama. In females, HTLV-II seropositivity was associated with early sexual intercourse (≤ 13 vs. >15 years; odds ratio [OR], 2.50; 95% confidence interval [CI], 1.11-6.14) and number of lifetime sex partners. One partner increased risk of seropositivity by 30% (OR, 1.30; CI, 1.05-1.64), and risk increased with number of partners. Similar risk was associated with number of long-term sexual relationships. Among males, intercourse with prostitutes was associated with HTLV-II seropositivity (OR, 1.68; CI, 1.04-2.72). These data support a role for sexual transmission in HTLV-II infection. Association of seropositivity with primary residence in a traditional village (OR, 3.75; CI, 1.02-15.38) and lack of formal education (0 vs. >6 years [OR, 3.89; CI, 1.67-9.82]) observed in males may reflect differences in sexual practices associated with acculturation.

Using both env and long terminal repeat (LTR) sequences, with maximal representation of genetic diversity within primate strains, we revise and expand the unique evolutionary history of human and simian T-cell leukemia/lymphotropic viruses (HTLV/STLV). Based on the robust application of three different phylogenetic algorithms of minimum evolution–neighbor joining, maximum parsimony, and maximum likelihood, we address overall levels of genetic diversity, specific rates of mutation within and between different regions of the viral genome, relatedness among viral strains from geographically diverse regions, and estimation of the pattern of divergence of the virus into extant lineages. Despite broad genomic similarities, type I and type II viruses do not share concordant evolutionary histories. HTLV-I/STLV-I are united through distinct phylogeographic patterns, infection of 20 primate species, multiple episodes of interspecies transmission, and exhibition of a range in levels of genetic divergence. In contrast, type II viruses are isolated from only two species (Homo sapiens and Pan paniscus) and are paradoxically endemic to both Amerindian tribes of the New World and human Pygmy villagers in Africa. Furthermore, HTLV-II is spreading rapidly through new host populations of intravenous drug users. Despite such clearly disparate host populations, the resultant HTLV-II/STLV-II phylogeny exhibits little phylogeographic concordance and indicates low levels of transcontinental genetic differentiation. Together, these patterns generate a model of HTLV/STLV emergence marked by an ancient ancestry, differential rates of divergence, and continued global expansion.

This study investigated HTLV-II infections in a cohort of HIV-I-infected intravenous drug users (IVDAs)(n=103)in Dublin. Serological and molecular analyses have demonstrated that 15 (14.6%) were infected with HTLV-II, which is the highest rate of infection so far documented in Europe, and is equivalent to that in urban areas of the United States. Restriction fragment length polymorphism (RFLP) analysis of the env region of the provirus revealed only HTLV-IIa infection. There was no evidence of HTLV-IIb subtype infection. Phlyogenetic analysis of the nucleotide sequences of the long terminal repeat (LTR) confirmed infection with the HTLVE-IIa subtype, and the demonstrated that the viruses clustered closely with HTLV-IIa isolates from North American IVDAs. Previous observations that IVDAs in southern Europe appear to be infected predominantly with the HTLV-IIb sub-type, along with the present report and evidence that the IVDAs in Sweden are infected with HTLV-IIa subtype, suggest different origins of HTLV-II infection in Europe.

We carried out a seroepidemiologic survey to define the prevalence of human T cell lymphotropic virus types 1/2 (HTLV-1/2) infections among aboriginal populations from isolated regions of northern Argentina and the Amazon region of Peru. Antibodies against HTLV were measured with agglutination tests and confirmed with by an immunofluorescence assay (IFA) and Western blotting. Five (6.94%) of 72 samples from the Tobas Indians in Argentina were positive by the IFA; two samples were typed as HTLV-1 (2.78%), two as HTLV-2 (2.78%), and one (1.39%) could not be typed because it had similar antibody titers against both viruses. No positive samples were found among 84 Andinos Puneños and 47 Matacos Wichis Indians. Seroprevalences of 2.50% (1 of 40) and 1.43% (1 of 70) for HTLV-1 were observed among Wayku and San Francisco communities in the Amazon region of Peru, and seroprevalences of 4.54% (1 of 22) and 2.38% (1 of 42) for HTLV-2 were observed among Boca Colorada and Galilea communities. No serologic evidence of human immunodeficiency virus (HIV) infection was found among the Indians tested. These results indicated the presence of HTLV-1 and HTLV-2 in the indigenous populations of Argentina and Peru. Moreover, the lack of HIV infection indicates that the virus has probably not yet been introduced into these populations.

We studied plasma samples from 2082 Mataco Indians living in 22 different communities in the western part of Formosa Province, northern Argentina. Samples were screened for HTLV-I/II antibodies by particle agglutination assay. All positive or borderline samples were then tested by an immunofluorescence assay (IFA) on C19 HTLV-II-producing cells. Western blot was used for confirmation of all IFA-positive plasma samples. The crude HTLV-II seroprevalence was 3.0% (62 of 2051), and 0.9% (5 of 588) in children less than 10 years old. The latter result suggests ongoing mother-to-child transmission, probably by breast feeding. There was a marked increase in HTLV-II seroprevalence with age (0.9%, 0-10 years; 1.6%, 11-20 years; 4.4%, 21-30 years; 3.4%, 31-40 years; 7.2%, 41-50 years; 5.7%, >50 years) in both male (p = 0.002) and female subjects (p = 0.00002). None of the 80 non-Indian inhabitants tested was HTLV-I/II seropositive. In a second study, among 105 Toba Indians from a village (Primavera) of the eastern part of this region, 23 were HTLV-II seropositive with a seroprevalence of 59% in those more than 40 years old. From seven of the Indians from Primavera, three others from neighboring regions (including two Tobas and one Pilaga), and one intravenous drug user (IVDU) from Rosario, DNA was extracted from peripheral blood mononuclear cells, and the gp21 transmembrane-encoding gene (590 bp) was amplified by PCR, cloned, and sequenced. LTR sequences were also obtained from the Pilaga, the IVDU, and one Toba. Molecular and phylogenetic analyses revealed that the Indians were all infected with closely related HTLV-II molecular strains belonging to the b subtype, while the IVDU was infected with an HTLV-II subtype a variant. Such data help to make a phylogenetic atlas of HTLV-II among Amerindian tribes and are crucial to gain new insights into the origin and modes of dissemination of this human retrovirus in the Americas.

Human T-cell lymphotropic virus type 1 (HTLV-1) is the etiologic agent of adult T cell leukemia/lymphoma and HTLV-1-associated myelopathy/tropical spastic paraparesis. HTLV-2 has occasionally been linked to neurological disorders. HTLV-1 infection is endemic in Japan, Melanesia, Australia, Sub-Saharan Africa, and Caribbean basin. This infection is uncommon in European countries and limited to immigrants from endemic regions. HTLV-2 infection is mainly present in Amerindian population and African Pygmy tribes. It is also very common among injection drug users (IDU) in Europe and North America, especially in HIV-1-co-infected individuals. In Spain, this last population is usually co-infected with hepatitis C virus (HCV).

Earlier virologic studies established that human T-cell lymphotropic virus type II (HTLV-II) is the predominant retrovirus type found among Seminole Indians in southern Florida. We studied 46 members of the Seminole tribe living on 3 reservations to determine the risk factors for HTLV-II and to investigate disease association with the virus. The donors’ plasma samples were evaluated with the enzyme-linked immunosorbent and Western blot assays. DNA extracted from their peripheral blood mononuclear cells were analyzed by type-specific polymerase chain reaction amplification and detection of the HTLV pol gene using the primer pair SK110/SK111, and the probes SK112 or SK188. One of 46 (2%) subjects was identified as HTLV-I positive and 11 (24%) were identified as HTLV-II positive. Restriction fragment length polymorphism and sequence analyses indicated that all of the HTLV-II strains were subtype b. Mitochondrial DNA analyses indicated that all of the HTLV-II-positive subjects had an Amerindian haplotype. HTLV-II was more prevalent in Indians who were >45 years of age or female, had multiple sex partners or had received a blood transfusion. However, only the latter risk factor was statistically significant. Three of the HTLV-II-positive Indians demonstrated signs and symptoms of an ataxic neuropathy. The data support that HTLV-IIb is endemic among the Seminoles and that they will be a key population for further virologic studies.

Cytokines from peripheral blood mononuclear cells (PBMC) from human T lymphotropic virus (HTLV)-II-infected persons were studied to delineate the mechanism(s) of spontaneous lymphocyte proliferation (SLP). Culturing HTLV-II-infected PBMC that spontaneously proliferate (SLP+) resulted in greater mRNA expression and production of interferon-gamma, interleukin (IL)-4, and IL-5, with a concomitant decrease in IL-10, than was seen with nonproliferating (SLP ) and normal PBMC. While IL-2 mRNA expression was higher, production was lower in SLP+ PBMC than in SLP and normal PBMC, implying that the proliferating cells are utilizing IL-2. Neutralization of IL-2 resulted in partial inhibition, suggesting that other cytokines also affect SLP. Addition of recombinant IL-10 inhibited the proliferation of SLP+ PBMC. Further, blocking costimulatory signals with monoclonal antibodies against CD80/CD86 resulted in increased IL-10 production with concomitant inhibition of SLP. The mechanism(s) underlying HTLV-II-associated SLP in vitro involve increased utilization of IL-2 and down-regulation of IL-10.

Post-transplantation lymphoproliferative disorders (PTLD) are a clinicopathologically heterogeneous group of lymphoid proliferations. The majority are of B-cell origin and associated with Epstein-Barr virus (EBV) infection. In contrast, the development of T-cell PTLD is much less common and EBV does not appear to be involved in pathogenesis. In this report we describe three patients who developed large granular lymphocyte (LGL) leukaemia after renal transplantation. These patients had clonal expansion of CD3+, CD8+, CD57+, CD56- LGL. We were unable to detect CMV antigen or find evidence for EBV or human T-cell leukaemia/lymphoma virus genome in the LGL from these patients. These data show that LGL leukaemia should be included as one of the types of T-cell proliferations which can occur post transplant.

The aim of this study was to determine the prevalence of human immunodeficiency virus type 1 (HIV-1) and human T lymphotropic virus types I and II (HTLV-I/II) infections in 226 haemophiliac patients treated at Fundação Hemominas in Belo Horizonte, Minas Gerais State, Brazil, and to verify association with other serological results. Patients positive for HTLV-I/II had also a neurological, haematological and ophthalmological evaluation. Fundação Hemominas offers comprehensive care for all haemophiliac patients in Minas Gerais. Thirty-six (15.9%) of the 226 patients showed reactive results to HIV-1 [ELISA, Abbott, USA, confirmed by Western blot (WB), Cambridge Biotech, USA, and/or immunofluorescence, Fiocruz, Brazil] and 16 (7.1%) had reactive sera to HTLV-I/II (ELISA, Ortho). Eleven of these 16 (4.9%) were positive, 3/16 (1.3%) were indeterminate and 2/16 (0.9%) were negative in the HTLV WB (Cambridge Biotech). Neurological, haematological and ophthalmological examination of 9/16 patients revealed no abnormality suggestive of HTLV disease. Of the 16 patients reactive to HTLV-I/II ELISA test, six (37.5%) were also positive to HIV-1 (chi 2 = 5.92; P = 0.01). Seropositivity for HTLV-I/II and HIV-1 was associated with advancing age and positive results for hepatitis C virus (HCV), Chagas' disease (T. cruzi infection) and syphilis. No association between the presence of HTLV with type and severity of haemophilia and hepatitis B results was detected. The prevalence of antibodies against HIV-1 is approximately three times that of HTLV-I/II and a patient positive for HTLV-I/II had a significantly increased risk of being positive for HIV-1, HCV and T. cruzi.

Health care workers, mainly in emergency and forensic services, are at risk of exposure to bloodborne pathogens. Human T-cell lymphotropic virus type I and type II (HTLV-I and HTLV-II) are cosmopolitan human delta retroviruses causing endemic infection in Japan, the Caribbean basin, South America, and sub-Saharan Africa, and in clusters among intravenous drug users in Europe and the United States. The seroprevalence of HTLV-I and HTLV-II among Brazilian blood donors ranges from 0.08% to 1.35%. HTLV-I transmission to a Japanese researcher has already been reported. We describe the transmission of HTLV-II infection to a Brazilian laboratory worker caused by a needlestick injury when she was recapping a syringe after collecting material for arterial blood gas analysis. To our knowledge, this is the first report of an occupational transmission of HTLV-II to a health care worker.

Disease associations of HTLV-II are poorly defined, despite a high seroprevalence among injection drug users (IDU). One hundred twenty-four HTLV-II-seropositive emergency room and clinic patients were matched by age, sex, and clinic to 120 HTLV-I/II-seronegative patients. Medical records were reviewed blinded to HTLV-II status, and International Classification of Disease 9th Clinical Modification (ICD-9CM)-coded diagnoses were compared between seropositive patients and controls. After adjustment for relevant confounding variables such as human immunodeficiency virus infection, HTLV-II-seropositive IDU had an increased risk of bacterial pneumonia (odds ratio [OR], 3.45; 95% confidence interval [CI], 1.58, 7.56), abscess (OR, 8.30; 95% CI, 4.02, 17.11), and lymphadenopathy (OR, 3.91; 95% CI, 1.24, 12.32) compared with HTLV-II-negative non-IDU patients. In contrast, HTLV-II-negative IDU were at only marginally increased risk of the same conditions, with OR of 1.76 (95% CI, 0.42, 7.40), 3.00 (95% CI, 0.94, 9.59), and 1.31 (95% CI, 0.15, 11.66), respectively. These results indicate that HTLV-II seropositivity may define a subgroup of IDU who are at particularly high risk of bacterial pneumonia, skin and soft tissue abscess, and lymphadenopathy. Whether HTLV-II has an etiologic role in predisposing IDU to bacterial infections and lymphadenopathy will require further investigation.

Serologic screening for human T cell lymphotropic virus types 1/2 (HTLV-1/2) infection in blood donors has been recently introduced in Brazil. Analysis of 351,639 blood donations in Sao Paulo from January 1992 to October 1993 identified 1,063 positive (0.30%) and 2,238 indeterminate (0.63%) samples based on serologic confirmation using a 21e Western blot. A detailed analysis (serologic, molecular, and virologic), based on a laboratory diagnostic algorithm for characterization of HTLV-1 and HTLV-2 infections was undertaken in 50 seropositive or seroindeterminate blood donors. Modified serologic assays (2.3 Western blot that incorporate type-specific recombinant peptides) performed in 29 HTLV-1/2 positive and 21 HTLV-1/2 indeterminate donors with the 21e Western blot identified 25 as infected with HTLV-1, four with HTLV-2, five with untypable HTLV-1/2, 15 as HTLV-1/2 indeterminate, and one as seronegative. Polymerase chain reaction (PCR) analysis using DNA amplification of proviral pol and tax sequences from peripheral blood mononuclear cells confirmed HTLV-1 and HTLV-2 infections in all 2.3 Western blot seropositive donors; of the five serologically untypable donors, three were confirmed to be HTLV-1 positive, one HTLV-2 positive, and one negative by PCR. All of the seroindeterminate donors were also negative by PCR. Furthermore, HTLV-1 could be isolated in cocultures from 10 of 18 infected donors. Cell lines developed from two HTLV-1-infected donors were of T cell phenotype (CD2+, CD3+), exhibiting surface markers of activated CD4 cells (CD4+ CD25+ HLA-DR+). Thus, we provide evidence for the high seroprevalence of HTLV infection in blood donor population in Sao Paulo, Brazil compared with North American donors and propose a comprehensive serologic and genotypic diagnostic algorithm for HTLV-infected donors that has strong implications for counseling of these individuals.Blood donors in Brazil have recently begun to be screened for infection with HTLV types 1 and 2. Of 351,639 blood donations screened in Sao Paulo from January 1992 to October 1993, 1063 positive and 2238 indeterminate samples were identified based upon serologic confirmation using the 21e Western blot. Detailed serologic, molecular, and virologic analysis, based upon a laboratory diagnostic algorithm for the characterization of HTLV-1 and HTLV-2 infections, was conducted upon 50 seropositive or seroindeterminate blood donors. 2.3 Western blot serologic assays, which incorporate type-specific recombinant peptides, performed in 29 HTLV 1/2 positive and 21 HTLV 1/2 indeterminate donors with the 21e Western blot identified 25 as infected with HTLV-1, 4 with HTLV-2, 5 with untypeable HTLV 1/2, 15 as HTLV 1/2 indeterminate, and 1 as seronegative. Polymerase chain reaction (PCR) analysis using DNA amplification of proviral pol and tax sequences from peripheral blood mononuclear cells confirmed HTLV-1 and HTLV-2 infections in all 2.3 Western blot seropositive donors. Of the 5 serologically untypeable donors, 3 were found to be HTLV-1-positive, 1 HTLV-2-positive, and 1 negative by PCR. All seroindeterminate donors were also negative by PCR. HTLV-1 could be isolated in cocultures from 10 of 18 infected donors.

T THE BEGINNING of the twentieth century, a relationship between viruses and leukemia in chickens was established. Since then, the causal role of oncoviruses, which are members of the Retroviridae subfamily, in the development of sarcomas and leukemia has been well established in animal models. In 1978, the first human retrovirus was isolated from the peripheral blood lymphocytes of a black patient with a lymphoproliferative disease originally considered a cutaneous T-cell lymphoma ~ but later characterized as an adult T-cell lymphoma (ATL). This virus was later named human T-lymphotropic virus type I (HTLV-I)I

The human T-cell lymphotropic viruses type I and type II are closely related human retroviruses that have similar biological properties, genetic organization and tropism for T lymphocytes. Along with the simian T-cell lymphoma virus type I, they define the group of retroviruses known as the primate T-cell leukemia/lymphoma viruses. Initially identified in 1980, the human T-cell lymphotropic virus type I has been implicated as the etiologic agent of adult T-cell leukemia/lymphoma and of a degenerative neurologic disorder known as tropical spastic paraparesis or human T-cell lymphotropic virus type I-associated myelopathy. The intriguing link between human T-cell lymphotropic virus type, T-cell malignancy, and a totally unrelated and non-overlapping neurological disorder suggests divergent and unique pathogenetic mechanisms. This review will address the epidemiology, molecular biology, and pathogenesis of human T-cell leukemia viruses.

AIM: Evaluation of a qualitative HTLV-I/II DNA polymerase chain reaction (PCR) test for the detection of HTLV-I/II DNA (Roche Diagnostic Systems, Branchburg, N.J., USA) in various panels. METHODS: The panels consisted of fresh EDTA blood samples from blood donors who were anti-HTLV-I/II ELISA repeatably reactive: 53 were Western blot (WB) positive, 228 were WB indeterminate and 15 were WB negative. Elevent ELISA-negative blood donors were used as negative controls. Furthermore, specimens from 1 HTLV-II-infected intravenous drug user and from 1 HTLV-II-infected blood donor were included in the panel. Peripheral blood lymphocytes were prepared by red blood cell lysis with the Roche washing solution and stored at < -23 degrees C until processing. Amplification products were analyzed with the HTLV-I/II detection kit. RESULTS: All 53 anti-HTLV-I/II ELISA- and WB-positive samples and both HTLV-II-positive samples tested positively by PCR. All 228 anti-HTLV-I/II ELISA-positive and WB-indeterminate, all 15 ELISA-positive and WB-negative and all II ELISA-negative control samples tested negative by PCR. CONCLUSION: The Roche Amplicor HTLV-I/II test is a simple test, suitable for the confirmation of HTLV-I and-II infection in individuals with indeterminate or positive WB patterns

The purpose of the study was to determine the seroprevalence of human T-lymphotropic virus types I and II (HTLV-I and HTLV-II) infections in an outpatient clinic population of human immunodeficiency virus (HIV)-1 infected persons as well as to identify the demographic and clinical characteristics and laboratory results associated with HTLV-I/II infections. During 1993-1995, 854 patients were tested for HTLV-I/II infection on entry into the clinic, of whom 25 were infected with HTLV-I and 35 with HTLV-II. Multivariate analysis revealed that patients with coinfections were more likely to be black, aged over 35 years, and have a history of injection drug use. HIV-1/HTLV-I coinfections were associated with higher median CD8 counts on entry (p < 0.05), and HIV-1/HTLV-II coinfections were associated with higher median percent CD4 counts (p < 0.05) compared with patients infected with HIV only. Coinfection was not associated with an increased diagnosis of AIDS. These findings indicate that HIV-1/HTLV-I/II coinfections are frequently diagnosed and are associated with unique immune phenotypes. Given the lack of information regarding the influence of dual infection on clinical status, differentiation of HTLV-I from HTLV-II infections may be important in understanding the clinical significance of retroviral coinfections.

Alternative algorithms were evaluated in order to reduce the number of false reactive results for antibodies against HTLV-1/2. From 20,210 samples tested, 0.37% (74/20,210) was reactive by ELISA Murex. Of these, 23 were confirmed as positive by the indirect immunofluorescence assay whereas 51 were negative, being the positive predictive value (PPV) 31.08%. From a combination of the ELISA Murex assay with the particle agglutination assay (PA) and ELISA MP, the following results were obtained: 26/74 were reactive by ELISA Murex and PA, PPV 88.5% and 32/74 were reactive by ELISA Murex and ELISA MP, PPV 71.8 %. The ROC curve analysis determined that for an RP 4.74, the values for sensitivity, specificity, PPV and NPV by ELISA Murex were 100%, 98.04%, 95.8% and 100%, respectively. We propose that reactive samples by ELISA Murex with an RP d 4.74 should be retested in duplicate by PA, and the resulting concordantly nonreactive samples should be defined as negative for HTLV-1/2.

Background. Human T-lymphotropic virus type 1 (HTLV-1) and HTLV-2 are prevalent at low levels among US blood donors, but recent data on their prevalence is lacking.

Background. Human T-lymphotropic virus type 1 (HTLV-1) and HTLV-2 are prevalent at low levels among US blood donors, but recent data on their prevalence is lacking. Methods. Data on all first-time blood donors in a large network of US blood centers were examined during 2000–2009. HTLV-1 and HTLV-2 antibodies were measured by enzyme immunoassay (EIA) with confirmation by immunofluorescence or recombinant immunoblot. Prevalence rates were calculated, and odds ratios were assessed using multivariable logistic regression. Results. Among 2 047 740 first-time donors, 104 were seropositive for HTLV-1 (prevalence, 5.1 cases/per 100 000; 95% confidence interval [CI], 4.1–6.1), and 300 were seropositive for HTLV-2 (prevalence, 14.7 cases/per 100 000; 95% CI, 13.0–16.3). The prevalence was lower than reported in the 1990s but stable from 2000 to 2009. HTLV-1 seropositivity was associated with female sex, older age, and black and Asian race/ethnicity. HTLV-2 seropositivity was associated with female sex, older age, nonwhite race/ethnicity, lower educational level, and residence in the western and southwestern United States. Conclusions. The HTLV-1 and HTLV-2 prevalences among US blood donors has declined since the early 1990s. A higher prevalence of HTLV-2 in the west and southwest may be attributed to endemic foci among Amerindians.

Summary Retroviral co-infections with human immunodeficiency virus type-1 (HIV-1) and human T cell leukaemia virus type 1 (HTLV-1) or type 2 (HTLV-2) are prevalent in many areas worldwide. It has been observed that HIV-1/HTLV-2 co-infections are associated with slower rates of CD4+ T cell decline and delayed progression to AIDS. This immunological benefit has been linked to the ability of Tax2, the transcriptional activating protein of HTLV-2, to induce the expression of macrophage inflammatory protein (MIP)-1α/CCL3, MIP-1β/CCL4 and regulated upon activation normal T cell expressed and secreted (RANTES)/CCL5 and to down-regulate the expression of the CCR5 co-receptor in peripheral blood mononuclear cells (PBMCs). This study aimed to assess the role of Tax2-mediated activation of the nuclear factor kappa B (NF-κB) signalling pathway on the production of the anti-viral CC-chemokines MIP-1α, MIP-1β and RANTES. Recombinant Tax1 and Tax2 proteins, or proteins expressed via adenoviral vectors used to infect cells, were tested for their ability to activate the NF-κB pathway in cultured PBMCs in the presence or absence of NF-κB pathway inhibitors. Results showed a significant release of MIP-1α, MIP-1β and RANTES by PBMCs after the activation of p65/RelA and p50. The secretion of these CC-chemokines was significantly reduced (P

Background HTLV-1 and HTLV-2 are retroviruses linked etiologically to various human diseases, and both of them can be transmitted by vertical route, sexual intercourse, blood transfusion and intravenous drug use. Recently, some HTLV-infected cases have been reported and this virus is mainly present in the Southeast coastal areas in China, but has not been studied for the people in Central China. Objectives To know the epidemiologic patterns among different population samples in Central China and further identify risk factor for HTLV-1 and HTLV-2 infection. Methods From January 2008 to December 2011, 5480 blood samples were screened for HTLV-1/2 antibodies by using enzyme immunoassay, followed by Western Blot. Results The prevalence of HTLV-1 and HTLV-2 was found with infection rates 0.13% and 0.05% among all population samples for HTLV-1 and HTLV-2, respectively. The highest percentages of infection, 0.39% and 0.20%, were found in the high risk group, while only 0.06% and 0.03% in the blood donor group. There was only one case of HTLV-1 infection (0.11%) among patients with malignant hematological diseases. Of seven HTLV-1 positive cases, six were co-infected with HBV, two with HCV and one with HIV. Among three HTLV-2 positive individuals all were co-infected with HBV, one with HCV. Conclusions HTLV-1 and HTLV-2 have been detected in the Central China at low prevalence, with the higher infection rate among high risk group. It was also found that co-infection of HTLV-1/2 with HIV and HBV occurred, presumably due to their similar transmission routes. HTLV-1/2 antibody screen among certain population would be important to prevent the spread of the viruses.

Introduction This study investigated the occurrence of Strongyloides stercoralis infestation and coinfection with HTLV-1/2 in Belém, Brazil. Methods S. stercoralis was investigated in stool samples obtained from individuals infected with HTLV-1/2 and their uninfected relatives. Results The frequency of S. stercoralis was 9% (9/100), including six patients infected with HTLV-1 (14.3%), two patients infected with HTLV-2 (11.1%), and one uninfected relative. Two cases of hyperinfestation by S. stercoralis were characterized as HTLV-1. Conclusions These results support the need for the routine investigation of S. stercoralis in patients with HTLV-1, in an attempt to prevent the development of severe forms of strongyloidiasis.

Blood donors in Canada have been tested for Human T-Cell Lymphotropic Virus (HTLV) since 1990. We report the epidemiology, risk factors and lookback/traceback of HTLV-positive donors/recipients.The annual HTLV rate was calculated from 1990 to 2010. Residual risk was estimated as the product of incidence and window period. Twenty-nine HTLV-positive donors and 116 matched controls (ratio 1 : 4) were interviewed about risk factors. For HTLV-positive donations, lookback investigations involved identification of all previous donations, and attempting to locate and test recipients. Traceback was initiated when transfusion transmission was queried for HTLV-positive blood recipients. All donors of products that the recipient received were identified, with an attempt to locate and test them.The HTLV rate decreased from 9.35 per 100,000 donations in 1990 to 1.11 in 2010. The residual risk of infection was 1 in 7.6 million donations. In logistic regression birth overseas (OR 18.7), history of sexually transmitted diseases (OR 32.9), sex with unknown background (OR 5.4) and blood transfusion (OR 8.9) were significant predictors. In the lookback study, of 109 HTLV-positive donors, 508 components were transfused, of whom 147 recipients were tested and 18 (12%) were positive. All were transfused prior to the implementation of donor testing. Twenty-three traceback investigations were requested involving 324 transfused untested products,of whom 219 (67.6%) of donors were tested and 13 (6%) were positive for HTLV.With testing of the blood supply, the risk from HTLV is very low and while most HTLV-positive donors have risk factors, deferrable risk is rare.

Hepatitis C is the major cause of liver transplantation and hepatocellular carcinoma and shows a global prevalence of 3%. Hepatitis C virus (HCV) is associated with extrahepatic manifestations (e.g., cutaneous affections) and psoriasis has been reported as a comorbidity. However, there are few studies analyzing this association.1) To evaluate anti-HCV prevalence (confirmed by the detection of HCV-RNA) in patients with psoriasis and its potential clinical implications; 2) to analyze the prevalence of other infections in this population: hepatitis B virus (HBV), human T lymphotropic virus, subtypes I and II (HTLVI/II), and human immunodeficiency virus, subtypes I and II (HIV I/II).This is cross sectional study that included patients older than 18 years-old with psoriasis from a Teaching Hospital in Salvador, Bahia. An epidemiological questionnaire was administered and serological tests were performed: surface HBV antigen (HBsAg), antibodies to HBsAg (anti-HBs), anti-HTL VI/II, anti-HIV I/II, and anti-HCV. Anti-HCV positive results were confirmed by HCV-RNA detection and viral genotype was determined. Skin lesions were evaluated using the Psoriasis Area and Severity Index (PASI). Liver biopsies were analyzed according to the METAVIR score.From the 140 patients included in the study, 7.1% were anti-HCV positive confirmed by the detection of HCV RNA. This prevalence was higher than that in the city of Salvador (1.5%). Other serological results were: HBsAg 0%, anti-HBs 25.8%, HTLV I/II (0,9%), and HIV I/II 0%. PASI score was higher in positive anti-HCV patients than in their negative counterparts (19.5 versus 13.4). Histopathological analysis showed 66.7% of patients with METAVIR F3/F4.Anti-HCV prevalence was higher in psoriasis patients than in the general population of the city. More severe skin lesions were found in HCV patients.