Patterns of HIV-1 and HTLV-I/II in intravenous drug abusers from the middle atlantic and central regions of the USA

Hijacking Host Immunity by the Human T-Cell Leukemia Virus Type-1: Implications for Therapeutic and Preventive Vaccines

Human T-cell Leukemia virus type-1 (HTLV-1) causes adult T-cell leukemia/lymphoma (ATLL), HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) and other inflammatory diseases. High viral DNA burden (VL) in peripheral blood mononuclear cells is a documented risk factor for ATLL and HAM/TSP, and patients with HAM/TSP have a higher VL in cerebrospinal fluid than in peripheral blood. VL alone is not sufficient to differentiate symptomatic patients from healthy carriers, suggesting the importance of other factors, including host immune response. HTLV-1 infection is life-long; CD4+-infected cells are not eradicated by the immune response because HTLV-1 inhibits the function of dendritic cells, monocytes, Natural Killer cells, and adaptive cytotoxic CD8+ responses. Although the majority of infected CD4+ T-cells adopt a resting phenotype, antigen stimulation may result in bursts of viral expression. The antigen-dependent “on-off” viral expression creates “conditional latency” that when combined with ineffective host responses precludes virus eradication. Epidemiological and clinical data suggest that the continuous attempt of the host immunity to eliminate infected cells results in chronic immune activation that can be further exacerbated by co-morbidities, resulting in the development of severe disease. We review cell and animal model studies that uncovered mechanisms used by HTLV-1 to usurp and/or counteract host immunity.

Tumorigenesis and diagnostic practice applied in two oncogenic viruses: Epstein Barr virus and T-cell lymphotropic virus-1-Mini review

To date, seven viruses have been reliably connected to various forms of human cancer: Epstein Barr Virus (EBV), Kaposi's sarcoma-associated herpesvirus (KSHV), high-risk Human papillomavirus (HPV), Merkel Cell Polyomavirus (MCPV), Hepatitis B virus (HBV), hepatitis C virus (HCV), and Human T-cell leukemia virus type 1 (HTLV1). This mini-review summarizes two of these viruses, EPV and HTLV-1, in terms of their general pathway of infection, the key mechanism of cancer induction, and the prominent technologies used to detect the infections. EBV is the first discovered human oncovirus and HTLV - I is the first human retrovirus and both were discovered from patient with distinct lymphoma clinical condition. Both the viruses can immortalize lymphocytes invitro and lymphomas are common manifestation of majority oncogenic viruses. Lymphomagenesis are discovered in associated with EBV, HTLV-I, Human Immunodeficiency virus (HIV), Kaposi sarcoma - associated herpes virus and hepatitis c virus. Later the undefined mechanism behind the induction of cancer by these viruses was unveiled gradually along with the responsible cofactors and mimicry mechanism. These two viruses contrast in their genetic structure, location of the infection, and latency, yet clinically, they generate similar cancer disorders. The major focus of this study is to brief the mechanism of these two unrelated viral cancer promoting agents on how they simulate a condition similar to lymphoma which may or may not undergo mimicry and cofactor utilization process, handpicked and vital genes behind the transformation mechanism are given accordingly.

HTLV-1 oncovirus-host interactions: From entry to the manifestation of associated diseases

Human T lymphotropic virus type-1 (HTLV-1) is a well-known human oncovirus, associated with two life-threatening diseases, adult T cell leukaemia/lymphoma (ATL) and HTLV-1 associated myelopathy/tropical spastic paraparesis (HAM/TSP). The study of this oncogenic virus is significant from two different aspects. First, HTLV-1 can be considered as a neglected public health problem, which may spread slowly worldwide. Second, the incidence of HTLV-1 associated diseases due to oncogenic effects and deterioration of the immune system towards autoimmune diseases are not fully understood. Furthermore, knowledge about viral routes of transmission is important for considering potential interventions, treatments or vaccines in endemic regions. In this review, novel characteristics of HTLV-1, such as the unusual infectivity of virions through the virological synapse, are discussed in the context of the HTLV-1 associated diseases (ATL and HAM/TSP).

Dichotomy in Fatal Outcomes in a Large Cohort of People Living with HTLV-1 in São Paulo, Brazil

Background: Despite its relatively low incidence of associated diseases, Human T-cell Leukemia Virus-1 (HTLV-1) infection was reported to carry a significant risk of mortality in several endemic areas. HTLV-1-associated diseases, adult T-cell leukemia/lymphoma (ATLL) and HTLV-1-associated myelopathy/tropical spastic paraperesis (HAM/TSP), as well as frequent coinfections with human immunodeficiency virus (HIV), hepatitis C virus (HCV), and Strongyloides stercoralis were associated to increased morbidity and mortality of HTLV-1 infection. Objective: To determine the mortality rate and its associated variables from an open cohort started in July 1997 at the HTLV Clinic, Emilio Ribas Institute (IIER), a major infectious disease hospital in São Paulo, Brazil. Methods: Since inception up to September 2018, we admitted 727 HTLV-1-infected individuals, with a rate of 30–50 new admissions per year. All patient data, including clinical and laboratory data, were regularly updated throughout the 21-year period, using a dedicated REDCap database. The Ethical Board of IIER approved the protocol. Results: During 21 years of clinical care to people living with HTLV-1 in the São Paulo region, we recruited 479 asymptomatic HTLV-1-infected individuals and 248 HAM/TSP patients, of which 632 remained under active follow-up. During a total of 3800 person-years of follow-up (maximum follow-up 21.5 years, mean follow-up 6.0 years), 27 individuals died (median age of 51.5 years), of which 12 were asymptomatic, one ATLL patient and 14 HAM/TSP patients. HAM/TSP diagnosis (but neither age nor gender) was a significant predictor of increased mortality by univariate and multivariate (hazard ratio (HR) 5.03, 95% CI [1.96–12.91], p = 0.001) Cox regression models. Coinfection with HIV/HCV was an independent predictor of increased mortality (HR 15.08; 95% CI [5.50–41.32]; p < 0.001), with AIDS-related infections as a more frequent cause of death in asymptomatics (6/13; p = 0.033). HIV/HCV-negative fatal HAM/TSP cases were all female, with urinary tract infection and decubitus ulcer-associated sepsis as the main cause of death (8/14, p = 0.002). Conclusions: All-cause mortality among people living with HTLV-1 in São Paulo differs between asymptomatic (2.9%) and HAM/TSP patients (7.3%), independent of age and gender. We observe a dichotomy in fatal cases, with HAM/TSP and HIV/HCV coinfection as independent risk factors for death. Our findings reveal an urgent need for public health actions, as the major causes of death, infections secondary to decubitus ulcers, and immune deficiency syndrome (AIDS)-related infections, can be targeted by preventive measures.

Serological detection of human T-cell lymphotropic virus types I and II among pregnant women in Ilorin, Nigeria

Human T-cell lymphotropic virus types I/II (HTLV-I/II) is endemic in some parts of the world including Nigeria. Reported prevalence rates in Nigeria have largely focused on blood donors. This study aims at determining the prevalence of HTLV infection among pregnant women in Ilorin North-central Nigeria. Serum samples from 276 pregnant women who were antenatal clinic attendees at General and Civil Service Hospitals in Ilorin were tested for the presence of HTLV-I/II antibodies using Enzyme Linked Immunosorbent Assay test kits from Diagnostic Automation INC., USA. Out of the 276 women tested, 3 tested positive giving a prevalence rate of 1.1%. The result was analyzed on the basis of age, marital status, nature of family, educational status, occupation, religion, parity, and gestational stage of the women. There was no statistical association of HTLV positivity with any of the variables. Although relatively lower than prevalence rate recorded among similar study groups in other parts of the country, the 1.1% prevalence in this study underscores the need for proper education and creation of awareness among antenatal clinic attendees, so as to reduce viral transmission and incidence of HTLV-related diseases.

Phylogenetic analysis of HTLV-1 in Iranian blood donors, HIV-1 positive patients and patients with beta thalassemia

Human T-cell lymphoma virus (HTLV) has been associated with various disease types. Since the discovery of the virus in 1980, seven subtypes of the virus have been identified. HTLV is widespread and endemic in some regions, such as Japan, Africa, South America, and northeast Iran. This study aimed to identify HTLV-1 genotype and also to analyze the nucleotide sequence of the LTR region in three groups, including blood donors, HIV-1+ patients, and β-thalassemia patients. In this cross-sectional study, 2200 samples were collected from blood donors in Tehran (2000 samples), HIV-1+ patients (100 samples) and β-thalassemia patients (100 samples). All samples were screened for anti-HTLV-I&II antibodies by ELISA. Then, genomic DNA was extracted from repeatedly positive samples, and nested PCR was performed for both the TAX and LTR regions. Purified PCR products were sequenced and analyzed, and finally, a phylogenetic tree was constructed using Mega7 software. The prevalence of the anti-HTLV-I&II antibody among blood donors and HIV-1+ patients was 1.7% (34/2000) and 12% (12/100), respectively. The PCR results confirmed that 0.05% (1/2000) of blood donors, 5% (5/100) of HIV-1+ patients, and 8% (8/100) of β-thalassemia patients were HTLV-I positive. All sequences were matched to HTLV-1 subtype a, subgroup A. Our phylogenetic analysis revealed that all sequenced samples belong to the endemic clusters of Iran. HTLV-1 genotypes in all samples were similar in three groups and were derived from the strains, which had been previously reported from Iran (AF00300/Mashhad and KT190712.1/Sabzevar).

Human T-Cell Lymphotropic Virus Types 1 and 2 Seropositivity among Blood Donors at Mbarara Regional Blood Bank, South Western Uganda

Background. The human T-cell lymphotropic virus types 1 and 2 (HTLV 1/2) are retroviruses associated with different pathologies. HTLV-1 causes adult T-cell leukemia/lymphoma (ATL) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP); HTLV-2 is not clearly associated with a known clinical disease. Both viruses may be transmitted by whole blood transfusion, from mother to child predominantly through breastfeeding, and by sexual contact. Presently, none of the regional blood banks in Uganda perform routine pretransfusion screening for HTLV. The aim of this study was to determine the prevalence of anti-human T-cell lymphotropic virus types 1/2 (HTLV-1/2) antibodies among blood donors at Mbarara Regional Blood Bank in South Western Uganda. A cross-sectional study was conducted between June 2014 and September 2014. Methodology. Consecutive blood samples of 368 blood donors were screened for anti-HTLV-1/2 antibodies using an enzyme linked immunosorbent assay (ELISA). Samples reactive on a first HTLV-1/2 ELISA were further retested in duplicate using the same ELISA. Of the three hundred and sixty-eight blood donors (229 (62.2%) males and 139 (37.8%) females), only two male donors aged 20 and 21 years were HTLV-1/2 seropositive, representing a prevalence of 0.54%. Conclusion. HTLV-1/2 prevalence is low among blood donors at Mbarara Regional Blood Bank. Studies among other categories of people at risk for HTLV 1/2 infection should be carried out.

Sexual transmission of human T-cell lymphotropic virus type 1

Human T-cell lymphotropic virus type 1 (HTLV-1) is endemic in many parts of the world and is primarily transmitted through sexual intercourse or from mother to child. Sexual transmission occurs more efficiently from men to women than women to men and might be enhanced by sexually transmitted diseases that cause ulcers and result in mucosal ruptures, such as syphilis, herpes simplex type 2 (HSV-2), and chancroid. Other sexually transmitted diseases might result in the recruitment of inflammatory cells and could increase the risk of HTLV-1 acquisition and transmission. Additionally, factors that are associated with higher transmission risks include the presence of antibodies against the viral oncoprotein Tax (anti-Tax), a higher proviral load in peripheral blood lymphocytes, and increased cervicovaginal or seminal secretions. Seminal fluid has been reported to increase HTLV replication and transmission, whereas male circumcision and neutralizing antibodies might have a protective effect. Recently, free virions were discovered in plasma, which reveals a possible new mode of HTLV replication. It is unclear how this discovery might affect the routes of HTLV transmission, particularly sexual transmission, because HTLV transmission rates are significantly higher from men to women than women to men.

Epidemiological Aspects and World Distribution of HTLV-1 Infection

The human T-cell leukemia virus type 1 (HTLV-1), identified as the first human oncogenic retrovirus 30 years ago, is not an ubiquitous virus. HTLV-1 is present throughout the world, with clusters of high endemicity located often nearby areas where the virus is nearly absent. The main HTLV-1 highly endemic regions are the Southwestern part of Japan, sub-Saharan Africa and South America, the Caribbean area, and foci in Middle East and Australo-Melanesia. The origin of this puzzling geographical or rather ethnic repartition is probably linked to a founder effect in some groups with the persistence of a high viral transmission rate. Despite different socio-economic and cultural environments, the HTLV-1 prevalence increases gradually with age, especially among women in all highly endemic areas. The three modes of HTLV-1 transmission are mother to child, sexual transmission, and transmission with contaminated blood products. Twenty years ago, de Thé and Bomford estimated the total number of HTLV-1 carriers to be 10-20 millions people. At that time, large regions had not been investigated, few population-based studies were available and the assays used for HTLV-1 serology were not enough specific. Despite the fact that there is still a lot of data lacking in large areas of the world and that most of the HTLV-1 studies concern only blood donors, pregnant women, or different selected patients or high-risk groups, we shall try based on the most recent data, to revisit the world distribution and the estimates of the number of HTLV-1 infected persons. Our best estimates range from 5-10 millions HTLV-1 infected individuals. However, these results were based on only approximately 1.5 billion of individuals originating from known HTLV-1 endemic areas with reliable available epidemiological data. Correct estimates in other highly populated regions, such as China, India, the Maghreb, and East Africa, is currently not possible, thus, the current number of HTLV-1 carriers is very probably much higher.

APOBEC3A, APOBEC3B, and APOBEC3H haplotype 2 restrict human T-lymphotropic virus type 1

The human APOBEC3 family consists of seven cytidine deaminases (A3A to A3H), some of which display potent antiretroviral activity against HIV-1 and other retroviruses. Studies that analyzed the effect of A3G on human T-lymphotropic virus type 1 (HTLV-1) infectivity resulted in conflicting findings, and our knowledge of HTLV-1 restriction by other A3 proteins remains limited. Since HTLV-1, much like HIV, targets CD4(+) T cells, we hypothesized that A3 proteins other than A3G restrict HTLV-1. All seven human A3 proteins were tested in HTLV-1 reporter and HIV-1 infectivity assays. We show that A3A, A3B, and A3H haplotype 2 (A3H hapII) acted as potent inhibitors of HTLV-1. Wild-type HIV-1, in contrast, was restricted by A3B and A3H hapII, but not by A3A. Catalytic site mutants of A3A, A3B, and A3H hapII showed that A3A and A3B restriction of HTLV-1 required deaminase activity. However, A3H hapII acted in a deaminase-independent manner when restricting HTLV-1, while requiring deaminase activity for HIV-1 restriction. We also analyzed A3 editing of HTLV-1 in five T-cell lines obtained from HTLV-1-infected patients. These cell lines contained extensively edited HTLV-1 sequences with G-to-A mutations in dinucleotide contexts suggestive of APOBEC3 mutagenesis. Comparison of the A3-induced mutations from reporter cells and the patient-derived cell lines indicate that A3G but also other A3 members, possibly A3A and A3B, affect HTLV-1 in vivo. Taken together, our data indicate that HTLV-1 is a likely target for multiple A3 proteins.

Shooting up: the interface of microbial infections and drug abuse

Illicit drug control has been on the global agenda for more than a century. Infections have long been recognized as one of the most serious complications of drug abuse. Drug users are susceptible to pulmonary, endovascular, skin and soft tissue, bone and joint, and sexually transmitted infections caused by a wide range of bacterial, viral, fungal and protozoal pathogens. In addition, injection drug users are at increased risk for parenterally acquired infections such as human immunodeficiency virus, hepatitis B virus, hepatitis C virus, tetanus and malaria. Factors related to drug use, such as unsterile injection practices, contaminated drug paraphernalia and drug adulterants, increase the exposure to microbial pathogens. Illicit drugs also affect several components of the complex immune system and thus modulate host immunity. In addition, lifestyle practices such as multiple sexual partners, overcrowded housing arrangements and malnutrition serve as co-factors in increasing the risk of infection. In this review we present an overview of the unique aspects of microbial pathogenesis, immune modulation and common infections associated with drug use. We have restricted the definition of drug abuse to the use of illegal drugs (such as opiates, marijuana, cocaine, heroin and amphetamines), not including alcohol and nicotine.

HTLV infection and its implication in gynaecology and obstetrics

INTRODUCTION

Worldwide, 20-30 million people are estimated to be infected with HTLV. HTLV-1 is endemic in Western Africa and Southern Japan, whereas HTLV-2 is considered to be spread among native American people.

MATERIALS AND METHODS

The impact of HTLV in gynaecology and obstetrics is being reviewed. Search strategy and selection criteria for identifying relevant data were performed by searching Medline, Current Contents, Web of Science, Embase and references from relevant articles. English and German gynaecological and infectious diseases textbooks as well as national and international guidelines and recommendations were also reviewed.

RESULTS

Transmission may occur by sexual intercourse or cellular blood products. Although materno-fetal transmission is debated, transmission through maternal breast milk has been confirmed. An HTLV-infection can lead to adult T-cell leukaemia (ATL) or cumulative opportunistic and neurological disorders that can occur with varying degrees of severity. Diagnosis can be done by antibody detection via the use of ELISA and western blot analysis as well as PCR diagnosis.

CONCLUSION

Due to inadequate treatment options and the lack of an effective vaccination, prevention is currently only possible by restricting transmission, including the usage of condoms during sexual intercourse or avoiding breastfeeding in HTLV-seropositive mothers. If, due to socio-economic reasons, breastfeeding cannot be avoided, short-term breastfeeding for a maximum of up to 6 months is suggested.

Human T-lymphotropic virus 1: recent knowledge about an ancient infection

Human T-lymphotropic virus 1 (HTLV-1) has infected human beings for thousands of years, but knowledge about the infection and its pathogenesis is only recently emerging. The virus can be transmitted from mother to child, through sexual contact, and through contaminated blood products. There are areas in Japan, sub-Saharan Africa, the Caribbean, and South America where more than 1% of the general population is infected. Although the majority of HTLV-1 carriers remain asymptomatic, the virus is associated with severe diseases that can be subdivided into three categories: neoplastic diseases (adult T-cell leukaemia/lymphoma), inflammatory syndromes (HTLV-1-associated myelopathy/tropical spastic paraparesis and uveitis among others), and opportunistic infections (including Strongyloides stercoralis hyperinfection and others). The understanding of the interaction between virus and host response has improved markedly, but there are still no clear surrogate markers for prognosis and there are few treatment options.

Global epidemiology of HTLV-I infection and associated diseases

Epidemiologic aspects of human T-lymphotropic virus type I (HTLV-I) infection have been thoroughly studied over the course of approximately 25 years since its first description. The geographic distribution of the virus has been defined, with Japan, Africa, Caribbean islands and South America emerging as the areas of highest prevalence. The reasons for HTLV-I clustering, such as the high ubiquity in southwestern Japan but low prevalence in neighboring regions of Korea, China and eastern Russia are still unknown. The major modes of transmission are well understood, although better quantitative data on the incidence of transmission, and on promoting/inhibiting factors, are needed. Epidemiologic proof has been obtained for HTLV-I's causative role in major disease associations: adult T-cell leukemia (ATL), HTLV-associated myelopathy/tropical spastic paraparesis (HAM/TSP), HTLV-associated uveitis and infective dermatitis. However, more and better studies are needed for other apparent disease outcomes such as rheumatologic, psychiatric and infectious diseases. Since curative treatment of ATL and HAM/TSP is lacking and a vaccine is unavailable, the social and financial cost for the individual, his/her family and the health system is immense. For this reason, public health interventions aimed at counseling and educating high-risk individuals and populations are of paramount importance.

Modulation of infection and type 1 cytokine expression parameters by morphine during in vitro coinfection with human T-cell leukemia virus type I and HIV-1

Infection of injection drug users (IDUs) with the human T-cell leukemia viruses (HTLVs) or HIV is considerably higher than in the non-IDU population. Also, coinfection with HIV-1 and HTLV type I (HTLV-I) occurs more frequently. There is little or no information on the effects of opiates (i.e., morphine) on HTLV infection alone or on coinfection of HTLV-I-infected cells with HIV-1. Therefore, in this report, we analyzed the in vitro effects of morphine on HIV or HTLV infection alone as well as on dual infection with HTLV-I and HIV-1. Morphine decreased the in vitro levels of interferon-gamma (IFN gamma) and IL-2 during single infections, and this effect was reversed by the addition of the opioid antagonist naloxone. In contrast, treatment with morphine resulted in a 31% and 36% increase in IFN gamma and IL-2 levels, respectively, during dual infection. In addition, naloxone had an apparent additive effect on the morphine-associated enhancement of IFN gamma and IL-2 expression in the dual-infection model. Despite the high levels of IFN gamma expression, the viability of the coinfected cells in the presence of morphine was maintained. Importantly, morphine treatment was associated with augmented viral reverse transcription activity in dually infected cultures, apparently to the benefit of HTLV-I. If a similar putative morphine-induced advantage for HTLV-I production also occurs during in vivo coinfection, opiates such as morphine could contribute to the observed increased rate of HIV-1/HTLV-I infection in the IDU population in a more direct fashion than was previously believed.

Cancer surveillance series: non-Hodgkin's lymphoma incidence by histologic subtype in the United States from 1978 through 1995

BACKGROUND

Clinical investigations have shown prognostic heterogeneity within the non-Hodgkin's lymphomas (NHLs) according to histology, but few descriptive studies have considered NHLs by subgroup. Our purpose is to assess the demographic patterns and any notable increases in population-based rates of different histologic subgroups of NHL.

METHODS

Using data collected by the Surveillance, Epidemiology, and End Results Program of the National Cancer Institute, we calculated incidence rates for the major clinicopathologic categories of NHL by age, race, sex, geographic area, and time period.

RESULTS

Among the 60 057 NHL cases diagnosed during the period from 1978 through 1995, total incidence (per 100 000 person-years) was 17.1 and 11.5 among white males and females, respectively, and 12.6 and 7.4 among black males and females, respectively. However, rates for follicular NHLs were two to three times greater among whites than among blacks, with little sex variation. Blacks demonstrated much higher incidence than whites for peripheral T-cell NHL, with the incidence rates higher in males than in females. For other NHL subgroups, the incidence rates for persons less than 60 years of age were generally higher among males than among females, with little racial difference; at older ages, the rates were higher among whites than among blacks, with little sex difference. High-grade NHL was the most rapidly rising subtype, particularly among males. Follicular NHL increased more rapidly in black males than in the other three race/sex groups. Overall, the broad categories of small lymphocytic, follicular, diffuse, high-grade, and peripheral T-cell NHL emerged as distinct entities with specific age, sex, racial, temporal, and geographic variations in rates.

CONCLUSIONS

Findings from our large, population-based study reveal differing demographic patterns and incidence trends according to histologic group. Future descriptive and analytic investigations should evaluate NHL risks according to subtype, as defined by histology and new classification criteria.

Non-HIV retroviral associations with rheumatic disease

While the human T-cell lymphotropic virus type I (HTLV-I) is the recognized cause of adult T cell leukemia, it is also associated with non-neoplastic, ostensibly autoimmune conditions, such as tropical spastic paraparesis. Moreover,among carriers of HTLV-I, the virus is strongly implicated in the development of a type of arthritis, which resembles rheumatoid arthritis (RA). Mice transgenic for HTLV-I tax develop RA-like pathology and Sjögren's syndrome. Patients with RA and SS in HTLV-I nonendemic regions, such as the United States, are usually serologically negative for antibodies to the structural proteins of HTLV. However, they appear to harbor HTLV-I tax in their peripheral blood mononuclear cells three times as often as individuals who present as healthy blood donors. Because HTLV-I tax transactivates numerous inflammatory cytokines and is not normally found in the human genome, treatment with tax antisense oligonucleotides may provide a new therapeutic approach for selected RA patients proven to be HTLV-I "tax only" positive.

Risk factors for human T cell lymphotropic virus type I among injecting drug users in northeast Brazil: possibly greater efficiency of male to female transmission

It was observed in the city of Salvador, State of Bahia, the highest seroprevalence of human T cell lymphotropic virus type 1 (HTLV-I) infection in Brazil as demonstrated by national wide blood bank surveys. In this paper, we report results of an investigation of drug use and sexual behavior associated with HTLV-I infection among male and female injecting drug users (IDUs) in Salvador. A cross sectional study was conducted in the Historical District of Salvador from 1994-1996 (Projeto Brasil-Salvador) and 216 asymptomatic IDUs were selected using the snowball contact technique. Blood samples were collected for serological assays. Sera were screened for human immunodeficiency virus (HIV-1/2) and HTLV-I/II antibodies by ELISA and confirmed by Western blot. The overall prevalence of HTLV-I/II was 35.2% (76/216). The seroprevalence of HTLV-I, HTLV-II and HIV-I was for males 22%, 11.3% and 44.1% and for females 46.2%, 10.3% and 74.4% respectively. HTLV-I was identified in 72.4% of HTLV positive IDUs. Variables which were significantly associated with HTLV-I infection among males included needle sharing practices, duration of injecting drug use, HIV-I seropositivity and syphilis. Among women, duration of injecting drug use and syphilis were strongly associated with HTLV-I infection. Multivariate analysis did not change the direction of these associations. Sexual intercourse might play a more important role in HTLV-I infection among women than in men.

Seroprevalence of HTLV-I and HTLV-II among a cohort of HIV-infected women and women at risk for HIV infection. Women's Interagency HIV Study

OBJECTIVES

To determine the seroprevalence of, and risk factors for, HTLV-I and HTLV-II infection among HIV-infected women and women at high risk for HIV infection.

DESIGN

Cross-sectional analysis of baseline data for women enrolled in the prospective Women's Interagency HIV Study (WIHS).

METHODS

From October 1994 through November 1995, 2657 women from five metropolitan areas in the United States (Chicago, Los Angeles, New York City [two sites], Northern California, and Washington DC) were enrolled in WIHS. An interview-based survey collected data on demographics, behavior, and medical history. HTLV-I and HTLV-II determinations were made using a combined HTLV-I/HTLV-II indirect immunofluorescent antibody (IFA) screening test, an IFA titration specificity test, and individual HTLV-I and HTLV-II confirmatory Western blots. Fisher's exact tests and logistic regression were used to determine univariate and multivariate independent predictors for HTLV-II infection.

RESULTS

Of 2625 women enrolled in WIHS with confirmed HIV results, 2487 (95%) were tested for HTLV-I and HTLV-II. Of these, 241 (10%) were HTLV-II-seropositive and 13 (0.5%) were HTLV-I-seropositive. On multivariate analysis, independent predictors of HTLV-II infection included injection drug use (OR = 5.2; p < .001), black race (OR = 3.6; p < 0.001), age >35 years (OR = 3.3; p < .001) and a history of sex with a male injecting drug user (OR = 1.9; p < .001). Among women infected with HIV, the seroprevalence of HTLV-II was 11% compared with 6% for women at risk for HIV but not infected (p < .001). However, HIV was not an independent predictor of HTLV-II infection in multivariate analysis.

CONCLUSIONS

This cross-sectional analysis confirms that HTLV-II is found commonly in HIV-infected women and uninfected women at risk for HIV in major urban areas throughout the United States and that HTLV-II is far more common than HTLV-I in these populations. Although injecting drug use is most strongly associated with HTLV-II infection, sexual transmission likely contributes to the high HTLV-II seroprevalence in this cohort.

HTLV-I in Northeast Brazil: differences for male and female injecting drug users

BACKGROUND

To investigate the seroprevalence of HTLV-I infection among male and female injecting drug users (IDUs).

METHODS

A cross-sectional study conducted in Salvador, Brazil, from 1994 to 1996 (Projeto Brasil-Salvador). The study population of 216 asymptomatic IDUs was selected using snowball contact technique. Data on demographics, sexual behavior, and drug use practices were obtained and blood samples collected for serologic assays. Sera were screened for HIV-1/2 and HTLV-I and HTLV-II antibodies by enzyme-linked immunosorbent assay (ELISA) and confirmed by Western blot.

RESULTS

The overall prevalence of HTLV-I/II was 35.2% (76 of 216). The seroprevalence of HTLV-I, HTLV-II, and HIV-1 was for males 22.0%, 11.3%, and 44.1%, and for females 46.2%, 10.3%, and 74.4%, respectively. Specific seroprevalence of HTLV-I infection demonstrated linear trend with increasing age and increasing duration of drug use. Using univariate analysis, the variables that were significantly associated with HTLV-I infection among males included needle sharing practices, duration of IDU, HIV-1 seropositivity, and positive test result for syphilis. Among women, duration of injecting drug use and positive test result for syphilis were strongly associated with HTLV-I infection.

CONCLUSIONS

Retrovirus infection is highly prevalent among IDUs in Salvador, Brazil and HTLV-I is more common that HTLV-II. Duration of drug use is an important correlate of HTLV-I infection.

Infection with HIV-1 group O

The author presents the case history of the first patient with HIV-1 group O reported in the United States. The various human retroviruses and their clinical syndromes are described and the increasing diversity of HIV-1 strains and their spread are documented. The discovery of the divergent group O and its spread from endemic areas are discussed. The clinician is alerted to the pitfalls of laboratory diagnosis and is advised to seek special studies when clinical findings and epidemiologic history suggest the possibility of HIV infection.

Are HTLV-II-seropositive injection drug users at increased risk of bacterial pneumonia, abscess, and lymphadenopathy?

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.

Differential serological diagnosis of HTLV-I and HTLV-II infection by external membrane protein peptide-based enzyme immunoassays

BACKGROUND

HTLV antibody screening assays detect both antibodies to the etiological agent of adult T-cell leukemia and tropical spastic paraparesis HTLV-I and to the less pathogenic HTLV-II. It is critical to make a differential diagnosis of the two viruses.

OBJECTIVES

To design and evaluate synthetic core and envelope-derived peptide enzyme immunoassays (EIA) for serological differential diagnosis.

STUDY DESIGN

Peptide EIAs were evaluated with a panel of 202 plasma samples comprised of HTLV antibody positive, serologically classified as confirmed, indeterminate, or non confirmed, characterized as HTLV-I, HTLV-II or neither by genomic amplification. The peptide EIA with the best performance was further used to differentiate between HTLV-I and HTLV-II antibodies in 807 samples from 18 countries in four continents and to provide ratios between the two infections.

RESULTS

The gp46 peptide EIA correctly identified 96.5% of HTLV-I and 98.6% of HTLV-II antibody-confirmed samples. HTLV-I was found exclusively in Japan and Caribbean countries; almost exclusively in Africa. HTLV-II represented 10-25% of samples from Canada, Chile and Venezuela and was predominant in the US.

CONCLUSIONS

Differential diagnosis between HTLV-I and HTLV-II can be reliably performed using specific peptides from the gp46 envelope protein of each virus.

No proof of HTLV-I/II in intravenous drug abusers with a high rate of HIV-1 infection in central Thailand

Serum specimens of 1,074 intravenous drug abusers (IVDA) were examined for infection with HIV-1, HTLV-I and HTLV-II in central Thailand. Three hundred and sixty-two of the specimens were seropositive for HIV-1 (33.7%). The HIV-1 seropositive IVDAs exhibited increased seropositivity with age through group 40-44 and significantly decreased seropositivity over the age of 45. In contrast, no seropositivity to either HTLV-I or -II was detected in the samples tested by a particle-agglutination assay for HTLV followed by type-specific Western blotting for HTLV. Reference to previous reports suggested that the rate of HIV infection in IVDAs has decreased with no HTLV-I or HTLV-II in Thailand when compared with that of the HIV infection in 1992.

Prevalence of infection by human T-cell leukemia virus types I and II in southern Spain

To assess the spread of human T-cell leukemia virus (HTLV) type I and II in different population groups at potential risk of infection in Spain, a total of 756 subjects were studied: 453 belonging to groups at risk for retrovirus infection, 255 with diseases potentially linked to HTLV-I/II infection and 48 immigrants from endemic areas. An HTLV-I viral-lysate enzyme immunoassay (EIA) with a recombinant transmembrane envelope protein incorporated was used to screen serum samples. Reactive specimens were confirmed by Western blot strips spiked with recombinant proteins that differentiated HTLV-I from HTLV-II. Infection was then verified by the polymerase chain reaction (PCR). Serum samples from 19 of the 756 subjects analyzed (2.5%) were reactive for HTLV by EIA. One of these was from an intravenous drug user (IVDU) in whom HTLV-II infection was confirmed by Western blot and PCR; a specimen from another IVDU showed Western blot reactivity for both retroviruses, but PCR results were negative. Lastly, Western blot confirmed the presence of HTLV in one of the immigrant subjects. Western blot did not verify HTLV infection in the remaining 16 cases, indicating a high rate of nonspecific anti-HTLV reactivity when a second-generation EIA screening test was applied. These results suggest that HTLV is present in Spain among populations at high risk for HTLV, although at a very low rate and restricted to intravenous drug users and individuals immigrating from endemic areas.

Prevalence of human T-cell lymphotropic virus type 1 (HTLV-1) and HTLV-2 infection among Spanish drug users measured by HTLV-1 assay and HTLV-1 and -2 assay. HTLV-1 and HTLV-2 Spanish Study Group

The prevalence of human T-cell lymphotropic virus type 1 (HTLV-1) and HTLV-2 infection in 1992 and 1993 was determined by testing 2,152 specimens from injection drug users living in 11 geographic areas in Spain. Results obtained by an authentic HTLV-1 and -2 test were compared with those obtained by an HTLV-1 assay. HTLV infection was identified in 7 of 11 regions, with an overall prevalence of 2.5% (range, 0.4 to 11.5%). Fourty-four (81%) of 54 subjects were infected with HTLV-2; the viral strains in the remaining 10 subjects could not be serologically typed. Underestimation of HTLV infection because of the low sensitivities of HTLV-1 enzyme immunoassays for HTLV-2 antibody was relatively low (< 20%). Therefore, previous epidemiologic findings generated with HTLV-1 enzyme immunoassays appear to be reasonably accurate. Our results suggest that the rate of HTLV infection may have been increasing recently among Spanish drug users.

Extraordinary high rate of HTLV type II seropositivity in intravenous drug abusers in south Vietnam

Serum specimens (n = 1899) were assayed for infections with HTLV-I, HTLV-II, and HIV-1 in seven classified groups of normal healthy controls, children, pregnant women, prostitutes, intravenous drug abusers, patients under going hemodialysis, and hemophiliacs in South and North Vietnam. Surprisingly, 125 of 954 samples from South Vietnam exhibited seropositivity for HTLV-II and 119 of these belonged to the group of IVDAs (n = 200). The remaining six positives were a healthy control, a prostitute, two children, and two patients under going hemodialysis. Two IVDAs who were seropositive for HTLV-I and 10 of 15 seropositives for HIV-1 were also positive for HTLV-II in this population. In contrast, no seropositives to any of the viruses were detected in the North Vietnamese samples (0 of 945). The HTLV-II-seropositive IVDAs exhibited increased seropositivity with age compared with HIV-1 seropositivity in the population, and there was no statistical relation between seropositivity for HTLV-II and HIV-1. The HTLV-IIs in South Vietnam IVDAs appeared, by subtype-specific peptide ELISA, to be a mixture of both subtypes a and b, with subtype a predominant. It seems possible that HTLV-II may have been introduced into this population from IVDAs from the United States during the Vietnam conflict, but in a period prior to, or early in, the introduction of HIV-1 to IVDAs.

HIV infection and cocaine use in methadone maintained and untreated intravenous drug users

In a survey of 424 intravenous drug users (IVDUs) of whom 107 were currently enrolled in a methadone maintenance program (MMP), we assessed risk behaviors for Human Immunodeficiency Virus (HIV) transmission and conducted HIV testing. We found that African Americans were over-represented in the HIV infected group and under-represented in the methadone maintenance treatment group. Furthermore, subjects in current methadone maintenance treatment reported fewer drug injections in the last 30 days, a reduced speedball (a heroin/cocaine mixture) injection frequency and reduced total cocaine and injected cocaine use. HIV infected subjects reported 20% more cocaine use and injected cocaine use than HIV negatives. However, this difference was due to African Americans reporting more cocaine use and at the same time being over-represented in the HIV infected group. Stratified analysis by ethnicity found significant MMP effects for all ethnic groups, but only one significant HIV status effect, and this was limited to African Americans. Cocaine injection frequency in African Americans was significantly higher for the HIV infected versus non-infected subjects. We conclude that i.v. cocaine use is a risk factor associated with HIV infection and that methadone maintenance treatment is associated with reducing this risk factor. Furthermore, African American cocaine users are at great risk for HIV infection, and increased efforts for engagement in treatment are necessary.

Detection of HTLV-II-seropositive blood donors in South Vietnam but not in North Vietnam

Approximately 1% (4/500) of blood donors exhibited seropositivity for HTLV-II in South Vietnam, but none (0/500) did in North Vietnam. Further, all individuals seropositive for HTLV-II were intravenous drug abusers who were seronegative for HIV-1 and HTLV-I. These findings suggest that HTLV-II infection may be specifically prevalent in drug abusers in South Vietnam.

A multicentric seroepidemiological survey of HTLV-I/II in Italy

BACKGROUND

Several studies carried out in the USA and in Europe have shown the presence of HTLV-I/II antibodies in subjects belonging to high-risk groups for HIV infection as well as blood donors. Concern about the presence of HTLV-I/II markers in the normal population, as well as the efficient transmission of HTLV-I/II by whole blood or infected blood cells have led several countries to include screening for anti-HTLV-I/II among the mandatory serological testing of blood donors.

OBJECTIVE

In order to assess the risk of HTLV-I/II infection related to blood transfusions, a multicentric survey for antibodies against HTLV-I and HTLV-II was carried out involving 10 Italian sites during the spring of 1991.

STUDY DESIGN

Serum specimens were collected from 14,598 blood donors, 1,411 injecting drug users, 1,015 thalassemics, 142 hemophiliacs and 138 hemodialysis patients. HTLV antibodies were detected by a screening EIA which combines a viral lysate with a recombinant HTLV-I env protein (p21e). The serological confirmation was performed by a semi-automated dot-blot immunoassay that detects gag p19 and p24 and env p21e specific antibodies, while the discrimination of HTLV-I and HTLV-II reactivities was carried out by EIAs employing synthetic peptides of the ENV region specific for each virus.

RESULTS

The seroprevalence of confirmed positives was 0.034% among blood donors and 3.61% among IDUs, while no sample of the other categories could be confirmed, although several were indeterminate and one thalassemic reacted against HTLV-I on peptide testing. HTLV-I reactivity was observed in one blood donor, while all 38 of the 51 confirmed seropositive IDU's reacted only to the HTLV-II synthetic peptide.

CONCLUSIONS

These data confirm a high prevalence of HTLV-II among Italian IDUs and show an HTLV-I/II seroprevalence among blood donors very similar to that which was found in the USA volunteer blood donors. A surveillance program among blood donors seems advisable in order to establish the possible need of a mandatory screening for HTLV-I/II.

HTLV-I and HTLV-II infections among HIV-1 seropositive patients in Sao Paulo, Brazil

To estimate the presence of, and the risk factors for HTLV-I and HTLV-II infections among HIV-1 infected subjects in Sao Paulo, Brazil, a serosurvey was performed in 471 HIV-1 infected patients, including 216 intravenous drug addicts (IVDA), 229 homosexual/bisexual men, and 26 with other risk factors. Serum samples were screened for HTLV seroreactivity by ELISA; reactive samples were analyzed by Western Blot (WB), using whole HTLV-I lysate as antigen. To confirm and discriminate HTLV-I and HTLV-II infections, sera presenting any bands on WB were further analyzed by a WB containing recombinant HTLV-I and HTLV-II proteins (WB 2.3), and by enzyme immunoassays using synthetic peptides specific for envelope proteins (Synth-EIA). In 22 cases, cell samples were available for polymerase chain reaction (PCR) studies. On WB, 114 sera were reactive and, of these, 37 and 25 were concordantly positive on both WB 2.3 and Synth-EIA procedures for HTLV-I and HTLV-II specific antibodies, respectively; 37 specimens were negative on both assays, and 15 gave discordant or indeterminate results. PCR findings confirmed concordant results obtained in the discriminatory serological assays. The prevalence rates of HTLV-I and HTLV-II infections were 15.3% and 11.1% in IVDA, and 0.9% and 0.4% in homosexual/bisexual men, respectively. No case of HTLV-I/HTLV-II co-infection was found.

Quo vadis: perinatal AIDS issues--2004

The HIV problem will inexorably increase over the next decade, with an increasing proportionate impact upon women and children over the next decade. HIV will become endemic, essentially worldwide. Some regions in the developed world may be relatively spared if current trends continue. This may reduce the willingness to expend necessary resources, particularly if trends toward increasing isolationism continue. There are already signs of a world becoming "bored" with AIDS and the chronicity of a difficult problem. This engenders an atmosphere ripe for increasing discrimination, with the development of loopholes in protective legislation. Already in the United States, some lawsuits concerning health care access among employees have been decided in the employer's favor, permitting them to restrict access to health insurance, despite other regulations which might have protected such workers. Similarly, some HIV-infected health care workers have been dismissed or lost their privileges in the 1990s, despite passage of the Americans with Disabilities Act as well as preceding legislation. It remains to be seen how society will cope with these complicated issues. The view of AIDS in 2004 presented above is pessimistic. There are some important rays of hope. Recent innovative vaccine work and new theoretical models may put us on the road to success, both with preventive and therapeutic vaccines. In particular, the first success in eliciting protection against vaginal HIV exposure, albeit partial, was reported in mid 1993. In a simian immunodeficiency virus (SIV) in vivo experimental model, cellular immunity to SIV was induced in macaques without their developing any signs of SIV infection. These macaques after rechallenge with low-dose SIV remained free of detectable SIV, so there may be an element of protection associated with specific cellular immune responses to immunodeficiency viruses. However, very high-dose SIV rechallenge experiments in similar macaques still led to acquisition of active SIV infection, suggesting that any such protection was only partial. It is also possible that cellular immune protection may be of varying efficacy against different types of exposure, particularly parenteral versus mucosal (such as sexual) exposures. There is also reason for specific optimism concerning interventions that might directly reduce the risk of perinatal transmission. Data from studies of twins suggest that a substantial proportion of perinatal transmission does not occur until after labor has commenced. Thus, caesarian sections may potentially reduce the risk of transmission to the fetus in some cases.(ABSTRACT TRUNCATED AT 400 WORDS)

Evaluation of a p21e-spiked western blot (immunoblot) in confirming human T-cell lymphotropic virus type I or II infection in volunteer blood donors. The Retrovirus Epidemiology Donor Study Group

Current algorithms for the serologic confirmation of human T-cell lymphotropic virus type I and II (HTLV-I/II) antibody reactivity are complicated. We evaluated the performance of an HTLV-I Western blot (immunoblot) spiked with recombinant p21e protein (p21e WB) as an alternative to current confirmatory methods. These methods include the HTLV-I viral lysate Western blot and either a radioimmunoprecipitation assay or a p21e enzyme-linked immunosorbent assay. Five hundred fifty nine blood donations obtained from five U.S. blood centers and classified as HTLV-I/II seropositive (n = 149) or seroindeterminate (n = 410) by routine testing methods were further evaluated by PCR for proviral DNA and by the p21e WB. On the basis of serologic and PCR testing, 155 donations were classified as HTLV-I/II infected. The sensitivity of the p21e WB was 97.4%, slightly exceeding that of routine confirmatory testing. The specificity of the p21e WB was 97.5%, as determined by testing of 404 seroindeterminate samples that were negative in the PCR. The positive predictive value of the p21e WB was 94%. In contrast, the specificity and positive predictive value of routine confirmatory testing were both 100%. Follow-up sampling of presumptive p21e WB false-positive donors substantiated the absence of HTLV-I/II infection. Although the p21e WB used in this study has high sensitivity and may be useful as a confirmatory assay in epidemiologic research studies, it may not be ideal as a confirmatory test for the notification of blood donors.

Coexistence of human T-lymphotropic virus types I and II among the Wayuu Indians from the Guajira Region of Colombia

High prevalences of human T-lymphotropic virus type II (HTLV-II) infection have been found recently among certain Amerindian groups in North, Central, and South America. To determine if the Amerindians of Colombia are similarly affected, 523 sera, collected between 1987 and 1990 from nine culturally distinct Indian groups from widely separated regions, were tested for IgG antibodies against HTLV-I/II using enzyme-linked immunosorbent assay (ELISA) and Western blot. In addition, 243 sera from five non-Indian (black) and mixed-Indian (mestizo) populations were studied. Of the 766 individuals tested, 44 were ELISA positive, but of these, only four were Western blot positive. Three of the individuals confirmed positive by Western blot were infected with HTLV-II and one was infected with HTLV-I, as determined by differential ELISA. All four seropositive individuals belonged to a group of 62 Wayuu Indians, giving overall HTLV-I and HTLV-II seroprevalences of 1.6% and 4.8%, respectively. The coexistence of HTLV-I and HTLV-II in this Amerindian group provides an opportunity to study the factors governing transmission of these retroviruses.

HTLV-II among Italian intravenous drug users and hemophiliacs

The seroprevalence of HTLV-I/II was evaluated in 1247 Italian individuals at high risk for HIV infection. The population studied consisted of 985 intravenous drug users (IVDUs), 474 of whom on methadone maintenance and 511 in a therapeutic community, 110 HIV-infected patients in various stages of HIV-related disease and 152 hemophiliacs. Sera were screened for antibody to HTLV-I/II by enzyme immunoassay (EIA) and confirmed by Western blot and radioimmunoprecipitation assay. Confirmed positive samples were further differentiated by EIA using HTLV-I and HTLV-II specific peptides. The overall prevalence of anti-HTLV-I/II was 4.0% in IVDUs, with the highest prevalence (8.2%) among HIV-infected symptomatic patients. None of the hemophiliacs was anti-HTLV-I/II positive, even though 63.1% tested positive for HIV antibodies. The trend of seroprevalence in drug users and the evaluation of possible risk factors demonstrated that HTLV-I/II infection has been present in Italy before the onset of HIV epidemic. The overall seroprevalence showed no significant changes during the 10 year period covered by this survey but correlated with HIV seropositivity, age and duration of drug use. Peptide testing showed that HTLV infection was mainly due to HTLV-II.

Detection of simian T-lymphotropic virus type I using the polymerase chain reaction

To develop the polymerase chain reaction (PCR) for the detection of simian T-lymphotropic virus type I (STLV-I) infection, cell lines or peripheral-blood mononuclear cells (PBMC) from 2 non-human primate species [African green monkeys (AGM), Cercopithecus aethiops; baboon, Papio cynocephalus] were evaluated for their STLV-I status using oligonucleotide primer pairs and probes specific for the tax and pol gene regions of the closely related human T-lymphotropic virus type I (HTLV-I). These PCR results were compared with serologic (Western blot assay) and viral culture (p24-antigen capture assay) data. PCR products for both gene regions were detected in established baboon, Japanese macaque and rhesus macaque STLV-I-producing cell lines. STLV-I tax and pol products were also detected in PBMC from 4 of 4 infected AGM and 4 of 4 infected baboons, each of which were also Western-blot-positive and p24-antigen-capture-positive. Of the remaining AGM (n = 7) and baboon (n = 1) which were PCR-negative, each was also Western-blot-negative and p24-antigen-capture-negative. Two seronegative and virus-culture-negative AGM were classified as PCR indeterminate with weak reactivity using tax primers. These primer pairs failed to amplify DNA from uninfected human PBMC, an uninfected human lymphoid cell line, a simian immunodeficiency virus macaque (SIVmac251)-infected cell line and a simian-retrovirus-type-D(SRV-D)-infected cell line. HTLV-II-pol-specific primer pairs failed to amplify DNA from STLV-I-infected cell lines and PBMC from STLV-I-infected monkeys. Further, HTLV-I pol and tax primer pairs successfully amplified RNA from HTLV-I- and STLV-I-infected cell lines by reverse transcriptase (RT)-PCR. We have demonstrated excellent specificity in the detection of STLV-I by PCR using these HTLV-I-derived primers and probes. Additionally, our data suggest that the tax and pol gene regions are conserved between HTLV-I and STLV-I strains found among these diverse species of non-human primates.

Comparison of six commercial human T-cell lymphotropic virus type I (HTLV-I) enzyme immunoassay kits for detection of antibody to HTLV-I and -II

Three licensed and three research human T-cell lymphotropic virus type I (HTLV-I) enzyme immunoassay (EIA) kits were evaluated with a panel of 213 serum or plasma samples which were previously tested by the indirect immunofluorescence method for HTLV-I and -II antibodies. The three research kits were found to be more sensitive and specific than the three licensed kits.

Human T-cell lymphotropic virus type I infection and pregnancy: a case-control study and 12-month follow-up of 135 women and their infants

Human T-cell lymphotropic virus type I (HTLV-I) infection is common in Gabon, but its influence on pregnancy is unknown. A single case of acute T-cell leukemia in a pregnant woman has been reported in the literature, but, as far as we know, we present the first case-control study analyzing the relationship between HTLV-I seropositivity and the course and outcome of pregnancy. The study concerned 45 HTLV-I seropositive pregnant women matched with 90 seronegative pregnant women. None has clinical features of HTLV-I infection during pregnancy or during the year after delivery. HTLV-I seropositivity did not significantly affect the course or outcome of pregnancy. After losing maternal antibodies to HTLV-I, none of the infants had seroconversion to HTLV-I 1 year after birth. Filaria infection was correlated with HTLV-I seropositivity, but confounding factors may account for this observation.

[Neurologic manifestations related to HTLV-1 viruses]

The human T-cell leukaemia virus type 1 was the first human retrovirus to be isolated in 1980 by R. Gallo and coworkers. As its name indicates, this virus is responsible for adult T-cell leukaemia. In 1985, the neurological manifestations associated with this disease were isolated from the tropical spastic paraplegia group in Martinique. Since that time, such manifestations have been reported in non-tropical countries in other foci of viral endemia and sporadically outside these regions. These neurological manifestations are totally independent of the haematological manifestations with which they are virtually never associated. Frequent in areas of viral endemia, they may be encountered in other countries open to human migrations, where they are too often overlooked.

Absence of HTLV-I and HTLV-II infection in prostitutes in the area of Seville, Spain

Infection with human retroviruses other than HIV in Spain has only been reported in isolated cases in African immigrants and intravenous drug abusers infected with HTLV-I. The status of the prostitute population is unknown. The sera of 88 prostitutes in Seville were therefore tested for HIV, HTLV-I and HTLV-II, and relevant epidemiological data were collected on the health status, sexual practices etc. In the prostitute population studied 2.5% of the non-intravenous drug abusers and 20% of the intravenous drug abusers were positive for HIV. However, infection with HTLV-I/II could not be demonstrated in any of them.

Relative prevalence and risk factors of HTLV-I and HTLV-II infection in US blood donors

The clinical significance of human T-cell lymphotropic virus type II (HTLV-II) infection, unlike that of HTLV-I, is unknown, and the major known association of HTLV-II seropositivity is with intravenous drug abuse. Screening of blood donors for HTLV-I, now routine in North America, does not distinguish this retrovirus from HTLV-II. To find out more about the seroepidemiology of and risk factors for HTLV I and II, blood from 480,000 volunteer donors in five geographically separate US urban centres was tested for antibodies to HTLV-I/II and HIV-1. Confirmed HTLV-I/II seropositive donors were then followed up by DNA amplification to distinguish type I from type II and by interviews focusing on possible risk factors. HTLV seroprevalence was 3.3 times greater than that for HIV-1 (0.043% vs 0.013%). DNA amplification on 65 of the 207 HTLV-I/II seropositive donors revealed that 34 (52%) had HTLV-II infection and 28 (43% had HTLV-I; 3 samples were uninformative. Interviews of 49 donors showed that whereas HTLV-I was principally associated with donor origin from endemic regions, the major risk factor for HTLV-II infection was intravenous drug use. The surprisingly high rate of HTLV-II infection in US blood donors raises important public health and donor counselling issues since HTLV-I infection is associated with adult T-cell leukaemia and a neurological disorder while the pathogenicity of HTLV-II is as yet unclear.