Sensitive and specific polymerase chain reaction assays for diagnosis of human T-cell lymphotropic virus type I (HTLV-I) and HTLV-II infections in HTLV-I/II-seropositive individuals.

To confirm and differentiate between human T-cell lymphotropic virus type I (HTLV-I) and HTLV-II infections, we analyzed by polymerase chain reaction (PCR) samples of peripheral blood lymphocytes from 98 individuals seropositive for HTLV-I/II using pol (SK110/111) and tax (SK43/44) consensus primer pairs. A total of 96 samples (97.9%) were positive by the tax generic probe, while 95 were typed by the HTLV-I and HTLV-II pol probes. The three pol-negative samples were successfully amplified and typed by nested PCR with primers internal to SK110 and SK111. Results of PCR with a lysate of leukocyte nuclei obtained by whole blood lysis were comparable to those obtained with peripheral blood lymphocytes from 16 HTLV-seropositive subjects.     

Synthetic peptide-based immunoassays for distinguishing between human T-cell lymphotropic virus type I and type II infections in seropositive individuals

Until now, serologic tests that distinguish the closely related human T-cell lymphotropic virus types I (HTLV-I) and II (HTLV-II) infections have not been available. Synthetic peptide assays, employing peptides derived from the core and envelope proteins of HTLV-I and HTLV-II (SynthEIA and Select-HTLV tests), were evaluated for the ability to serologically discriminate HTLV-I and HTLV-II infections. Of 32 HTLV-I- and 57 HTLV-II-positive serum specimens from individuals whose infections were confirmed by polymerase chain reaction, the SynthEIA test categorized 29 (91%) as HTLV-I and 50 (88%) as HTLV-II, and 10 (11%) were nontypeable. In contrast, the Select-HTLV test categorized 32 (100%) as HTLV-I and 55 (96%) as HTLV-II, and 2 (2%) were nontypeable. The specificity of both the assays in seropositive serum specimens was 100% in that none of the specimens were incorrectly classified. Additional serum specimens obtained from clinically diseased patients from the United States (n = 8) and asymptomatic carriers and patients from Japan (an endemic population for HTLV-I; n = 40) were categorized as HTLV-I by at least one of the assays, while serum specimens from Guaymi Indians from Panama (an endemic population for HTLV-II; n = 13) were categorized as HTLV-II. Thus, peptide enzyme immunoassays appear to represent a simple technique employing chemically synthesized antigens for discrimination between antibodies of HTLV-I and HTLV-II.     

Development of a supersensitive polymerase chain reaction method for human T lymphotropic virus type II (HTLV-II) and detection of HTLV-II proviral DNA from blood donors in Japan

A supersensitive polymerase chain reaction procedure was developed to detect human T-lymphotropic virus type II (HTLV-II) proviral genome. Six primer pairs covering the various regions of HTLV-II were compared and selected on the basis of specificity and sensitivity. Among them, one primer pair of the pol region of HTLV-II (II pol) was able to amplify and detect even 0.1 fg of the cloned plasmid HTLV-II DNA (seven copies) by regular ethidium bromide staining on polyacrylamide gel. By using this procedure, we screened 189 HTLV-I seropositive blood donors from Yamaguchi and Fukuoka Red Cross Blood Centers, Japan. There were four positive samples detectable with the HTLV-II-specific pol primer pair, as well as with the HTLV-I tax primer pair. The amplified DNAs of two specimens were cloned and sequenced. The sequences of the HTLV-I tax region from both specimens were identical to that of HTLV-I. On the other hand, those of the HTLV-II pol region were identical to that of HTLV-II, except for one base substitution in a clone from one subject. These results indicate that dual infection of HTLV-I and HTLV-II in the same persons occurs among Japanese blood donors.     

Human T lymphotropic virus types I and II proviral sequences in Argentinian blood donors with indeterminate Western blot patterns

Human T-cell lymphotropic virus (HTLV) seroindeterminate blood donors have been reported worldwide including Argentina. To investigate the significance of HTLV-I/II seroindeterminate Western blot (WB) patterns, we conducted an 8-year cross-sectional study. Of 86,238 Argentinian blood donors, 146 sera were reactive by screening tests. The WB results indicated that 20% were HTLV-I reactive, 8% HTLV-II reactive, 61% indeterminate, and 11% negative. The overall seroprevalence was 0.034% for HTLV-I, 0.014% for HTLV-II, and 0.103% for indeterminate. In 57 reactive specimens, HTLV-I/II provirus could be examined by type specific PCR for tax, pol, and env regions. When at least two gene fragments were amplified HTLV-I/II infection was considered confirmed. PCR results confirmed all WB seropositive samples for HTLV-I (n = 15), and HTLV-II (n = 7), and the only WB negative case was also PCR negative, showing a complete concordance between PCR and WB. However, of 34 WB seroindeterminate sera studied by PCR, in 5 was proviral DNA amplified. According to our criteria PCR confirmed one to be HTLV-I, and one HTLV-II, 3 remained indeterminate since only tax sequences were amplified. Among WB indeterminate samples tested by PCR, most of their serological profile showed reactivity to gag codified proteins but lacked env reactivities (70%). One sample with a WB gag pattern showed proviral tax sequences, but of the four samples with reactivity to env proteins GD21 (n = 3) or rgp46II (n = 1) PCR results indicated that one was HTLV-I, one was HTLV-II, and two were indeterminate (only tax sequences). In conclusion, the majority of HTLV-seroindeterminate WB donors exhibited a gag indeterminate profile lacking HTLV provirus, and were thus considered uninfected. However, seroreactivity to env proteins, in particular to GD21, may indicate infection and a follow-up study of each seroreactive blood donor should be considered.     

Seroprevalence of HTLV-1 and HTLV-2 among intravenous drug users and persons in clinics for sexually transmitted diseases.

Background. The human T-cell lymphotropic virus Type I (HTLV-I) is associated with adult T-cell leukemia and myelopathy, whereas HTLV-II infection has uncertain clinical consequences. We assessed the seroprevalence of these retroviruses among intravenous drug users and among patients seen at clinics for sexually transmitted diseases (STD clinics). METHODS. We used serum samples that were collected in eight cities in 1988 and 1989 during surveys of human immunodeficiency virus infection among intravenous drug users entering treatment and persons seen in STD clinics. The serum samples were tested for antibodies to HTLV, and positive specimens were tested further by a synthetic peptide-based enzyme-linked immunosorbent assay to differentiate between HTLV-I and HTLV-II. RESULTS. Among 3217 intravenous drug users in 29-drug-treatment centers, the median seroprevalence rates of HTLV varied widely according to city (range, 0.4 percent in Atlanta to 17.6 percent in Los Angeles). Seroprevalence increased sharply with age, to 32 percent in persons over 44 years of age. HTLV infection was more common among blacks (15.5 percent) and Hispanics (10.7 percent) than among whites (4.1 percent), and it was strongly associated with a history of heroin injection (P less than or equal to 0.001). Among 5264 patients in 24 STD clinics, the median rates of HTLV infection were much lower (range, 0.1 percent in Atlanta and Newark to 2.0 percent in Los Angeles). Again, this infection was more common among intravenous drug users (7.6 percent) than among non-drug users (0.7 percent). Eighty-four percent of the seropositive samples from drug-treatment centers and 69 percent of those from STD clinics were due to HTLV-II infection (P = 0.03). CONCLUSIONS. HTLV infections are common among intravenous drug users and are primarily caused by HTLV-II. Among patients seen at STD clinics, HTLV is strongly associated with intravenous drug use, but the retrovirus is also prevalent among non-drug users.     

Indications for the presence of antibodies cross-reactive with HTLV-I/II, but not HIV, in patients with myelodysplastic syndrome.

Serological evidence is presented for the fact that patients with the myelodysplastic syndrome exhibit a statistically significant reactivity in confirmatory assays for antibodies to human T-lymphotropic viruses types I and II (HTLV-I/II). This antibody reactivity, evident by indirect immunofluorescence and Western blot, was not confined to HTLV core antigens but extended to native and recombinant envelope glycoproteins. The effect was also observed in cases of acute myeloic leukemia, albeit to a lesser degree. It was essentially absent from patients with chronic myeloic leukemia or lymphocytic leukemias and healthy or multitransfused controls. No antibodies to human immunodeficiency viruses types 1 or 2 were detected in any of the specimens. The investigated clinical population had no known risk factor for retroviral infection other than a history of multiple platelet transfusions, and none of the specimens was seropositive for HTLV-I or HTLV-II according to recommended criteria. The cause of this cross-reactivity remains to be determined.     

Prevalence of HIV-1 non-B subtypes, syphilis, HTLV, and hepatitis B and C viruses among immigrant sex workers in Madrid, Spain

Sexually transmitted disease (STD) remains a major public health challenge in developed countries, exacerbated by the advent of the HIV epidemic. The objectives of this study were to assess the prevalence of serological markers of syphilis, HIV-1/2, HTLV-I/II, HBV, and HCV infections among immigrant sex workers in Madrid, Spain and to characterize the HIV-1 variants in seropositive individuals. Sera from 762 immigrant commercial sex workers (75.3% from sub-Saharan Africa, 18.2% from South America, and 6.4% from Eastern Europe) were collected between 1998 and 2003 in Madrid and examined. Antibody detection was performed by screening assays (RPR, ELISAs) and confirmed by FTA-Abs, LIAs and Western-blot tests. HIV-1 subtyping was carried out by phylogenetic analyses of the protease and envelope genes. Antibodies to HIV-1 were found in 5.2%, while 3.5% tested positive for HBsAg, 3% for syphilis antibodies, 0.8% for HCV antibodies, and 0.2% for HTLV-I antibodies. None were reactive for HIV-2 or HTLV-II antibodies. HIV-1 seroprevalence among Africans and Ecuadorians was 4.5 and 10.9%, respectively. All HIV-1 seropositive Ecuadorians were transsexual men, and 28.6% had active syphilis infection. Up to 80% of HIV-1 positive specimens were characterized as non-B subtypes, with subtypes G, A, and G/A recombinants being the most frequent among African individuals. In contrast, South Americans with HIV-1 infection carried exclusively subtype B variants. A relatively high proportion of immigrant sex workers in Madrid were infected with HIV-1 and syphilis, whereas infections with hepatitis viruses or HTLV were uncommon.     

Seroepidemiology of HTLV-I/II in Argentina: an overview

In this report, the results of seroepidemiologic studies of human T-lymphotropic virus type I (HTLV-I) and type II (HTLV-II) infections in different population groups in Argentina have been compiled. The studies have shown a high prevalence of HTLV-I/II infection in blood donors in the provinces in the north of Argentina (1.0% in Jujuy, 0.7% in Salta, and 0.6% in Formosa) and a low prevalence in the provinces in the central region of the country (相似文献   

HTLV-Associated Diseases: Human Retroviral Infection and Cutaneous T-Cell Lymphomas

An array of neurologic, oncologic, and autoimmune disorders are associated with infection with the human pathogenic retroviruses human T-cell leukemia virus types I and II (HTLV-I, II), as well as the human immunodeficiency viruses (HIV). The cutaneous T-cell lymphomas, mycosis fungoides (MF) and its hematogenous variant Sezary Syndrome (SS), share similar clinical and pathological features to HTLV-I-associated adult T-cell leukemia (ATL) and speculation of a retroviral link to MF and SS, especially in areas non-endemic for ATL, has lead to an intensified search for HTLV- and HIV-like agents in these diseases. To further explore a potential role for human retroviruses in MF and SS, skin biopsy-derived or peripheral blood mononuclear cell-derived DNA from 17 patients (MF, n=7; erythrodermic MF (EMF), n=5; SS, n=5) from the North Eastern United States were screened using gene amplification by PCR and a liquid hybridization detection assay. Previously published primers and probes for HTLV-I (LTR, gag, pol, env, and pX), and our own primers and probes for HTLV-I (gag, pol, and env), HTLV-II (pol and env) and HIV-I (gag and pol) were employed. Serum antibodies to HTLV-I were negative in all but one EMF patient. The single HTLV-I seropositive patient carrying a diagnosis of EMF generated positive amplified signals for all of the eight HTLV-I regions tested. Ultimately, this individual evolved to exhibit clinical manifestations indistinguishable from ATL. The other 16 patients were negative for all 12 HTLV and HIV retroviral regions. Our findings suggest that none of the known prototypic human retroviruses are associated with seronegative MF and SS. The uniformly positive results for HTLV-I in the seropositive patient suggests that this patient initially presented with a smoldering form of ATL and illustrates the difficulty that sometimes may be encountered in the differential diagnosis of MF, SS, and ATL based solely on clinical and histopathological criteria.     

Detection of antibodies to trans-activator protein (p40taxI) of human T-cell lymphotropic virus type I by a synthetic peptide-based assay.

Antibodies to human T-cell lymphotropic virus type I (HTLV-I) trans-activator protein (p40taxI) were determined in serum specimens from individuals infected with HTLV-I (n = 138) and HTLV-II (n = 19). Western blot (immunoblot) analysis using recombinant tax demonstrated the presence of anti-tax antibodies in 96% of patients (25 of 26) with HTLV-I-associated myelopathy, 43% of those (20 of 46) with adult T-cell leukemia, and 61% of asymptomatic HTLV-I blood donors (40 of 66); only one of the HTLV-II specimens reacted with the recombinant tax protein. Synthetic peptides (Tax8(106-125), Tax22(316-335), Tax-23(331-350), and Tax-24(336-353) representing the immunodominant epitopes of¿ p40taxI detected anti-tax antibodies in 66 (48%), 50 (36%), 66 (48%), and 64 (46%) of 138 HTLV-I-positive specimens, respectively. An enzyme immunoassay using an equimolar ratio of these four peptides allowed sensitive detection of anti-tax antibodies in 96% of patients (25 of 26) with HTLV-1-associated myelopathy, 52% of adult T-cell leukemia patients (24 of 46), and 62% of asymptomatic HTLV-1-infected donors (41 of 66). The synthetic peptide-based cocktail assay was HTLV-I specific, since none of the HTLV-II-infected specimens reacted with these peptides. Interestingly, the corresponding regions from the HTLV-II tax protein, Tax8II(106-125), and Tax-22II(312-331) did not react with either HTLV-II or HTLV-I specimens. Thus, a synthetic peptide-based assay composed of immunodominant epitopes located towards the amino terminus and the C terminus of p40taxI provides a reliable and sensitive assay for the detection of anti-tax antibodies in seroepidemiologic studies.     

Differential antibody responsiveness to p19 gag results in serological discrimination between human T lymphotropic virus type I and type II.

A new algorithm based upon the differential antibody responses to two gag gene products (p19 and p24) of human T lymphotropic virus (HTLV) has been suggested for serologic discrimination of HTLV type I (HTLV-I) and type II (HTLV-II) [Lillihoj et al., 1990]. To evaluate the practical usefulness of this algorithm, serum specimens from HTLV-seropositive individuals whose infection was confirmed by PCR analysis to be HTLV-I (n = 60) or HTLV-II (n = 61) were analyzed by western blot. The intensities of the antibody response to p24gag and p19gag were scored by one individual without prior knowledge of PCR results. According to the algorithm, specimens with p19 greater than or equal to p24 were classified as HTLV-I, whereas specimens with p19 less than p24 were classified as HTLV-II. Of 60 PCR confirmed HTLV-I specimens, 56 had p19 greater than or equal to p24 (93%) while 4 had p19 less than p24. Of 61 PCR confirmed HTLV-II specimens, 56 had p19 less than p24 (92%) and 5 had p19 greater than or equal to p24. The overall accuracy of serologic differentiation when using this algorithm was 92%, as 4 of 60 HTLV-I (7%) and 5 of 61 HTLV-II (8%) could have been wrongly classified. Although the differential antibody response to p19gag and p24gag provides a simple means of serologically distinguishing between HTLV-I and HTLV-II infection in population-based epidemiological studies, in a clinical context more accurate means of confirmation are required. The dominant p19gag responses were mapped to the C-terminus of p19 (p19(102-117)).(ABSTRACT TRUNCATED AT 250 WORDS)     

The Origin and Evolution of Human T-Cell Lymphotropic Virus Types I and II

Studies on human T-cell lymphotropic virus types I (HTLV-I) and II (HTLV-II) are briefly reviewed from the viewpoint of molecular evolution, with special reference to the evolutionary rate and evolutionary relationships among these viruses. In particular, it appears that, in contrast to the low level of variability of HTLV-I among different isolates, individual isolates form quasispecies structures. Elucidating the mechanisms connecting these two phenomena will be one of the future problems in the study of the molecular evolution of HTLV-I and HTLV-II.     

Human T-cell lymphotropic virus types I and II (HTLV-I and -II) infection among seroindeterminate cases in Argentina

Human T-cell lymphotropic virus (HTLV) seroindeterminate cases have been reported among blood donors (BD) and in at-risk populations worldwide, including Argentina. The objective of the present work was to study the presence of HTLV-I/II infection and its association to specific Western blot (WB) patterns among healthy BD and at-risk populations in Argentina. We analyzed 83 HTLV-I/II seroindeterminate WB cases diagnosed among BD (n = 49) and in different at-risk populations (n = 34) for human retroviruses infections. Multiple indeterminate WB patterns were observed. Out of the total, 13.2% (11/83) of the cases were found to be HTLV-I/II positive by nested-PCR (n-PCR), including 13.2% (11/83) HTLV-I and 2.4% (2/83) presenting HTLV-I and -II co-infection. Most of their serological profiles showed reactivity to gag or env codified proteins. Two samples amplified only one of the six analyzed genes (1 HTLV-I pol gene and 1 HTLV-II tax gene). There was no association between the presence of Trypanosoma cruzi infection and an HTLV-I/II indeterminate WB pattern (only 3 of the 83 samples were positive for T. cruzi antibodies). In conclusion, the majority of HTLV-seroindeterminate WB donors lacked HTLV provirus and was thus considered uninfected. However, when seroreactivity to Env and Gag proteins are observed on the WB and especially in at-risk populations, HTLV infection should be suspected; such individuals should be followed-up and retested.     

Spontaneous lymphocyte proliferation in human T-cell lymphotropic virus type I (HTLV-I) and HTLV-II infection: T-cell subset responses and their relationships to the presence of provirus and viral antigen production.

Spontaneous lymphocyte proliferation (SLP) during in vitro culture of mononuclear cells (MCs) characterizes over half of asymptomatic individuals infected with human T-cell lymphotropic virus type I (HTLV-I) or HTLV-II. Both CD4 and CD8 T-cell subsets within MC cultures are activated during SLP, as judged by high-density CD25 (CD25bright) expression; it is unclear, however, whether both cell subsets can directly undergo SLP. In the present investigation, the SLP capacities of purified CD8 and CD4 cells were examined in subjects infected with HTLV-I (n = 19) or HTLV-II (n = 54) in relation to the SLP status of MCs from each subject. No increase in SLP was observed for CD8 or CD4 cells from SLP-negative (SLP-) HTLV-infected subjects, whereas robust SLP characterized CD8 cells from all SLP-positive (SLP+) individuals, regardless of HTLV type. In contrast, SLP+ CD4 cells characterized only 23% (7 of 31) of HTLV-II+ SLP+ individuals, whereas SLP+ CD4 cells characterized 100% of HTLV-I+ SLP+ individuals. In cocultures of HTLV-II+ SLP+ CD8 cells and autologous SLP- CD4 cells, sizable proportions of both CD8 cells and CD4 cells coexpressed CD25bright, suggesting that SLP- CD4 cells were activated in the presence of SLP+ CD8 cells. PCR analysis for tax sequences detected provirus in most CD4- and CD8-cell preparations from HTLV-seropositive individuals, regardless of type and the SLP status of cell subsets. To determine whether SLP was associated with activation of viral genes, levels of HTLV-I and HTLV-II core antigen (Ag) in supernatants were measured. Viral Ag production and SLP responses were significantly correlated for both CD4 and CD8 cells in both HTLV-I and HTLV-II infections. However, inhibition of CD8- or CD4-cell SLP by cyclosporin A or anti-Tac (anti-CD25) did not reduce Ag production, indicating that Ag production is not coupled to SLP. These findings show that CD4 cells from SLP+ HTLV-I+ and SLP+ HTLV-II+ individuals differ in SLP capacity, that the absence of SLP does not indicate a lack of infection, and that production of viral Ag is associated with, but not dependent on, SLP.     

江门市桑拿按摩女性从业人员性传播疾病／艾滋病感染情况分析

目的了解江门市桑拿按摩女性从业人员性传播疾病／艾滋病的流行情况。方法对213位桑拿按摩女性从业人员进行性病病原体检测。结果在213名桑拿按摩女性从业人员中发现性病84例，性病感染率为39．44％，其中HIV抗体阳性1例（0．47％），细菌性阴道病16例（7．51％），淋病7例（3．29％），衣原体性宫颈炎38例（17．84％），尖锐湿疣1例（0．47％），梅毒14例（6．57％），念珠菌性阴道病7例（3．29％）。结论桑拿按摩女性从业人员是性病的高危人群，应主动定期对该人群进行监测，并加强行为干预和治疗。     

Quantitation of HTLV-I and II proviral load using real-time quantitative PCR with SYBR Green chemistry.

BACKGROUND: Human T-lymphotropic virus type I (HTLV-I) is linked etiologically with adult T cell leukemia/lymphoma and HTLV-I-associated myelopathy/tropical spastic paraparsis (HAM/TSP). Human T-lymphotropic virus type II (HTLV-II) is associated with HAM/TSP and, in HIV coinfected patients only, rare cases of cutaneous T cell lymphoma. Proviral load may be important in the pathogenesis of HTLV-associated disease. MATERIALS AND METHODS: A real time quantitative PCR assay using SYBR Green intercalation was established. Primers targeting the tax region were standardized against MT2 and MOT cell line DNA for HTLV-I and HTLV-II, respectively. HTLV-I/II copy number was normalized to the amount of cellular DNA by quantitation of the HLA-DQ alpha gene. We measured proviral load in peripheral blood mononuclear cells (PBMCs) in a large cohort of 120 HTLV-I and 335 HTLV-II seropositive former blood donors. We also assessed the intra- and inter-assay reproducibility of the assay. RESULTS: Proviral load for HTLV-I infected patients ranged from 3.1 x 10(0) to 1.8 x 10(5)copies/10(6) PBMCs with a mean of 1.6 x 10(4) and a median of 3.0 x 10(3). HTLV-I was undetectable in 7 of 120 cases (5.8%). Proviral load for HTLV-II infected patients ranged from 1.1 x 10(0) to 1.0 x 10(6)copies/10(6) PBMCs with a mean of 2.8 x 10(4) and a median of 5.0 x 10(2). HTLV-II was undetectable in 31 out of 335 cases (9.3%). CONCLUSION: The assay has excellent dynamic range from 10(6) to 10(0)copies/reaction, good intra- and inter-assay reproducibility, and a lower limit of detection of a single copy per reaction. The sensitivity and high dynamic range allow determination of a broad range of HTLV-I/II proviral load in clinical subjects. This assay will facilitate the study of the relationship between proviral load and pathogenesis.     

Evaluation of a new, fully automated immunoassay for detection of HTLV-I and HTLV-II antibodies

Screening blood donations for human T-lymphotropic virus types I and II (HTLV-I/II) continues to be important in protecting the safety of blood products and controlling the global spread of these retroviruses. We have developed a fully automated, third generation chemiluminescent immunoassay, ARCHITECT rHTLV-I/II, for detection of antibodies to HTLV-I/II. The assay utilizes recombinant proteins and synthetic peptides and is configured in a double antigen sandwich assay format. Specificity of the assay was 99.98% (9,254/9,256, 95% CI = 99.92-100%) with the negative specimens from the general population including blood donors, hospital patients and pregnant women from the US, Japan and Nicaragua. The assay demonstrated 100% sensitivity by detecting 498 specimens from individuals infected with HTLV-I (n = 385) and HTLV-II (n = 113). ARCHITECT rHTLV-I/II results were in complete agreement with the Murex HTLV-I/II reference assay and 99.7% agreement with the Genelabs HTLV Blot 2.4 confirmatory assay. Analytical sensitivity of the assay was equivalent to Murex HTLV-I/II assay based on end point dilutions. Furthermore, using a panel of 397 specimens from Japan, the ARCHITECT rHTLV-I/II assay exhibited distinct discrimination between the antibody negative (Delta Value = -7.6) and positive (Delta Value = 7.6) populations. Based on the excellent specificity and sensitivity, the new ARCHITECT rHTLV-I/II assay should be an effective test for the diagnosis of HTLV-I/II infection and also for blood donor screening.     

Human T-cell leukemia/lymphoma viruses. Life cycle, pathogenicity, epidemiology, and diagnosis.

Human T-cell leukemia/lymphoma virus type I (HTLV-I) was discovered in 1980, and it subsequently was found to be the cause of adult T-cell leukemia/lymphoma. A progressive neurologic disease known as tropical spastic paraparesis, or HTLV-I-associated myelopathy, has also been linked to infection with HTLV-I. A related virus, HTLV type II (HTLV-II), has been isolated from patients with hairy-cell leukemia, but it has not been proved to be the cause of any disease. In late 1988, US blood banks began screening all blood donations for antibodies to HTLV-I/II. This program has resulted in the identification of many unexpectedly seropositive blood donors and provided much information about the prevalence of HTLV-I/II in the United States. In this article, I review the replication of these agents, as well as their pathogenesis, diagnosis, and mechanisms of spread.     

Primary isolation of human T-cell leukemia-lymphoma virus types I and II: use for confirming infection in seroindeterminate blood donors.

We describe the use of an immunofluorescence assay and coculture to confirm human T-cell leukemia-lymphoma virus (HTLV) infection. Peripheral blood mononuclear cells from 32 of 32 seropositive donors were positive in the immunofluorescence assay, and 63% of their cocultures produced p24 antigen. Specific antibodies distinguished HTLV type I (HTLV-I) from HTLV-II. HTLV-I or HTLV-II was isolated from donors with indeterminate serologic test results.     

Hepatitis C and arboviral antibodies in the island populations of mauritius and Rodrigues

A serological survey for antibodies to hepatitis C virus (HCV), dengue viruses (DEN), West Nile virus (WN), and sindbis virus (SIN) was carried out in sera of selected groups of the population of the Islands of Mauritius (n = 449) and Rodrigues (n = 115), Indian Ocean. 8.3% of 564 sera were positive for anti-HCV. In Mauritius, 2.1% of sera of healthy individuals were found with anti-HCV. The highest prevalence was found in sexually transmitted disease (STD) patients and prison inmates with 46.2% and 43.8%, respectively. None of the sera from blood donors sampled from Rodrigues Island had anti-HCV. Antibodies to arbo-viruses were detected in sera of individuals from both islands. Anti-DEN IgG was detected in 3.8% of sera from Mauritius and 0.9% from Rodrigues. Anti-WN IgG was detected in 2.2% of sera from Mauritius and 0.9% from Rodrigues. All sera from Rodrigues were without anti-SIN IgG, 1.1% of those from Mauritius were positive. This suggests that arboviruses occur on these islands. © 1994 Wiley-Liss, Inc.