Geographic distribution of HTLV-I and identification of a new high-risk population

Re-emergence of human T-lymphotropic viruses in West Africa

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

Epidemiology and Etiopathology of Human T-Lymphotropic Viruses: Diagnostic and Clinical Implications for Non-Endemic Areas

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

Mogamulizumab-induced photosensitivity in patients with mycosis fungoides and other T-cell neoplasms

BACKGROUND

Mogamulizumab (Mog) is a defucosylated, therapeutic monoclonal antibody, targeting CCR4 and was first approved in Japan for the treatment of adult T-cell leukaemia/lymphoma (ATLL), followed by cutaneous T-cell lymphoma and peripheral T-cell lymphoma.

OBJECTIVE

To retrospectively investigate development of photosensitivity in patients with mycosis fungoides and other T-cell neoplasms after treatment with Mog.

METHODS

We treated seven cutaneous lymphoma patients with Mog. Upon combination treatment with narrow-band UVB, we noticed that four patients developed photosensitivity dermatitis following Mog therapy, including two cases of mycosis fungoides, one case of adult T-cell leukaemia/lymphoma and one case of EB virus-associated T-cell lymphoproliferative disorder. Phototest was performed with UVA and UVB, and immunohistochemical staining for CD4, CD8 and Foxp3 was conducted in both photosensitivity and lymphoma lesions.

RESULTS

Phototest revealed that the action spectrum of the photosensitivity was UVB in three cases and both UVB and UVA in one case. Histopathologically, the photosensitive lesions were characterized by a lichenoid tissue reaction with a CD8⁺ T cell-dominant infiltrate, sharing the feature with chronic actinic dermatitis, an autoreactive photodermatosis with a cytotoxic T-cell response. Foxp3⁺ regulatory T cells (Tregs) were decreased in the photosensitivity lesions compared with the lymphoma lesions.

CONCLUSION

Increased incidence of photosensitivity reaction was observed during Mog treatment. Decreased number of Tregs in the lesional skin suggests that this reaction is possibly induced by autoreactive cytotoxic T cells.

Dermatology in the North American Indian/Alaska Native population

Dermatology is greatly understudied in the American Indian/Alaska Native (AIAN) population. This topic deserves attention in light of the changing demographics of the United States and the healthcare disparities faced by AIAN, including access to dermatologic care. In this review, we discuss disorders that are more prevalent or otherwise important in the AIAN population, such as cutaneous malignancies, photodermatoses, acanthosis nigricans, connective tissue disorders, cutaneous infections, hypertrophic scar formation, and Heck's disease. We aim to provide an updated review and increase awareness of the dermatologic needs of the AIAN population.

Defective epidermal innate immunity and resultant superficial dermatophytosis in adult T-cell leukemia/lymphoma

PURPOSE

Superficial dermatophytosis is quite commonly seen in patients with adult T-cell leukemia/lymphoma (ATLL), as approximately 50% of the patients develop cutaneous mycotic infections. Because superficially infected fungi in the stratum corneum of the epidermis cannot directly contact with T cells infiltrating in the upper dermis, some perturbation of epidermal innate immunity has been postulated. Interleukin (IL)-17-producing helper T cells (Th17) can induce the keratinocyte production of antimicrobial peptides such as human β defensin (HBD)-2 and LL-37, which play an essential role in cutaneous innate immunity.

EXPERIMENTAL DESIGN

We investigated the frequency of circulating Th17 cells, serum levels of cytokines, and epidermal expression of HBD-1, 2, 3, and LL-37 in ATLL patients with or without superficial dermatophytosis.

RESULTS

The frequency of peripheral Th17 cells and the serum level of IL-17 was significantly decreased in ATLL patients, whereas the serum IL-10 and TGF-β1 levels were increased as compared with healthy controls. Furthermore, ATLL patients with dermatophytosis had higher IL-10 and TGF-β1 levels and lower IL-17 levels than did those without dermatophytosis. Immunohistochemical study revealed that the epidermal expression of both HBD-2 and LL-37 were significantly lower in ATLL patients with dermatophytosis than in non-ATLL patients with dermatophytosis.

CONCLUSIONS

Taken together, these results suggest that the keratinocyte production of antimicrobial peptides promoted by Th17 cells is reduced in ATLL patients, leading to the perturbed innate immunity and the frequent occurrence of superficial dermatophytosis.

Type of skin eruption is an independent prognostic indicator for adult T-cell leukemia/lymphoma

Cutaneous involvement is seen in ~ 50% of adult T-cell leukemia/lymphoma (ATLL) patients. We investigated the association between skin eruption type and prognosis in 119 ATLL patients. ATLL eruptions were categorized into patch (6.7%), plaque (26.9%), multipapular (19.3%), nodulotumoral (38.7%), erythrodermic (4.2%), and purpuric (4.2%) types. When the T stage of the tumor-node-metastasis-blood (TNMB) classification of mycosis fungoides/Sézary syndrome was applied to ATLL staging, 16.0% were T1, 17.7% T2, 38.7% T3, and 4.2% T4, and the remaining 23.5% were of the multipapular and purpuric types. For the patch type, the mean survival time (median survival time could not be estimated) was 188.4 months. The median survival times (in months) for the remaining types were as follows: plaque, 114.9; multipapular, 17.3; nodulotumoral, 17.3; erythrodermic, 3.0; and purpuric, 4.4. Kaplan-Meier curves of overall survival showed that the erythrodermic type had the poorest prognosis, followed by the nodulotumoral and multipapular types. The patch and plaque types were associated with better survival rates. Multivariate analysis demonstrated that the hazard ratios of the erythrodermic and nodulotumoral types were significantly higher than that of the patch type, and that the eruption type is an independent prognostic factor for ATLL. The overall survival was worse as the T stage became more advanced: the multipapular type and T2 were comparable, and the purpuric type had a significantly poorer prognosis than T1.

Peripheral T-cell lymphomas, unspecified (or not otherwise specified): a review

Peripheral T-cell lymphomas (PTCL) comprises a heterogeneous group of haematological tumours, which originate from mature T-cells, and constitute less than 15% of all non-Hodgkin's lymphomas (NHLs) in adults. The current WHO classification recognizes nine distinct clinicopathologic peripheral T-cell NHLs, being the 'unspecified variant' (PTCL-U) the most common subtype. These neoplasms often present in advanced stage at diagnosis, and most commonly have an aggressive clinical course requiring prompt treatment. The rarity of these tumours requires additional studies to better understand their biology and search for new therapies which may hopefully improve the dismal outcome of most patients. This review aims to describe the pathobiological aspects as well the clinical characteristics and current therapeutic strategies of the PTCLs, with special attention to the group of PTCL-U.

Is seroprevalence of HTLV-I/II among blood donors in Lebanon relevant?

Human T-cell lymphotropic virus type I (HTLV-I) is associated with certain hematologic and neurologic disorders. Seroprevalence studies demonstrated that the distribution of HTLV-I is heterogeneous worldwide and not specific to 1 region. Because blood is one of the major routes of transmission of the virus, blood banks of several countries routinely screen all blood donations for HTLV-I. The aim of the present study was to assess the seroprevalence rate of HTLV-I/II antibodies among Lebanese blood donors. Between August 2001 and March 2002, consecutive blood samples of 3529 blood donors were collected at blood banks of 4 major hospitals in Lebanon. Initial enzyme-linked immunosorbent assay (ELISA) screening resulted in 23 (0.7%) positive samples, of which 12 (0.3%) were reconfirmed positive by ELISA. Further analysis by Western blot resulted in 2 (0.06%) positive samples, of which 1 tested positive for HTLV-I by PCR (0.028%). Although its very low prevalence among Lebanese blood donors does not support routine screening of Lebanese blood donors for HTLV-I, screening of blood donors from other nationalities may be exercised, especially those from HTLV-I endemic areas.

Eosinophilia associated with adult T-cell leukemia: role of interleukin 5 and granulocyte-macrophage colony-stimulating factor

To clarify the mechanism of eosinophilia in adult T-cell leukemia (ATL), we studied three ATL patients having marked eosinophilia. Eosinophil-predominant colony-stimulating activity was detected in the serum of one patient and in the conditioned media (CM) from cultured ATL cells from two patients. Soluble interleukin 5 (IL-5), but no interleukin 3 (IL-3) and granulocyte-macrophage colony-stimulating factor (GM-CSF), was detected in sera from all patients. On the other hand, GM-CSF was produced in vitro by ATL cells from all cases, whereas detectable IL-3 and IL-5 was produced by cells from only one, suggesting that in the other two cases, the serum IL-5 was produced by the normal reacting lymphocytes. The fact that no patient showed marked neutrophilia supports the possibility that IL-5 may have a leading role in the development of eosinophilia, with GM-CSF produced by ATL cells playing a complementary role.

Non-Hodgkin's lymphomas in Mexico. A clinicopathological and molecular analysis

It is now well established that the clinical and histopathological characteristics of non-Hodgkin's lymphomas may vary significantly throughout the world. However, only a few reports have been published in Latin American countries. In this work, the clinical and pathologic findings of 264 patients with non-Hodgkin's lymphomas in Mexico City were analyzed. Diffuse large (14%) and diffuse mixed cell types (20%) predominated among nodal lymphomas. Within the group of patients with high grade malignancies, immunoblastic sarcomas were the most common (40/48). It is important to mention that follicular lymphomas were sporadic (4.5%). Among extranodal lymphomas the most commonly involved site was the gastrointestinal tract (11.3%), followed by the midline (6%). Molecular analysis of 65 cases with immunoglobulin and T-cell receptor gene probes showed that most lymphomas were of B-cell lineage (66%). The remaining group was composed of T-cell (25%) and bigenotypic malignancies (9%). All attempts to establish a correlation between the clinical stage and histopathological types with the genetic findings were not successful. However, pre-B and bigenotypic lymphomas were observed mainly in patients over 60 years of age. This study highlights some relevant characteristics of non-Hodgkin's lymphomas in Mexico.

Search for human T-lymphotropic virus type I carriers among northeastern Chinese

Human T-lymphotropic virus type I (HTLV-I) is thought to be the causative agent of adult T-cell leukemia/ lymphoma (ATL). This virus infection is endemic in southwestern Japan, parts of Africa and the Caribbean Islands. We examined sera of 1645 subjects of Liaoning province, northeastern China to detect HTLV-I carriers in an effort to reveal the migratory route taken by the early Japanese (Jomon people). As a result, all sera were found to be negative as tested by particle-agglutination (PA), immunofluorescence (IF), enzyme-linked immunoabsorbent (ELISA) and Western blotting methods. This suggests that the Jomon people, who are thought to have brought HTLV-I to the Japan archipelago tens of thousands of years ago, did not come from northeast China.

Stimulation of leukaemic cells from adult T-cell leukaemia patients with bacterial superantigens

Bacterial superantigens stimulate T cells in a manner that is restricted to the Vbeta of the T-cell receptor. We examined the ability of adult T-cell leukaemia (ATL) cells to respond to these superantigens. Mononuclear cells from 10 patients were cultured with staphylococcal enterotoxin A (SEA), staphylococcal enterotoxin B (SEB) or toxic shock syndrome toxin-1 (TSST-1), and their response was determined by MTT assay and 3H-thymidine incorporation assay. Cells from six patients showed a specific response to a single superantigen. In two cases the cells responded to TSST-1 and bore Vbeta2, the known target of TSST-1. In three cases the cells responded to SEA with one bearing Vbeta9, a target of SEA, and one bearing Vbeta16. In one case the cells responded to SEB. Most of the cells which proliferated in response to superantigens were determined genetically to be leukaemic. The response to TSST-1 was inhibited by anti-Vbeta2 antibody. The responding cells showed a strongly enhancement expression of interleukin-2 receptor. These findings indicate that leukaemic cells from a proportion of ATL patients have an ability to respond to T-cell receptor-dependent superantigens. This suggests that bacterial infection in such patients may contribute to the expansion of ATL cells.

Human T-lymphocyte transformation with human T-cell lymphotropic virus type 2

Human T-cell lymphotrophic virus type 2 (HTLV-2), a common infection of intravenous drug users and subpopulations of Native Americans, is uncommon in the general population. In contrast with the closely related HTLV-1, which is associated with both leukemia and neurologic disorders, HTLV-2 lacks a strong etiologic association with disease. HTLV-2 does shares many properties with HTLV-1, including in vitro lymphocyte transformation capability. To better assess the ability of HTLV-2 to transform lymphocytes, a limiting dilution assay was used to generate clonal, transformed lymphocyte lines. As with HTLV-1, the transformation efficiency of HTLV-2 producer cells was proportionately related to the number of lethally irradiated input cells and was comparable to HTLV-1-mediated transformation efficiency. HTLV-2-infected cells were reproducibly isolated and had markedly increased growth potential compared to uninfected cells; HTLV-2 transformants required the continued presence of exogenous interleukin 2 for growth for several months and were maintained for over 2 years in culture. All HTLV-2-transformed populations were CD2 and/or CD3 positive and B1 negative and were either CD4+ or CD8+ populations or a mixture of CD4+ and CD8+ lymphocytes. Clonality of the HTLV-2 transformants was confirmed by Southern blot analysis of T-cell receptor beta chain rearrangement. Southern blot analysis revealed a range of integrated full-length genomes from one to multiple. In situ hybridization analysis of HTLV-2 integration revealed no obvious chromosomal integration pattern.

[HTLV-I/II infection in the state of Bahia]

The city of Salvador, capital of Bahia, presents a population with the highest prevalence of HTLV-I infection in Brazil. Until now, only one study has investigated this infection in other cities of this state, even though by using a small sample. With objective to evaluate the prevalence of HTLV-I/II antibodies in four cities of the state of Bahia. Serum samples from 1,539 individuals who lived in Catolândia, Ipupiara, Jacobina and Prado were screened by ELISA, and repeatedly reactive samples confirmed by Western Blot. Forty-seven (3.1%) samples were positive by ELISA, and 44 of them were tested by Western blot: 5 (0.3%) were positive, 8 (0.5%) were indeterminate (all of them from Jacobina) and 31 were negative. The overall prevalence of HTLV-I antibodies was 0.3%. This prevalence varied from 0.0% (Prado) to 0.7% (Jacobina), but differences were not statistically significant (p > 0.21). None of these individuals presented HTLV-II antibodies. Jacobina showed the highest prevalence of HTLV-I infection among the cities studied, although the overall prevalence was low. In conclusion, further epidemiological, clinical and virological studies will be of paramount importance to obtain a better understanding of the natural history of this infection in Jacobina.

Retroviral coinfections at a New Orleans HIV outpatient clinic

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.

Evaluation of a new HTLV-I/II polymerase chain reaction

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.

Immunogenetics of HTLV-I/II and associated diseases

The ethnic background of human T-lymphotropic virus types I and II (HTLV-I/II) infections and associated diseases was investigated in association with human leukocyte antigens (HLA) (alleles) and haplotypes. Japanese HTLV-I carriers were characterized by two categories of HLA class I antigens (A24, A26, B7, B61, Cw1, and Cw7) and class II alleles (DRB1 *0101, 0803, 1403, 1501, and 1502 and DQB1 *0303, 0501, and 0601); one category was associated with adult T-cell leukemia (ATL) patients and the other with HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP) patients. The ATL-associated haplotypes had unique DRB1-DQB1 alleles (0901-0303, 1501-0602, 1401-0503), which were correlated with a low immune responsiveness to HTLV-I, while the HAM/TSP haplotypes had different DRB1-DQB1 alleles (0101-0501, 0803-0601, 1502-0601), which were correlated with a high immune responsiveness to HTLV-I. Both ATL- and HAM/TSP-associated haplotypes were found among HTLV-I carriers and the patients from other ethnic groups (Jamaican blacks, Andes natives, South American mestizos, and Mashhadi Jews). HLA haplotypes of HTLV-II carriers were different from those of HTLV-I carriers among South American natives. These results suggested that HTLV-I/II infections and the associated diseases might be determined by immunogenetic factors segregated with HLA alleles and haplotypes.

Human endogenous retroviruses: nature, occurrence, and clinical implications in human disease

Retroviral diagnostics have become standard in human laboratory medicine. While current emphasis is placed on the human exogenous viruses (human immunodeficiency virus and human T-cell leukemia virus), evidence implicating human endogenous retroviruses (HERVs) in various human disease entities continues to mount. Literature on the occurrence of HERVs in human tissues and cells was analyzed. Substantial evidence documents that retrovirus particles were clearly demonstrable in various tissues and cells in both health and disease and were abundant in the placenta and that their occurrence could be implicated in some of the reproductive diseases. The characteristics of HERVs are summarized, mechanisms of replication and regulation are outlined, and the consistent hormonal responsiveness of HERVs is noted. Clear evidence implicating HERV gene products as participants in glomerulonephritis in some cases of systemic lupus erythematosus is adduced. Data implicating HERVs as etiologic factors in reproductive diseases, in some of the autoimmune diseases, in some forms of rheumatoid arthritis and connective tissue disease, in psoriasis, and in some of the inflammatory neurologic diseases are reviewed. The current major needs are to improve methods for HERV detection, to identify the most appropriate HERV prototypes, and to develop diagnostic reagents so that the putative biologic and pathologic roles of HERVs can be better evaluated.

HTLV-I associated myelopathy in Porto Alegre (Southern Brazil)

HTLV-I associated myelopathy/tropical spastic paraparesis (TSP/HAM) have been increasingly described in practically all regions of Brazil. Five confirmed and documented cases of patients with TSP/HAM in Rio Grande do Sul are reported; in all of them spastic paraparesis, neurogenic bladder and superficial and/or profound sensitive disorders were observed in variable degrees. One patient presented a relapsing-remitting course with a cerebellar ataxia (multiple sclerosis-like pattern). Everyone was submitted to clinical, serological, urodynamic, neurophysiologic and neuroradiologic investigation. The aim of this study was to present the southern region of Brazil as an area with significant endemicity for HTLV-I/II infection (prevalence of 0.42% between blood donors), and also to show the existence of patients with neurologic disease associated with this retrovirus.

Mechanisms of Tax Regulation of Human T Cell Leukemia Virus Type I Gene Expression

During the last several years, the human T cell leukemia virus type I (HTLV-I) has become recognized as an important cause for public health concern throughout the world. HTLV-I is the causative agent of a variety of clinical diseases, including an aggressive lymphoproliferative disorder named adult T cell leukemia. HTLV-I induces pathogenicity in the infected host cell through the synthesis of a virally encoded protein called Tax. Expression of Tax is critical to the life cycle of the virus, as the protein greatly increases the efficiency of HTLV-I gene transcription and replication. Furthermore, Tax has been shown to deregulate the transcription of many cellular genes, leading to the hypothesis that the presence of Tax promotes unchecked growth in the HTLV-I-infected cell. The mechanism of Tax trans-activation of HTLV-I gene expression is not known. Tax does not bind directly to the Tax-responsive promoter elements of the virus, but appears to function through interaction with certain cellular DNA binding proteins, including activating transcription factor 2 and cAMP response element binding protein that recognize these sequences. This review summarizes some of the recent work in the field aimed at elucidating the mechanism of Tax trans-activation of HTLV-I gene expression. Copyright 1995 S. Karger AG, Basel

Human T cell lymphotropic virus type 1 in Zimbabwe

Human T cell lymphotrophic virus type 1 (HTLV-1) causes myelopathy and adult T cell leukaemia. Knowledge of its distribution in Africa is limited. We performed HTLV-1 testing by enzyme immunoassay, with immunofluorescence assay confirmation, on 931 blood donors, 88 human immunodeficiency virus (HIV) seronegative patients with clinical features of acquired immune deficiency syndrome, 23 multi-transfused haemophiliacs, 8 patients with haematological malignancies, and 32 patients with neurological disease. One blood donor and 3 neurological patients, all 3 with spinal cord syndromes, were HTLV-1-seropositive. Two of the 3 HTLV-1-positive myelopathy patients were co-infected with HIV and both experienced unusually rapid progression of neurological disease. HTLV-1 is uncommon but can be associated with myelopathy in Zimbabwe.

Human T-cell leukemia virus type I Tax associates with and is negatively regulated by the NF-kappa B2 p100 gene product: implications for viral latency

Human T-cell leukemia virus type I (HTLV-I) is the etiologic agent of the adult T-cell leukemia, an aggressive and often fatal malignancy of activated human CD4 T cells. HTLV-I encodes an essential 40-kDa protein termed Tax that not only transactivates the long terminal repeat of this retrovirus but also induces an array of cellular genes. Tax-mediated transformation of T cells likely involves the deregulated expression of various cellular genes that normally regulate lymphocyte growth produced by altered activity of various endogenous host transcription factors. In particular, Tax is capable of modulating the expression or activity of various host transcription factors, including members of the NF-kappa B/Rel and CREB/ATF families, as well as the cellular factors HEB-1 and p67SRF. An additional distinguishing characteristic of HTLV-I infection is the profound state of viral latency that is present in circulating primary leukemic T cells. In this study, we demonstrate that HTLV-I Tax can physically associate with p100, the product of the Rel-related NF-kappa B2 gene, both in transfected cells and in HTLV-I-infected leukemic T-cell lines. Furthermore, the physical interaction of Tax with p100 leads to the inhibition of Tax-induced activation of the HTLV-I and human immunodeficiency virus type 1 long terminal repeats, reflecting p100-mediated cytoplasmic sequestration of the normally nuclearly expressed Tax protein. In contrast, a mutant of Tax that selectively fails to activate nuclear NF-kappa B expression does not associate with p100. Together, these results suggest that the cytoplasmic interplay of Tax and p100 may play an important role in the initiation and maintenance of HTLV-1 latency observed in adult T-cell leukemia.

Human T-cell leukemia virus type I Tax associates with and is negatively regulated by the NF-kappa B2 p100 gene product: implications for viral latency

Human T-cell leukemia virus type I (HTLV-I) is the etiologic agent of the adult T-cell leukemia, an aggressive and often fatal malignancy of activated human CD4 T cells. HTLV-I encodes an essential 40-kDa protein termed Tax that not only transactivates the long terminal repeat of this retrovirus but also induces an array of cellular genes. Tax-mediated transformation of T cells likely involves the deregulated expression of various cellular genes that normally regulate lymphocyte growth produced by altered activity of various endogenous host transcription factors. In particular, Tax is capable of modulating the expression or activity of various host transcription factors, including members of the NF-kappa B/Rel and CREB/ATF families, as well as the cellular factors HEB-1 and p67SRF. An additional distinguishing characteristic of HTLV-I infection is the profound state of viral latency that is present in circulating primary leukemic T cells. In this study, we demonstrate that HTLV-I Tax can physically associate with p100, the product of the Rel-related NF-kappa B2 gene, both in transfected cells and in HTLV-I-infected leukemic T-cell lines. Furthermore, the physical interaction of Tax with p100 leads to the inhibition of Tax-induced activation of the HTLV-I and human immunodeficiency virus type 1 long terminal repeats, reflecting p100-mediated cytoplasmic sequestration of the normally nuclearly expressed Tax protein. In contrast, a mutant of Tax that selectively fails to activate nuclear NF-kappa B expression does not associate with p100. Together, these results suggest that the cytoplasmic interplay of Tax and p100 may play an important role in the initiation and maintenance of HTLV-1 latency observed in adult T-cell leukemia.

The effect of ethnic differences on the pattern of HTLV-I-associated T-cell leukemia/lymphoma (HATL) in the United States

Human T-cell lymphotropic virus Type I (HTLV-I) is the primary etiologic factor for adult T-cell leukemia/lymphoma (ATL). Although HTLV-I is endemic in Japan and the Caribbean islands, the reported clinical and epidemiologic features of ATL in these 2 parts of the world are quite different. ATL has been diagnosed at a younger age and is reported more frequently as the lymphomatous type rather than the acute type with leukemia in the Caribbean basin as compared with the presentation in Japan. In order to characterize ATL in the United States, a registry has been established at the National Cancer Institute for the purpose of recording all cases originally diagnosed in the United States. This registry was utilized to examine the effect of ethnic differences on age of onset and clinical features of ATL, using the same data base. Clinical and laboratory information was obtained from 177 patients suspected of having ATL, who were treated at the National Institutes of Health, or had biological samples sent for evaluation, or were reported in the literature. Histopathologic review and virologic studies were performed by standardized methods. Of 177 patients registered, 127 were considered as having ATL, according to an algorithm combining clinical, pathologic and laboratory features. Presenting features in the confirmed cases consisted primarily of lymphadenopathy (76.6%), hypercalcemia (72.5%), leukemia (82%), skin involvement (48.2%) and hepatomegaly (53.6%). Patients of Japanese ancestry were generally older (median age 63, range 51 to 73 years) than patients of African-American descent (median age 39, range 7 to 75 years) and presented more often with leukemia (90 vs. 69%).(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical and demographic features of HTLV-1 associated myelopathy/tropical spastic paraparesis (HAM/TSP) in Rio de Janeiro, Brazil

In Rio de Janeiro (RJ) most cases of paraparesis of obscure origin are associated with the human T-cell lymphotropic virus type I (HTLV-I). Thirty-four consecutive patients with HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP) from RJ were evaluated. Most patients came from low socio-economic levels. There was no difference in terms of gender. The main affected racial group was white. A history of sexually transmitted diseases was a major risk factor for HAM/TSP and a positive serology for syphilis was found in 26.5% of the patients. The major clinical findings were of a spastic paraparesis with generalized brisk tendon jerks and bilateral Babinki's sign. Sensation was abnormal in 25 patients (73.5%) and five (14.7%) had a sensory level. Three patients (8.8%) had optic atrophy. The cerebrospinal fluid showed a lymphocytic pleocytosis with a mean total protein content of 0.4 g/litre, and an increased intrathecal IgG synthesis in 59.4% of patients. HAM/TSP and multiple sclerosis (MS) occur indigenously in RJ and some HAM/TSP cases can be sometimes confused with MS. Therefore we propose that, in places where MS coexist with HAM/TSP, HTLV-I antibodies should be sought routinely in those MS suspected cases with prominent spastic paraparesis.

Seroepidemiological survey of HTLV-I infection in French Polynesia, Cook Islands and Fiji

Different population groups of French Polynesia, Cook Islands and Fiji were screened for Human T-Lymphotropic Virus type I (HTLV-I) antibodies. Among 1487 individuals sampled in French Polynesia, twelve were considered Western Blot (WB) indeterminate and one was considered WB-positive for HTLV-I infection. This positive subject originated from France and was a blood donor. Out of 196 Polynesians of the Cook Islands, one was WB-indeterminate. Among populations sampled in Fiji, one of 222 Melanesians was found WB-indeterminate and one of 211 Indians was WB-indeterminate.

HTLV-II infection in Florida Indians

A significantly increased prevalence of antibodies to human T-cell leukemia virus (HTLV) has been described in several native American populations in the United States and Latin America. Initial virologic studies indicate that HTLV-II is the predominant virus responsible for this antibody pattern. We obtained blood samples from 106 Seminole Indians living on four reservations in Southern Florida. Seropositivity to HTLV-I/II was found in 14 (13.2%) of these individuals. Polymerase chain reaction (PCR) documented HTLV-II and the absence of HTLV-I in 7 of the 9 donors available for follow-up testing of white blood cells. Evaluation of various risk factors excluded blood transfusion or intravenous drug use as an important contributing factor to the HTLV-II seroprevalence rate. These studies support the hypothesis that HTLV-II is endemic in many native American tribes in the Western hemisphere.

Non-Hodgkin lymphoma in Gabon and its relation to HTLV-I

A case-control study was performed in Libreville, Gabon, to determine whether a relationship can be established between the relatively high proportion of non-Hodgkin lymphoma (NHL) among all cancer cases and the high seroprevalence rate of HTLV-I observed, and to discover whether cases of adult T-leukemia/lymphoma (ATLL) related to HTLV-I exist in Gabon. From November 1987 to April 1989, a total of 32 patients with NHL were recruited; 6 were infants with Burkitt's lymphoma and 26 were adults with NHL. Each patient was matched with 2 asymptomatic controls for age, sex and ethnic group. HTLV-I serology was done by ELISA and Western blot. Comparison of the groups was done by chi-square analysis. None of the 6 infants with Burkitt's lymphoma and none of their controls had antibodies to HTLV-I. Of the 26 patients with NHL, 7 (26.9%) had HTLV-I antibodies. Among the 52 controls, the HTLV-I rate was 13.4% (n = 7). There was no difference between cases and controls (Fisher's exact test, p = 0.16). Among the 26 NHL, 4 cases fitted the criteria of ATLL and were HTLV-I-positive; 3 others who were positive for HTLV-I were a woman with lymphoblastic gastric NHL and 2 old men with an unclassified lymphoma. From the results of this limited series it is not possible to state that there is an association between NHL and HTLV-I infection. Nevertheless, cases of ATLL related to HTLV-I are reported from this area. Based on the HTLV-I seroprevalence rates reported in Gabon, the estimated incidence rate of ATL among seropositive people in Gabon appears much lower than in Japan. Different explanations can be proposed, but under-diagnosis of ATLL is probably one of the main factors.

Sexually transmitted diseases and travelers

Sexually active travelers are at risk for a variety of STDs, including traditional venereal infections such as gonorrhea, chlamydial urethritis, syphilis, chancroid, and herpes simplex infection. More recently, hepatitis B, hepatitis C, and HIV-1 have also been described. Risk varies depending on the geographic area of travel and the type of sexual contact. Physicians should be aware of the prevalence of antimicrobial resistance of N. gonorrhoeae and H. ducreyi because this will affect empiric antibiotic therapy. Prevention should focus on proper and consistent usage of barrier contraceptives.

T-cell lymphoma in Singapore: pathology, clinical findings and association with HTLV-1 antibodies

Of 128 cases of malignant lymphomas studied in Singapore between 1986 and 1988, 28 were identified as peripheral T-cell lymphomas. Sera from two of the 128 cases were positive for HTLV-1 antibodies and both cases had the clinical and pathological features of adult T-cell leukaemia/lymphoma. The pathological and clinical features of the 28 cases of peripheral T-cell lymphoma are presented in detail. Survival data indicated no significant difference between the low grade and high grade histological types. Three of the patients had previous or concomitant malignancies. The percentage of T-cell lymphomas associated with HTLV-1 infection in Singapore is low compared to those areas in which HTLV-1 is endemic.

Acute adult T-cell leukemia/lymphoma presenting with florid cutaneous disease

Adult T-cell leukemia/lymphoma (ATLL) is characterized by cutaneous disease, hypercalcemia, associated HTLV-I infection, and a fulminant course refractory to therapy. A patient with acute ATLL is described, and the natural history of ATLL is reviewed.

Activated, HTLV-1-specific cytotoxic T-lymphocytes are found in healthy seropositives as well as in patients with tropical spastic paraparesis

In human T cell lymphoma/leukemia virus (HTLV-1)-infected people with tropical spastic paraparesis (TSP), there are activated HTLV-1-specific cytotoxic T lymphocytes (CTL) in the circulation and lymphocytic infiltrates in spinal cord lesions that are rich in CD8+ T cells. These observations suggest a role for virus-specific CTL in the pathogenesis of TSP. We have examined the anti-HTLV-1 cytotoxic activity of freshly isolated CD8+ T cells from peripheral blood lymphocytes of eight subjects seropositive for HTLV-1. Four of five subjects with TSP had circulating activated anti-Tax CTL. However, two of three seropositive subjects without TSP also had activated anti-Tax CTL. These observations show that such activated CTL are not confined to patients with TSP and raise some uncertainty about their significance in the pathogenesis of the disease. In cultures of CD8+ T cells from two TSP subjects, we detected CTL with other HTLV-1 specificities, without exogenous antigenic stimulation. A CTL epitope in the middle region of Tax and one in the C terminus of Pol have been mapped at the peptide level and the HLA Class 1 molecules restricting their recognition have been defined.

Human retroviruses

It was only in 1980 that the first human retrovirus, HTLV-1, was isolated. Since then, HTLV-2, HIV-1 and HIV-2 have been identified. All four viruses are transmitted with varying efficiency sexually, vertically from mother to infant, and through blood by transfusion or contamination. HTLV-1 is endemic in populations in south-west Japan, Taiwan, sub-Saharan Africa, the Caribbean, southern USA, central and south America, Australia, Papua New Guinea, Solomon Islands and western Asia. There is now epidemic spread amongst IVDUs in north and south America and southern Europe. HTLV-1 is the aetiological agent of adult T-cell leukaemia/lymphoma (ATL) and tropical spastic paraparesis/HTLV-1 associated myelopathy (TSP/HAM). Other associations which may be causative are with polymyositis, infective dermatitis, gastrointestinal malignant lymphoma and chronic lymphatic leukaemia. ATL appears to be due to malignant transformation of HTLV-1 infected cells, and TSP/HAM to chronic activation of these cells. The epidemiology of HTLV-2 is being separated only recently from HTLV-1 through the application of PCR. It has a low level of endemicity in populations of central Africa, and central and south America. It is being spread epidemically amongst IVDUs in north America and southern Europe. Its association with any pathology in man remains uncertain. HIV-1 is epidemic and spreading rapidly throughout the world. In areas where homosexual contact was the predominant mode of transmission, heterosexual spread is becoming increasingly important. The areas where heterosexual contact is the predominant mode of transmission include the worst affected populations in the world, for example sub-Saharan Africa and some of the Caribbean. There have been recent and explosive increases of HIV-1 seroprevalence in IVDUs and female prostitutes in Asia, especially Thailand and India. Of the diverse pathology following infection, only the haematological consequences are reviewed in detail: these include anaemia, leucopenia, thrombocytopenia, disorders of coagulation and lymphomas. HIV-2, compared to HIV-1, is less infectious and causes less immunosuppression with more slowly progressive disease. It is prevalent in west Africa, but is spreading, albeit slowly, far beyond.

Monoclonal antibodies and chemiluminescence immunoassay for detection of the surface protein of human T-cell lymphotropic virus

Monoclonal antibodies (MAbs) raised against human T-cell lymphotropic virus type I (HTLV-I) recognized five distinct antigenic domains of viral env gene-encoded proteins. By using recombinant env proteins and synthetic peptides as mapping antigens, it was determined that the most immunogenic region represented a central portion of the retroviral surface protein (domain 2; amino acids 165 to 191). However, only a single MAb was able to react strongly with native viral proteins. This antibody (clone 6C2) was directed to an epitope within domain 4 (amino acids 210 to 306) of the retroviral env gene and reacted with envelope proteins in both HTLV-I and HTLV-II, as determined by immunoprecipitation, solid-phase binding, and immunoblotting. No reactivity against envelope components of other human retroviruses, including human immunodeficiency virus types 1 and 2, was present. Flow cytometry data demonstrated that MAb 6C2 reacted with cell lines chronically infected with HTLV-I or HTLV-II and also with surface antigens expressed on fresh adult T-cell leukemia cells, following up-regulation with interleukin-2. By a chemiluminescence immunoassay procedure, picogram amounts of viral surface protein could be detected in the unconcentrated supernatants of HTLV-infected cell lines and in diagnostic cultures. Levels of env and gag proteins released by cells into culture supernatants were not directly related to percent expression of cell surface viral-coat proteins. Further, the molar ratio of p19 to gp46 in conditioned media varied from strain to strain, possibly reflecting differences in viral assembly or packaging mechanisms. MAb 6C2 will be of value in characterizing the biochemical and immunological behavior of retroviral env gene proteins and in studying the interaction of HTLV-I and HTLV-II with their receptors.

HTLV-1 envelope sequences from Brazil, the Caribbean, and Romania: clustering of sequences according to geographic origin and variability in an antibody epitope

We sequenced the envelope genes of Human T-cell leukemia type I viruses (HTLV-I) derived from five Brazilian, two Caribbean, and one Romanian case of adult T-cell leukemia after amplification of the complete env gene by PCR. A comparison with previously reported HTLV-I sequences revealed that, although highly homologous, no two env sequences were identical. All envelope sequences differed from each other by 0.3-2.1% nucleotide differences. The five Brazilian sequences clustered together and were about as different from each other (0.5-0.75% nucleotide difference) as were three previously reported Japanese sequences (0.7-0.95%). In contrast, sequences of Caribbean origin were less homogeneous (0.5-1.9% nucleotide differences within this group). The Romanian sequence was not significantly more divergent than any of the others and was closest to our two Caribbean sequences. We observed two changes in a region (aa 176-209) which has previously been shown to contain a linear antibody epitope recognized by most human sera from seropositive individuals. One of these changes affects the binding of monoclonal antibodies to this epitope demonstrating the variability of an antibody epitope in the HTLV-I envelope.

A serosurvey for HTLV-I among high-risk populations and normal adults in Egypt

The prevalence of antibodies to human T-cell lymphotropic virus type I (HTLV-I) was determined in high-risk groups and normal adults in Egypt. Among 647 individuals tested, 6 (0.9%) were confirmed positive by western blot analysis. These included 2 (0.7%) of 279 drug addicts, 1 (3.3%) of 30 patients with sexually transmitted diseases, and 3 (2.2%) of 133 healthy individuals. Antibody was not detected in 47 blood recipients or 158 prostitutes. There was no correlation between sex or geographical location and HTLV-I infection. Fifty-three of the 647 sera (8%) were initially reactive by ELISA, but only 12 sera were repeatedly reactive. Since only 4 of these repeatedly reactive sera were confirmed by the western blot, the frequency of false positives using the DuPont screening ELISA was 1.2% (8/643). Two additional sera, confirmed positive by western blot, had been reactive, but not repeatedly, by ELISA. In comparison to the prevalence of HTLV-I antibody among risk groups in many parts of the world, the prevalence in Egypt was low.

HTLV-1 associated T cell lymphoma in South East Asia: case report and family study

Geographic clustering of human T cell lymphoma/leukaemia virus type 1 (HTLV-1) infection is well recognised, particularly in south western Japan, parts of West and Central Africa, the south eastern United States and the Caribbean islands. Sporadic cases have been reported in many other parts of the world. The first case of HTLV-1 associated leukaemia/lymphoma (ATLL) in South East Asia is reported. Contact tracing showed a high incidence of carriers among the relatives.

Low prevalence of human T-cell leukaemia virus-I and -II infection among drug users in Amsterdam, The Netherlands

The prevalence of human T-cell leukaemia virus-I and -II infection was studied in a cohort of 346 intravenous and nonintravenous drug users in Amsterdam. Three participants (0.86%) had antibodies to HTLV-I by two commercially available HTLV-I enzyme immunoassays (EIA). Infection in these three subjects was confirmed by radioimmunoprecipitation assay. In the immunoblot study, only two of the three subjects were considered positive, since the serum of the third subject had antibodies to p24 only. By means of the polymerase chain reaction two participants (male intravenous drug users infected with human immunodeficiency virus; HIV) appeared to be infected with HTLV-I and one subject (a male nonintravenous drug user from Surinam) with HTLV-II. It is concluded that HTLV-I and HTLV-II circulate sporadically among drug users in Amsterdam and that risky injecting behaviour, which led to an HIV epidemic among intravenous drug users, has not led so far to an appreciable transmission of the other retroviruses among this group.

The epidemiology of HTLV-I infection

It has been 10 years since the discovery of the human T-cell lymphotropic virus type I (HTLV-I), the first human retrovirus. During the past decade, significant progress has been made in understanding the transmission of the virus and defining its geographic distribution. It has been shown conclusively that HTLV-I is a causal factor in the induction of both adult T-cell leukemia/lymphoma and HTLV-I-associated myelopathy. However, the pathogenesis of each of these conditions is not clear, and in the light of the evidence of immune dysfunction seen among carriers of the infection, it is likely that other associated diseases will be identified. The challenge in the next decade will be to develop and implement therapeutic interventions among carriers to prevent such diseases as well as to curtail transmission within endemic populations.

Geographical distribution of subjects seropositive for human T-cell leukemia virus type 1 in Papua New Guinea

Of 1471 sera collected from 1986 to 1989 in Papua New Guinea (PNG), 2.2% were found to be positive for anti-HTLV-1 antibody by successive particle agglutination and immunofluorescence tests. The seropositive rate varied in different provinces and was higher in the coastal areas of the main island and in neighboring small islands than in the highlands of PNG. The frequency of HTLV-1 infection of children was higher, but the age-dependent increase in antibody positivity, generally observed in other HTLV-1 endemic areas of the world, was not clear in PNG. No difference was observed in antibody prevalence in males and females in this study.

Antibody profile of early HTLV-I infection

To define the antibody profile of early seroconversion in infection with human T-cell lymphotropic virus type I (HTLV-I), consecutive serum samples from 10 subjects presumed to have seroconverted on the basis of the particle agglutination test were studied by three enzyme immunoassays and two confirmatory tests (radioimmunoprecipitation and western blot). 3 samples positive and 1 sample indeterminate in the confirmatory tests were reactive in one enzyme immunoassay, which used recombinant envelope antigen, but not in the other two enzyme immunoassays. 2 of 38 particle-agglutination-negative samples had a prozone effect. The confirmatory tests identified 8 seroconverters (7 women, 1 man); their serum samples were used to study the antibody reactivity by western blot assays to HTLV-I specific antigens (three recombinant proteins spanning the N-terminal, middle, and C-terminal env glycoprotein gp46; a recombinant transmembrane protein gp21; a recombinant tax protein; and three gag proteins [p28, p24, and p19]). All 8 seroconverters had antibody reactivities to the C-terminal region (aminoacid residues 229-308) of gp46 and to gag p19 and p24 when their seroconversion was detected.

Viruses and cancer. Causal associations

This review first considered some general problems in establishing causal links between a virus and a human cancer and offered some guidelines in the pursuit of this objective. Second, it reviewed the current causal associations for several candidate oncogenic viruses in relation to the tumors with which they are associated. These include Epstein-Barr virus in relation to Burkitt's lymphoma, nasopharyngeal carcinoma, Hodgkin's disease, and non-Hodgkin's lymphoma; hepatitis B and C viruses in relation to hepatocellular carcinoma; human T-cell leukemia/lymphoma virus type 1 and atypical leukemia/lymphoma; and human papilloma viruses in relation to cervical carcinoma. For some, the causal relationship is strong: hepatitis B virus with hepatocellular carcinoma, and human T-cell leukemia/lymphoma virus with adult T-cell leukemia/lymphoma. For one, the causal relationship is moderate: Epstein-Barr virus with African Burkitt's lymphoma. For others it is incomplete or inconclusive: Epstein-Barr virus with Hodgkin's disease and non-Hodgkin's lymphoma, and hepatitis C virus with hepatocellular carcinoma. Current techniques do not permit an answer for some: human papilloma virus with cervical carcinoma.

Examination of HTLV-I ELISA-positive leukemia/lymphoma patients by western blotting gave mostly negative or indeterminate reaction

We used enzyme-linked immunosorbant assay (ELISA) and Western blotting, with "purified" human T-cell leukemia virus I (HTLV-I), to test for HTLV-I antibodies in 2583 plasma samples from 1053 leukemia/lymphoma patients treated at Roswell Park Memorial Institute, mostly between 1972 and 1984, and in 110 sera samples from normal healthy persons. The results demonstrate that ELISA and Western blot assay have limitations for HTLV-I antibody detection in an adult T-cell leukemia/lymphoma (ATL) nonendemic population. This conclusion is based on the many false reactives obtained by ELISA, and weak and indeterminate reaction (mostly p19 band) on Western blotting. All moderate to strongly HTLV-I ELISA-positive samples tested were negative for human immunodeficiency virus (HIV) antibodies. Although 6/27 mycosis fungoides (MF) patients tested gave mostly a weak reaction on HTLV-I ELISA, 3/6 MF patients gave multiple bands (p19, p31, p36, gp46) on Western blotting and three samples from one patient gave the same p31, p36, and gp46 bands. This may suggest involvement of some HTLV-I-related virus in MF. These results also indicate that prevalence of HTLV-I infection in leukemia/lymphoma patients was rare, if it exists at all, since, despite the reactivity of some sera with HTLV-I-suspected antigens, none of the samples satisfy the USPHS criteria for positivity which is based on the detection of antibodies to gag protein p24 and to an env gene product gp46 or gp61/68.

HTLV-1 and tropical spastic paraparesis. 2. The human T-cell lymphotropic virus type 1

Human T-lymphotropic viruses (HTLV) are causally associated with adult T-cell leukaemia and with a progressive form of lower limb paralysis known as tropical spastic paraparesis. HTLV-1 is endemic in parts of Japan, the Caribbean, West Africa and probably South America, and is associated with disease in these areas. Horizontal transmission is probably most common through sexual intercourse which, it is postulated, must be more efficient from male to female because virus carriage is more prevalent in women in endemic areas. Vertical transmission appears to be principally through breast milk. Poor housing and hygiene may facilitate transmission.

High prevalence of serum antibody against human T cell leukemia virus type I (HTLV-I) among the Bismam Asmat population (Indonesian New Guinea)

An unusually high prevalence (45%) of serum antibodies to human T cell leukemia virus type I (or to an antigenically related virus) in comparison with that observed against other viral pathogens (human immunodeficiency virus type 1, herpes simplex virus, human cytomegalovirus, varicella zoster virus, and respiratory syncytial virus) has been observed in a group of Bismam Asmat (Papua) subjects, living in a very limited and geographically isolated area of Indonesian New Guinea.