Epidemiology, treatment, and prevention of human tcell. Jan 17, 2006 nunavut health officials report at least one death related to human tcell lymphotropic virus type 1 htlv1 and fewer than 20 infected persons. Human tcell leukemia virus type 1 htlv1, the first human retrovirus to. Human tcell leukemia virus type 1 htlv 1, the first human retrovirus to be discovered, is present in diverse regions of the world, where its infection is usually neglected in health care settings and by public health authorities. Click on the link to view a sample search on this topic. Htlv1 is spread from an infected person to other people by. Human t cell leukemia virus type 1 htlv 1, the etiological agent of adult tcell leukemialymphoma atll and the demyelinating neuroinflammatory disease known as htlv 1 associated myelopathytropical spastic paraparesis hamtsp, was the first human retrovirus to be discovered. Human t cell lymphotropic virus type 1 htlv 1 was the first retrovirus discovered in humans and is endemic in several parts of the world. Since it is usually asymptomatic in the beginning of the infection and disease typically manifests later in life, silent transmission occurs, which is. Infection can occur by sexual contact with an infected individual, through sharing of contaminated needles and syringes by intravenous drug users, or as the result of a transfusion of contaminated blood. Opportunistic infections in patients with htlv1 infection.
Human tcell lymphotropic virus type 1 htlv1 is the agent of htlv1associated myelopathytropical spastic paraparesis hamtsp, observed in up to 5% of infected individuals. The virus can be transmitted from mother to child, through sexual contact, and through contaminated blood products. Human tlymphotropic virus type i infection the lancet. A patient had adult tcell leukemialymphoma in the unusual setting of coinfection with human immunodeficiency virus type 1 hiv 1 and human tcell lymphotropic virus type i htlv 1. Guidelines for counseling persons infected with human tlymphotropic virus type i htlv i and type ii htlv ii centers for disease control and. Pdf frequency of human tcell lymphotropic virus htlv. Apr 07, 2016 htlv 1 and htlv 2 coinfection seem to have different effects on hiv infected individuals. Cells involved in bloodcell formation can be infected as well iarc 1996, 2012, jacobson and massoud 20, carpentier et al.
Htlv1 proviral load is routinely measured in our center to monitor htlv1infected carriers. The htlvi virus is thought to have originated from multiple zoonotic events, likely involving the transmission of the virus from monkeys to humans. A representative visualization patterns of virus host reads derived from fulllength type pro viruses, 50defective type proviruses, and. Human tlymphotropic virus types i, ii htlv i, ii arup. Human tlymphotropic virus type i htlv iassociated myelopathytropical spastic paresis hamtsp muscle pain, stiffness, and weakness myalgias and myopathy changes in bowel andor bladder function. The transmission of hiv the virus responsible for aids and htlv type i infection are similar. Estimates of the number of htlv 1 infected carriers, based on approximately 1. Human tcell lymphotropic virus type 1 cas no none assigned known to be a human carcinogen also known as htlv 1 carcinogenicity human tcell lymphotropic virus type 1 htlv 1 is known to be a human carcinogen based on sufficient evidence from studies in humans. Infected cells can entry in places where mucosa integrity is damaged. Epidemiology of from 1995 through 1998, donors were.
A cosmopolitan b central african group c melanesian group d new central african group description and significance. The leukemic cells were cd4 positive and showed clonal genetic rearrangement of the tcell receptor complex. Neurological manifestations in human tcell lymphotropic. Jul 12, 2017 the merck manual for health care professionals provides information on htlv 1 associated myelopathytropical spastic paraparesis. Dec 10, 2014 human tcell leukemia virus, type 1 htlv1 occurs when a person is infected by the human tcell leukemia retrovirus.
Infection with human t cell lymphotropic virus type 1 htlv1 is a global epidemic affecting. Geographical distribution of areas with a high prevalence of htlv1. A representative visualization patterns of virus host reads derived from full length type pro viruses, 50defective type proviruses, and. Recommendations for counseling persons infected with human. Geographical distribution of areas with a high prevalence.
Recent research on the molecular virology and immunology of htlv 1 shows the importance of the hosts immune response in reducing the risk of these diseases, and is beginning to explain. The infected cd4 positive host cell produces new htlv1 virus particles 1, and htlv1 derived antigenic peptides complexed with class i and class ii human major histocompatibility complex hla proteins on its surface 2. Pubmed is a searchable database of medical literature and lists journal articles that discuss htlv 1 associated myelopathytropical spastic paraparesis. Bypass of htlv 1 infected cells through a damaged mucosa. It is thought to have migrated during ancient times with native american indians in north and south america, with australian aborigines and the melanesian people of the south west pacific, and to japan. The host cell infected by htlv1 is the cd4 positive t cell t helper cell. Infection with the human tcell leukemia virus type 1 htlv 1 was identified as a risk factor for bronchiectasis, and one previously unknown, among indigenous adults in central australia, a casecontrolled study reports. In people for whom htlv 1 was the only identifiable cause of. The human tlymphotropic viruses, type i htlv i and type ii htlv ii, are closely related but distinct retroviruses that can infect humans. Peripheral blood mononuclear cells from individuals infected. A subset of 45 human tcell lymphotropic virus type 1 htlv 1, 45 human tcell lymphotropic virus type 2 htlv 2, and 45 seronegative subjects was selected. Seroprevalence and demographic determinants of human tlymphotropic virus type 1 and 2 infections among firsttime blood donors united states, 20002009.
The full text of this article is available as a pdf 142k. Epidemiology of human tcell lymphotropic virus type 1. It has been 10 years since the discovery of the human tcell lymphotropic virus type i htlv i, the first human retrovirus. However most infections occur through breastfeeding and if this is avoided less than 1 in 20 babies will become infected. It can also be spread from mother to child during birth or breastfeeding. Downregulation of proinflammatory cytokines in htlv1. Htlv 1 basic leucine zipper factor hbz gene has a critical role in htlv 1 infectivity and the development of atl and hamtsp.
Issac sobol, says residents need to take this very seriously, but adds, its not what we consider an. No other virus or bacteria is known to cause cancer so efficiently, robert explains. There are areas in japan, subsaharan africa, the caribbean, and south america where more than 1 % of the. Spontaneous in vitro proliferation of peripheral blood mononuclear cells pbmc is an important immunological feature of htlv 1 infected individuals. Based on small studies, the clinical course of pregnancy does not seem to be altered by the presence of infection by htlv 1 and babies appear normal at. Pdf brain metabolism changes in patients infected with htlv1. Thus, htlv1 infection is considered a risk factor for s.
Articles on htlv 1 replication, pathogenesis, treatment and prevention and identify essential areas of unmet need in htlv 1 basic and translational research. However, some of the available data is contradictory. Human t lymphotropic virus type 1 htlv 1 causes disabling and fatal diseases, yet there is no vaccine, no satisfactory treatment, and no means of assessing the risk of disease or prognosis in infected people. The elisa is the most commonly used screening test for htlv1 infection araujo et al. This parasite infection has been related to htlv1 clonal expansion in asymptomatic individuals. Human t cell lymphotropic virus type 1 htlv 1 infection can lead to development of adult t cell leukemialymphoma atl or htlv 1 associated myelopathytropical spastic paraparesis hamtsp in a subset of infected subjects. Aug 07, 2018 arguably, htlv1 is the most cancercausing agent we know. Infection with human tcell lymphotropic virus type 1 htlv1.
During the past decade, significant progress has been made in understanding the transmission of the virus and defining its geographic distribution. Htlv1infected t cells contain a single integrated provirus. Htlv 1 infects an epithelial cell and produces new virions that are then released through the basal surface. Frequency of human tcell lymphotropic virus htlv type 1 and 2 infection in hiv infected patients. No crossreactivity with antibodies to hiv 1 or hiv2 has been demonstrated for this assay. In donors originating from eastern europe, the middle east, and latin america, prevalences are 7. Evidence shows that the virus is spread more easily from a man to a woman, than from a woman to a man.
Epidemiological aspects and world distribution of htlv 1 infection. Despite the serious health problem caused by infection with all htlv 1 subtypes, infection by these viruses has become a neglected condition and only palliative treatments are available to the 1020 million of htlv 1 infected individuals living mostly in resource deprived countries. Human t cell lymphotropic virus type 1 infection among men. Based on small studies, the clinical course of pregnancy does not seem to be altered by the presence of infection by htlv1 and babies appear normal at birth. About 1 to 2% of the brazilian population is estimated to be infected, but most infected htlv 1 individuals do not know about their own infection, which favors the continuity of sexual and vertical virus transmission. The emerging picture is that htlv 1 infection, which was previously thought to be latent, is in fact a persistent active infection, and that the htlv 1 specific ctl response plays a critical role in limiting the replication of htlv 1, the proviral load, and the risk of the inflammatory disease hamtsp. Evidence indicates that human tcell lymphotropic virus type 1 htlv 1 infection leads to chronic immunosuppression and a greater susceptibility to infectious diseases.
Its related to hiv, yet youve probably never heard of it. Also, htlv1 infected individuals with infective dermatitis have an increase of htlv1 positive clones. Oct 25, 2012 human t lymphotropic virus type 1 htlv 1 appears to persist in the chronic phase of infection by driving oligoclonal proliferation of infected t cells. Currently, an estimated 1020 million people worldwide are infected with this virus. The cellular receptor for the virus has been mapped to chromosome 17, 20 but has not yet been identified. However, opportunistic infections also occur in individuals with human t cell lymphotrophic virus type 1 htlv 1 infection.
Human tcell leukemia virus type 1 htlv 1 tax is expressed at the same level in infected cells of htlv 1 associated myelopathy or tropical spastic paraparesis patients as in asymptomatic carriers but a lower level in adult tcell leukemia cells. Here, we report opportunistic infections in two japanese htlv 1 seropositive patients. Human tcell lymphotropic virus type i htlviassociated. About 1 in 20 people will develop disease, mostly due to htlv 1 but this usually occurs much after initial infection. Despite the high prevalence of chronic pain in individuals infected with htlv1, predictive and protective factors for its. It is a retrovirus that infects a type of white blood cell called a tcell or tlymphocyte. Htlv 1 prevalence may be high outside areas where htlv 1 previously was known to be endemic.
This conclusion is based on evidence from epidemiological. Guidelines for counseling persons infected with human t. Although htlv 1 infection remains asymptomatic in the majority of patients, it is also associated with several clinical conditions, such as adult t cell leukemialymphoma 2, strongyloides stercoralis hyperinfection 3. Other neurological signs and symptoms including peripheral paresthesias and dysesthesias, hyperreflexia, tremor, deafness, changes in vision. Secondly, infection of macaques with htlv1 viruses unable to infect dendritic cells, due to mutations in the regulatory p8 and p12 proteins, led to. Oral manifestations in individuals infected by htlv1 virus medcrave. Human tcell lymphotropic virus type 1 or human tlymphotropic virus type 1 htlv i, also called the adult tcell lymphoma virus type 1, is a retrovirus of the human tlymphotropic virus htlv family that has been implicated in several kinds of diseases including very aggressive adult tcell lymphoma atl, htlv iassociated myelopathy, uveitis, strongyloides stercoralis hyperinfection and.
Since it is usually asymptomatic in the beginning of the infection and disease. The virus is also more common in people who are 40 years. For example, only 1 in 100,000 blood donors in the uk was found to carry htlv ii compared with 1 donor in 20,000 for htlv i. The nature of the htlv1 provirus in naturally infected individuals. Brain metabolism changes in patients infected with htlv1. Htlv 1 is a retrovirus that has infected 1020 million people worldwide, and is considered the first retrovirus to be causal for adult tcell leukemia atl. Lymphotropic virus type 1 infection in blood donors, israel shmuel stienlauf, 1 vered yahalom, eli schwartz, eilat shinar, gad segal, and yechezkel sidi the prevalence of infection with human tcell lymphotropic virus type 1 htlv 1 in blood donors from israel is 1 infection 100,000 persons. Aug 20, 2019 in 1979, human tcell lymphotropic virus htlv was isolated in a patient with adult cutaneous tcell lymphoma atl. Clinical characteristics of patients in peru with human t. Htlv1 associated myelopathytropical spastic paraparesis.
Pdf the human tcell leukemia virus typei htlv 1 is the causal agent of htlv associated myelopathytropical spastic paraparesis hamtsp. The prevalence of infection with human tcell lymphotropic virus type 1 htlv 1 in blood donors from israel is 1 infection 100,000 persons. Oct 01, 2004 htlv1associated tsp is frequently diagnosed in areas of htlv1endemicity. Recommendations for counseling persons infected with human t. Serological and molecular methods for the diagnosis of htlv1 infection.
Guidelines for counseling persons infected with human tlymphotropic virus type i htlv i and type ii htlv ii centers for disease control and prevention and the u. Eight of the 10 patients had a low htlv proviral load virus 1 htlv 1 has infected human beings for thousands of years, but knowledge about the infection and its pathogenesis is only recently emerging. Recommendations for preventing transmission of infection with. After primary infection, htlv 1 reppolymerase ii 5. Despite low prevalence, many htlv1infected patients who do not fulfill criteria for hamtsp present with neurological complaints related to sensory, motor. Htlv 1 associated myelopathytropical spastic paraparesis hamtsp is a progressive disease of the nervous system that affects less than 2% of people with htlv 1 infection signs and symptoms vary but may include slowly progressive weakness and spasticity of one or both legs, exaggerated reflexes, muscle contractions in the ankle, and lower back pain. Pdf factors associated with pain in individuals infected by. No treatments exist for acute or chronic htlv infection. Nunavut health officials report at least one death related to human tcell lymphotropic virus type 1 htlv 1 and fewer than 20 infected persons. I causes several inflammatory diseases in the eyes, muscles, lungs and joints other than the cns. Human t lymphotropic virus type 1 htlv1 causes disabling and fatal diseases, yet there is no. Show full abstract this manuscript will discuss various skin findings associated with htlv 1 along with a case report of rare cutaneous manifestations of htlv1 infection.
People who exhibit signs or symptoms usually are exposed to the infection for long periods before it becomes manifest. Together with the stlvs, htlvs form the primate tcell lymphotropic viruses. Htlv 1 is an abbreviation for human tcell lymphotropic virus type 1, also called human tcell leukemia type 1, a virus that has been implicated in several kinds of diseases, including tropical spastic paraparesis, and as a virus cancer link for leukemia see adult tcell leukemialymphoma. As an acquired immunodeficiency, human immunodeficiency virus hiv infection is primarily responsible for opportunistic infections in infected patients. Human t cell leukaemia viruses use a receptor determined by human chromosome 17. Despite the serious health problem caused by infection with all htlv1 subtypes, infection by these viruses has become a neglected condition and only. Htlv i is a very old virus, which appears to have infected and moved with mankind for hundreds, perhaps thousands of years. Htlv 1 infection induces the clonal proliferation of tlymphocytes. Cancercausing htlv1 virus common in parts of australia. However, the association between spontaneous proliferation and. It has been shown conclusively that htlv i is a causal factor in the induction of both adult tcell leukemialymphoma and. Htlv1 infects t cells, mainly cd4 t cells and, to a lesser ex tent, cd8 t cells cytotoxic t cells, which kill damaged or infected cells. The electronic search was enhanced by a manual search of the reference lists of all.
Geographical distribution of the main foci of htlv 1 infection. How these people have become infected with htlv ii is often uncertain as on many occasions no risk factors are identified. The who guidelines recommend that newly identified seropositive individuals have additional blood collected for repeat. Antiretroviral agents have demonstrated the ability to inhibit htlv replication, but there has been limited research in asymptomatic carriers of htlv 1, in whom the proviral load is already typically low. The diagnosis of htlv1 infection and its associated diseases, including peripheral neuropathies, requires additional investigation of the clinical findings. Recommendations for counseling persons infected with human tlymphotrophic virus, types i and ii summary. Htlv1 is spread by blood transfusions, sexual contact and sharing needles. In 2005, two more related viruses, htlv3 and htlv4, were reported in. Epidemiological aspects and world distribution of htlv1. But now, high rates of htlv 1 in parts of australia are prompting some. Aug 20, 2010 human tlymphotropic virus 1 htlv 1 is divided into 4 subtypes.
Signs and symptoms of this condition vary but may include. Frequency of human tcell lymphotropic virus htlv type 1. Htlv 1 is a very old virus, which appears to have infected and moved with humans for hundreds, if not thousands of years. Sharing needles, syringes or other equipment used for injecting drugs sexual contact. Human tcell lymphotropic virus type 1 or human tlymphotropic virus type 1 htlv i, also called the adult tcell lymphoma virus type 1, is a retrovirus of the human tlymphotropic virus htlv family that has been implicated in several kinds of diseases including very aggressive adult tcell lymphoma atl, htlv iassociated myelopathy, uveitis, strongyloides stercoralis hyper infection and. Htlv i can be transmitted from person to person in four ways.
The htlv1 virions infect susceptible neighbouring cd4 positive cells. Htlv1 infection of dendritic cells has been recently shown to play a major role. Our recent highthroughput sequencing study revealed a large number often 10 4 of distinct proviral integration sites of htlv 1 in each host that is greatly in excess of previous estimates. Htlv type i and type ii nord national organization for. Cancercausing htlv1 virus is common in parts of australia. Information on the human tlymphotropic virus type 1 htlv 1 virus which infects white blood cells including the geographic range of the disease, symptoms, how it is spread, not breastfeeding if you have htlv1, how to protect again htlv1, the lack of treatment, the low risk of htlv1 transmission by blood transfusion, and htlv1 testing. Although there is no evidence that hcws infected with htlv iiilav have transmitted infection to patients, a risk of transmission of htlv iiilav infection from hcws to patients would exist in situations where there is both 1 a high degree of trauma to the patient that would provide a portal of entry for the virus e. This led to the discovery of the first htlv, designated htlv 1, and marked the beginning of the human retrovirus era. Infection with human t cell lymphotropic virus type 1 htlv 1 is a global epidemic affecting.
Htlv1, the other pathogenic yet neglected human retrovirus. In patients with hamtsp, who typically have high htlv 1 viremia, 612 months of zidovudine plus lamivudine failed to show clinical. Htlv 1 is the only known retrovirus to directly cause cancer in humans. Human tlymphotropic virus type 1 htlv1 infection, a frequently ignored but important disease, is hyperendemic in the south of japan and endemic in africa, the caribbean, and latin america. A subgroup of patients experiences rapid disease progression. Many other human cell types can be infected in vitro, but appreciable productive replication occurs only in the cd4 positive t cell. Because of risk behaviors, mainly sexual, men who have sex with men msm are at high risk of acquiring htlv 1 infection.
The retrovirus human tcell leukemia virus type 1 htlv1 integrates into the host dna. A characteristic of htlv1 infection, especially in the chronic phase, is that the virus. Htlv1 infection linked to bronchiectasis in indigenous. Pdf the human tcell leukemia virus typei htlv1 is the causal agent of htlvassociated myelopathytropical spastic paraparesis hamtsp. Human tlymphotropic virus type 1 htlv 1 infection, a frequently ignored but important disease, is hyperendemic in the south of japan and endemic in africa, the caribbean, and latin america.
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