Recommendations for counseling persons infected with human t. To study the seroprevalence of human tlymphotropic virus type i htlv i in a sexually active population and to determine sexual behavior risk factors for infection. Human tlymphotropic virus 1 is a singlestranded rna virus of the deltaretrovirus genus. Users can classify of up to sequences in a single analysis. 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. Human tlymphotropic virus types i, ii htlv i, ii arup. Although this virus generally causes no signs or symptoms, scientists suspect that some affected people may later develop neurological problems andor chronic lung infections.
The aap recommends that those who are htlv i or htlv ii positive should not breastfeed or donate breastmilk. Htlv type i and type ii nord national organization for. Htlv are a group of human retroviruses that are known to cause a type of cancer called adult tcell leukemialymphoma atl and also a demyelinating disease called htlv 1 associated myelopathytropical spastic paraparesis hamtsp. More recently, 2 other types of htlv were identified, htlv 3 and htlv 4.
Infection with the human tcell lymphotropic virus type 1 htlv 1, although asymptomatic in most cases, can lead to potentially grave consequences, such as adult tcell leukemialymphoma and htlv 1 associated myelopathy tropical spastic paraparesis. Crosssectional seroprevalence study using enzymelinked immunosorbent assay elisa and western blot. Transmission of htlv1 requires celltocell contact, as the virus is unstable outside of cells. However, htlv1 is often never suspected or diagnosed since most people 95% never develop any signs or symptoms of the infection. The aap recommends that those who are htlv i or htlv ii positive should not.
Human t lymphotropic virus type 1 htlv 1 proviral load in asymptomatic carriers, htlv 1 associated myelopathytropical spastic paraparesis, and other neurological abnormalities associated with htlv 1infection. It was discovered by robert gallo and colleagues htlv 2 is prevalent among the indigenous populations in africa and the indianamerican tribes in central and south america as well as among drug users in europe and. Htlv1 is a very old virus, which appears to have infected and moved with humans for hundreds, if not thousands of years. All 10 men had asymptomatic htlv 1 infections, but 2 men had a high proviral load 1 %, which places them at risk for htlv associated disease. If arup consult does not answer your test selection and interpretation questions, or if youd like to suggest ways to improve content or usability, please leave a message for the arup clinical content team. No crossreactivity with antibodies to hiv 1 or hiv2 has been demonstrated for this assay. Four distinct lineages of human tlymphotropic virus htlv have been identified since the discovery of type 1 in the early 1980s. The prevalence of infection with human tcell lymphotropic virus type 1 htlv 1 in blood donors from israel is 1 infection100,000 persons. Moreover, viral replication can be enhanced by proinflammatory responses of th17. Human tlymphotropic virus htlv1, treatment for hamtsp. Exploring the host htlv 1 interactions and the molecular mechanisms underlying.
Regarding the prevention of sexual transmission of htlv, programs should. Endemic foci of infection have been reported in japan, melanesia, iran, central and west africa, the caribbean, and south america 5. High htlv 1 proviral load, a marker for htlv 1 associated myelopathytropical spastic paraparesis, is also detected in patients with infective dermatitis associated with htlv 1. Htlv 1 is known to cause malignant and neurological disease in humans, whilst htlv 2 has been associated with unusual cases of htlv 1 associated myelopathytropic spastic paraparesis ham. Reports have documented kidney, liver, and lung transplant transmission of htlv 1. Htlv 1 is spread by blood transfusions, sexual contact and sharing needles.
Human tlymphotropic virus type i and ii htlv1, htlv2. Aug 20, 2019 primo j, siqueira i, nascimento mc, et al. 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. Although htlv1 infection remains asymptomatic in the majority of patients, it is also associated with several clinical conditions, such as adult t cell leukemialymphoma, strongyloides stercoralis hyperinfection, crusted scabies, uveitis, and tropical spastic. Htlv 1 was the first described human retrovirus and was soon found to be associated with severe clinical diseases, including a devastating lymphomaleukemia and other inflammatory diseases. Approximately 25% of htlv i carriers will develop atl. She had negative results for htlv 1 on 2 previous occasions.
The human t cell leukaemia virus type 1, or htlv 1, is a sexually transmitted virus that causes severe health conditions in humans. Sep 01, 2011 human tlymphotropic virus1 htlv1 is the etiologic agent of adult t cell leukemia atl and htlv1associated myelopathytropical spastic paraparesis hamtsp. It is known to cause several diseases like adult t. More detailed information about the symptoms, causes, and treatments of htlv 1 is available below. In donors originating from eastern europe, the middle east, and latin america, prevalences are 7. High prevalence of human tlymphotropic virus type 1 htlv1 in immigrant maletofemale transsexual sex workers with hiv1 infection. The main htlv 1 highly endemic regions are the southwestern part of japan, subsaharan africa and. Htlv 1 is a very old virus, which appears to have infected and moved with humans for hundreds, if not thousands of years. The nature of the htlv1 provirus in naturally infected individuals. The software bases the subtyping of the htlv1 in the long terminal repeats ltr region of the genome only. 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.
The geographic areas of the highest prevalence are japan, africa, the caribbean islands and south america. The deadliest of these conditions is a type of cancer affecting the bodys t cells. Author summary the human tcell lymphotropic virus type 1 htlv 1 causes lifelong infection in humans. Human tcell lymphotropic virus type 1 exposures following.
Human tcell lymphotropic virus types 1 and 2 htlv 1 and htlv 2 were described in 1980 1, 2, and they were the first human retroviruses described. Areas of the world that are endemic to the htlv 1 virus are the caribbean, southern japan, equatorial africa, middle east, south america, and melanesia. There are four known strains of htlv including htlv type 1 htlv 1, htlv 2, htlv 3 and htlv. Human tlymphotropic virus htlv type i and ii are two closely related retroviruses with 70 % nucleotide sequence homology. Lasp htlv1 subtyping tool is a web application that uses phylogenetics methods for subtyping sequences. Virus affecting the immune system and associated with a particular leukemialymphoma. Human tcell lymphotropic virus type 1 htlv 1 is known to be a human carcinogen based on sufficient evidence from studies in humans. Aug 20, 2019 in 1979, human tcell lymphotropic virus htlv was isolated in a patient with adult cutaneous tcell lymphoma atl.
Four different types of human tlymphotropic viruses htlv have been described in humans. Type 1 htlv is irregularly distributed throughout the world, as opposed to type 2 virus, which is a new world virus, more common among americans in north, central, and south america. Human tlymphotropic virus type 1 htlv 1 was the first retrovirus infecting humans to be discovered in 1980 1, and 1520 million people are estimated to be infected worldwide 24. Pdf on mar 27, 2015, graham p taylor and others published human tlymphotropic virus type 1 htlv 1 and htlv 1 associated myelopathytropical spastic paraparesis ham tsp. Most of the cases are asymptomatic, and few cases progress to malignancies and neural diseases. Geographical distribution of areas with a high prevalence. Data were analyzed using quantasoft software biorad. Feb 23, 2016 human tlymphotropic virus type 1 htlv 1 was the first retrovirus infecting humans to be discovered in 19801, and 1520 million people are estimated to be infected worldwide24. Prevalence and risk factors for human tlymphotropic virus. Htlv1induced leukotriene b4 secretion by t cells promotes t. Sexual transmission of human tlymphotropic virus type i. Infection caused by human tlymphotropic virus type 1 htlv i can be observed in some areas of iran in form of endemic. Despite being the first recognized human retrovirus, much about its pathogenesis and clinical impact remains unknown. More rarely, htlv i may lead to arthropathy, uveitis inflammation of the eye, pneumonitis and thyroid problems.
It is a retrovirus that infects a type of white blood cell called a tcell or tlymphocyte. A subgroup of patients experiences rapid disease progression. Human tcell lymphotropic virus type 1 htlv1 infects 1020 million people worldwide in a number of distinct geographical regions. Effects of valproate on tax and hbz expression in htlv1 and. Risk factors associated with htlv1 vertical transmission in. The human t cell leukaemia virus type 1, or htlv1, is a sexually transmitted virus that causes severe health conditions in humans. Human tcell leukemia virus type 1 genetic and rare. Their geographical distribution and a possible association with human disease are currently being investigated, and not much is known.
While it is well established that the extracellular surface component su of the htlv envelope glycoprotein env harbors all of the determinants of interaction with the receptor, identification of su. A virus closely related to htlv i, human tlymphotropic virus 2 htlv ii shares approximately 70% genomic homology structural similarity with htlv i. Human t lymphotropic viruses htlvs are complex deltaretroviruses that do not contain a protooncogene in their genome, yet are capable of transforming primary t lymphocytes both in vitro and in vivo. There are four known strains of htlv including htlv type 1 htlv 1, htlv 2, htlv 3 and htlv 4. Recommendations for counseling persons infected with human.
Human tlymphotropic virus type i and ii htlv 1, htlv 2 reading time. If arup consult does not answer your test selection and interpretation questions, or if youd like to suggest ways to improve content or usability, please leave. Human tcell leukemia virus type 2 genetic and rare. Statistical analysis was performed using spss software ver. Htlv 1 associated tsp is frequently diagnosed in areas of htlv 1 endemicity. The human tcell leukemia virus type 1 htlv 1, identified as the first human oncogenic retrovirus 30 years ago, is not an ubiquitous virus. Designing a human tlymphotropic virus type 1 htlvi. Human tlymphotropic virus type 1 htlv 1 was the first retrovirus infecting humans to be discovered in 19801, and 1520 million people are estimated to be infected worldwide24. This led to the discovery of the first htlv, designated htlv 1, and marked the beginning of the human retrovirus era. Human tlymphotropic virus type 1 htlv 1 causes disorders such as chronic inflammatory progressive myelopathy, which is known as htlv 1associated myelopathy mah, characterized by. Aug 20, 2010 human tlymphotropic virus 1 htlv 1 is divided into 4 subtypes. A populationbased study in the city of salvador, located in. Recommendations for counseling persons infected with human tlymphotrophic virus, types i and ii summary. 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.
A cosmopolitan b central african group c melanesian group d new central african group description and significance. Human t cell lymphotropic virus type 1 htlv 1 infection increases the cd4 count in human immunodeficiency virus type 1 hiv 1 infected patients submitted to antiretroviral therapy arv. The three main transmission modes are from mother to child, sexual, and via blood transfusion or organ transplantation iarc 2012. Riskfactor data were gathered by administered questionnaire.
Among htlv1infected individuals, 9095% remain asymptomatic throughout their lives. Epidemiological aspects and world distribution of htlv1. Pdf high prevalence of human tlymphotropic virus type 1. Hypothesis tests were 2sided, and sas software, version 8. The primerdesign genesig kit for human tlymphotropic virus 1 htlv 1 genomes is designed for the in vitro quantification of htlv 1 genomes. Human tcell lymphotropic virus type 1 htlv 1 is transmitted through exposure to contaminated blood, through sexual contact, and from a mother who has the virus to her child at birth or through breastfeeding via breast milk. 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. The rates of human tcell leukemia virus type 1, or htlv 1, infection are exceeding 40% among adults in remote regions of central australia, with indigenous communities being the hardest hit. Htlv 2 was first isolated from a patient with tlymphocytic hairy cell leukemia but has not been unequivocally proven to be a pathogen. This conclusion is based on evidence from epidemiological and molecular studies, which show that htlv 1 causes adult tcell. The human tlymphotropic viruses, type i htlv i and type ii htlv ii, are closely related but distinct retroviruses that can infect humans. Htlv 1 is prevalent mostly in japan, africa, the caribbean islands, and south america.
Although most infected individuals remain asymptomatic htlv 1 causes severe disease in at least 5% of carriers. Mothertochild transmission of human tcell lymphotropic. Htlv1host interactions on the development of adult t cell. Qualitative screening detection of human tcell lymphotropic virus types 1 and 2 htlv 1 and htlv 2specific antibodies with confirmation and differentiation between htlv 1 and htlv 2 infection reflex tests lists tests that may or may not be performed, at an additional charge, depending on the result and interpretation of the initial tests. 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. The frequency of defectivetype proviruses in htlv1 infected humanized mice was lower than. Htlv 1 prevalence may be high outside areas where htlv 1 previously was known to be endemic. Jun 22, 2017 the human tlymphotropic virus type 1 htlv1 is estimated to infect 520 million people worldwide 1. Dna with 1% and 10% ed gdna were visualized on integrative genomics viewer igv. Htlv 1 is present throughout the world with clusters of high endemicity in southern japan, the. A high prevalence of human tlymphotropic virus htlv 12. Human tcell lymphotropic virus type 1 and its oncogenesis. The human lymphotropic virus type 1 htlv1 is a member of the retroviridea family, which infects about 1020 million people in the world. The retrovirus human tcell leukemia virus type 1 htlv1 integrates into the host dna, achieves.
Human tcell leukemia virus htlv 1 and 2 are deltaretroviruses that infect a wide range of cells. Diagnosis may occur during screening for blood donation. Relationship between human t lymphotropic virus htlv type 1. Mar 20, 2020 adult tcell leukemialymphoma atl is a human tcell leukemia virus type 1 htlv1associated tcell malignancy with generally poor prognosis. Oct 01, 2004 infection with human t cell lymphotropic virus type 1 htlv1 is a global epidemic affecting. Human tcell leukemia virus, type 1 htlv 1 occurs when a person is infected by the human tcell leukemia retrovirus. Htlv ii infection is particularly common in iv drug abusers, and has been found in clusters among certain south american indians. Epidemiology, treatment, and prevention of human tcell. Seroprevalence of human tcell lymphomaleukemia virus type1. Htlv 1 is present throughout the world, with clusters of high endemicity located often nearby areas where the virus is nearly absent. The abbott prism htlv ihtlv ii assay is an in vitro chemiluminescent immunoassay chlia for the qualitative detection of antibodies to human tlymphotropic virus type i andor human tlymphotropic virus type ii antihtlvi htlvii in human serum or plasma. Handle all avioq htlv iii biological materials as though capable of transmitting infectious agents. Its prevalence varies widely across different populations and geographic regions.
It can also be spread from mother to child during birth or breastfeeding. Human tcell leukemia virus htlv type 1 was the first human oncogenic. Human tlymphotropic virus type 1 htlv1 is found in indigenous peoples of the. Clinical characteristics of patients in peru with human t.
Currently, an estimated 1020 million people worldwide are infected with this virus. The transactivator tax of human tcell leukemia virus type 1 htlv1 interacts with campresponsive element cre binding and cre modulator proteins that bind to the 21basepair enhancer of htlv1. May 17, 2018 among 192 mothers with htlv 1 infection and their 499 respective exposed children, only 288 57. Six different htlv 1 subclasses exist, and each subtype is endemic to a particular region.
In the present study we estimate the number of htlv 1 infections that occur annually due to mother to child transmission mtct in brazil and within its regions. Pdf human tlymphotropic virus type 1 htlv1 and htlv. Allows subtyping of human tlymphotropic virus type1 htlv1 sequences. View pdf the challenge of describing the epidemiology of htlv in the amazon region of brazil. 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. Epidemiology of human tcell lymphotropic virus type 1. In all but 1 casepatient, htlv 1 was the only bloodborne virus detected. Proteomic profiling of htlv1 carriers and atl patients. Human tlymphotropic virus htlv is a virus that may cause blood or nerve disease. Human tlymphotropic virus an overview sciencedirect. In a monkey study sodiumvalproate together with zidovudine reduced the htlv 1 proviral load without the initial proviral load rise.
Sodiumvalproate has been shown to initially increase and then reduce htlv 1 proviral load in patients with hamtsp. Human t lymphotropic virus type 1 htlv1 proviral load in asymptomatic carriers, htlv1 associated myelopathytropical spastic paraparesis, and other neurological abnormalities associated with htlv1infection. Htlv1 associated myelopathytropical spastic paraparesis. Cancercausing htlv1 virus is common in parts of australia. Human tcell lymphotropic virus type 1 htlv 1 infects 1020 million people worldwide in a number of distinct geographical regions. Technical report geographical distribution of areas with a high prevalence of htlv 1 infection 3 background in 1980, htlv 1 human tcell leukaemialymphoma virus type 1 was the first oncogenic human retrovirus to be discovered. Apr 05, 2014 seroprevalence of human tcell lymphomaleukemia virus type1 htlv1 antibodies among blood donors at enugu, nigeria augustine ejike okoye,1 obike godswill ibegbulam,2 robinson chukwudi onoh,3 ngozi immaculata ugwu,1 chukwudi simon anigbo,2 charles emeka nonyelu2 1department of haematology and immunology, federal teaching hospital abakaliki, ebonyi state, nigeria. Human tcell leukemia virus type 1 genetic and rare diseases nih. Estimation of htlv1 vertical transmission cases in brazil. Doctors raise alarm about ancient htlv1 virus in australia. But after a while the proviral levels increased again. Although, after a long period of time, a small percentage 35% of infected individuals will progress to htlvassociated myelopathytropical spastic paraparesis hamtsp or adult tcell leukaemialymphoma atll, the large number of infected carriers. Glut1, the major vertebrate glucose transporter, has been shown to be the htlv env receptor. Information on the human tlymphotropic virus type 1 htlv1 virus which infects white blood cells including the geographic range of the disease, symptoms, how it is spread, not breastfeeding if you have htlv 1, how to protect again htlv 1, the lack of treatment, the low risk of htlv 1 transmission by blood transfusion, and htlv 1 testing.
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