Silent dissemination of HTLV-1 in an endemic area of Argentina. Epidemiological and molecular evidence of intrafamilial transmission

Submitted by Sandra Infurna ([email protected]) on 2017-07-18T13:04:33Z No. of bitstreams: 1 anacarolina_vicente_etal_IOC_2017.pdf: 865469 bytes, checksum: 9807da08afb62e9bdd5e68f2e19c4cfe (MD5)Approved for entry into archive by Sandra Infurna ([email protected]) on 2017-07-18T13:18:38Z (GMT) No. of bitstreams: 1 anacarolina_vicente_etal_IOC_2017.pdf: 865469 bytes, checksum: 9807da08afb62e9bdd5e68f2e19c4cfe (MD5)Made available in DSpace on 2017-07-18T13:18:38Z (GMT). No. of bitstreams: 1 anacarolina_vicente_etal_IOC_2017.pdf: 865469 bytes, checksum: 9807da08afb62e9bdd5e68f2e19c4cfe (MD5) Previous issue date: 2017Universidad Nacional de Córdoba. Facultad de Ciencias Mèdicas. Instituto de Virologia "Dr. J. M. Vanella". Córdba, Argentina.Universidad Nacional de Córdoba. Facultad de Ciencias Mèdicas. Instituto de Virologia "Dr. J. M. Vanella". Córdba, Argentina.Universidad Nacional de Córdoba. Facultad de Ciencias Mèdicas. Instituto de Virologia "Dr. J. M. Vanella". Córdba, Argentina.Hospital San Roque. Departamento de Enfermedades Infecciones. San Salvador de Jujuy, Argentina.Universidad Nacional de Córdoba. Facultad de Ciencias Mèdicas. Instituto de Virologia "Dr. J. M. Vanella". Córdba, Argentina.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Genética Molecular de Microorganismos. Rio de Janeiro, RJ. Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Genética Molecular de Microorganismos. Rio de Janeiro, RJ. Brasil.Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Matemática. Córdoba, Argentina.Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Matemática. Córdoba, Argentina.Universidad Nacional de Córdoba. Facultad de Ciencias Mèdicas. Instituto de Virologia "Dr. J. M. Vanella". Córdba, Argentina.Universidad Nacional de Córdoba. Facultad de Ciencias Mèdicas. Instituto de Virologia "Dr. J. M. Vanella". Córdba, Argentina.Molecular and epidemiological studies of transmission routes and risk factors for infection by HTLV-1 are extremely important in order to implement control measures, especially because of the high prevalence of HTLV-1 in several regions of the world. San Salvador de Jujuy, Northwest Argentina, is a highly endemic area for HTLV-1 and foci of tropical spastic paraparesis/HTLV-1-associated myelopathy

The low evolutionary rate of human T-cell lymphotropic virus type-1 confirmed by analysis of vertical transmission chains

The evolutionary rate of the human T-cell lymphotropic virus type-1 (HTLV-1) is considered to be very low, in strong contrast to the related human retrovirus HIV. However, current estimates of the HTLV-1 rate rely on the anthropological calibration of phylogenies using assumed dates of human migration events. To obtain an independent rate estimate, we analyzed two variable regions of the HTLV-1 genome (LTR and env) from eight infected families. Remarkable genetic stability was observed, as only two mutations in LTR (756 bp) and three mutations in env (522 bp) occurred within the 16 vertical transmission chains, including one ambiguous position in each region. The evolutionary rate in HTLV-1 was then calculated using a maximum-likelihood approach that used the highest and lowest possible times of HTLV-1 shared ancestry, given the known transmission histories. The rates for the LTR and env regions were 9.58 x 10(-8)-1.25 x 10(-5) and 7.84 x 10(-7)-2.33 x 10(-5) nucleotide substitutions per site per year, respectively. A more precise estimate was obtained for the combined LTR-env data set, which was 7.06 x 10(-7)-1.38 x 10(-5) substitutions per site per year. We also note an interesting correlation between the occurrence of mutations in HTLV-1 and the age of the individual infected

HTLV in the Americas: challenges and perspectives.

The first description of the human T-lymphotropic virus type 1 (HTLV-1) was made in 1980, followed closely by the discovery of HTLV-2, in 1982. Since then, the main characteristics of these viruses, commonly referred to as HTLV-1/2, have been thoroughly studied. Central and South America and the Caribbean are areas of high prevalence of HTLV-1 and HTVL-2 and have clusters of infected people. The major modes of transmission have been through sexual contact, blood, and mother to child via breast-feeding. HTLV-1 is associated with adult T-cell leukemia/lymphoma (ATL), HTLV-associated myelopathy/tropical spastic paraparesis (HAM/TSP), and HTLV-associated uveitis as well as infectious dermatitis of children. More clarification is needed in the possible role of HTLV in rheumatologic, psychiatric, and infectious diseases. Since cures for ATL and HAM/TSP are lacking and no vaccine is available to prevent HTLV-1 and HTLV-2 transmission, these illnesses impose enormous social and financial costs on infected individuals, their families, and health care systems. For this reason, public health interventions aimed at counseling and educating high-risk individuals and populations are of vital importance. In the Americas this is especially important in the areas of high prevalence

Family tree of index cases infected with HTLV-1.

<p>Family tree of index cases infected with HTLV-1.</p

Variables associated with HTLV-1 infection among families in the endemic area of Argentina.

<p>Variables associated with HTLV-1 infection among families in the endemic area of Argentina.</p

Common familiar polymorphisms on 552 nucleotides of LTR sequence from family isolates of Jujuy, considering J02029 as reference strain.

<p>Common familiar polymorphisms on 552 nucleotides of LTR sequence from family isolates of Jujuy, considering J02029 as reference strain.</p

Frequency of HTLV-1 infection in mother-offspring and spouse-spouse pairs in the endemic area of Argentina.

<p>Frequency of HTLV-1 infection in mother-offspring and spouse-spouse pairs in the endemic area of Argentina.</p