Transmissão intrafamiliar do Vírus linfotrópico de Células T Humanas tipo 1 em Belém, Pará, Brasil

Abstract

Retroviruses belong to a group of infectious agents that have received more attention from the scientific community since the early 19706, when cellular oncogenes have been reported related to them. From these preliminary studies it was described the first human retrovirus, virus Human T lymphotropic 1 (HTLV-1)20. Besides the leukemia/lymphoma adult T cell, HTLV-1 is also causing a degenerative neurological disease associated myelopathy tropical spastic HTLV-1/paraparesia (HAM / TSP) 7, 21. Blood samples from patients and their families living with the virus, seen in the NMT/UFPA were analyzed by molecular method, aiming to investigate the intrafamilial transmission of HTLV-1. Intrafamilial transmission was observed with 100% similarity between the nucleotide bases in nine (75%) of the 12 families studied, of which two families showed vertical transmission, sexual transmission had three families and three families who had both types of transmission. It was observed that three families change occurred in more than one nucleotide base pair, and in two families diverged by 0.2% and 0.4%, ie, had high similarity between their nucleotides (> 99.4 %), suggesting that in this case there intrafamilial transmission of HTLV-1. In one family there was a difference of 1.83%, indicating no intrafamilial transmission. The nucleotide sequence of the 5 'LTR segment and phylogenetic analysis showed high similarity entres the strains isolated in this study and confirmed the occurrence of the Cosmopolitan subtype Transcontinental subgroup. This study provides molecular evidence of intrafamilial transmission of HTLV-1 in patients treated at the Tropical Medicine Center UFPA. In this study the routes of transmission as breastfeeding and sex, was more prevalent for this spread.