RESUMO
Human T-cell lymphotropic virus type 1 prevalence estimates are usually based on serological screening of blood donors, pregnant women, and other selected population groups. Previously, data on the global epidemiology of human T-cell lymphotropic virus type 1 infection have been summarized unsystematically and without a focus on general populations. To assess the implications of the virus for healthcare systems it is essential to know its past and present prevalence. The widely cited estimate that 10-20 million people are infected with human T-cell lymphotropic virus type 1 worldwide was calculated from data that are now 25 years old. This estimate may therefore no longer reflect the global epidemiology. The objective of this study was to collate published data that are truly representative of the general population through a systematic review of the literature. Fifty-nine relevant studies were identified and the 17 that met the inclusion criteria were all cross-sectional designs; none reported incidence. The prevalence of human T-cell lymphotropic virus type 1 was highest in the two studies of Japanese islands (36.4%; 95% CI: 29.9-42.8) and lowest in studies from Mongolia, Malaysia and India. In Haiti the prevalence was 3.8% (95% CI: 1.78-5.86); in Africa between 6.6% (95% CI: 4.0-9.9) and 8.5% (95% CI: 6.99-10.10) in Gabon, and 1.05% (95% CI: 0.63-1.47) in Guinea. Only three studies were from West Africa and none were from the South; the only study from India was from the north of the country. We conclude that there is a paucity of general population data from countries in which human T-cell lymphotropic virus type 1 is endemic, and that new studies are required to reevaluate the global burden of infection.
Assuntos
Infecções por HTLV-I/epidemiologia , Vírus Linfotrópico T Tipo 1 Humano/isolamento & purificação , África/epidemiologia , Ásia/epidemiologia , Haiti/epidemiologia , Humanos , PrevalênciaRESUMO
We compared the genetic diversity of the Brazilian human T-cell lymphotropic virus type 1 isolates with those found in KwaZulu-Natal (KZN), South Africa, and with the genetic background of the hosts. The seroprevalence rate in KZN was 1.7%. All sequences belonged to the A subgroup. The presence of South African sequences in two different clusters from Brazil, and the finding of the beta-globin haplotype in infected hosts are consistent with the transmission of this virus from southern Africa to Brazil.