Decline in prevalence and asymmetric distribution of human T cell lymphotropic virus 1 and 2 in blood donors, State of Minas Gerais, Brazil, 1993 to 2007

Abstract

Introduction: Human T cell lymphotropic virus types 1 and 2 (HTLV-1/2) are endemic in Brazil and are screened for in transfusion services since 1993. This study evaluated the evolution of the prevalence of HTLV-1 and 2 in blood donors of the Hemominas Foundation from 1993 to 2007, and its geographical distribution in State of Minas Gerais, Brazil. Methods: The Hemominas Foundation is a centralized blood center in Minas Gerais, Brazil. The sources of data were the Hemominas Foundation Technical Bulletin and files from the centralized serological laboratory. Donors were tested in the period using enzyme linked immuno sorbent assays (ELISA), followed by Western blot, when repeatedly reactive. The data were analyzed by EPIINFO 6.2 and TABWIN 3.5 softwares. Results: The average seroprevalence in the period 1993-2007 was 0.1%. A steady decline occurred from 0.4% in 1993 to below 0.1% in 2002 and later, with a transient peak of 0.5% in 1994. HTLV reactivity distribution was asymmetrical in the state, with regions of higher prevalence, interspersed with low prevalence areas. Comparison of positive and negative donors verified that increasing age was proportional to virus positivity. Odds ratio for age ranged from 1.43 (30 to 39 years-old) to 3.09 (50 to 65 years-old). Women had a greater chance of being positive (OR-1.64), as previously described. Conclusions: Possible explanations for HTLV-1/2 prevalence decline are the exclusion of positive donors from the donor pool, an increase in repeat donors and ELISA test improvement, with reduction in the number of false positive results.

Seroprevalence of HTLV-1/2 among blood donors in the state of Maranhão, Brazil

“…This was also observed in other studies,6., 13., 15. with prevalences among males of 54.95%, 59.4%, and 57.8%. However, this is usually explained by the higher numbers of male donors than female donors.…”

“…At HEMOACRE, a value of 0.11% was observed using the same kit (Elisa Murex®), and values ranging from 0.08% to 1.80% were found between 1989 and 1996, which were also within the national average 7 . At HEMOMINAS, a value of 0.1% was observed between 1993 and 2007 using ELISA 13 . At Hemonúcleo de Patos, in the state of Paraíba, Braga et al 14 found a prevalence of 0.025% of HTLV-1 between 2002 and 2011.…”

Human T lymphotropic virus types 1 and 2: a point of view

“…Seroprevalence rates were in the order of 1 to 2 per thousand first time donors which is higher than in the United States and Europe but lower than in the Brazilian general population (24) .…”

Human T-Lymphotropic Virus-1/2 Detected in Drug Abused Prisoners Imprisoned in Correctional Facilities in Central of Java Indonesia

“…The huge number of HTLV-1-infected men among blood donors could be a consequence of the high number of donors of this gender. An age-and-gender-cohort effect due to the characteristics of blood donors worldwide could not be excluded [12].…”