A case-control study of HTLV-infection among blood donors in Salvador, Bahia, Brazil - associated risk factors and trend towards declining prevalence

Abstract

Previous data suggest that Salvador, the capital of the State of Bahia, a northeastern state of Brazil, has the highest prevalence of HTLV infection in blood donors among Brazilian cities. The aim of this case-control study was to identify the determinants of risk for HTLV infection among blood donors in the city of Salvador. Between January 2000 and December 2003, 504 blood donors with positive screening tests for HTLV infection (unconfirmed prevalence of 0.48%) were invited to participate in our study. A total of 154 had performed a Western Blot (WB) test, 139 were of which found to be positive (false positive screening rate 9.9%). Using a standardized questionnaire, a single interviewer obtained information on demographic, socioeconomical and educational characteristics, as well as sexual behavior from 91 out of the 139 positive by WB and from 194 HTLV-negative blood donors. Prevalence of HTLV infection was 0.48%. Multivariate analysis revealed women (OR 3.79 [1.61-8.88], p=0.002), low family income* (OR 3.37 [1.17-9.66], p=0.02), self-reported history of sexual transmitted diseases (OR 6.15 [2.04-18.51], p=0.001), 2 or more sexual partners during life (OR 9.29 [2.16-39.94], p=0.0020) and inconsistent use of condoms (OR 4.73 [1.98-11.26], p=0.0004) as risk factors for HTLV infection. In accordance with previous published data, our results point to an association between low socio-economical level, poor education and unsafe sexual behavior with HTLV infection. We observed a lower prevalence of HLTV infection when compared to previous data.

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

“…A study conducted in the State of Bahia in 2006 by Mota et al showed a prevalence of 0.5% in blood donors 4 . This prevalence was lower than that determined in 1993 by the same group (1.4%), showing a significant decline over this period 5 .…”

Endocrine and metabolic disorders in HTLV-1 infected patients

“…[1][2][3] The HTLV-1 infection is endemic in Japan and several countries in South America, Caribbean and Africa. 2,[4][5][6][7] The transmission pathways of HTLV-1 infection include vertical, parenteral and sexual transmission. 2,7 Risk factors associated with HTLV-1 infection include: hemotransfusion, low socioeconomic status, low education level, high-risk sexual behavior, anal sex, fi rst sexual relationship before 18 year-old and having more than 3 sexual partners in life.…”

“…2,[4][5][6][7] The transmission pathways of HTLV-1 infection include vertical, parenteral and sexual transmission. 2,7 Risk factors associated with HTLV-1 infection include: hemotransfusion, low socioeconomic status, low education level, high-risk sexual behavior, anal sex, fi rst sexual relationship before 18 year-old and having more than 3 sexual partners in life. 7,8 Several studies have been evidencing association between HTLV-1 infection and endocrinopathies and other metabolic disorders such as autoimmune thyroid diseases, hypercalcemia, type 1 diabetes mellitus and pseudohypoparathyroidism.…”

“…2,7 Risk factors associated with HTLV-1 infection include: hemotransfusion, low socioeconomic status, low education level, high-risk sexual behavior, anal sex, fi rst sexual relationship before 18 year-old and having more than 3 sexual partners in life. 7,8 Several studies have been evidencing association between HTLV-1 infection and endocrinopathies and other metabolic disorders such as autoimmune thyroid diseases, hypercalcemia, type 1 diabetes mellitus and pseudohypoparathyroidism. 1,[9][10][11][12] Due to the importance of these disturbances in the clinical spectrum of the HTLV-1 infection, this study aims to review the current knowledge about the endocrine diseases related to the HTLV-1 infection.…”

Declínio da prevalência do HTLV-1/2 em doadores de sangue do Hemocentro Regional da Cidade de Uberaba, Estado de Minas Gerais, 1995 a 2008

“…Outros estudos mostram prevalência de infecção pelo HTLV, através da técnica do WB, de 0,07% em Maringá-PR (entre 2003 e 2006) 23 , 0,11% em Rio Branco-AC (entre 1998 e 2001) 24 e 0,3% no interior da Bahia (década de 90) 25 , sendo a Bahia o estado com maiores índices de prevalência 1,26 .…”