No abstract

SUMMARYHuman T-cell leukemia virus type 1 (HTLV-1), the first human retrovirus to be discovered, is present in diverse regions of the world, where its infection is usually neglected in health care settings and by public health authorities. Since it is usually asymptomatic in the beginning of the infection and disease typically manifests later in life, silent transmission occurs, which is associated with sexual relations, breastfeeding, and blood transfusions. There are no prospects of vaccines, and screening of blood banks and in prenatal care settings is not universal. Therefore, its transmission is active in many areas such as parts of Africa, South and Central America, the Caribbean region, Asia, and Melanesia. It causes serious diseases in humans, including adult T-cell leukemia/lymphoma (ATL) and an incapacitating neurological disease (HTLV-associated myelopathy/tropical spastic paraparesis [HAM/TSP]) besides other afflictions such as uveitis, rheumatic syndromes, and predisposition to helminthic and bacterial infections, among others. These diseases are not curable as yet, and current treatments as well as new perspectives are discussed in the present review.

Background Very few studies have measured disease penetrance and prognostic factors of Chagas cardiomyopathy among asymptomatic Trypanosoma cruzi–infected persons. Methods and Results We performed a retrospective cohort study among initially healthy blood donors with an index T cruzi–seropositive donation and age-, sex-, and period-matched seronegatives in 1996 to 2002 in the Brazilian cities of São Paulo and Montes Claros. In 2008 to 2010, all subjects underwent medical history, physical examination, ECGs, and echocardiograms. ECG and echocardiogram results were classified by blinded core laboratories, and records with abnormal results were reviewed by a blinded panel of 3 cardiologists who adjudicated the outcome of Chagas cardiomyopathy. Associations with Chagas cardiomyopathy were tested with multivariate logistic regression. Mean follow-up time between index donation and outcome assessment was 10.5 years for the seropositives and 11.1 years for the seronegatives. Among 499 T cruzi seropositives, 120 (24%) had definite Chagas cardiomyopathy, and among 488 T cruzi seronegatives, 24 (5%) had cardiomyopathy, for an incidence difference of 1.85 per 100 person-years attributable to T cruzi infection. Of the 120 seropositives classified as having Chagas cardiomyopathy, only 31 (26%) presented with ejection fraction <50%, and only 11 (9%) were classified as New York Heart Association class II or higher. Chagas cardiomyopathy was associated (P<0.01) with male sex, a history of abnormal ECG, and the presence of an S3 heart sound. Conclusions There is a substantial annual incidence of Chagas cardiomyopathy among initially asymptomatic T cruzi–seropositive blood donors, although disease was mild at diagnosis.

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.

HTLV-I/II infection is present in all regions of Brazil, but its prevalence varies according to the geographical area, being higher in Bahia, Pernambuco and Pará. It has been estimated that Brazil has the highest absolute number of infected individuals in the world. Blood donors screening and research conducted with special groups (indigenous population of Brazil, IV drug users and pregnant women) are the major sources of information about these viruses in our Country. HTLV-I causes adult T cell leukemia/lymphoma (ATLL), HTLV associated myelopathy/tropical spastic paraparesis (HAM/TSP), HTLV associated uveitis (HAU), dermatological and immunological abnormalities. HTLV-II is not consistently associated with any disease. Diagnosis is established using screening (enzymatic assays, agglutination) and confirmatory (Western blot, PCR) tests. The viruses are transmitted by blood and contaminated needles, by sexual relations and from mother to child, especially by breast feeding. Prevention efforts should focus on education of positive blood donors, infected mothers and IV drug users.

No abstract

Background The safety of the blood supply is ensured through several procedures from donor selection to testing of donated units. Examination of the donor deferrals at different centers provides insights into the role that deferrals play in transfusion safety. Methods A cross-sectional descriptive study of prospective allogeneic blood donors at three large blood centers located in São Paulo, Belo Horizonte and Recife, Brazil from August 2007 to December 2009 was conducted. Deferrals were grouped into similar categories across the centers, and within each center frequencies out of all presentations were determined. Results Of 963,519 prospective blood donors at the three centers, 746,653 (77.5%) were accepted and 216,866 (22.5%) were deferred. Belo Horizonte had the highest overall deferral proportion of 27%, followed by Recife (23%) and Sao Paulo (19%). Females were more likely to be deferred than males (30% versus 18%, respectively). The three most common deferral reasons were low hematocrit/hemoglobin (Ht/Hb), medical diagnoses and higher-risk behavior. Conclusion The types and frequencies of deferral vary substantially among the three blood centers. Factors that may explain the differences include demographic characteristics, the order in which health history and vital signs are taken, the staff training, an the way deferrals are coded by the centers among other policies. The results indicate that blood donor deferral in Brazil has regional aspects that should be considered when national policies are developed.

The purpose of this study was to determine the seroprevalence of human immunodeficiency virus (HIV-1/2), human T-cell lymphotropic virus (HTLV-I/II), hepatitis B virus (HBV), hepatitis C virus (HCV), Treponema pallidum and Trypanosoma cruzi among 63 male prisoners in Manhuaçu, Minas Gerais, Brazil and to compare this with data from eligible blood donors. The positive results were as follows: 11/63 (17.5%) for HBV, 5/63 (7.4%) for syphilis, 4/63 (6.3%) for HCV, 3/63 (4.8%) for Chagas' disease, 2/63 (3.2%) for HIV-1/2 and 1/63 (1.6%) for HTLV-I/II. The seroprevalence in prisoners was higher than among blood donors, mainly for antibodies to HIV-1/2, HCV and HBV. This is probably due to low social economic level, illiteracy, higher proportion with a prior history of intravenous drug use and/or unsafe sexual behavior. Therefore, these prisoners constitute a high risk group and routine screening and counseling are recommended.