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Background Human T-cell lymphotropic virus type 1 (HTLV-1) is a retrovirus that causes severe diseases, such as aggressive cancer or progressive neurological disease. HTLV-1 affects mainly people in areas with low human development index and can be transmitted from mother to child, primarily through breastfeeding. Refraining from breastfeeding is an effective intervention to reduce the risk of infection in infants. However, HTLV-1 antenatal screening is not offered globally. According to WHO, the scarcity of cost-effectiveness studies is considered one of the major barriers to the implementation of policies to prevent HTLV-1 infection. Therefore, this study aimed to assess the cost-effectiveness of antenatal screening and postnatal interventions to prevent HTLV-1 mother-to-child transmission in Brazil and to develop an open-access, editable, mathematical model that can be used by other countries and regions to assess different scenarios. Methods In this cost-utility analysis, we constructed a decision tree and a Markov model to assess the cost-effectiveness of HTLV-1 antenatal screening and postnatal interventions (ie, avoidance of breastfeeding, by suppression of lactation with cabergoline, and provision of formula feed) to reduce transmission. For our model, we used data from Brazil and we took the perspective of the public health-care system to estimate costs. Findings The implementation of both screening and interventions would result in the prevention of 1039 infections in infants every year in Brazil with an incremental cost-effectiveness ratio (ICER) of US$11415 per quality-adjusted lifeyear (QALY). 88% of all probabilistic sensitivity analysis simulations had ICER values lower than the Brazilian costeffectiveness threshold ($18 107·74 per QALY). HTLV-1 prevalence in pregnant women, the risk of HTLV-1 transmission when breastfeeding lasts for 6 months or more, and the cost of screening tests were the variables with the largest effect on ICER. Interpretation HTLV-1 antenatal screening is cost-effective in Brazil. An open-access model was developed, and this tool could be used to assess the cost-effectiveness of such policy globally, favouring the implementation of interventions to prevent HTLV-1 mother-to-child transmission worldwide. (AU)

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ABSTRACT Serological screening for human T-cell lymphotropic virus type 1 (HTLV-1) is usually performed using enzyme-linked immunosorbent assay (ELISA), particle agglutination, or chemiluminescence assay kits. Due to an antigen matrix improvement entailing the use of new HTLV antigens and changes in the format of HTLV screening tests, as well as newly introduced chemiluminescence assays (CLIAs), a systematic evaluation of the accuracy of currently available commercial tests is warranted. We aimed to assess the performance of commercially available screening tests for HTLV infection diagnosis. A diagnostic accuracy study was conducted on a panel of 397 plasma samples: 200 HTLV-negative plasma samples, 170 HTLV-positive plasma samples, and 27 plasma samples indeterminate by Western blotting (WB). WB-indeterminate samples (i.e., those yielding no specific bands for HTLV-1 and/or HTLV-2) were assessed by PCR, and the results were used to compare agreement among the commercially available ELISA screening tests. For performance analysis, WB-indeterminate samples were excluded, resulting in a final study panel of 370 samples. Three ELISA kits (Murex HTLV-1/2 [Murex], anti-HTLV-1/2 SYM Solution [SYM Solution], and Gold ELISA HTLV-1/2 [Gold ELISA]) and one CLIA kit (Architect rHTLV- 1/2) were evaluated. All screening tests demonstrated 100% sensitivity. Concerning the HTLV-negative samples, the SYM Solution and Gold ELISA kits had specificity values of 99.5%, while the Architect rHTLV-1/2 test presented 98.1% specificity, followed by Murex, which had a specificity of 92.0%. Regarding the 27 samples with WB-indeterminate results, after PCR confirmation, all ELISA kits showed 100% sensitivity but low specificity. Accuracy findings were corroborated by the use of Cohen's kappa value, which evidenced slight and fair agreement between PCR analysis and ELISAs for HTLV infection diagnosis. Based on the data, we believe that all evaluated tests can be safely used for HTLV infection screening.

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OBJETIVOS: analisar a aplicação do protocolo do Projeto Nascer Maternidades, estratégia do Ministério da Saúde para a adoção de medidas profiláticas e/ou terapêuticas no momento do parto, para gestantes com sorologias para sífilis/Aids desconhecidas, no primeiro ano de implantação em uma maternidade de referência em Feira de Santana, Bahia, Brasil. MÉTODOS: foram analisadas sorologias para HIV e sífilis solicitadas no pré-natal e na maternidade e a adoção de medidas profiláticas e/ou terapêuticas. Os dados foram coletados em uma amostra randomizada de 337 prontuários de gestantes admitidas para assistência obstétrica no período de julho de 2003 a julho de 2004. RESULTADOS: no pré-natal, 8,4 por cento das gestantes realizaram sorologia para HIV e 8 por cento para sífilis. Na maternidade, o teste rápido para HIV foi realizado para 17,7 por cento das gestantes e o VDRL para 97,8 por cento. A profilaxia das gestantes infectadas pelo HIV foi aplicada no momento do parto...

OBJECTIVES: to analyze the implementation of the Nascer Maternidades Project protocol, a guideline from the Brazilian Ministry of Health for prophylactic/therapeutic measures on delivery for pregnant women whose serological status vis-à-vis syphilis/HIV was unknown in the first year of implementation, at Maternity Hospital Referral Centre in Feira de Santana, Bahia, Brazil. METHODS: the women's serum was analyzed for HIV and syphilis, as requested during prenatal sessions or at the maternity hospital, and prophylactic and/or therapeutic measures were adopted. Data were obtained from 337 randomized medical records of pregnant women admitted to obstetric care between July 2003 and July 2004. RESULTS: during the prenatal follow-up, 8.4 percent and 8.05 of the pregnant women were tested for HIV and syphilis, respectively. On delivery, HIV rapid test was performed to 17.7 percent and VDRL to 97.8 percent. Prophylactic measures for HIV were taken on delivery in the case of HIV-infected women...

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We report the molecular and epidemiological characterization of 128 human T cell lymphotropic virus type 1 (HTLV-1) isolates from Brazilian patients with different clinical manifestations of the infection. Thirty-two percent of the patients were asymptomatic, 44% had HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP), and 23% had adult T cell leukemia/lymphoma (ATLL). Phylogenetic analysis performed using part of the LTR region of the viral genome revealed that all Brazilian isolates belonged to the Cosmopolitan subtype, with the following distribution within the Transcontinental subgroup: 81.6% within the Latin American cluster and 15.8% outside the Latin American cluster. Two isolates belonged to the Japanese subgroup. Molecular analysis of the tax region showed a high nucleotide similarity ( approximately 99%) with 41 prototype sequences, including the ATK-1 isolate. The mean number of nucleotide substitutions ranged from 1 to 8. Five specific nucleotide substitutions, C7401T, T7914C, C7920T, C7982T, and G8231A, were highly conserved among the Brazilian isolates (79.6%), with a frequency ranging from 81.6% to 100% in the sample group and from 18.4% to 24.1% in the prototypes used, suggesting the existence of a molecular signature. These changes were not correlated with a specific clinical status of the patients and could be a molecular characteristic of the HTLV-1 strains that circulate in Brazil.

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It was observed in the city of Salvador, State of Bahia, the highest seroprevalence of human T cell lymphotropic virus type 1 (HTLV-1) infection in Brazil as demonstrated by national wide blood bank surveys. In this paper, we report results of an investigation of drug use and sexual behavior associated with HTLV-I infection among male and female injecting drug users (IDUs) in Salvador. A cross sectional study was conducted in the Historical District of Salvador from 1994 to 1996 (Projeto Brasil-Salvador) and 216 asymptomatic IDUs were selected using the snowball contact technique. Blood samples were collected for serological assays. Sera were screened for human immunodeficiency virus (HIV-1/2) and HTLV-I/II antibodies by ELISA and confirmed by Western blot. The overall prevalence of HTLV-I/II was 35.2 per cent (76/216). The seroprevalence of HTLV-I, HTLV-II and HIV-1 was for males 22 per cent, 11.3 per cent and 44.1 per cent and for females 46.2 per cent, 10.3 per cent and 74.4 per cent respectively. HTLV-I was identified in 72.4 per cent of HTLV positive IDUs. Variables which were significantly associated with HTLV-I infection among males included needles sharing practices, duration of injecting drug use, HIV-1 seropositivity and syphilis. Among women, duration of injecting drug use and syphilis were strongly associated with HTLV-I infection. Multivariate analysis did not change the direction of these associations. Sexual intercourse might play a more important role in HTLV-I infection among women than in men.

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Efforts to characterize HIV-1 polymorphism and anti-HIV immune response are being made in areas where anti-HIV/AIDS vaccines are to be employed. Anti-HIV-1 humoral immune response is being studied in infected individuals resident in Rio de Janeiro, in distinct cohorts involving recent seroconvertors, pregnant women or intravenous drug users (IDU). Comparative analysis of specificity of antibody response towards epitopes important for anti-HIV-1 immune response indicate quantitative differences between cohorts, with an exceptionally strong response in IDUs and weakest response in pregnant women. However, a comparative analysis between pregnant women cohorts from Rio de Janeiro and Rio Grande do Sul indicated an even lower response (with exception of the anti-V3-C clade peptide recognition) for the southern cohort. Studied analysing the immune function of the humoral response indicate a quite elevated occurrence of antibodies capable of neutralizing heterologous primary HIV-1 isolates from Rio de Janeiro. Attempts to correlate seroreactivity with HIV-1 neutralization with respect to HIV-1 polymorphism were not very successfull: while the Brazilian B clade B" variant could be recognized by binding assays, no significant distinction of HIV-1 clades/variants was observed in viral neutralization assays.

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Com o objetivo de avaliar a resposta de anticorpos da classe IgG a componentes estruturais do vírus, 85 soros de pacientes brasileiros, compreendendo todo o espectro da infecçäo pelo HIV foram analisados pela técnica de Western blot. Os soros confirmados como positivos pelas técnicas de imunofluorescência indireta e imunoenzimática. Embora os soros de alguns pacientes estudados reagissem menos intensamente com o polipeptídeo de 55 KDa, näo observamos nenhuma diferença de reatividade entre os soros de pacientes com as diversas forma clínicas. Entretanto, a grande freqüência de reatividade ao polipeptídeo de 24 KDa nos pacientes com AIDS sugere que o padräo de resposta imune seja similar aos pacientes africanos

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