Performance of commercially available serological screening Tests for human T-Cell lymphotropic virus infection in Brazil

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.

Aplicação do protocolo do Projeto Nascer Maternidades em uma maternidade de referência em Feira de Santana, Bahia, Brasil / Implementation of Projeto Nascer Maternidades the in a reference maternity of the city of Feira de Santana, State of Bahia, Brazil

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...

Risk factors for human T cell lymphotropic virus type I among injecting drug users on Northeast Brazil: possibly greater efficiency of male to female transmission

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.

HIV specific humoral immune response in Rio de Janeiro, Brazil

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.

Patterns of serologic response to human immunodeficiency virus type 1 (HIV-1) in brazilians with different clinical forms of HIV infection

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