Prevalence of antibody to human T cell lymphotropic virus types 1/2 among aboriginal groups inhabiting northern Argentina and the Amazon region of Peru.

We carried out a seroepidemiologic survey to define the prevalence of human T cell lymphotropic virus types 1/2 (HTLV-1/2) infections among aboriginal populations from isolated regions of northern Argentina and the Amazon region of Peru. Antibodies against HTLV were measured with agglutination tests and confirmed with by an immunofluorescence assay (IFA) and Western blotting. Five (6.94%) of 72 samples from the Tobas Indians in Argentina were positive by the IFA; two samples were typed as HTLV-1 (2.78%), two as HTLV-2 (2.78%), and one (1.39%) could not be typed because it had similar antibody titers against both viruses. No positive samples were found among 84 Andinos Puneños and 47 Matacos Wichis Indians. Seroprevalences of 2.50% (1 of 40) and 1.43% (1 of 70) for HTLV-1 were observed among Wayku and San Francisco communities in the Amazon region of Peru, and seroprevalences of 4.54% (1 of 22) and 2.38% (1 of 42) for HTLV-2 were observed among Boca Colorada and Galilea communities. No serologic evidence of human immunodeficiency virus (HIV) infection was found among the Indians tested. These results indicated the presence of HTLV-1 and HTLV-2 in the indigenous populations of Argentina and Peru. Moreover, the lack of HIV infection indicates that the virus has probably not yet been introduced into these populations.

Immunofluorescence assay reactivity patterns of serum samples presenting indeterminate Western blot results for antibodies to HIV-1 and HTLV-I/II in Cordoba, Argentina.

Serum samples (n: 110) from blood donors and high risk individuals from Cordoba, Argentina with indeterminate HIV-1 and HTLV-I/II Wb profiles were studied for specific antibodies to HTLV-I/II and HIV-1 by indirect immunofluorescence assay (IFA) and for the presence or absence of HIV-1 and HTLV-I/II specific bands by Wb. This study was carried out in order to characterize their putative reactions with HIV-1 and HTLV-I/II proteins and to resolve the retrovirus infection status of these individuals. Results indicated that blood donors sera displaying indeterminate HIV-1 or HTLV-I/II Wb patterns were not immunoreactive to HTLV-I/II and HIV-1 on IFA. However, a high rate of indeterminate HIV-1 and HTLV-I/II Wb samples from high risk individuals had positive HTLV-I/II and HIV-1 IFA results respectively. Our study supports the growing evidence that HTLV-HIV indeterminate seroreactivity in low risk population is due to a cross reaction against nonviral antigens, and in high risk populations the indeterminate samples show serological cross-recognition between HIV-1 proteins and HTLV-I/II proteins on Wb. These results point out the necessity to investigate the HTLV-I/II reactivity in indeterminate HIV-1 samples and vice versa in order to confirm the diagnosis. Finally, this study shows the potential usefulness of IFA in elucidating the status of HIV-1 and HTLV-I/II infection of individuals with indeterminate Wb profiles, thus enabling resolution of retrovirus infection status.

[Evaluation of commercial equipment used in blood banks in Córdoba for the detection of anti-HTLV-I/II antibodies]. / Evaluación de los equipos comerciales utilizados en los bancos de sangre de Córdoba para la detección de anticuerpos anti HTLV-I/II.

In order to assess the efficiency of currently used screening tests, Abbott HTLV-I/HTLV-II EIA, Vironostika HTLV-I/II Organon Teknika, Particle Agglutination (PA) assay Serodia Fujirebio Inc. (Tokyo, Japan) for HTLV-I/II antibody detection in blood donors samples, a panel of 100 sera from different blood banks of Córdoba city were studied. An "in house" indirect immunofluorescence assay (IFA) was used as reference test. The correlation rates were: 66% for Abbott HTLV-I/HTLV-II EIA, 97% for Vironostika HTLV-I/II Organon Teknika EIA and 99% for PA Serodia. Vironostika HTLV-I/II Organon Teknika EIA and PA Serodia assay proved to be more reliable for HTlV-I/II antibody screening in blood donors from Córdoba, yielding a very low rate of false positive results as compared with Abbot HTLV-I/HTLV-II EIA.

[HTLV-I/II seroprevalence and risk factors associated with infection in a blood donor population in Córdoba, Argentina]. / Seroprevalencia de HTLV-I/II y factores de riesgo asociados a la infección en la población de donantes de sangre de Córdoba, Argentina.

In this study we have determined the seroprevalence of infections by HTLV-I/II in the blood donor population from the city of Córdoba. A total of 5476 blood donor sera were screened for HTLV-I/II antibodies by particle agglutination assay (PA) (SERODIA HTLV-I, Fujirebio INC, Tokyo, Japan). The reactive sera samples were confirmed by an "in house" indirect immunofluorescence assay (IFA). 14 out of 5476 blood donors studied were PA reactive and were confirmed positive by IFA, showing a prevalence of 0.26% (95% confidence interval: 0.126%-0.394%). All the positive samples, except one, met the criteria for HTLV-I. Although one HTLV-I infected donor was an intravenous drug abuser and two donors were born in highly endemic areas for HTLV-I, no specific risk factors were identified among the others. The demonstration that HTLV-I circulates in blood donor population of Córdoba, points out that the systematic screening of blood for HTLV-I/II antibodies must be implemented in the blood banks, in an attempt to prevent the spread of infections with this oncogenic virus in Argentina.

[Absence of HTLV-I/II virus circulation in blood donors from the provinces of Santa Fe and Santiago del Estero]. / Ausencia de circulación de los virus HTLV-I/II en donantes de sangre de las provincias de Santa Fe y Santiago del Estero.

In the present study, we evaluated the seroprevalence of HTLV-I/II infection among the blood donors in Santa Fe and Santiago del Estero provinces. A total of 1327 serum samples from blood donors from Rafaela blood bank of Santa Fe province and 3382 serum samples from blood donors from Dr Edgar Bouzon blood bank of Santiago del Estero province were studied. The antibody screening was done by particle agglutination assay (PA) (SERODIA, Fujirebio Inc., Tokyo, Japan) or by enzyme immuno assay (EIA) (Abbott HTLV-I/HTLV-II EIA, Abbott, Germany). The "in house" indirect immunofluorescence assay (IFA) and Western blot (Bioblot HTLV Biokit, Barcelona, Spain) were used as confirmatory assays. All the samples resulted negative for specific antibodies against HTLV-I/II. These results suggest that HTLV-I/II are not circulating in low risk populations in these provinces or that the prevalences of infection would be lower than that reported by blood banks in other provinces of Argentina.

Seroprevalencia de HTLV-I/II y factores de riesgo asociados a la infección en la población de donantes de sangre de Córdoba, Argentina / HTLV-I/II seroprevalence and risk factors associated with infection in a blood donor population in Córdoba, Argentina

In this study we have determined the seroprevalence of infections by HTLV-I/II in the blood donor population from the city of Córdoba. A total of 5476 blood donor sera were screened for HTLV-I/II antibodies by particle agglutination assay (PA) (SERODIA HTLV-I, Fujirebio INC, Tokyo, Japan). The reactive sera samples were confirmed by an "in house" indirect immunofluorescence assay (IFA). 14 out of 5476 blood donors studied were PA reactive and were confirmed positive by IFA, showing a prevalence of 0.26 (95 confidence interval: 0.126-0.394). All the positive samples, except one, met the criteria for HTLV-I. Although one HTLV-I infected donor was an intravenous drug abuser and two donors were born in highly endemic areas for HTLV-I, no specific risk factors were identified among the others. The demonstration that HTLV-I circulates in blood donor population of Córdoba, points out that the systematic screening of blood for HTLV-I/II antibodies must be implemented in the blood banks, in an attempt to prevent the spread of infections with this oncogenic virus in Argentina.

Evaluación de los equipos comerciales utilizados en los bancos de sangre de Córdoba para la detección de anticuerpos anti HTLV-I/II / Evaluation of commercial equipment used in blood banks in Córdoba for the detection of anti-HTLV-I/II antibodies

In order to assess the efficiency of currently used screening tests, Abbott HTLV-I/HTLV-II EIA, Vironostika HTLV-I/II Organon Teknika, Particle Agglutination (PA) assay Serodia Fujirebio Inc. (Tokyo, Japan) for HTLV-I/II antibody detection in blood donors samples, a panel of 100 sera from different blood banks of Córdoba city were studied. An "in house" indirect immunofluorescence assay (IFA) was used as reference test. The correlation rates were: 66 for Abbott HTLV-I/HTLV-II EIA, 97 for Vironostika HTLV-I/II Organon Teknika EIA and 99 for PA Serodia. Vironostika HTLV-I/II Organon Teknika EIA and PA Serodia assay proved to be more reliable for HTlV-I/II antibody screening in blood donors from Córdoba, yielding a very low rate of false positive results as compared with Abbot HTLV-I/HTLV-II EIA.

Ausencia de circulación de los virus HTLV-I/II en donantes de sangre de las provincias de Santa Fe y Santiago del Estero / Absence of HTLV-I/II virus circulation in blood donors from the provinces of Santa Fe and Santiago del Estero

In the present study, we evaluated the seroprevalence of HTLV-I/II infection among the blood donors in Santa Fe and Santiago del Estero provinces. A total of 1327 serum samples from blood donors from Rafaela blood bank of Santa Fe province and 3382 serum samples from blood donors from Dr Edgar Bouzon blood bank of Santiago del Estero province were studied. The antibody screening was done by particle agglutination assay (PA) (SERODIA, Fujirebio Inc., Tokyo, Japan) or by enzyme immuno assay (EIA) (Abbott HTLV-I/HTLV-II EIA, Abbott, Germany). The "in house" indirect immunofluorescence assay (IFA) and Western blot (Bioblot HTLV Biokit, Barcelona, Spain) were used as confirmatory assays. All the samples resulted negative for specific antibodies against HTLV-I/II. These results suggest that HTLV-I/II are not circulating in low risk populations in these provinces or that the prevalences of infection would be lower than that reported by blood banks in other provinces of Argentina.