Establishment and maintenance of persistent infection by picobirnavirus in greater rhea (Rhea Americana).

A study aimed to determine the infection model that picobirnavirus (PBV) established in birds was conducted in a farm of greater rheas in Córdoba, Argentina. Analysis of stools collected during a longitudinal study involving seven birds provided evidence that PBV is acquired very early in life and establishes a persistent infection in the host, which is characterized by intermingled periods of high, low and silent viral activity. Genomic analysis indicated that the rheas excreted virus with nucleotide sequence identity between 90.5-100 % and that more than one PBV strain with different electropherotype profiles could be involve in the infection. This report provides the first evidence of persistent infection of PBV in birds. The natural history of PBV infection has begun to be understood, and it appears that asymptomatic PBV-infected mammals and birds could persistently excrete the virus in stool samples, contributing to wide circulation of the virus in the environment.

Genetic analysis of a novel human adenovirus with a serologically unique hexon and a recombinant fiber gene.

In February of 1996 a human adenovirus (formerly known as Ad-Cor-96-487) was isolated from the stool of an AIDS patient who presented with severe chronic diarrhea. To characterize this apparently novel pathogen of potential public health significance, the complete genome of this adenovirus was sequenced to elucidate its origin. Bioinformatic and phylogenetic analyses of this genome demonstrate that this virus, heretofore referred to as HAdV-D58, contains a novel hexon gene as well as a recombinant fiber gene. In addition, serological analysis demonstrated that HAdV-D58 has a different neutralization profile than all previously characterized HAdVs. Bootscan analysis of the HAdV-D58 fiber gene strongly suggests one recombination event.

Discrepancies in viral gastroenteritis diagnosis: an unusual dual reovirus-adenovirus infection case.

BACKGROUND: A variable rate of false-positive results may be observed with commercial assays for the detection of rotavirus and adenovirus antigen in stool specimens, depending on the quality of the reagents and the presence of potentially interfering substances in stool samples. OBJECTIVE: The present report analyse the discrepant results that could be obtained by the commercially available diagnostic tests and that can mask the reliable viral diagnosis. STUDY DESIGN: One fecal sample was collected from a hospitalized child aged 6 months with acute watery diarrhea and dehydration. The fecal specimen was processed the same day for the rotavirus and adenovirus antigen detection. RESULTS: The sample was positive for rotavirus antigen by one-step membrane test based on immunochromatographic assays (ICA) and enzyme immunoassays (EIA) monoclonal test but it was negative by an EIA polyclonal test, polyacrylamide gel electrophoresis (PAGE) and RT-PCR assays. In the other hand, the sample was positive for adenovirus antigen by ICA and EIA adenovirus type 40/41. Finally, the sample showed by PAGE an electrophoretic profile resembled that of reovirus. CONCLUSION: The use of a wide repertory of diagnosis tests allowed to reach an unusual reovirus-adenovirus type 40/41 dual infection. This case also point out the potential participation of reovirus in the ethiology of the diarrhea illness.

Molecular diversity of partial-length genomic segment 2 of human picobirnavirus.

OBJECTIVES: This study was carried out in order to evaluate the efficacy of the recently developed picobirnavirus (PBV) sets of primers and to establish the phylogenetic relationships of Argentine strains with PBV strains isolated in China and the USA. METHODS: Thirteen fecal specimens tested as positive for PBV by polyacrylamide gel electrophoresis were analyzed by reverse transcription-polymerase chain reaction assays using primers target to the genomic segments 2 of PBV strains isolated in China and the USA. The amplicons were sequenced and analyzed. RESULTS: Primers derived from the China strain produced amplicons in only 4 of the 13 specimens (30.76%). No sample was revealed as positive with the primers derived from the US strain. DNA sequencing of polymerase chain reaction products differed in nucleic acid and amino acid sequences by 13.9-42.28% and 18.1-51.1%, respectively. Despite this strain diversity, three domains of conserved nucleotide sequences as well as the amino acid motif D-S-D typical of RNA-dependent RNA polymerase gene of double-strand RNA viruses were identified. Comparatively, these conserved regions were also identified in homologous PBV strains from the USA and China. Phylogenetic analysis showed no time or geographic clustering. CONCLUSIONS: These findings provide evidence that PBV may represent an emerging heterogeneous group of viruses.

Twenty year study of the occurrence of reovirus infection in hospitalized children with acute gastroenteritis in Argentina.

We studied the occurrence of reovirus infection in children hospitalized with acute gastroenteritis in Argentina during a 20-year interval (1981 through 2001). Three of 2854 (0.10%) stools were positive for reovirus but negative for adenovirus, astrovirus and rotavirus. Children infected with reovirus were <1 year old; one had meningoencephalitis in addition to gastroenteritis. This study indicates that reovirus is an uncommon cause of childhood gastroenteritis requires medical assistance.

[Human herpesvirus-6 circulation in healthy adults and oncologic patients]. / Circulación del virus Herpes 6 humano en adultos normales y en pacientes oncológicos.

The aim of this paper was to assess the prevalence of antibodies to HHV-6 in the general population and study the virus circulation among individuals with cancer, in order to analyze HHV-6 involvement in lymphoproliferative disorders. A total of 200 sera from the general population and 67 from patients with neoplasia were studied. The latter were divided in 3 groups: lymphoma/myeloma, leukemia and non-immune solid tumors. HHV-6 antibodies (IgG and IgM) were assayed by IFA and viral genomes were detected using nested PCR. The prevalence of the infection in the healthy population was 63.5% with a titer geometric mean (TGM) of 48.67 +/- 1.23. A control group was obtained by systematic sampling of the healthy population. Among the patients with neoplasia, the prevalence was 95.5%. In the lymphoma/myeloma group, TGM was 268.73 +/- 1.62; in the leukemia group it was 151.1 +/- 1.88 and in the non-immunogenic solid tumors group it was 95.67 +/- 1.57. Statistically significant differences were observed (p < 0.01) between the control group and the lymphoma/myeloma and leukemia groups. Serum IgM or free viral genomes were not detected in any serum sample. The antibody prevalence found in the general population documents the high circulation of this lymphotropic virus which could indirectly contribute to the pathogenesis of the lymphoproliferative disorder.

Circulacion del virus Herpes 6 humano en adultos normales y en pacientes / Human herpesvirus-6 circulation in healthy adults and oncologic patients

The aim of this paper was to assess the prevalence of antibodies to HHV-6 in the general population and study the virus circulation among individuals with cancer, in order to analyze HHV-6 involvement in lymphoproliferative disorders. A total of 200 sera from the general population and 67 from patients with neoplasia were studied. The latter were divided in 3 groups: lymphoma/myeloma, leukemia and non-immune solid tumors. HHV-6 antibodies (IgG and IgM) were assayed by IFA and viral genomes were detected using nested PCR. The prevalence of the infection in the healthy population was 63.5 percent with a titer geometric mean (TGM) of 48.67 +/- 1.23. A control group was obtained by systematic sampling of the healthy population. Among the patients with neoplasia, the prevalence was 95.5 percent. In the lymphoma/myeloma group, TGM was 268.73 +/- 1.62; in the leukemia group it was 151.1 +/- 1.88 and in the non-immunogenic solid tumors group it was 95.67 +/- 1.57. Statistically significant differences were observed (p < 0.01) between the control group and the lymphoma/myeloma and leukemia groups. Serum IgM or free viral genomes were not detected in any serum sample. The antibody prevalence found in the general population documents the high circulation of this lymphotropic virus which could indirectly contribute to the pathogenesis of the lymphoproliferative disorder.

Circulación del virus Herpes 6 humano en adultos normales y en pacientes oncológicos. / [Human herpesvirus-6 circulation in healthy adults and oncologic patients]

The aim of this paper was to assess the prevalence of antibodies to HHV-6 in the general population and study the virus circulation among individuals with cancer, in order to analyze HHV-6 involvement in lymphoproliferative disorders. A total of 200 sera from the general population and 67 from patients with neoplasia were studied. The latter were divided in 3 groups: lymphoma/myeloma, leukemia and non-immune solid tumors. HHV-6 antibodies (IgG and IgM) were assayed by IFA and viral genomes were detected using nested PCR. The prevalence of the infection in the healthy population was 63.5

with a titer geometric mean (TGM) of 48.67 +/- 1.23. A control group was obtained by systematic sampling of the healthy population. Among the patients with neoplasia, the prevalence was 95.5

. In the lymphoma/myeloma group, TGM was 268.73 +/- 1.62; in the leukemia group it was 151.1 +/- 1.88 and in the non-immunogenic solid tumors group it was 95.67 +/- 1.57. Statistically significant differences were observed (p < 0.01) between the control group and the lymphoma/myeloma and leukemia groups. Serum IgM or free viral genomes were not detected in any serum sample. The antibody prevalence found in the general population documents the high circulation of this lymphotropic virus which could indirectly contribute to the pathogenesis of the lymphoproliferative disorder.

Circulacion del virus Herpes 6 humano en adultos normales y en pacientes / Human herpesvirus-6 circulation in healthy adults and oncologic patients

The aim of this paper was to assess the prevalence of antibodies to HHV-6 in the general population and study the virus circulation among individuals with cancer, in order to analyze HHV-6 involvement in lymphoproliferative disorders. A total of 200 sera from the general population and 67 from patients with neoplasia were studied. The latter were divided in 3 groups: lymphoma/myeloma, leukemia and non-immune solid tumors. HHV-6 antibodies (IgG and IgM) were assayed by IFA and viral genomes were detected using nested PCR. The prevalence of the infection in the healthy population was 63.5 percent with a titer geometric mean (TGM) of 48.67 +/- 1.23. A control group was obtained by systematic sampling of the healthy population. Among the patients with neoplasia, the prevalence was 95.5 percent. In the lymphoma/myeloma group, TGM was 268.73 +/- 1.62; in the leukemia group it was 151.1 +/- 1.88 and in the non-immunogenic solid tumors group it was 95.67 +/- 1.57. Statistically significant differences were observed (p < 0.01) between the control group and the lymphoma/myeloma and leukemia groups. Serum IgM or free viral genomes were not detected in any serum sample. The antibody prevalence found in the general population documents the high circulation of this lymphotropic virus which could indirectly contribute to the pathogenesis of the lymphoproliferative disorder.(AU)

Agentes virales asociados al sindrome diarreico en pacientes trasplantados renales / Viral agents related to diarrheic syndrome in kidney transplanted patiens

El objetivo del presente estudio fue documentar la frequencia de agentes virales clásicos y emergentes y su asociación etiológica con el síndrome diarreico en pacientes transplantados renales en Córdoba, Argentina. Se estudiaron 42 muestras fecales de individuos transplantados renales, internados y ambulatórios, con o sin diarrea, todas obtenidas después del transplante. Los pacientes se encontraban bajo triple terapia inmunosupresora con esteroides, azatioprina y ciclosporina ó tacrolimus. Los resultados obtenidos revelaron la presencia de ratovirus grupo A y picobirnavirus en tres de nueve pacientes con síndrome diarreico severo (33.33 porciento), en ausencia de otros patógenos bacterianos entéricos. La presencia de estos agentes virales se correlacionó con niveles elevados de ciclosporina en sangue (> 290 ng/ml) o bien con un tratamiento inmunosupresor prolongado. En contraste, no se detectó ningún virus en la etiología de cuadros diarreicos severos en pacientes transplantados renales.

Agentes virales asociados al sindrome diarreico en pacientes trasplantados renales / Viral agents related to diarrheic syndrome in kidney transplanted patiens

El objetivo del presente estudio fue documentar la frequencia de agentes virales clásicos y emergentes y su asociación etiológica con el síndrome diarreico en pacientes transplantados renales en Córdoba, Argentina. Se estudiaron 42 muestras fecales de individuos transplantados renales, internados y ambulatórios, con o sin diarrea, todas obtenidas después del transplante. Los pacientes se encontraban bajo triple terapia inmunosupresora con esteroides, azatioprina y ciclosporina ó tacrolimus. Los resultados obtenidos revelaron la presencia de ratovirus grupo A y picobirnavirus en tres de nueve pacientes con síndrome diarreico severo (33.33 porciento), en ausencia de otros patógenos bacterianos entéricos. La presencia de estos agentes virales se correlacionó con niveles elevados de ciclosporina en sangue (> 290 ng/ml) o bien con un tratamiento inmunosupresor prolongado. En contraste, no se detectó ningún virus en la etiología de cuadros diarreicos severos en pacientes transplantados renales. (AU)

Detección del virus papiloma humano en lesiones cancerosas orales en la ciudad de Córdoba / Human papillomavirus detection in oral cancer lesions in the city of Córdoba

El cáncer oral es un proceso que involucra diferentes factores etiológicos y mecanismos, a luz de los conceptos actuales de cocarcinogénesis. Existen evidencias histológicas y de hibridación que sugieren la participación del virus papiloma humano (HPV) en la carcinogénesis oral. La Cátedra de Anatomía Patológica de la Facultad de Odontología de la Universidad Nacional de Córdoba recibe aproximadamente el 20 por ciento de los pacientes con lesiones cancerosas orales en esta ciudad. En el período comprendido entre los años 1992-1997 fueron examinadas 1950 biopsias, 4,77 por ciento (93/1950) de ellas fueron diagnosticadas como neoplasias malignas, de éstas el 79,57 por ciento (74/93) fueron carcinomas. Treinta y tres carcinomas orales (44,6 por ciento; 33/74) fueron seleccionados al azar e incluí dos en el estudio. Se incluyeron 33 extendidos celulares de pacientes con mucosa oral normal. Los materiales fueron estudiados por microscopia óptica y por la técnica de hibridación "in situ" para la detección del DNA de HPV. Los datos fueron analizados mediante el test de chi cuadrado. La prevalencia de HPV entre las 33 muestras casos estudiada fue 27,27 por ciento, 9/33 fueron positivos para HPV en condiciones no estrictas. Un material fue positivo en condiciones estrictas para HPV 16, un carcinoma verrugoso. En las muestras de mucosa oral normal no se detectó HPV. Entre los HPV positivos, 3/9 (33,33 por ciento) fueron carcinomas espinocelulares y 5/9 (55,56 por ciento) carcinomas verrugosos. Uno fue un melanoma. El carcinoma verrugoso fue la neoplasia asociada con más frecuencia a la infección por HPV (x2=20,5; con un nivel de confianza del 95 por ciento); lo que podría sugerir un mayor papel del HPV en la patogénesis del carcinoma verrugoso. La presencia viral encontrada en lesiones cancerosas refuerza la naturaleza multicausal del cáncer oral. El HPV es una circunstancia que incrementa la probabilidad de malignidad, y que cuando se reduce, disminuye la frecuencia de cáncer.

Detección del virus papiloma humano en lesiones cancerosas orales en la ciudad de Córdoba / Human papillomavirus detection in oral cancer lesions in the city of Córdoba

El cáncer oral es un proceso que involucra diferentes factores etiológicos y mecanismos, a luz de los conceptos actuales de cocarcinogénesis. Existen evidencias histológicas y de hibridación que sugieren la participación del virus papiloma humano (HPV) en la carcinogénesis oral. La Cátedra de Anatomía Patológica de la Facultad de Odontología de la Universidad Nacional de Córdoba recibe aproximadamente el 20 por ciento de los pacientes con lesiones cancerosas orales en esta ciudad. En el período comprendido entre los años 1992-1997 fueron examinadas 1950 biopsias, 4,77 por ciento (93/1950) de ellas fueron diagnosticadas como neoplasias malignas, de éstas el 79,57 por ciento (74/93) fueron carcinomas. Treinta y tres carcinomas orales (44,6 por ciento; 33/74) fueron seleccionados al azar e incluí dos en el estudio. Se incluyeron 33 extendidos celulares de pacientes con mucosa oral normal. Los materiales fueron estudiados por microscopia óptica y por la técnica de hibridación "in situ" para la detección del DNA de HPV. Los datos fueron analizados mediante el test de chi cuadrado. La prevalencia de HPV entre las 33 muestras casos estudiada fue 27,27 por ciento, 9/33 fueron positivos para HPV en condiciones no estrictas. Un material fue positivo en condiciones estrictas para HPV 16, un carcinoma verrugoso. En las muestras de mucosa oral normal no se detectó HPV. Entre los HPV positivos, 3/9 (33,33 por ciento) fueron carcinomas espinocelulares y 5/9 (55,56 por ciento) carcinomas verrugosos. Uno fue un melanoma. El carcinoma verrugoso fue la neoplasia asociada con más frecuencia a la infección por HPV (x2=20,5; con un nivel de confianza del 95 por ciento); lo que podría sugerir un mayor papel del HPV en la patogénesis del carcinoma verrugoso. La presencia viral encontrada en lesiones cancerosas refuerza la naturaleza multicausal del cáncer oral. El HPV es una circunstancia que incrementa la probabilidad de malignidad, y que cuando se reduce, disminuye la frecuencia de cáncer. (AU)