Genetic and antigenic evolution profiles of G1 rotaviruses in córdoba, Argentina, during a 27-year period (1980-2006).

Rotavirus G1 strains represent the most common genotype that causes diarrhea in humans and has been incorporated into both, monovalent and multivalent, rotavirus licensed vaccines. The aim of this study was to determine the evolution profile of G1 rotaviruses in Córdoba, Argentina, over a 27-year period (1980-2006). Intragenotype diversity, represented by lineages within rotavirus circulating strains, was observed. Phylogenetic analysis of the VP7-gene of G1 rotavirus clinical strains showed the circulation of G1 lineage IV and V strains in the 1980s, and co-circulation of lineage I and II strains in the 1990s and 2000-2006. The distribution of G1 in lineages could be linked to multiple nucleotide substitutions distributed across lineages that did not correlate with the emergence of G1 antigenic variants. Moreover, temporal lineage distribution was not linked to significant changes in G1 prevalence. Therefore, the continuous and dominant circulation of G1 over time could not be related to the emergence of antigenic variants in the community. Continuous rotavirus surveillance is necessary to understand rotavirus evolution and to measure how genetic and antigenic changes might affect the effectiveness of vaccines in the future.

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.

[Evaluation of surface water quality in recreational areas, an integrative proposal of chemical and microbiological markers]. / Evaluación de la calidad de aguas superficiales en espacios recreacionales , una propuesta integradora de marcadores químicos y microbiológicos.

Climate change affects the interactions between water systems, ecosystems, and the atmosphere. It also increases the risk of the presence of microorganisms which affect the systems that use these resources. The impact of the population on the water resources has become more evident in recent years, highlighting the close relationship between the levels of inorganic components and microbiological contamination of water and community health. The characterization of the variables that account for water pollution is a complex process. In this paper, it is proposed to quantified nitrites and phosphorous as chemical markers and fecal coliforms, genomic human adenovirus and/or picobirnavirus and infectious human enterovirus detection as microbiological markers for the prevention of water-borne infections in individuals exposed to superficial aqueous matrices by recreational activities.

El cambio climático afecta a las interacciones entre los sistemas hídricos, los ecosistemas y la atmósfera. También aumenta el riesgo de la presencia de microorganismos que afectan a los sistemas que utilizan estos recursos. El impacto de la población sobre los recursos hídricos se ha hecho más evidente en los últimos años, destacando la estrecha relación entre los niveles de componentes inorgánicos así como la contaminación microbiológica del agua y la salud de la comunidad. La caracterización de las variables que dan cuenta de la contaminación del agua es un proceso complejo. En este trabajo se propone la cuantificación de nitritos y fósforo como marcadores químicos y la detección de coliformes fecales, adenovirus humanos genómicos y/o picobirnavirus y enterovirus humanos infecciosos como marcadores microbiológicos para la prevención de infecciones de origen hídrico en individuos expuestos a matrices acuosas superficiales por actividades recreativas.

IgG subclasses and DNA detection of HHV-6 and HHV-7 in healthy individuals.

Human herpesvirus 6 (HHV-6) and 7 (HHV-7) are common opportunistic agents in immunocompromised hosts, although infection with HHV-6 and HHV-7 can also be observed in immunocompetent hosts. Despite similar biology and epidemiology, this study evaluated differences in the IgG subclass distribution associated with HHV-6 and HHV-7 in seropositive, healthy persons. The identified subclasses were also compared with the detection of HHV-6 and HHV-7 DNA. For these assays, sera, plasma, and saliva samples were obtained from 40 healthy blood donors in Argentina who were seropositive for both HHV-6 and HHV-7. HHV-6 and HHV-7 DNA were detected in saliva and plasma samples using nested PCR, and specific IgG subclasses were determined using immunofluorescent assays of sera samples. HHV-7 DNA was detected in 90% of all plasma samples and in 100% of saliva samples. In contrast, HHV-6 DNA was not detected in any of the plasma samples, and it was detected in only 6 of 40 saliva samples. Determination of IgG subclass distributions showed that HHV-6 was restricted to IgG1, whereas HHV-7 IgG subclasses included two groups, one restricted only to IgG1 and the other to IgG1 and IgG3. These results demonstrate the differences between HHV-6 and HHV-7 DNA range detection in saliva and plasma samples, as well as the IgG subclass patterns for each virus type, in healthy persons in Argentina.

HHV-6 IgG4 isotype response following measles infection.

Human herpesvirus 6 (HHV-6) is widespread in the human population by infecting most individuals in early childhood. After primary infection, HHV-6 establishes a latent infection by remaining in circulating mononuclear cells of healthy individuals. The HHV-6 antibody titer increases after primary infection with measles virus. The present study was undertaken to determine the specific antiviral IgG1, IgG2, IgG3, and IgG4 subclass response patterns to HHV-6 in HHV-6-seropositive individuals with natural measles virus infection, measles vaccination, and rubella virus infection. The purpose of this study was to examine HHV-6-specific IgG isotype response in patients with acute virus coinfection. Serum samples were obtained from individuals who were seropositive for HHV-6 after natural primary infection with measles virus during an outbreak, measles vaccination, or rubella virus infection, and from healthy individuals. Sera were examined by indirect immunofluorescence assays for detection of HHV-6-specific IgG1, IgG2, IgG3, and IgG4 antibodies. A high percentage (69%) of those infected with measles virus had an HHV-6 IgG1 and IgG4 response (P < 0.001, chi(2) test), whereas persons vaccinated against measles, those infected with rubella, and healthy individuals showed an HHV-6 IgG1 response. These results demonstrate that natural measles virus infection induces an HHV-6 IgG isotype response, which suggests a shift in immune activity from a Th1 to a Th2 response. J. Med. Virol. 82:396-399, 2010. (c) 2010 Wiley-Liss, Inc.

A novel human adenovirus hexon protein of species D found in an AIDS patient.

To date, human adenoviruses are classified into 53 types (types 1-51 and types 53 and 54), which have been grouped into six species named A through F, and the recently identified type 52 has been proposed as member of a new species, G. Type classification is based on type-specific epitopes within loop 1 (L1) and loop 2 (L2) of the hexon protein, which contain seven hypervariable regions that are responsible for type specificity. In this paper, we present the characterization of an adenovirus strain isolated from a male AIDS patient in Cordoba, Argentina. This strain was found to be a member of species D by genomic Sma I restriction analysis. Sequencing of the L1 and L2 regions of the hexon gene and immunological characterization by virus neutralization revealed this hexon to be unique and distinct from the previously identified hexons of types within species D. A seroepidemiologic study in the human population of Cordoba showed that this strain was not endemic in the local human population.

Detection of human herpesvirus 6 (HHV-6) and human herpesvirus 7 (HHV-7) DNA in endocervical samples from a positive and negative HPV woman of Córdoba, Argentina.

AIMS: The purpose of the present study was to elucidate the presence of human herpesvirus 6A (HHV-6A), HHV-6B and HHV-7 in samples of the uterine cervix through detection of viral DNA. We analysed normal tissues, samples with low-grade squamous intraepithelial lesions (LSILs) and high-grade squamous intraepithelial lesions (HSILs). We correlated the presence of HHV-6 and HHV-7 with the finding of human papillomavirus (HPV) in mucosal samples. METHODS: Cervical samples were examined and grouped as follows: group 1 (n=29), normal cytology; group 2 (n=61), samples with LSIL; group 3 (n=35), samples with HSIL. Molecular biology examinations were performed in all samples to detect HHV-6, HHV-7 and HPV DNA and to typify HHV-6 species. RESULTS: Group 1: normal cytology and HPV (-): HHV-6: 6.8% (2/29), HHV-7: 79.3% (23/29); group 2: LSIL and HPV (-): HHV-6: 93.1% (27/29), HHV-7: 96.5% (28/29); LSIL and HPV (+): HHV-6: 0% (0/32), HHV-7: 90.6% (29/32); group 3: HSIL and HPV (-): HHV-6: 20% (2/10), HHV-7: 70% (7/10); HSIL HPV (+): HHV-6: 12% (3/25), HHV-7: 68% (17/25). HHV-6A DNA was not detected in any samples. CONCLUSIONS: (1) Both HHV-6 and HHV-7 infect the mucosal cells of the cervix with higher prevalence of HHV-7. (2) The higher prevalence of HHV-6 in LSIL HPV (-) samples compared with those with normal cytology indicates that it constitutes a possible risk factor for atypia production. (3) The presence of HHV-7 in all samples questions its role in the production of atypia. (4) The finding of HHV-6 and HHV-7 suggests that the cervical mucosa is a possible transmission pathway for these viruses.

Age-Related Patterns of DNA Detection and Specific IgG Subclasses in Healthy HHV-6- and HHV-7-Infected Individuals.

Human herpesvirus 6A (HHV-6A), Human herpesvirus 6B (HHV-6B), and Human herpesvirus 7 (HHV-7) can persist by establishing a lifelong infection which could have implications on the immunocompetent host. The aim of this work is to contribute with some knowledge about the HHV-6 A/B and HHV-7 infection in healthy individuals. We have carried out a longitudinal study in seropositive healthy individuals for the detection of viral DNA in saliva and plasma samples, and for determining a specific IgG isotype immune response, which enabled the performance of these viruses to be observed over time. Furthermore, an elderly population was transversely studied to provide data of the activity of these viruses in the older population. In the longitudinal study, HHV-6 DNA was occasionally detected and an isotype immune response with a specific IgG1 profile, while in the older group HHV-6 DNA was frequently detected and an isotype immune response with specific IgG1, IgG3, and IgG4. HHV-7 DNA was frequently detected in both groups and isotype patterns of specific IgG1, IgG3, and IgG4. The results of this study highlight that the long-lasting relationship in healthy HHV-6 A/B-infected individuals have the imprint of age groups.

Searching variables to assess recreational water quality: the presence of infectious human enterovirus and its correlation with the main variables of water pollution by multivariate statistical approach in Córdoba, Argentina.

Surface waters are used by local populations for different purposes, such as recreational activities, water source for human and animal consumption, and irrigation among others, which lead to the need for management strategies on water health and associated risks. During this study, we investigated physicochemical parameters, fecal coliform bacteria, and infectious human enterovirus detection to determine the water quality in different beaches (categorized as an urban area, non-urban areas, and an intermediate position) from San Roque Dam, in Argentina. Multivariate techniques were applied. Principal component analysis allowed identification of subgroup of variables responsible for the water quality. A cluster analysis and multivariate analysis of variance showed the urban beach as the highest pollution area. The following variables (measured at the urban beach) would be enough to describe the quality of the aquatic body: nitrites, fecal coliforms, total phosphorous, and infectious human enterovirus. The infectious human enterovirus was an independent variable detected in 69.1% of the samples showing a steady frequency of detection during the whole period studied and could identify human fecal contaminations as a source of water pollution. The selected variables would contribute to water quality regarding the risk for human health using San Roque dam waters for recreational propose.

Loss of maternally-derived human herpesvirus-7 immunity and natural infection in Argentinian infants.

BACKGROUND: Human herpes virus-7 (HHV-7) infection is widespread throughout the world. No data are available in Argentina about loss of maternally-derived HHV-7 immunity and natural infection. OBJECTIVES: The objective of this study was to characterize the time when children lose maternal antibodies and become susceptible to natural infection. METHODS: Sera from 39 pregnant women and 207 infants between 2 and 29 months of age were tested. Determination of IgG antibodies was made by indirect immunofluorescence. RESULTS: The seropositive ratio fell in the 2-4 month group (15% seropositive) and increased between 5 months (47% seropositive) and 23 months (67%). Geometric mean titers (GMT) of the infants aged 2-4 months (GMT = 60) were statistically different (p < 0.0001, Student's t-test) to those from the group of pregnant women (GMT = 83) and those from the other infant groups (p < 0.001, least significant difference (LSD) test). The GMT of the groups between 5 and 23 months did not show significant differences whereas those of infants between 24 and 29 months (GMT = 179, 79% seropositive) were different from all the groups studied (p < 0.0001, LSD test). CONCLUSIONS: This study shows a significant association between the loss of passive HHV-7 antibody and age. HHV-7 enters the susceptible population at 5 months, leading to the high prevalence of antibodies between 24 and 29 months of age. This study also shows that natural infection by HHV-7 in children during their first years of life follows the infection pattern found in developing countries.

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.

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.

Isotype immune response of IgG antibodies at the persistence and reactivation stages of human herpes virus 6 infection.

BACKGROUND: Infections with human herpes virus 6 (HHV-6) are very common. After primary infection, the virus remains latent and persists at low level in cells and tissues. Not usually associated with disease in the immunocompetent host, HHV-6 infection is a major cause of opportunistic viral infections in the immunosuppressed. The different stages of HHV-6 infection are difficult to characterize in the laboratory. OBJECTIVES: The aim of this paper was to assess the isotype patterns of IgG antibodies against HHV-6 in seropositive subjects during different stages of the virus activity. STUDY DESIGN: From a total of 190 human serum samples from 43 healthy children, 24 pregnant women and 24 patients with bone marrow transplants, 111 sera were processed by indirect immunofluorescence assay for the detection of IgG1, IgG2, IgG3 and IgG4 specific antibodies. The mean geometrical title (MGT) of the antibodies was calculated. RESULTS: All pregnant women had IgG1 (24/24; 100%; MGT 46). A 95% (41/43) of healthy infants had IgG1 (MGT 57). In bone marrow transplants, 58% (14/24) of the patients showed seroconversion (MGT 529) with an isotype response of IgG1 and IgG4 during the observation period. Remaining bone marrow transplant patients, who had the IgG without any variations (MGT 184), had isotype IgG1. CONCLUSIONS: These results revealed two different immune isotype response patterns. One of them is restrictive to IgG1 in the latent phase of HHV-6 infection in healthy children, pregnant women and transplant patients with stable levels of antibodies whereas IgG1 and IgG4 are detected in the reactivation of HHV-6 in transplant patients. The IgG isotype immune responses may contribute to the existing set of serological markers in characterizing the different stages of natural infection of HHV-6.

[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.

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.

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.

Infecciones asintomáticas por Chlamydia trachomatis: un problema controlable en la población adolescente / Asymptomatic Chlamydia trachomatis infection in adolescent population: a manageable problem

La detección precoz de la infección por Chlamydia trachomatis (CT) asintomática (70-75%) reduce la incidencia de complicaciones, sobre todo las relacionadas a la infertilidad y esterilidad en ambos sexos siendo relevante en las mujeres. Objetivos: Conocer la prevalencia de CT en la población asintomática de jóvenes y adolescente (JA) de la ciudad de Córdoba (Argentina); evaluar los factores de riesgo y proponer un programa de detección adecuado a nuestro medio. Métodos: Se estudiaron, entre enero de 2004 y enero de 2006, 427 JA de ambos sexos entre 18 y 24 años (221 estudiantes universitarios (GU) y 206 adolescentes no universitarios (GNU) con nivel socio económico bajo). Se realizó PCR en orina con dos técnicas: plásmido y proteína de la membrana externa de CT; cultivo en líneas celulares para las muestras positivas; y tratamiento de los individuos positivos y control posterior. Resultados: La prevalencia global fue 8,7% (37/427) siendo mayor en las mujeres (13,7% vs. 4,1%; p = 0.0004), en el GNU (13.1 vs. 4.5%; p = 0.001) y en aquellos con las necesidades básicas (NB) insatisfechas (14.8% vs. 6.1%; p = 0.0006). No hubo diferencias significativas (DS) con respecto al comportamiento sexual y al uso de diferentes métodos anticonceptivos. Los antecedentes previos de exudado vaginal o uretral y adenomegalias inguinales tuvieron un elevado valor predictivo negativo (93,01% y 94,2%, respectivamente). Conclusiones: Es recomendable efectuar tamizaje de jóvenes en diferentes escenarios con técnicas sensibles. Los programas basados en los factores de riesgo son inadecuados en nuestro medio. La información y la educación general y sexual deben ser consideradas herramientas imprescindibles para controlar esta infección.

Análise de una propuesta para el cambio de paradgma educacional en bacteriologia y virología médicas, Facultad de Ciencias Médicas, Universidad Nacional de Córdoba / Analysis of a proposal for the change of the educational paradgm in bacteriology and virology, Facultad de Ciencias Médicas, Universidad Nacional de Córdoba

El carácter del pensamiento científico señala un camino metodológico que incluye la exigencia del trabajo del estudiante sobre la información, y no su mera recepción y reproducción. Es imprescindible otorgar a los estudiantes la oportunidad de descubrir los procesos cognitivos utilizados en la producción del conocimiento científico. En este trabajo se presenta el resultado de la puesta en marcha de una dinámica de taller en una asignatura básica, la respuesta de los alumnos, y el análisis de la misma. En la Cátedra de Bacteriología y Virología Médicas de la Facultad de Ciencias Médicas de la Universidad Nacional de Córdoba, cursaron durante el año 1997 un total de 1700 alumnos. La asignatura se desarrolló con dos actividades que trabajaron los mismos contenidos desde dos concepciones diferentes de aprendizaje: (I) actividad de taller, no obligatoria, constructiva, y (II) actividad teórico-práctica, obligatoria y transmisiva. Se realizaron dos encuestas de opinión voluntarias y anónimas respecto a la valoración que otorgó el educando a estas dos actividades y sus fundamentos, una en la mitad y la otra al final del ciclo. El 90,55 por ciento calificó la actividad tradicional como positiva, y el 9,45 por ciento como negativa. Respecto a la actividad de taller el 60,5 por ciento la calificó como positiva y el 39,5 por ciento como negativa. El mismo contenido desarrollado con dos actividades hizo posible el análisis del impacto que dos metodologías diferentes produjeron en los alumnos. La respuesta de los alumnos a la actividad tradicional fue mejor que la observada a la actividad de taller (p <0.001). Las diferencias en la aceptación por parte de los alumnos entre las dos propuestas revelaron la mayor dificultad de una estrategia metodológica alternativa en el modelo educacional actual

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.