Updating the knowledge of hepatitis E: new variants and higher prevalence of anti-HEV in Argentina.

INTRODUCTION: Hepatitis E is a disease of global distribution, with significant morbidity and mortality, whose scope and burden continue to emerge in low endemic countries. MATERIAL AND METHODS: In 2012, we studied the prevalence of anti-HEV antibodies in 202 adult serum samples. We also analyzed samples from 143 patients with acute non-A-C hepatitis from January 2011 to December 2013. Acute HEV infections were diagnosed with anti-HEV IgM and/or HEV RNA. HEV RNA was also investigated in 94 swine fecal samples. HEV RNA was sequenced and characterized. RESULTS: We found higher values of prevalence than those previously reported in the 1990s. The overall prevalence of anti-HEV IgG antibodies was 15.4%. The prevalence was 10.6% in the 123 adults voluntarily screened on World Hepatitis Day 2012 in Buenos Aires city and 14.8, 16.7 and 35.7% respectively in the smaller groups of healthcare workers, blood donors and HIV-positive patients from different regions of the country. Nine acute HEV infections were diagnosed in the three years analyzed. We characterized new human variants of subgenotype 3a and 3i. New subgenotype 3i variants were found in swine from two distant provinces closely related to the human ones. CONCLUSIONS: These results enlarge the knowledge of HEV and contribute with new information. However, higher values of prevalence found in small groups need to be confirmed in larger studies. Many aspects of the spectrum of the disease and the reservoirs and routes of transmission are still unknown and thus deserve additional research.

Molecular surveillance of hepatitis A virus in Argentina: first subgenotype IB detected in a traveler.

By using molecular surveillance of hepatitis A virus, we characterized for the first time a subgenotype IB imported case in Argentina, a country with universal vaccination since 2005. The case was a crew member of a cruise ship. We consider this a case alert because of its multiple implications.

Infection by Brazilian and Dutch swine hepatitis E virus strains induces haematological changes in Macaca fascicularis.

BACKGROUND: Hepatitis E virus (HEV) has been described as an emerging pathogen in Brazil and seems to be widely disseminated among swine herds. An autochthonous human case of acute hepatitis E was recently reported. To obtain a better understanding of the phenotypic profiles of both human and swine HEV strains, a experimental study was conducted using the animal model, Macaca fascicularis. METHODS: Six cynomolgus monkeys (Macaca fascicularis) were inoculated intravenously with swine HEV genotype 3 that was isolated from naturally and experimentally infected pigs in Brazil and the Netherlands. Two other monkeys were inoculated with HEV genotype 3 that was recovered from Brazilian and Argentinean patients with locally acquired acute and fulminant hepatitis E. The haematological, biochemical, and virological parameters of all animals were monitored for 67 days. RESULTS: Subclinical hepatitis was observed in all monkeys after inoculation with HEV genotype 3 that was recovered from the infected swine and human patients. HEV RNA was detected in the serum and/or faeces of 6 out of the 8 cynomolgus monkeys between 5 and 53 days after inoculation. The mild inflammation of liver tissues and elevations of discrete liver enzymes were observed. Seroconversions to anti-HEV IgM and/or IgG were detected in 7 animals. Reactivities to anti-HEV IgA were also detected in the salivary samples of 3 animals. Interestingly, all of the infected monkeys showed severe lymphopenia and a trend toward monocytosis, which coincided with elevations in alanine aminotransferase and antibody titres. CONCLUSIONS: The ability of HEV to cross the species barrier was confirmed for both the swine (Brazilian and Dutch) and human (Argentinean) strains, thus reinforcing the zoonotic risk of hepatitis E in South America. Cynomolgus monkeys that were infected with HEV genotype 3 developed subclinical hepatitis that was associated with haematological changes. Haematological approaches should be considered in future studies of HEV infection.

Clinical implications of hepatitis A virus ribonucleic acid detection and genotyping in acute liver failure in children in Argentina.

OBJECTIVES: To investigate the detection of hepatitis A virus ribonucleic acid in patients with acute liver failure and to assess if the results have any clinical implications for the evolution of acute liver failure in children. Hepatitis A infection, a vaccine-preventable disease, is an important cause of acute liver failure in children in Argentina. Universal vaccination in 1-yr-old children was implemented in June 2005. DESIGN: Observational study in which patients were divided into Group 1 consisting of positive hepatitis A virus ribonucleic acid and Group 2 consisting of negative hepatitis A virus ribonucleic acid. SETTING: Pediatric intensive care unit in National Pediatric Hospital "Dr. J. P. Garrahan," Buenos Aires, Argentina. PATIENTS: Thirty-three patients with the diagnosis of acute liver failure secondary to hepatitis A virus infection and admitted to the Garrahan Pediatric Hospital between September 2003 and September 2005 were enrolled in the study. Twenty of these children were admitted to the pediatric intensive care unit. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Samples for total ribonucleic acid detection and genotyping were obtained from serum and/or stools on admission. We found positive hepatitis A virus ribonucleic acid in 13 patients and negative hepatitis A virus ribonucleic acid in 20 patients. The following clinical variables were evaluated: time of evolution, hospital stay, admission to the pediatric intensive care unit, pediatric intensive care unit stay, time on mechanical ventilation, criteria for orthotopic liver transplantation, and mortality. Characterization of the isolates did not reveal differences related to genotype; all cases were IA. No statistical significance was found as to the variables. However, positive hepatitis A virus ribonucleic acid showed lower percentages of pediatric intensive care unit admissions, criteria for orthotopic liver transplantation, number of orthotopic liver transplantation, and mortality than the group of patients with negative hepatitis A virus ribonucleic acid. CONCLUSIONS: Hepatitis A virus genotyping studies did not show any particularities, all cases were IA and, thus, apparent associations between genotype and the clinical presentation of acute liver failure could not be found.

Molecular characterization of hepatitis A virus isolates from Argentina.

Hepatitis A, a vaccine preventable disease, is now of transitional or intermediate endemicity in Argentina, as the epidemiologic pattern of the disease has shifted with improvements in living conditions in some parts of the country. Increase in the susceptibility of older children and adults has led to increasing disease incidence. Molecular epidemiology has played an important role in the understanding of HAV infection by identifying modes of spreading and by permitting the monitoring of changes in circulating virus brought about by prevention programs. South American isolates characterized are limited. Eighty-two sporadic and outbreak isolates from Argentina were sequenced in the VP1/2A region of HAV genome over a 9-year period. All the isolates belonged to subgenotype IA. All our sequences grouped into two big clusters. Apparently, at least two lineages have been co-circulating in the same place at the same time. Despite great genetic variability, few point amino acid changes could be deduced. Four sequences showed an Arg --> Lys substitution at 1-297 which characterized the genotype IB at the amino acid level. Many isolates carried a conservative amino acid substitution Leu --> Ile at position 42 of the 2A domain, previously described as a possible fingerprint of HAV sequences in Brazil. The other rare changes have been found before, except for a 1-277 Asn --> Ser substitution displayed in two isolates that has not been previously reported. Argentina recently implemented universal vaccination in 1-year-old children. Molecular tools would be useful in an active surveillance program.

Duración de la viremia y la excreción fecal del virus en niños con Hepatitis A / Duration of viremia and fecal shedding of the virus in Hepatitis A infected children

La infección por el virus de hepatitis A (HAV) es endémica en Argentina. El uso de técnicas moleculares permitió extender la detección del RNA del HAV en sueroy heces en pacientes con diferentes presentaciones clínicas. Comparamos la sensibilidad del protocolo de RT-PCR que usamos con cebadores dirigidos a distintas regiones del genoma, resultando la detección de la región VP3 C terminal la más sensible. Se obtuvieron prospectivamente muestras de suero y materia fecal de 20 niños con hepatitis aguda autolimitada por HAV. El RNA del HAV fue detectado en 18/20 niños en muestras basales y en 19/20 sumando una muestra posterior. El RNA del HAV fue detectable en 9/20 acientes hasta 30 días en suero; en materia fecal en 2/20 hasta 60 días y en 1/20 hasta 90 días. La secuencia genómica para la región VP1/2A en 8 muestras demostró que todas pertenecían al subgenotipo IA, aunque eran diferentes entre sí. Solo en 1/11 niños con falla hepatica fulminante fue posible la detección del RNA del HAV utilizando la región VP3 C terminal y el genotipo fue I. La reciente introducción de la vacunación universal en niños de 1 año de edad en Argentina podría disminuir drásticamente la circulación del virus, emergiendo nuevas fuentes de infección y permitiendo la introducción de nuevos genotipos. Las técnicas moleculares aplicadas al estudio de la historia natural de la infección y a la vigilancia epidemiológica contribuyenal control y la toma de decisiones eficientes en políticas de Salud Pública.

Hepatitis A virus (HAV) infection is endemic in Argentina. Molecular tools have allowed HAV RNA detection to be extent to sera and feces from patients with different clinical backgrounds. We compare the sensitivity of the RT-PCR protocol we follow using primers targeting different genomic regions and VP3 C terminal was the most sensitive. Sequential sera and fecal samples were obtained from 20 children with acute self limited Hepatitis A. HAV RNA was detectable in 18/20 children if sera and stool specimens were collected at the onset of symptoms and in 19/20 if a later sample was considered. HAV RNA was detectable in serum from 9/20 patients until day 30 and in feces from 2 patients until day 60 and until day 90 in one. Genomic sequences from VP1/2A region in 8 samples showed they all belong to subgenotype IA although they were different between them. HAV RNA was detectable only in 1/11 sera from children with acute liverfailure when VP3 C terminal fragment was searched and it belonged to genotype I. Universal vaccination in one year old children was recently implemented in Argentinaand it will dramatically enable the decrease of the viral circulation, making new sources of infection emerge and allowing the introduction of new genotypes. The application of molecular tools to the study of the natural history of infection and to the epidemiologicsurveillance may contribute to efficient control and lead to rational decisions in public health policies.

Duración de la viremia y la excreción fecal del virus en niños con Hepatitis A / Duration of viremia and fecal shedding of the virus in Hepatitis A infected children

La infección por el virus de hepatitis A (HAV) es endémica en Argentina. El uso de técnicas moleculares permitió extender la detección del RNA del HAV en sueroy heces en pacientes con diferentes presentaciones clínicas. Comparamos la sensibilidad del protocolo de RT-PCR que usamos con cebadores dirigidos a distintas regiones del genoma, resultando la detección de la región VP3 C terminal la más sensible. Se obtuvieron prospectivamente muestras de suero y materia fecal de 20 niños con hepatitis aguda autolimitada por HAV. El RNA del HAV fue detectado en 18/20 niños en muestras basales y en 19/20 sumando una muestra posterior. El RNA del HAV fue detectable en 9/20 acientes hasta 30 días en suero; en materia fecal en 2/20 hasta 60 días y en 1/20 hasta 90 días. La secuencia genómica para la región VP1/2A en 8 muestras demostró que todas pertenecían al subgenotipo IA, aunque eran diferentes entre sí. Solo en 1/11 niños con falla hepatica fulminante fue posible la detección del RNA del HAV utilizando la región VP3 C terminal y el genotipo fue I. La reciente introducción de la vacunación universal en niños de 1 año de edad en Argentina podría disminuir drásticamente la circulación del virus, emergiendo nuevas fuentes de infección y permitiendo la introducción de nuevos genotipos. Las técnicas moleculares aplicadas al estudio de la historia natural de la infección y a la vigilancia epidemiológica contribuyenal control y la toma de decisiones eficientes en políticas de Salud Pública.(AU)

Hepatitis A virus (HAV) infection is endemic in Argentina. Molecular tools have allowed HAV RNA detection to be extent to sera and feces from patients with different clinical backgrounds. We compare the sensitivity of the RT-PCR protocol we follow using primers targeting different genomic regions and VP3 C terminal was the most sensitive. Sequential sera and fecal samples were obtained from 20 children with acute self limited Hepatitis A. HAV RNA was detectable in 18/20 children if sera and stool specimens were collected at the onset of symptoms and in 19/20 if a later sample was considered. HAV RNA was detectable in serum from 9/20 patients until day 30 and in feces from 2 patients until day 60 and until day 90 in one. Genomic sequences from VP1/2A region in 8 samples showed they all belong to subgenotype IA although they were different between them. HAV RNA was detectable only in 1/11 sera from children with acute liverfailure when VP3 C terminal fragment was searched and it belonged to genotype I. Universal vaccination in one year old children was recently implemented in Argentinaand it will dramatically enable the decrease of the viral circulation, making new sources of infection emerge and allowing the introduction of new genotypes. The application of molecular tools to the study of the natural history of infection and to the epidemiologicsurveillance may contribute to efficient control and lead to rational decisions in public health policies.(AU)

Identification of the first strain of swine hepatitis E virus in South America and prevalence of anti-HEV antibodies in swine in Argentina.

In Argentina, a country considered non-endemic for hepatitis E virus (HEV) infection, serologic evidence of HEV infection has been observed in different human population groups. In other countries, a high degree of genetic relatedness has been observed between human and swine HEV genotype 3 sequences, suggesting zoonosis as one probable route of infection. This is the first identification of swine HEV in South America. HEV RNA was detected and sequenced in the ORF 1 and ORF 2 regions from swine fecal samples from a herd located in Pergamino, in the province of Buenos Aires. These strains all group into genotype 3 and exhibit a close relationship to two novel HEV variants previously identified in Argentina from sporadic acute cases of non-A to -C hepatitis in humans. In addition, using a modified commercial ELISA, the presence of anti-HEV antibodies was surveyed in five provinces across the country and all five showed a prevalence of HEV antibodies, ranging from 4% to 58%. The results suggest that swine could be an important reservoir for virus transmission in Argentina as has been suggested for other non-endemic areas. The Argentine human strains and swine strain described in this article seem to be closely related to a human Austrian strain, suggesting a potential European origin of HEV infection in these cases.

[Duration of viremia and fecal shedding of the virus in hepatitis A infected children]. / Duración de la viremia y lla excreción fecal del virus en niños con hepatitis A.

Hepatitis A virus (HAV) infection is endemic in Argentina. Molecular tools have allowed HAV RNA detection to be extent to sera and feces from patients with different clinical backgrounds. We compare the sensitivity of the RT-PCR protocol we follow using primers targeting different genomic regions and VP3 C terminal was the most sensitive. Sequential sera and fecal samples were obtained from 20 children with acute self limited Hepatitis A. HAV RNA was detectable in 18/20 children if sera and stool specimens were collected at the onset of symptoms and in 19/20 if a later sample was considered. HAV RNA was detectable in serum from 9/20 patients until day 30 and in feces from 2 patients until day 60 and until day 90 in one. Genomic sequences from VP1/2A region in 8 samples showed they all belong to subgenotype IA although they were different between them. HAV RNA was detectable only in 1/11 sera from children with acute liver failure when VP3 C terminal fragment was searched and it belonged to genotype I. Universal vaccination in one year old children was recently implemented in Argentina and it will dramatically enable the decrease of the viral circulation, making new sources of infection emerge and allowing the introduction of new genotypes. The application of molecular tools to the study of the natural history of infection and to the epidemiologic surveillance may contribute to efficient control and lead to rational decisions in public health policies.