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.

Electron microscopy of buffalo green monkey kidney cells persistently infected with hepatitis A virus and immunolocalization of HAV antigens.

Studies were carried out to analyse the ultrastructural changes and the distribution of hepatitis A virus (HAV)/antigens at subcellular level in buffalo green monkey kidney (BGMK) cells persistently infected with HM-175 strain of HAV. HAV infected BGMK cells showed distinct abnormalities in the endoplasmic reticulum and cytoplasmic membrane as compared to uninfected cells. The abnormalities were characterized by wavy arrays, structures like myelin, annulate lamellae, cytoplasmic inclusion bodies and vesicles. The wavy arrays within the cytoplasm of the host cells appeared to represent degenerating membranes. A complex myelin like body was found in close association with a group of virus like particles. Annulate lamellae like structures involving single paired membrane were detected infrequently whereas the cytoplasmic vesicles were numerous in these cells. An indirect immunogold technique was utilized to localize the HAV antigenin infected cells. A high density immunogold label for HIV like particles was predominantly detected in cytoplasmic vesicles. These results suggest a strong association of membrane substructure in vesicle forms with the compartmentalized replication of HAV within persistently infected host cells.

Detection of poliovirus, hepatitis A virus and rotavirus from sewage and water samples.

A modified adsorption-elution technique for concentration of enteric viruses from sewage and water samples was developed. The viruses in water were concentrated by negatively charged membrane filtration, eluted with 2.9% tryptose phosphate broth containing 6% glycine pH 9.0, and reconcentrated using centrifugation by a speedVac concentrator. The presence of poliovirus, hepatitis A virus (HAV) RNA, and rotavirus antigen was determined by cell culture isolation, nested polymerase chain reaction (nested PCR), and enzyme-linked immunosorbent assay (ELISA), respectively. A total of 100 sewage and water samples were collected from various sources in congested communities in Bangkok, concentrated and examined for those enteric viruses. Of 20 surface water samples from canals which located near sewage drains, 15% were positive for HAV RNA by nested PCR. Of 48 domestic sewage samples from man-holes of underground sewers, 8% were positive for rotavirus antigen by ELISA. Even though the samples were concentrated 256-2,000 fold, poliovirus was not found by isolation in cell culture.

Hepatitis virales / Viral hepatitis

En esta revisión se describen los virus hepatotropos actualmente conocidos, su epidemiología con referencia especial a los datos nacionales relativos a los virus A, B, C y E; su historia natural y sus aspectos clínicos más relevantes. Se enfatizan, además los diferentes marcadores virales serológicos, para el diagnóstico de infección aguda o crónica. Se incluyen también los diferentes tratamientos y las medidas de prevención (pasivas o activas) recomendadas actualmente

Los virus de la hepatitis: del A al TT / Hepatitis virus: from A to TT

A great progress in the knowledge about hepatitis virus has occurred in the last decades and several virus have been identified. Virus B, C and D are transmitted parenterally, while virus A and E use the enteral route. Highly effective vaccines for A and B hepatitis are presently available. Virus C is an important cause of chronic liver disease at the present moment. Since the identification of virus C and E, the number of acute hepatitis denominated as non A non B has decreased considerable. Although there are still patients with viral hepatitis of unknown origin and there is considerable effort to identify the agents causing them. Virus G and TT are frequently present in the sera of patients with chronic liver diseases but their real pathogenic role is not completely elucidated

Anticuerpos séricos contra el virus hepatitis A en sujetos de nivel socioeconómico medio y bajo en comunas urbanas de Santiago / Serum antibodies against hepatitis A virus among subjects of medium and low socioeconomic levels in urban Santiago

Background: The epidemiology of hepatitis A virus (HAV) infection is closely associated to the level of hygiene and sanitation of the population. Newly industrialising areas experience a transition from high to intermediate endemicity, which is characterized by a shift in the exposure age to HAV, from early childhood to school ages or adolescence. Aim: To measure the prevalence of HAV antibodies in subjects living in urban Santiago. Subjects and methods: A HAV antibody survey in five medium and low socioeconomic level urban districts of northern Santiago, was conducted in 1996. Healthy subjects aged 1 to 39 years old were recruited from randomly selected households. Results: Five hundred three subjects were studied. Anti HAV antibodies were found in 13.2, 29.5, 59.6, 78.1, 95.6 and 98.2 percent of individuals aged 1 to 4, 5 to 9, 10 to 14, 15 to 19, 20 to 29 and 30 to 39 years old, respectively. Conclusions: The profile of positive antibodies is compatible with an intermediate pattern of transmission of HAV. The current data supports the idea that infection is shifting towards older ages. A progressive increase in the number of susceptible school age children and teenagers is propitious for the occurrence of common source hepatitis A outbreaks

Duality of patterns in hepatitis a epidemiology: a study involving two socioeconomically distinct populations in Campinas, Sao Paulo State, Brazil

A avaliaçäo da prevalencia de anticorpos contra o virus da hepatite A em duas populaçöes com diferentes niveis sócio-economicos foi realizada pela analise de 101 e 82 amostras de soros provenientes de grupos de alto e baixo nivel sócio-economico, respectivamente, utilizando um teste imunoenzimatico comercial. A prevalência no grupo de baixo nivel sócio-economico foi 95,0 por cento enquanto que no grupo de alto nivel sócio-economico foi apenas 19,6 por cento (p < 0,001). Estes dados mostram uma dualidade no Brasil : a prevalência de anti-HAV em individuos de nivel sócio-economico baixo e similar aquela dos paises em desenvolvimento enquanto que nos individuos de alto nivel sócio-economico e compativel com o padrao de paises desenvolvidos. O controle desta infecçäo depende primariamente da melhoria das condiçöes sanitarias, mas especialmente em populaçöes de alto-nivel sócio-economico, o uso da vacinaçäo contra a hepatite A e altamente aconselhavel para evitar o aparecimento da doença em adultos

Exámenes virológicos disponibles en la actualidad / Virological tests available today

Actualmente se ha hecho imprescindible la confirmación del diagnóstico etiológico de las infecciones virales. Para los médicos que trabajan alejados de los centros de estudio y universidades, es útil disponer de las posibilidades de diagnóstico viral y su correcta forma de certificación y envío de muestras. Se describen aquí las indicaciones de algunos exámenes virológicos disponibles en la Universidad de Chile y Universidad Católica de Chile

Intragastric infection induced in marmosets (Callithrix jacchus) by a Brazilian hepatitis A virus (HAF-203)

Several specied of non-human primates have been used in studies on experimental infection with hepatitis A virus (HAV). Attempts to infect a South-American marmoset (Callithrix jacchus) with a Brazilian HAV isolate (HAF-203) are described here. Four seronegative animals were inoculated intragastrically and one was sacrificed on day 11,20,47 and 62 after infection. One uninfected animal was included as control. Liver, small intestine, lymph node, spleen and kidney samples were collected for histological diagnosis and immunocytochemistry studies. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) serum enzymes and anti-HAV antibodies were monitored by a colorimetric procedure (Abbott) and an enzyme immunoassay (ELISA), respectively. Feces were collected daily for HAV antigen (HAVAg) detection by ELISA. Increased levels of HAVAg were detected in hepatocytes 11 days after infection, with a gradual decrease during the course of infection. Shedding of HAVAg in feces was observed from the late incubation to the early acute phase (20th day to 47th day after infection). The end of the incubation period was indicated by the initial increases in serum ALT and AST. Severe hepatic lesions such as piecemeal necrosis and bridging necrosis were detected during the acute phase, coinciding with the maximum transaminase levels and the appearance of anti-HAV antibodies. On the 62nd day (convalescent phase), the hepatic tissue showed evidence of regeneration and the transaminase values had returned to baselines. The serological, biochemical, antigenic and histological evidence of hepatitis A was similar to that observed in several primate models inoculated with other HAV isolates. The data suggest that C. jacchus can be a valuable model for the study of hepatitis A and for the evaluation of HAV vaccines

Primary isolation of a brazilian strai9n of hepatitis A virus (HAF-203) and growth in a primate cell line (FRhK-4)

Although hepatitis A is endemic in Brazil, this is the first report describing the isolation of a Brazilian strain of hepatitis A virus (HAV). Fecal specimens obtained from patients in the acute phase of hepatitis A were iunoculated into fetal Rhesus kidney cell cultures (FRhK-4). Only one inoculum, denoted HAF-203, could be propagated serially. Both cell lysates and tissue culture fluids of infected cells were used as inocula and evaluated for viral antigen and RNA content by enzyme immunoassay and cDNA-RNA hybridization, respectively. Cell lysates gave better yields when used as viral inocula. After three passages, viral RNA and antigen were detected in cell lysates 4 and 14 days post-infection, respectively. Using tissue culture fluid as inoculum, the incubation period was decreased from 49 to 7 days after 4 serial passages, reflecting the adaptation of HAF-203 to growth in FRhK-4 cells. FRhK-4 cells can now be used for HAV antigen production for diagnostic assays and molecular characterization

Serologic classification of acute viral hepatitis at San Lazaro Hospital, Manila, Philippines.

Sixty-four out of 189 jaundiced patients at San Lazaro Hospital were defined as acute viral hepatitis cases. Of this number, 22 (34.4%) were positive for hepatitis A markers while 26 (40.6%) were positive for hepatitis B markers. Hepatitis D infection accounted for 1.6%, while non-A, non-B hepatitis accounted for 21.9%.

Incidencia de hepatopatias víricas en la Provincia de Corrientes en distintas poblaciones

Se analiza la incidencia de marcadores de hepatitis A y B en 600 personas de distintas característicias: 276 agentes sanitarios, 56 presidiarios, 36 hemodializados, 32 prostitutas y 200 parturientas. Se determina que mas del 90% de las poblaciones estudiadas tuvieron contacto con el VHA. Con respecto al VHB la incidencia en los distintos grupos (medida en positividad del anti-HBc) es variable de acuerdo al riesgo: Sanitarios 19,20%, Presidiarios 12.50%, Hemodializados 86.11% Prostitutas 53.12% y Parturientes 2%