Etiological role of hepatitis E virus in sporadic fulminant hepatitis

Visual and auditory evoked responses in acute severe hepatitis

Evoked responses have not been studied in patients with acute severe hepatitis (ASH) with or without hepatic encephalopathy. This prospective study was undertaken to find out diagnostic as well as prognostic value of visual evoked responses (VER), and brain stem auditory evoked responses (BAER) in patients with ASH with or without encephalopathy. Visual evoked responses and BAER were studied in 20 patients (14 males and six females) with ASH. The patients were diagnosed as having severe hepatitis if acute hepatitis was associated with raised serum bilirubin and serum transaminases, and if they had a prothrombin time index of < 50%. After a detailed neuropsychiatric examination of each patient, the study sample was divided into two groups of 10 patients: ASH without encephalopathy (ASH-WOE), and ASH with encephalopathy (fulminant hepatic failure, FHF). The median P100 latencies of FHF patients were significantly increased compared with controls and patients in the ASH-WOE group. Abnormal P100 latencies, exceeding 95th percentile values of the controls, were present in one patient in the ASH-WOE group and six patients in the FHF group. The median interpeak latencies I-III, III-V and I-V were significantly prolonged in the FHF group. Interpeak latencies III-V were also increased significantly in patients in the ASH-WOE group. While abnormal BAER were seen frequently in both groups, VER abnormalities were largely confined to patients in the FHF group. In the FHF group, six out of 10 patients survived and exhibited clinical improvement in the status of hepatic encephalopathy. Evoked responses were repeated after 2-3 weeks of recovery in these patients and VER abnormalities showed a tendency to normalize, thereby suggesting a prognostic implication. The incidence of abnormal VER in hepatic encephalopathy complicating ASH far exceeded that of abnormal BAER. Markedly prolonged P100 latencies in FHF patients indicate poor prognosis.

Case fatality rate of acute hepatitis in Italy: results from a 10 year surveillance

Using data from the surveillance system for acute viral hepatitis we have evaluated the case fatality rate of viral hepatitis in Italy. 71 deaths (0.3%) occurred among the 21,553 reported acute viral hepatitis cases from 1985-1994. None reported history of exposure to drugs or toxins. The highest case fatality rate was observed for B and NANB hepatitis (0.5%). One death occurred among the 6,353 (0.02%) hepatitis A cases and 1 among the 909 (0.1%) anti-HCV positive NANB hepatitis cases. The case fatality for Delta hepatitis was 0.2% (1/422). Case fatality rate was similar in both sexes; increasing with age; 0.03% were < 15 years of age, 0.1%, 15-24 year-old, and 0.5%, > or = 25 years. Subjects older than 24 years of age accounted for 81.4% of total deaths. Intravenous drug use, blood transfusion and other parenteral exposures were the three most frequent non-mutually exclusive sources of infection reported by subjects who died from B and NANB hepatitis. These findings indicate that the survival rate of acute B and NANB hepatitis is lower than that of acute hepatitis A; moreover in Italy, as in other Western countries, acute HCV seems to cause liver failure only rarely.

Hepatitis E virus infection in north-east Italy: serological study in the open population and groups at risk

Developed western countries are considered to be relatively free from endemic foci of hepatitis E virus (HEV) infections. The aim of this study was to assess the seroepidemiology of HEV in north-east Italy. Of the 2361 individuals studied 1889 were representative of the general population and 472 were from groups at high risk for viral infections: 279 drug users and 193 patients on chronic haemodialysis. All sera were tested for hepatitis C virus antibody (HCVAb), human immunodeficiency virus antibody (HIVAb) and for hepatitis B virus (HBV) serology. Two solid-phase enzyme-linked immunosorbent assays (ELISA) were used to study the seroepidemiology of HEV IgG, the first (using recombinant antigens) for confirmation of initially reactive samples. The prevalence of circulating hepatitis E virus antibody (HEVAb) was 2.6% in the open population, 5.4% among drug users and 9.3% among patients on chronic haemodialysis. In the open population a positive relationship between age and prevalence of HEVAb was observed. A relationship between presence of HEVAb and serological evidence of previous HBV or HCV infections was also observed in this study. It was concluded that HEV infections are present in north-east Italy and are more frequent among subjects at risk for blood-borne viral infections. The positive correlation, observed in the open population, between age and prevalence of HEVAb suggests the presence of a cohort effect.

Acute viral hepatitis types E, A, and B singly and in combination in acute liver failure in children in north India

The aetiological agents responsible for, and the outcome of, acute liver failure were investigated prospectively in 44 children (29 males, 15 females) attending a tertiary health care facility in India. The children were between the ages of 2 months and 13 years. Studies for viral infections and other etiologies could be carried out in 40 patients. Specific aetiological labels were possible in 35 (87.5%) patients. Thirty (75%) had evidence of acute viral hepatitis. Acute hepatitis E virus (HEV) infection was found in a total of 18 children, with hepatitis A (HAV) in 16, hepatitis B in 5, and C in 1. Seven had isolated infection with hepatitis E, five with A, and four with B. Nine had both E and A infection. Superinfection of HEV was observed in a child with Indian childhood cirrhosis (ICC). Acute HEV infection was confirmed by immunoblot assay in all the patients and in eight of these, HEV-RNA was also detected in the serum. HAV was involved in 37.5% of cases with isolated infection in 10% (4 of 40). The aetiological factors associated with acute liver failure, apart from HAV and HEV, were other hepatotropic viruses (22.5%), Wilson's disease (5%), ICC (5%), and hepatotoxic drugs (7.5%). In five patients, no serological evidence of acute viral hepatitis could be found, neither did the metabolic screen yield any result. It was observed that enterically transmitted hepatitis viruses (HAV and HEV) were associated with 60% of acute hepatic failure in children. Mixed infection of HAV and HEV formed the single largest aetiological subgroup. In developing countries, where hepatitis A and E infections are endemic, severe complications can arise in the case of mixed infection. This may contribute to most of the mortality from acute liver failure during childhood.

An Indian strain of hepatitis E virus (HEV): cloning, sequence, and expression of structural region and antibody responses in sera from individuals from an area of high-level HEV endemicity

Hepatitis E virus (HEV) is responsible for a majority of sporadic and epidemic viral hepatitides in India and other developing countries. Even though the genomes of four geographically distinct strains of HEV have been cloned and sequenced, the Indian strain of HEV remains largely uncharacterized. We have cloned and sequenced about 2.2 kb of the HEV genome constituting the structural region from an Indian strain of HEV. The nucleotide and amino acid sequences show a high degree of conservation with sequences from other HEV strains. Open reading frames (ORF) 2 and 3 were expressed in Escherichia coli as N-terminal hexahistidine epitope fusions. The purified proteins were then used in an immunoblot assay to evaluate the antibody status in sera from individuals from an area of high-level HEV endemicity. The anti-ORF2 antibodies were found to be nonspecific and could not be correlated to clinical disease. The immunoglobulin M anti-ORF3 was found to be specific for the presence of acute disease. The implications of these findings in HEV diagnosis and vaccine development are discussed.

Protracted viremia during acute sporadic hepatitis E virus infection

BACKGROUND/AIMS

Hepatitis E virus (HEV) is associated with epidemic and sporadic hepatitis in developing countries. The disease is largely self-limited with no long-term sequelae. The source of HEV for maintenance of the disease in an endemic area is unknown. This study investigated the occurrence and duration of viremia in patients with acute sporadic HEV infection.

METHODS

In 26 of 37 patients with sporadic acute non-A, non-B viral hepatitis, HEV infection was diagnosed based on positivity for immunoglobulin M anti-HEV and/or presence of viremia as shown by reverse-transcription polymerase chain reaction. In 4 patients, fecal samples were analyzed for presence of virus using polymerase chain reaction. Multiple samples were studied at varying times in 20 patients.

RESULTS

Viremia was detected in 19 of 26 patients. Two patients had viremia in the absence of immunoglobulin M anti-HEV. Four patients had protracted viremia of 45-112 days' duration. One patient showed fecal virus shedding up to the 52nd day of illness.

CONCLUSIONS

Protracted viremia and prolonged fecal shedding of HEV were shown in a small group of patients. These patients may serve as temporary virus carriers responsible for continuous contamination of the sewage water.

Hepatitis C: progress and problems

The hepatitis C virus (HCV), a single-stranded RNA virus, is the major cause of posttransfusion hepatitis. HCV isolates differ in nucleotide and amino acid sequences. Nucleotide changes are concentrated in hypervariable regions and may be related to immune selection. In most immunocompetent persons, HCV infection is diagnosed serologically, using antigens from conserved regions. Amplification of RNA may be necessary to detect infection in immunosuppressed patients. Transmission by known parenteral routes is frequent; other means of spread are less common and may represent inapparent, percutaneous dissemination. Infection can lead to classical acute hepatitis, but most infected persons have no history of acute disease. Once infected, most individuals apparently remain carriers of the virus, with varying degrees of hepatocyte damage and fibrosis ensuing. Chronic hepatitis may lead to cirrhosis and hepatocellular carcinoma. However, disease progression varies widely, from less than 2 years to cirrhosis in some patients to more than 30 years with only chronic hepatitis in others. Determinants important in deciding outcome are unknown. Alpha interferon, which results in sustained remission in selected patients, is the only available therapy. Long-term benefits from such therapy have not been demonstrated. Prevention of HCV infection by vaccination is likely to be challenging if ongoing viral mutation results in escape from neutralization and clearance.