Hepatitis A

Opinion statement Hepatitis A infection is typically transmitted by the fecal-oral route. Symptomatic infection is highly dependent on the age of the patient and usually follows a self-limited course. Once diagnosed, clinical and biochemical follow-up in the outpatient setting is generally appropriate. Treatment aims are to achieve symptomatic relief and to maintain adequate hydration and caloric intake. In patients with more severe disease, hospitalization may be needed to accomplish aggressive symptomatic therapy and close monitoring of liver function tests and mental status. Prompt evaluation for liver transplantation is appropriate in the rare case where fulminant liver failure develops. Given the absence of specific therapy for hepatitis A virus infection, the most important health care intervention is prevention of infection and/or transmission, which can be accomplished with the safe and effective use of immune globulin and commercially available vaccines.     

Hepatitis A

Hepatitis A remains an important cause of community-acquired hepatitis in the United States and in the world. In recent years, improvements in personal hygiene and environmental sanitation have led to declines in overall hepatitis A infection rates in developed countries, although sporadic outbreaks still occur with similar rates of hospitalization and loss of work. Therapy remains supportive and prevention holds the key to elimination of widespread infection. Acute infection can be prevented or attenuated with IG or with inactivated, highly immunogenic vaccines. Elderly persons and those with advanced liver disease are at higher risk of the consequences of acute HAV, and they represent target populations for immediate vaccination. Challenges for the future include strategies for broad-based population vaccination, including cost-effective approaches.     

Hepatitis A Vaccine

Hepatitis A continues to cause sporadic cases, epidemics, and occasional deaths in the United States. A killed virus vaccine for immunization against hepatitis A has recently been approved by the Food and Drug Administration. One hundred percent seroconversion occurs after a series consisting of a primary dose and a second booster shot 6–12 months later. Co-administration of immune-globulin and hepatitis A vaccine lowers ultimate antibody levels 50% compared with vaccine alone. Targets for immunization will probably be children, international travelers, military personnel, and food handlers. It will also be useful for general vaccination in areas where smoldering epidemics occur. Natural immunity levels in the United States population have undergone a significant decline since 1980 and are currently in the 21–33% range. Prescreening for immunity is likely to be cost-effective in persons over age 40.     

Idiopathic Autoimmune Chronic Hepatitis Triggered by Hepatitis A

Hepatitis A virus (HAV) infection is a well-recognized cause of acute hepatitis with jaundice in adults. However, chronic sequelae of HAV infection are so rare and so poorly defined that their existence remains speculative. In this report we describe a middle-aged woman in whom serologically defined acute hepatitis A appeared to trigger the onset of autoimmune chronic active hepatitis. This and two previously reported cases suggest that in certain individuals, presumably with a genetic predisposition to tbe development of autoimmune bepatitis, HAV infection may be tbe precipitating event in tbe patbogenesis of tbis disorder.     

Viral Hepatitis: A Review

An understanding of the various serological markers and their clinical significance is essential in dealing with cases of hepatitis. Which markers imply infectivity, which predict chronicity and which signal recovery must be part of the clinician's armamentarium. A rapidly growing area of prophylaxis with hyperimmune globulin and immune serum globulin and new viral component vaccines are now in the forefront of viral hepatology.     

丙型肝炎病毒与甲乙型肝炎病毒重叠感染的研究

对485例病毒性肝炎患者进行了抗HCV、抗HAV-IgM、HBV-M检测.各型病毒性肝炎患者中抗HCV阳性率15.05％,慢性肝炎、肝硬变和重型肝炎阳性率高于急性肝炎;抗HCV阳性者中,27.40％有输血或血浆史;57.53％HBV-M阳性,其中HBsAg阳性占54.76％,抗HBc阳性达88.10％;既往有HBV感染者占33.33％.HBV与HCV重叠感染中慢性肝炎占58.06％,IAV与HCV重叠感染以急性肝炎多见(94.44％),HCV与甲乙型肝炎病毒三重感染可加速肝炎重症化的进程。     

Hepatitis A in French Hemophiliacs

The prevalence of serum antibodies to hepatitis A virus (HAV) in 793 hemophilia A (HA) and 89 hemophilia B (HB) patients coming from 10 French Hemophilia Centers and treated since 1986–1987 with solvent/detergent (SD)-treated products is reported. The results indicated seropositivity to HAV of 29.9% in HA and 40.4% in HB patients. There was no difference among the patients according to severity of the disease, HIV serology or administration of factor VIII during the last 12 months. Seropositivity increased with age from 5.2% in HA children to 42.4% in adults (in HB the respective prevalences in the same groups were 7.7% and 56.1%). When compared to normal controls (n = 585), the prevalence of HAV seropositivity was not excessive in HA patients (n = 206). 19/20 children exclusively treated with a very-high-purity SD-factor VIII concentrate (Centre régional de transfusion sanguine, Lille) remained HAV seronegative. Six cases of HAV contamination were reported in patients with severe HA, probably reflecting the level of HAV endemy in the normal population in France. No special risk of HAV transmission linked to the SD products used in France since 1986 had thus been identified.     

A Case of Ischemic Hepatitis

We present a case of an obese young man who developed ischemic hepatitis, severe coagulopathy, acute renal failure, and encephalopathy. Heart failure and hypovolemia were absent. Oxygen arterial saturation was very low, between 77% and 99% during the day, with no history of respiratory failure. A diagnosis of obstructive sleep apnea was made clinically and confirmed by performing formal polysomnography. The polysomnographic study showed multiple episodes of apneas and hypopneas with severe oxygen desaturation. The patient was treated with continuous positive airway pressure through a nose mask and clinical manifestations related to profound nocturnal desaturation were ameliorated. He was discharged 32 days after admission with normal results of laboratory tests. This case report is presented to support the hypothesis that hypoxic hepatitis was directly related to severe arterial hypoxemia.     

Hepatitis A Virus Anicteric Encephalitis Coexistent with Hepatitis C Virus Infection

A 34-yr-old male presented with acute encephalitis. The encephalitis was due to an anicteric hepatitis A virus infection superimposed upon coexistent hepatitis C virus infection. Neurologic syndromes due to hepatitis A virus infection have all been associated with jaundice. Neurologic complications of hepatitis C virus infections have not been described. Identification of hepatitis A virus as an etiology of viral encephalitis can reduce the need for extensive costly evaluations, and unnecessary empiric antibiotics. Further clinical experience will determine if hepatitis C virus produces neurologic manifestations.     

A Review of Hepatitis B Virus and Hepatitis C Virus Immunopathogenesis

Despite the advances in therapy, hepatitis B virus (HBV) and hepatitis C virus (HCV) still represent a significant global health burden, both as major causes of cirrhosis, hepatocellular carcinoma, and death worldwide. HBV is capable of incorporating its covalently closed circular DNA into the host cell’s hepatocyte genome, making it rather difficult to eradicate its chronic stage. Successful viral clearance depends on the complex interactions between the virus and host’s innate and adaptive immune response. One encouraging fact on hepatitis B is the development and effective distribution of the HBV vaccine. This has significantly reduced the spread of this virus. HCV is a RNA virus with high mutagenic capacity, thus enabling it to evade the immune system and have a high rate of chronic progression. High levels of HCV heterogeneity and its mutagenic capacity have made it difficult to create an effective vaccine. The recent advent of direct acting antivirals has ushered in a new era in hepatitis C therapy. Sustained virologic response is achieved with DAAs in 85–99% of cases. However, this still leads to a large population of treatment failures, so further advances in therapy are still needed. This article reviews the immunopathogenesis of HBV and HCV, their properties contributing to host immune system avoidance, chronic disease progression, vaccine efficacy and limitations, as well as treatment options and common pitfalls of said therapy.