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World Journal of Gastroenterology Apr 2022Each hepatitis virus-Hepatitis A, B, C, D, E, and G-poses a distinct scenario to the patient and clinician alike. Since the discovery of each virus, extensive knowledge... (Review)
Review
Each hepatitis virus-Hepatitis A, B, C, D, E, and G-poses a distinct scenario to the patient and clinician alike. Since the discovery of each virus, extensive knowledge regarding epidemiology, virologic properties, and the natural clinical and immunologic history of acute and chronic infections has been generated. Basic discoveries about host immunologic responses to acute and chronic viral infections, combined with virologic data, has led to vaccines to prevent Hepatitis A, B, and E and highly efficacious antivirals for Hepatitis B and C. These therapeutic breakthroughs are transforming the fields of hepatology, transplant medicine in general, and public and global health. Most notably, there is even an ambitious global effort to eliminate chronic viral hepatitis within the next decade. While attainable, there are many barriers to this goal that are being actively investigated in basic and clinical labs on the local, national, and international scales. Herein, we discuss pertinent clinical information and recent organizational guidelines for each of the individual hepatitis viruses while also synthesizing this information with the latest research to focus on exciting future directions for each virus.
Topics: Antiviral Agents; Hepatitis A; Hepatitis B; Hepatitis B virus; Hepatitis, Viral, Human; Humans
PubMed: 35582678
DOI: 10.3748/wjg.v28.i14.1405 -
Gastroenterology Clinics of North... Jun 2020Hepatitis A virus (HAV) is a positive-strand RNA virus that is transmitted feco-orally through person-to-person contact. Outbreaks are often linked to poor sanitation,... (Review)
Review
Hepatitis A virus (HAV) is a positive-strand RNA virus that is transmitted feco-orally through person-to-person contact. Outbreaks are often linked to poor sanitation, overcrowding, or food and water contamination. Infection is often asymptomatic in children, but adults present with jaundice, abdominal pain, hepatitis, and hyperbilirubinemia. Diagnosis is through detection of immunoglobulin M antibodies against HAV, and treatment is supportive. Vaccination is the mainstay of prevention and should be given before exposure whenever possible.
Topics: Abdominal Pain; Alanine Transaminase; Anorexia; Biomarkers; Hepatitis A; Hepatitis A Vaccines; Humans; Jaundice; Risk; Serologic Tests; Travel
PubMed: 32389358
DOI: 10.1016/j.gtc.2020.01.002 -
Intervirology 2010Due to improved living conditions and subsequent changes in hepatitis A epidemiology, the disease burden of hepatitis A is increasing in many regions. Recently, Korea... (Review)
Review
Due to improved living conditions and subsequent changes in hepatitis A epidemiology, the disease burden of hepatitis A is increasing in many regions. Recently, Korea has faced a large, community-wide outbreak of hepatitis A, which has prompted a vaccination program. The clinical spectrum of hepatitis A virus infection ranges from asymptomatic infection to fulminant hepatitis. Clinical manifestations depend on the age of the host: less than 30% of infected young children are symptomatic, while about 80% of infected adults manifest severe hepatitis with remarkably elevated serum aminotransferases. Fulminant hepatitis is rare, with a reported incidence from 0.015 to 0.5%. Atypical manifestations include relapsing hepatitis and prolonged cholestasis, and complicated cases with acute kidney injury have been reported. Extrahepatic manifestations, such as autoimmune hemolytic anemia, aplastic anemia, pure red cell aplasia, pleural or pericardial effusion, acute reactive arthritis, acute pancreatitis, acalculous cholecystitis, mononeuritis, and Guillain-Barré syndrome, have been rarely reported. Management of hepatitis A includes general supportive care, and critical decisions regarding liver transplantation await further studies on prognostic predictors. Fundamental management of hepatitis A is active vaccination. However, a vaccination program should be adapted to the regional situation, according to differing epidemiology and disease burden.
Topics: Adult; Case Management; Hepatitis A; Hepatitis A virus; Humans; Korea; Prognosis; Young Adult
PubMed: 20068336
DOI: 10.1159/000252779 -
Cold Spring Harbor Perspectives in... Sep 2018Hepatitis A virus (HAV) is transmitted by the fecal-oral route and is a major cause of acute viral hepatitis. The clinical manifestations of HAV infection range from... (Review)
Review
Hepatitis A virus (HAV) is transmitted by the fecal-oral route and is a major cause of acute viral hepatitis. The clinical manifestations of HAV infection range from asymptomatic infection to acute liver failure (ALF), but do not include progression to chronic hepatitis. Risk factors for severe acute hepatitis A are older age (>40 years) and preexisting liver disease. Some patients may show atypical clinical features such as relapsing hepatitis, prolonged cholestasis, or extrahepatic manifestations. Almost all hepatitis A patients spontaneously recover with supportive care. However, in the case of ALF (<1%), intensive care and urgent decision on liver transplantation are required. Liver injury during hepatitis A is not directly caused by HAV but is known to be caused by immune-mediated mechanisms. In this review, the natural history and clinical manifestations of hepatitis A are described. In addition, mechanisms of immunopathogenesis in hepatitis A are discussed.
Topics: Acute Disease; Disease Progression; Hepatitis A; Hepatitis A Vaccines; Hepatitis A virus; Humans; Liver; Liver Failure, Acute; Liver Transplantation; Risk Factors
PubMed: 29440324
DOI: 10.1101/cshperspect.a031708 -
World Journal of Gastroenterology Apr 2021Viral infections affecting the liver have had an important impact on humanity, as they have led to significant morbidity and mortality in patients with acute and chronic... (Review)
Review
Viral infections affecting the liver have had an important impact on humanity, as they have led to significant morbidity and mortality in patients with acute and chronic infections. Once an unknown etiology, the discovery of the viral agents triggered interest of the scientific community to establish the pathogenesis and diagnostic modalities to identify the affected population. With the rapid scientific and technological advances in the last centuries, controlling and even curing the infections became a possibility, with a large focus on preventive medicine through vaccination. Hence, a comprehensive understanding of hepatitis A, B, C, D and E is required by primary care physicians and gastroenterologists to provide care to these patients. The review article describes the epidemiology, pathogenesis, clinical presentation, diagnostic tools and current medication regimens, with a focus on upcoming treatment options and the role of liver transplantation.
Topics: Hepatitis A; Hepatitis, Viral, Human; Humans; Liver Transplantation; Vaccination
PubMed: 33967551
DOI: 10.3748/wjg.v27.i16.1691 -
Virulence Dec 2021Hepatitis A is an acute infection of the liver, which is mostly asymptomatic in children and increases the severity with age. Although in most patients the infection... (Review)
Review
Hepatitis A is an acute infection of the liver, which is mostly asymptomatic in children and increases the severity with age. Although in most patients the infection resolves completely, in a few of them it may follow a prolonged or relapsed course or even a fulminant form. The reason for these different outcomes is unknown, but it is generally accepted that host factors such as the immunological status, age and the occurrence of underlaying hepatic diseases are the main determinants of the severity. However, it cannot be ruled out that some virus traits may also contribute to the severe clinical outcomes. In this review, we will analyze which genetic determinants of the virus may determine virulence, in the context of a paradigmatic virus in terms of its genomic, molecular, replicative, and evolutionary features.
Topics: Child; Hepatitis A; Hepatitis A virus; Humans; Virulence
PubMed: 33843464
DOI: 10.1080/21505594.2021.1910442 -
Viruses Sep 2021The hepatitis A virus (HAV) is a leading cause of acute viral hepatitis worldwide. It is transmitted mainly by direct contact with patients who have been infected or by... (Review)
Review
The hepatitis A virus (HAV) is a leading cause of acute viral hepatitis worldwide. It is transmitted mainly by direct contact with patients who have been infected or by ingesting contaminated water or food. The virus is endemic in low-income countries where sanitary and sociodemographic conditions are poor. Paradoxically, improving sanitary conditions in these countries, which reduces the incidence of HAV infections, can lead to more severe disease in susceptible adults. The populations of developed countries are highly susceptible to HAV, and large outbreaks can occur when the virus is spread by globalization and by increased travel and movement of foodstuffs. Most of these outbreaks occur among high-risk groups: travellers, men who have sex with men, people who use substances, and people facing homelessness. Hepatitis A infections can be prevented by vaccination; safe and effective vaccines have been available for decades. Several countries have successfully introduced universal mass vaccination for children, but high-risk groups in high-income countries remain insufficiently protected. The development of HAV antivirals may be important to control HAV outbreaks in developed countries where a universal vaccination programme is not recommended.
Topics: Antiviral Agents; Disease Outbreaks; Hepatitis A; Hepatitis A virus; Homosexuality, Male; Humans; Incidence; Male; Risk Factors; Sexual and Gender Minorities; Travel
PubMed: 34696330
DOI: 10.3390/v13101900 -
American Family Physician Oct 2021Hepatitis A is a common viral infection worldwide that is transmitted via the fecal-oral route. The incidence of infection in the United States decreased by more than... (Review)
Review
Hepatitis A is a common viral infection worldwide that is transmitted via the fecal-oral route. The incidence of infection in the United States decreased by more than 90% after an effective vaccine was introduced, but the number of cases has been increasing because of large community outbreaks in unimmunized individuals. Classic symptoms include fever, malaise, dark urine, and jaundice and are more common in older children and adults. People are most infectious 14 days before and seven days after the development of jaundice. Diagnosis of acute infection requires the use of serologic testing for immunoglobulin M anti-hepatitis A antibodies. The disease is usually self-limited, supportive care is often sufficient for treatment, and chronic infection or chronic liver disease does not occur. Routine hepatitis A immunization is recommended in children 12 to 23 months of age. Immunization is also recommended for individuals at high risk of contracting the infection, such as persons who use illegal drugs, those who travel to areas endemic for hepatitis A, incarcerated populations, and persons at high risk of complications from hepatitis A, such as those with chronic liver disease or HIV infection. The vaccine is usually recommended for pre- and postexposure prophylaxis, but immune globulin can be used in patients who are too young to be vaccinated or if the vaccine is contraindicated.
Topics: Adolescent; Adult; Alanine Transaminase; Child; Child, Preschool; Hepatitis A; Hepatitis A Vaccines; Humans; Infant; Middle Aged; Post-Exposure Prophylaxis; Risk Factors; Young Adult
PubMed: 34652109
DOI: No ID Found -
American Journal of Obstetrics and... Mar 2022Viral hepatitis in pregnancy may be caused by many types of viruses that cause systemic infection or target hepatocytes in their pathogenesis. Because viral hepatitis... (Review)
Review
Viral hepatitis in pregnancy may be caused by many types of viruses that cause systemic infection or target hepatocytes in their pathogenesis. Because viral hepatitis during pregnancy may represent acute or chronic infection or the reactivation of a prior infection, a high clinical suspicion, medical history review, and awareness of risk factors for the acquisition of infection are important management principles. The route of infection varies widely and ranges from fecal-oral transmission for the hepatitis A and E viruses to vertical transmission for hepatitis B, blood-borne transmission for hepatitis C, and sexual transmission for the herpes simplex virus. For this reason, the exposure details about travel, food preferences, drug use, and sexual contacts are important to elicit. Although routine prenatal screening is recommended for chronic viral hepatitis caused by hepatitis B and C, most other causes of viral hepatitis in pregnancy are detected in the setting of compatible signs and symptoms (fatigue, abdominal discomfort, jaundice, scleral icterus) or incidentally noted transaminitis on routine labs. Serologic testing is helpful for diagnosis with molecular testing as indicated to guide the management of hepatitis B and C. Preventive vaccines for hepatitis A and B with established safety of use in pregnancy are recommended for women who are at risk of acquisition. Postexposure prophylaxis for hepatitis A is a single dose of immunoglobulin and vaccination can be used if immunoglobulin G is not available. Antiviral therapy with tenofovir disoproxil fumarate is recommended as prophylaxis in pregnant women with active hepatitis B and an elevated viral load (>200,000 IU/mL) during the third trimester to prevent vertical transmission. The neonate exposed to hepatitis B at birth should receive immunoglobulin G and a monovalent birth dose vaccine within 12 hours, followed by completion of the 3-dosage vaccine series. The prevalence of hepatitis C in women of reproductive age has increased in the United States, and the role of antiviral therapy during pregnancy is of great interest. Cesarean delivery is not currently recommended for the sole purpose of reducing vertical transmission risk in pregnant women with viral hepatitis. Breastfeeding is recommended in women with hepatitis A, B, and C. New and promising prevention and treatment options for hepatitis B and C are under investigation. Investigators and regulatory authorities should ensure that these clinical trials for promising antivirals and vaccines are designed to include pregnant and lactating women.
Topics: Antiviral Agents; Female; Hepatitis A; Hepatitis B; Hepatitis B Vaccines; Hepatitis B virus; Hepatitis B, Chronic; Hepatitis C; Humans; Immunoglobulin G; Infant, Newborn; Infectious Disease Transmission, Vertical; Lactation; Pregnancy; Pregnancy Complications, Infectious; Viral Load
PubMed: 34516961
DOI: 10.1016/j.ajog.2021.09.002 -
Viruses May 2021Hepatitis A virus (HAV) infection is a common cause of acute viral hepatitis worldwide. Despite decades of research, the pathogenic mechanisms of hepatitis A remain... (Review)
Review
Hepatitis A virus (HAV) infection is a common cause of acute viral hepatitis worldwide. Despite decades of research, the pathogenic mechanisms of hepatitis A remain incompletely understood. As the replication of HAV is noncytopathic in vitro, a widely accepted concept has been that virus-specific cytotoxic T cells are responsible for liver injury. However, accumulating evidence suggests that natural killer (NK) cells, NKT cells, and even non-HAV-specific CD8 T cells contribute to liver damage during HAV infection. In addition, intrinsic death of virus-infected hepatocytes has been implicated as a cause of liver injury in a murine model of hepatitis A. Furthermore, genetic variations in host factors such as T cell immunoglobulin-1 (TIM1) and IL-18 binding protein (IL-18BP) have been linked to hepatitis A severity. This review summarizes the current knowledge of the mechanisms of hepatocellular injury in hepatitis A. Different mechanisms may be involved under different conditions and they are not necessarily mutually exclusive. A better understanding of these mechanisms would aid in diagnosis and treatment of diseases associated with HAV infection.
Topics: Animals; Carcinoma, Hepatocellular; Hepatitis A; Hepatitis A virus; Hepatocytes; Humans; Liver; Liver Neoplasms; Mice
PubMed: 34066709
DOI: 10.3390/v13050861