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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 -
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 -
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 -
Archives of Disease in Childhood Apr 1994
Review
Topics: Adolescent; Adult; Child; Child, Preschool; Hepatitis A; Hepatitis B; Hepatitis C; Hepatitis D; Hepatitis E; Hepatitis, Viral, Human; Humans; Infant
PubMed: 8185372
DOI: 10.1136/adc.70.4.343 -
Viruses Apr 2023Hepatitis A and hepatitis E are relatively common causes of liver disease. Both viruses are mainly transmitted through the faecal-oral route and, consequently, most... (Review)
Review
Hepatitis A and hepatitis E are relatively common causes of liver disease. Both viruses are mainly transmitted through the faecal-oral route and, consequently, most outbreaks occur in countries with poor sanitation. An important role of the immune response as the driver of liver injury is also shared by the two pathogens. For both the hepatitis A (HAV) and hepatitis E (HEV) viruses, the clinical manifestations of infection mainly consist of an acute disease with mild liver injury, which results in clinical and laboratory alterations that are self-limiting in most cases. However, severe acute disease or chronic, long-lasting manifestations may occur in vulnerable patients, such as pregnant women, immunocompromised individuals or those with pre-existing liver disease. Specifically, HAV infection rarely results in fulminant hepatitis, prolonged cholestasis, relapsing hepatitis and possibly autoimmune hepatitis triggered by the viral infection. Less common manifestations of HEV include extrahepatic disease, acute liver failure and chronic HEV infection with persistent viraemia. In this paper, we conduct a non-systematic review of the available literature to provide a comprehensive understanding of the state of the art. Treatment mainly consists of supportive measures, while the available evidence for aetiological treatment and additional agents in severe disease is limited in quantity and quality. However, several therapeutic approaches have been attempted: for HAV infection, corticosteroid therapy has shown outcome improvement, and molecules, such as AZD 1480, zinc chloride and heme oxygenase-1, have demonstrated a reduction in viral replication in vitro. As for HEV infection, therapeutic options mainly rely on the use of ribavirin, and some studies utilising pegylated interferon-alpha have shown conflicting results. While a vaccine for HAV is already available and has led to a significant reduction in the prevalence of the disease, several vaccines for HEV are currently being developed, with some already available in China, showing promising results.
Topics: Humans; Female; Pregnancy; Hepatitis A; Hepatitis E; Hepatitis E virus; Acute Disease
PubMed: 37243166
DOI: 10.3390/v15051080 -
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 -
Clinical Microbiology Reviews Jan 2006Current serologic tests provide the foundation for diagnosis of hepatitis A and hepatitis A virus (HAV) infection. Recent advances in methods to identify and... (Review)
Review
Current serologic tests provide the foundation for diagnosis of hepatitis A and hepatitis A virus (HAV) infection. Recent advances in methods to identify and characterize nucleic acid markers of viral infections have provided the foundation for the field of molecular epidemiology and increased our knowledge of the molecular biology and epidemiology of HAV. Although HAV is primarily shed in feces, there is a strong viremic phase during infection which has allowed easy access to virus isolates and the use of molecular markers to determine their genetic relatedness. Molecular epidemiologic studies have provided new information on the types and extent of HAV infection and transmission in the United States. In addition, these new diagnostic methods have provided tools for the rapid detection of food-borne HAV transmission and identification of the potential source of the food contamination.
Topics: Animals; Hepatitis A; Hepatitis A virus; Humans; Molecular Epidemiology
PubMed: 16418523
DOI: 10.1128/CMR.19.1.63-79.2006 -
Clinical and Molecular Hepatology Sep 2017Hepatitis A virus is one of the most frequent causes of foodborne infection, which is closely associated with sanitary conditions and hygienic practices. The clinical... (Review)
Review
Hepatitis A virus is one of the most frequent causes of foodborne infection, which is closely associated with sanitary conditions and hygienic practices. The clinical spectrum of acute hepatitis A is wide, ranging from mild case without any noticeable symptoms to severe case with acute liver failure leading to mortality. The severity and outcome are highly correlated with age at infection. In developing countries, most people are infected in early childhood without significant symptom. Ironically, in area where sanitary condition has improved rapidly, adults who do not have immunity for viral hepatitis A (VH-A) in early childhood is accumulating. Adults without immunity are exposed to risks of symptomatic disease and large outbreaks in society. In Korea, where hygiene has improved rapidly, acute hepatitis A is a significant health burden that needs to be managed with nationwide health policy. The incidence of symptomatic VH-A has increased since 2000 and peaked in 2009. Korea has designated hepatitis A as a group 1 nationally notifiable infectious disease in 2001. Since 2001, mandatory surveillance system has been established to detect every single case of acute hepatitis A. Universal, nationwide vaccination program for newborns was introduced in 2015. In this review, we will present the current epidemiologic status of viral hepatitis A, and evaluate the effectiveness of the current nationwide strategies for the control of viral hepatitis A in Korea. Furthermore, we presented some action proposals that can help eliminate viral hepatitis A, which is a significant health burden in Korea.
Topics: Age Factors; Antibodies, Viral; Hepatitis A; Humans; Military Personnel; Republic of Korea; Risk; Seroepidemiologic Studies
PubMed: 28942621
DOI: 10.3350/cmh.2017.0034 -
Human Vaccines & Immunotherapeutics Apr 2016Viral hepatitis is a serious global public health problem. It is also a common cause of jaundice and gestational complications in pregnant women. Moreover, infected... (Review)
Review
Viral hepatitis is a serious global public health problem. It is also a common cause of jaundice and gestational complications in pregnant women. Moreover, infected mothers can transmit the virus to their fetus or neonate, which may increase disease burden and decrease quality of life. To date, commercial vaccines have been developed for hepatitis A, B, and E and are available to the general population. The Advisory Committee on Immunization Practices currently accepts emergency vaccination against hepatitis A and B during pregnancy due to benefits that overweight the potential risks. While there are limited data from trials with limited numbers of samples that suggest the efficacy or safety of hepatitis B and E vaccines in pregnant women, additional data are necessary to provide evidence of vaccination during pregnancy.
Topics: Clinical Trials as Topic; Female; Hepatitis A; Hepatitis A Vaccines; Hepatitis B; Hepatitis B Vaccines; Hepatitis E; Humans; Infant, Newborn; Pregnancy; Pregnancy Complications, Infectious; Vaccination; Viral Hepatitis Vaccines
PubMed: 26833263
DOI: 10.1080/21645515.2015.1132129