Viral Hepatitis Overview and HAV Details

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Questions and Answers

What is the primary mode of transmission for HAV infection?

Fecal-oral transmission (correct)

Vector-borne transmission

Airborne transmission

Bloodborne transmission

How long can HAV be detected in feces after the initial infective contact?

12 weeks

1 week

8 weeks (correct)

2 weeks

Which group of individuals is NOT considered at risk for HAV infection?

Family contacts of an infected person

Vaccinated travelers (correct)

Intravenous drug users

Homosexuals

What is the period during which humans are most susceptible to HAV infection?

During and following the clinical onset Signup and view all the answers

What is unique about the cytopathic effect of HAV?

It lacks cytopathic effects. Signup and view all the answers

What type of immunity is developed after an HAV infection?

Life-long immunity Signup and view all the answers

What characteristic is associated with asymptomatic HAV infections?

They are more common in children. Signup and view all the answers

Once HAV enters the body, where does the first round of replication occur?

In the bowel and oropharynx Signup and view all the answers

What role do NK cells and cytotoxic T cells play in the context of viral hepatitis?

They help in viral clearance through cytokine and interferon action. Signup and view all the answers

Which of the following accurately describes the production of IgM antibodies in hepatitis A?

They serve as a marker for current or recent infection. Signup and view all the answers

During which period do IgG antibodies become predominant after an HAV infection?

After the onset of jaundice. Signup and view all the answers

What is the average incubation period for hepatitis A virus infection?

21 days Signup and view all the answers

Which of the following metabolic processes is affected by hepatic injury in hepatitis A?

Erratic glycaemia Signup and view all the answers

What symptom is most frequently associated with the non-specific digestive syndrome in HAV infection?

Bloating Signup and view all the answers

What type of hepatitis A infection form is more common in children?

Anicteric form Signup and view all the answers

Which factor contributes to hepatic lesions observed in hepatitis A?

Immunologic mechanisms induced by viral antigens Signup and view all the answers

What is often observed in hepatocytolysis syndrome prior to jaundice?

Increase in transaminases (AST, ALT) Signup and view all the answers

In acute hepatitis A, how do the average values of serum bilirubin levels compare to those in acute hepatitis B?

Lower in hepatitis A Signup and view all the answers

What does a significant increase in bilirubin levels typically indicate in a patient with jaundice?

Severe forms of liver disease Signup and view all the answers

What aspect of hematological syndrome is not commonly found?

Elevated leukocyte count Signup and view all the answers

What is indicated by a reduced prothrombin index (PI) and increased INR?

Severe liver injury Signup and view all the answers

Which of the following is NOT a function affected by liver failure?

Hormonal regulation Signup and view all the answers

What does a significant elevation of GGT and alkaline phosphatase suggest?

Cholestatic syndrome Signup and view all the answers

In the context of liver disease, what can high levels of serum ammonium indicate?

Detoxification dysfunction Signup and view all the answers

What characterizes the prolonged form of hepatitis A?

Persistence of clinical and/or biological changes for several weeks or months Signup and view all the answers

What percentage of adults experience cholestatic hepatitis A?

4-10% Signup and view all the answers

Which feature is NOT associated with fulminant hepatitis A?

High incidence in children Signup and view all the answers

What specific risk does acute hepatitis A pose to pregnant women and their fetuses?

Longer elimination of HAV in feces if infected in late pregnancy Signup and view all the answers

How does HIV infection affect the progression of acute hepatitis A?

Can cause persistent elevations in transaminases Signup and view all the answers

What is a key aspect of the laboratory diagnosis of acute hepatitis A?

Epidemiological and clinical data Signup and view all the answers

What distinguishes the non-specific laboratory data in acute hepatitis A?

It shares similarities across different types of acute hepatitis Signup and view all the answers

What vaccination recommendation is advised for patients with chronic liver diseases regarding hepatitis A?

Vaccination against both hepatitis A and B Signup and view all the answers

What is the main site of replication for HBV in the human body?

Hepatocytes Signup and view all the answers

During which stage of HBV infection does the immune system actively clear the virus?

Replicative with immunological clearance Signup and view all the answers

What is a potential outcome if the host's immune response is particularly active after HBV infection?

HBs seroconversion Signup and view all the answers

What is the role of CD8 lymphocytes in HBV infection?

Recognizing infected hepatocytes and mediating cytolysis Signup and view all the answers

What happens to HBV DNA levels during the integrative stage after a strong immune response?

They become undetectable in serum but remain detectable in liver Signup and view all the answers

What facilitates cytolytic aggression in HBV infection?

Cytotoxic T lymphocytes and macrophages Signup and view all the answers

Which stage of HBV infection is characterized by minimal cytolysis and no symptoms?

Replicative with immune tolerance Signup and view all the answers

What can serve as a reservoir for HBV despite not causing inflammatory lesions?

Lymph nodes and circulating lymphocytes Signup and view all the answers

What is the average incubation period for HBV infection?

60-90 days Signup and view all the answers

Which antibodies are considered protective against HBV?

HBV surface antibodies Signup and view all the answers

During which period of HBV infection do symptoms like hyperchromic urine and discolored stools typically occur?

Prodromal period Signup and view all the answers

What symptom is NOT commonly associated with the onset of acute hepatitis B?

Discolored stools Signup and view all the answers

What characterizes the convalescent period of HBV infection?

Persistence of hepatomegaly Signup and view all the answers

Which syndrome is specifically described in children during HBV infection?

Gianotti-Crosti syndrome Signup and view all the answers

What is the typical evolution of HBV infection in most cases?

Self-limiting and favorable Signup and view all the answers

What is a common feature of jaundice during the evolution of HBV infection?

It is typically intense and prolonged Signup and view all the answers

Study Notes

Acute Viral Hepatitis

Acute viral hepatitis are systemic infections primarily affecting the liver.
They are a significant public health concern due to high morbidity, mortality and significant healthcare costs.
Five viruses account for over 90% of hepatitis infections: HAV, HBV, HCV, HDV, and HEV.
HAV is an RNA virus, while HBV is a DNA virus. Other viruses, HCV, HDV and HEV are RNA viruses.

Viral Hepatitis A (HAV)

HAV is a spherical RNA virus (27nm).
It lacks an envelope.
It is antigenically unitary.
It replicates in the liver, bile and feces.
It is thermostable and resistant to acid and organic solvents.
HAV is inactivated by boiling, intense chlorination, autoclaving, UV exposure, and formaldehyde.
It is transmitted enterally.
Clinical manifestation can range from asymptomatic to severe.

HAV Epidemiology

HAV is spread worldwide, with seasonal outbreaks.
The source of infection is a diseased patient, either symptomatic or asymptomatic.
Infectivity period is two weeks before to two weeks after the onset of clinical symptoms.
Transmission is fecal-oral, through contact or contaminated water/food.
Risk groups include: Close contacts, healthcare workers, travelers to high-endemic regions, people with risk of infection.

HAV pathogenesis

HAV is ingested and replicates in the oropharynx and gut.
Replication in the small intestines, followed by transportation via the portal vein to the liver.
HAV does not cause direct cell damage in vitro or in vivo.
Hepatocellular damage is cause by an immune response.
Virus is excreted in feces.

HAV Clinical Picture

The incubation period is 15-45 days.
Prodromal (preicteric) phase (3-5 days), with general symptoms such as fever malaise and myalgias.
Icteric phase (duration variable 4-21 days), with jaundice (and hyperchromic urine and acholic stools).
Convalescent period (2-6 months): recovery and return to normal.
Anicteric form: most frequent in children, with no jaundice.
Fulminant form: Extremely rare, severe and rapidly progressing.
Cholestatic form: Prolonged jaundice.

HAV Laboratory Diagnosis

Elevated transaminases (AST, ALT).
Increased bilirubin (direct and indirect).
Detection of IgM antibodies during acute infection.
Detection IgG antibodies after recovery (for immunity).
Fecal detection.

Hepatitis B (HBV)

HBV is a DNA virus belonging to the Hepadnaviridae family.
The complete HBV particle is known as Dane particle (42nm), consisting of outer shell and inner core.
Envelop with proteins like HBs Ag.
Core contains DNA polymerase.

HBV Epidemiology

HBV is a global health concern.
It is transmitted through parenteral routes (transfusions, IV drug use), non-parenteral routes.
Risk groups include IV drug users, healthcare workers, patients on dialysis, and people with multiple sexual partners.
Vertical transmission is possible from mother to child.
Transmission mostly occurs via blood-to-blood contact.

HBV Pathogenesis

HBV enters the body and replicates within the liver.
The body mounts an immune response against the virus, causing inflammation and cell death in the liver.
Chronic infection can develop with potential complications such as cirrhosis and liver cancer.
The HBV genome is partially double stranded DNA that has multiple open reading frames.
HBV-DNA polymerase mediates the DNA replication in reverse transcription.

HBV Clinical Picture

Incubation period: 60-90 days.
Prodromal period (1-3 weeks): nonspecific symptoms (fatigue, low-grade fever).
Icteric period (2-6 months): jaundice followed by resolution of symptoms.
Fulminant hepatitis is a severe form characterized by rapidly progressing liver failure.
Chronic or prolonged infection is characterized by persistence of symptoms and inflammation for months to years.

HBV Laboratory Diagnosis

Detection of HBsAg: surface antigen, early marker.
Detection of Anti-HBs: antibody, indicates previous infection.
Detection of Anti-HBc: antibody, appears early in infection.
Detection of Anti-HBe: Antibody, indicates remission.
HBV-DNA: Indicates the viral replication

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Description

Explore the key aspects of acute viral hepatitis, focusing on the hepatitis A virus (HAV). This quiz covers the characteristics, epidemiology, and clinical manifestations of HAV, along with its transmission and inactivation methods. Test your knowledge about these significant public health concerns and their impact on healthcare.