Hepatitis B Virus Overview

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Questions and Answers

What type of virus is Hepatitis B Virus (HBV)?

DNA virus (correct)

Envelope virus

RNA virus

Retrovirus

Which family does Hepatitis B Virus (HBV) belong to?

Retroviridae

Orthomyxoviridae

Adenoviridae

Hepadnaviridae (correct)

What is the complete virus of Hepatitis B Virus (HBV) commonly referred to as?

HBV particle

Dane Particle (correct)

Serum Hepatitis Virus

Hepadnavirus

Which of the following statements is true regarding HBV?

HBV is a DNA virus causing serum hepatitis. Signup and view all the answers

Which disease is primarily caused by the Hepatitis B Virus (HBV)?

Serum hepatitis Signup and view all the answers

Which tests are primarily used to assess liver function?

Liver function tests Signup and view all the answers

What is the main target of the assessment in liver function tests?

Liver cells Signup and view all the answers

Why are liver function tests crucial in medical evaluations?

They provide insight into liver cell health Signup and view all the answers

Which of the following is NOT typically included in liver function tests?

Platelet count Signup and view all the answers

What does a high level of liver enzymes often indicate?

Possible liver damage or disease Signup and view all the answers

What is a common cause of needle prick injuries among medical personnel?

Infections from emergency patients Signup and view all the answers

What does vertical transmission refer to?

Infection during pregnancy or lactation Signup and view all the answers

Which scenario illustrates a risk of vertical transmission?

A mother lactates while sick Signup and view all the answers

What is a significant concern for medical personnel regarding needle-related injuries?

They can result in infections from patients Signup and view all the answers

Which of the following is NOT related to vertical transmission?

Transmission via blood transfusions Signup and view all the answers

What is the role of immunoglobulin in relation to HBV?

It regulates antibody production against HBV without requiring the antigen. Signup and view all the answers

When is immunoglobulin typically administered regarding HBV exposure?

Within the first 24 hours of exposure. Signup and view all the answers

What precaution should be taken by doctors during a C-section related to infections?

Be cautious of potential needle pricks. Signup and view all the answers

What may the doctor encounter if not cautious during a C-section?

Exposure to infectious agents through a needle prick. Signup and view all the answers

Why is it important to administer immunoglobulin without the antigen in the early stages?

To provide immediate protection against the virus. Signup and view all the answers

What is a key characteristic of the virus mentioned that distinguishes it from other viruses?

It heals without resulting in scarring. Signup and view all the answers

Why is the healing process of this virus significant?

It avoids potential complications associated with scarring. Signup and view all the answers

Which of the following could be a misconception about the healing process of this virus?

It is similar to healing from common colds. Signup and view all the answers

How does the healing mechanism of this virus compare to that of other viruses?

This virus uniquely heals without scarring. Signup and view all the answers

What implication does the lack of scarring in the healing process have?

It could lead to faster recovery for patients. Signup and view all the answers

What characteristic of the condition affects the skin in a localized manner?

Unilateral dermatome involvement Signup and view all the answers

Where is the virus dormant in relation to the sensory supply?

Dorsal root ganglion Signup and view all the answers

What is the role of the dorsal root ganglion concerning the virus mentioned?

It stores the virus in a dormant state. Signup and view all the answers

How does the described condition primarily manifest on the skin?

It creates localized symptoms in a single dermatome. Signup and view all the answers

What does the term 'dermatome' refer to in this context?

An area of skin supplied by sensory fibers of a single spinal nerve root Signup and view all the answers

Study Notes

Viral Infectious Agents

Viral infectious agents are a topic covered in block 1.2 lectures.
The lecture notes are from the 2024-2025 academic year.
Lecture notes are by Mohammed Alibrahem and Arwa Alzaid.
Note-taking highlighters are used to organize the information.

Herpes Simplex Viruses (HSV) Type 1

Herpesviridae viruses are known for latent sequences in their pathogenesis.
HSV is one example of a virus with latent viral infection.
Primary HSV infection occurs upon first exposure, usually in children.
Transmission is typically by direct contact (e.g., saliva, tears)
Clinically, primary infection presents as vesicles on erythematous bases.
Vesicles rupture and dry, forming crusts that heal without scarring within 7-10 days.
This differs from other viruses that heal with scarring.

Clinical Types of HSV-1 Infection

The commonest type of primary HSV-1 infection is acute gingivostomatitis.

Pathogenesis & Clinical Picture: Secondary Infection

Latent infections are present in the dorsal root ganglion of the face (trigeminal ganglion) in HSV-1.
Virus particles are transported along axons to the sensory dorsal root ganglion.
Some virus particles establish latent infection.
HSV-1 latency is in the trigeminal ganglion and lasts the lifetime of the host.
Reactivation can occur every 2-3 years due to stressful conditions and the host's immune status.

Recurrent Herpes Labialis

Recurrent herpes labialis (fever blisters or cold sores) is a result of reactivation of primary gingivostomatitis.
This can occur when immune status is lower.

Varicella-Zoster Virus (VZV)

VZV infection has two clinical forms:
- Primary infection: varicella (chickenpox). This is characterized by a generalized eruption.
- Reactivation infection: zoster (shingles). This infection causes a localized form.

Chickenpox (Varicella): Primary Infection

This is usually seen in children aged 4-10.
Droplet infection is the main transmission route.
Approximately 90% of adults have been infected in childhood, but 10% remain susceptible.

Shingles (Zoster): Reactivation

This occurs in adults.
This results from the reactivation of a latent varicella infection in neurons.
The virus travels to the ganglion via the periphery along nerve axons or blood during the viraemic stage of varicella infection from childhood.

Varicella Rash: Clinical features

The rash starts on the trunk, first, then spreads to the limbs. (Generalized).
Initially, a macular rash becomes elevated above the skin as macules.
These evolve into papules, then into vesicles filled with clear fluid.
The filled vesicles then become pustules, that crust and eventually heal.
Healing is without scarring.

Zoster Rash: Clinical Features

The rash is unilateral or confined to limited areas on one side of the body,
This is due to one dermatome being affected.
The rash is characterized by painful vesicular eruptions.
This is important to know so that professionals can pinpoint the affected nerve.

Laboratory Diagnosis

Smears of vesicular lesions and direct virus detection.
Serology — detecting specific VZV antibodies (IgM or rising IgG titre) using ELISA.

Poxviridae Family

The poxviruses are the largest of all viruses.
They are large enough that they can be seen with a light microscope (300nm)
They are brick-shaped with complex symmetry.
Poxvirues are enveloped viruses with double-stranded DNA.
Smallpox was once of medical importance but is now eradicated.

Hepatitis B Virus (HBV)

HBV is a DNA virus of the Hepadnaviridae family.
It causes serum hepatitis.
The complete virus particle is called a Dane particle.
Diagnosis can be confirmed by various means.
HBV is spherical or tubular, which is caused by the surface antigen HBsAg
HBV can be transmitted sexually, parenterally, from mother to infant, and through various other contacts.

HIV

HIV is an enveloped virus.
It is easily disinfected once outside the host.
It enters the blood to infect.
HIV has various structures, such as a glycoprotein complex made from gp120 and gp41.

HIV Structure and Genome

HIV has a core and a capsid.
The HIV genome is made up of two identical copies of positive-sense, single-stranded RNA.

HIV Transmission

HIV can be transmitted sexually.
It can be transmitted by blood or blood products.
It can sometimes be transmitted during pregnancy or through breastfeeding.

HIV Diagnosis

Antibody screening tests are used to determine HIV infection.
An initial positive test often requires confirmatory tests such as western blot testing.

Further testing for HIV

Nucleic acid tests – e.g., PCR
CD4 counts are used to determine the progression and stage of the infection.

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Description

This quiz explores key facts about the Hepatitis B Virus (HBV), including its classification, effects on liver function, and implications for medical personnel. Test your understanding of the risks associated with HBV and the importance of liver function tests in diagnosis.