Hepatitis

 

🦠 COMMONLY OCCURRING COMMUNICABLE DISEASES

HEPATITIS

🔹 INTRODUCTION

Hepatitis refers to inflammation of the liver resulting in injury to liver cells.

It can be caused by:

• Toxins
• Certain drugs
• Alcohol abuse
• Bacterial infections
• Viral infections

The term hepatitis also refers to a group of viral infections affecting the liver, mainly:

• Hepatitis A (HAV)
• Hepatitis B (HBV)
• Hepatitis C (HCV)
• Hepatitis D (HDV)
• Hepatitis E (HEV)

These account for the majority of hepatitis cases worldwide.

🔹 TYPES OF VIRAL HEPATITIS

Common viruses causing hepatitis:

• HAV, HBV, HCV, HDV, HEV (major causes ~95%)
• Others:
• Herpes simplex virus
• Cytomegalovirus
• Epstein–Barr virus
• Yellow fever virus
• Adenovirus

🔹 ETIOLOGY (CAUSES)

Major causes include:

• Use of infected needles/syringes
• Intravenous drug abuse
• Transfusion of infected blood/products
• Unprotected sexual contact
• Poor sanitation and contaminated food/water

🔹 MODES OF TRANSMISSION

Virus	Source	Transmission Route
HAV	Feces	Fecal–oral
HBV	Blood/body fluids	Parenteral, sexual
HCV	Blood	Parenteral
HDV	Blood	Parenteral
HEV	Feces	Fecal–oral

🔹 HEPATITIS A (HAV)

Causes

• Contaminated food and water
• Raw shellfish from polluted water
• Poor sanitation

Features

• Highly contagious
• Acute infection only (no chronic disease)
• Full recovery is common

Virus Characteristics

• Small, non-enveloped RNA virus
• Replicates in cytoplasm

Pathophysiology

• Enters via oral route
• Travels to liver → infects hepatocytes
• Liver damage occurs due to:
• Direct viral effect
• Immune response

🔹 HEPATITIS B (HBV)

Causes

• Blood transfusion
• Needle sharing
• Sexual transmission
• Perinatal transmission

Features

• Can be acute or chronic
• May lead to:
• Cirrhosis
• Hepatocellular carcinoma

Virus Characteristics

• DNA virus (Hepadnavirus)
• Replicates via reverse transcription

Important Antigens

• HBsAg → Surface antigen
• HBcAg → Core antigen
• HBeAg → High infectivity marker

Pathophysiology

• Virus itself does not destroy cells
• Liver damage due to immune response (T-cells)
• Chronic infection → weak immune response

🔹 HEPATITIS C (HCV)

Causes

• Blood transfusion
• Needle sharing
• Mother-to-child transmission
• Sharing personal items (razors, toothbrushes)

Features

• Often asymptomatic
• High chance of chronic infection
• May lead to:
• Cirrhosis
• Liver cancer

Virus Characteristics

• RNA virus (Flaviviridae family)

Pathophysiology

• Targets hepatocytes
• Persistent infection → chronic inflammation → fibrosis

🔹 HEPATITIS D (HDV)

Key Point

• Requires HBV for replication

Types

1.     Co-infection (HBV + HDV together)

• Usually self-limiting
• Rare chronic infection

2.     Superinfection (HDV in HBV carrier)

• Severe disease
• Rapid progression to cirrhosis
• High risk of liver failure

Pathophysiology

• Severe immune-mediated liver damage

🔹 HEPATITIS E (HEV)

Causes

• Contaminated water (endemic areas)
• Undercooked pork (non-endemic areas)

Features

• Acute infection
• Dangerous in pregnant women

🔹 HDV SUPERINFECTION IN HBV

• Occurs in chronic HBV patients
• Leads to:
• Acute flare of hepatitis
• Rapid disease progression
• Cirrhosis within 2 years (10–15% cases)

Diagnosis Tip

• IgM anti-HBc helps differentiate:
• High → Acute HBV
• Low/negative → Chronic HBV

🔹 PREVENTION

• Vaccination (HBV, HAV)
• Safe blood transfusion
• Use sterile needles
• Safe sex practices
• Clean drinking water
• Proper hygiene

🔹 IMPORTANT EXAM POINTS ⭐

• HAV & HEV → Fecal-oral
• HBV, HCV, HDV → Blood-borne
• HDV requires HBV
• HCV → highest chronicity
• HBV → vaccine available
• HEV → severe in pregnancy

🦠 INFECTION WITH HDV AFTER HBV (SUPERINFECTION)

When a patient already has chronic Hepatitis B, exposure to Hepatitis D can lead to superinfection.

🔹 Key Features

• Occurs in chronic HBV carriers
• Causes acute flare of hepatitis
• Often misdiagnosed as acute HBV infection

🔹 Diagnosis Tip

• IgM anti-HBc levels
• High → Acute HBV
• Low/negative → Chronic HBV (suggests HDV superinfection)

🔹 Clinical Course

• Severe and rapidly progressive
• Leads to:
• Chronic hepatitis
• Cirrhosis (10–15% within 2 years)

🔹 Important Points

• HDV suppresses HBV replication
• In HBV + HDV + Hepatitis C:
• HCV replication is reduced

🦠 HEPATITIS E (HEV)

🔹 Overview

• Caused by Hepatitis E virus
• Usually acute and self-limiting
• Does not commonly cause chronic infection (except in immunocompromised)

🔹 Transmission

• Fecal–oral route
• Contaminated water
• Undercooked pork (non-endemic areas)

🔹 High-Risk Groups

• Pregnant women (severe disease)
• Organ transplant patients
• HIV patients

🔹 Virus Structure & Pathophysiology

• RNA virus (Hepevirus genus)
• Non-enveloped, icosahedral
• Genome:
• ORF-1 → replication proteins
• ORF-2 → capsid protein
• ORF-3 → function unclear

🔹 Genotypes

• Genotype 1 & 2 → Humans
• Genotype 3 & 4 → Zoonotic

🦠 HEPATITIS G (GBV-C)

🔹 Overview

• Also called GB virus C (GBV-C)
• Belongs to Flaviviridae family

🔹 Key Fact

• Infects humans but does NOT cause significant disease

🔹 Structure

• Enveloped RNA virus
• Similar to HCV (~25% homology)

🔹 Replication

• Occurs mainly in:
• Lymphocytes (CD4, CD8, B cells)
• Low levels in liver

🦠 SYMPTOMS OF VIRAL HEPATITIS

🔹 Common Symptoms

• Nausea and vomiting
• Loss of appetite
• Fatigue and weakness
• Fever
• Dark urine
• Pale stools
• Jaundice
• Abdominal pain

🔹 Hepatitis-Specific Symptoms

🟢 Hepatitis A

• Usually mild
• Rare: acute liver failure (elderly, chronic liver disease)

🔵 Hepatitis B

·        Often asymptomatic in children

·        Chronic cases →

• Cirrhosis
• Liver failure
• Kidney problems

·        Co-infection with HDV → severe complications

🟠 Hepatitis C

·        Chronic disease symptoms:

• Fatigue
• Weight loss
• Muscle & joint pain
• Depression
• Cognitive issues

·        Advanced (cirrhosis):

• Ascites
• Bleeding tendency
• Hepatic encephalopathy

🔴 Hepatitis D

• Similar to HBV
• More severe disease
• Can worsen HBV symptoms

🟡 Hepatitis E

• Malaise
• Arthritis
• Pancreatitis
• Neurological complications:
• Guillain-Barré syndrome
• Bell’s palsy
• Neuropathy

🧪 DIAGNOSIS

🔹 Blood Tests

Detect antibodies against hepatitis viruses.

🔹 Liver Function Tests (LFTs)

• ALT (SGPT)
• AST (SGOT)
• ALP
• GGT

🔹 Acute Viral Hepatitis Panel

Includes:

• HAV IgM → Acute HAV
• HBc IgM → Acute HBV
• HBsAg → Current HBV infection
• HCV antibody → Exposure (not active vs past)

🔹 Additional Tests

• HBV surface antibody → Immunity
• HDV antibody & RNA → HDV infection
• HEV IgM → Acute HEV
• GBV-C RNA → Detection via PCR

🔹 Liver Biopsy

Used to:

• Assess liver damage
• Stage hepatitis B & C
• Guide treatment

💊 TREATMENT

🟢 Hepatitis A

• No specific treatment
• Supportive care only

🔵 Hepatitis B

Acute:

• Usually self-limiting

Chronic:

Antiviral drugs:

• Lamivudine
• Entecavir
• Adefovir
• Telbivudine

Other:

• Interferon therapy

Severe Cases:

• Liver transplantation

Prevention:

• Vaccination (HBsAg-based vaccine)

🟠 Hepatitis C

Treatment Goal:

• Complete viral cure

Drugs:

• Sofosbuvir + Ledipasvir
• Sofosbuvir + Simeprevir
• Ribavirin ± Interferon

Important:

• No vaccine available

🔴 Hepatitis D

• Interferon-alpha (long-term)
• No specific vaccine
• Prevent by HBV vaccination

🟡 Hepatitis E

• Mostly supportive treatment
• Ribavirin in severe cases
• Pegylated interferon in chronic cases

🛡️ PREVENTION

• Safe drinking water
• Good sanitation
• Personal hygiene
• Avoid contaminated food
• Safe sex practices
• Sterile needles
• Vaccination (HBV, HAV)

⭐ HIGH-YIELD EXAM POINTS

• HDV needs HBV (most important MCQ)
• Superinfection > Co-infection severity
• HEV severe in pregnancy
• HCV → highest chronicity
• HBV → vaccine available
• GBV-C → non-pathogenic

 

 

 

Informed consent Form

 

✅ INFORMED CONSENT FORM (ICF)

🔹 Definition

Informed consent is a mandatory ethical and legal process in research involving human subjects.
It ensures that participants voluntarily agree to participate after understanding all aspects of the study.

🔹 Importance

• Protects rights, safety, and well-being of participants
• Ensures transparency in research
• Required by Ethics Committee/IRB approval
• Maintains legal and ethical compliance

📝 FORMAT AND STYLE OF ICF

• Written in 2nd person (“You”)
• Avoid starting sentences with “You understand…”
• Use simple, layman language
• Avoid technical/medical jargon (or explain clearly if used)
• Use 12-point font (larger for elderly/children if needed)
• Must be typed (not handwritten)
• May include:
• Tables
• Flowcharts (for better understanding)
• Must include:
• Participant signature
• Investigator signature
• Date
• Witness signature (if applicable)

📋 COMPONENTS OF INFORMED CONSENT FORM

1. PURPOSE OF THE STUDY

• Explain in simple terms
• Clearly state:
• Why the study is being done
• That it is research
• Define terms like:
• Randomization
• Double-blind
• Placebo-controlled

2. PROCEDURES

• Describe:
• Study steps and activities
• Duration of participation
• Include:
• Inclusion & exclusion criteria
• Tests/interviews/questionnaires
• Add table/flowchart if helpful

3. RISKS AND DISCOMFORTS

• Mention:
• Physical risks
• Psychological risks
• Social/economic risks
• Include:
• Foreseeable risks
• Unforeseeable risks statement
• Example: blood collection risks

4. BENEFITS

• Describe expected benefits:
• To participant
• To society/science ⚠️ Note:
• Compensation ≠ Benefit
• Free treatment ≠ Benefit

5. COMPENSATION / COSTS / REIMBURSEMENT

• Mention:
• Payment (if any)
• Travel reimbursement
• Clearly state:
• Any extra costs to participant

6. WITHDRAWAL FROM STUDY

• Participant can:
• Withdraw anytime without penalty
• Mention:
• Conditions for investigator termination
• Safe withdrawal procedures

7. CONFIDENTIALITY

• Explain:
• How data will be protected
• Who can access data
• Assure:
• Privacy of participant identity

8. NEW FINDINGS

• Participants will be informed if:
• New information affects their decision to continue

9. ALTERNATIVES TO PARTICIPATION

• Explain:
• Other treatment options (if applicable)
• Option to refuse participation

10. COMPENSATION FOR INJURY

• State:
• Treatment/compensation if injury occurs
• Applicable mainly in clinical trials

11. OTHER CONSIDERATIONS

• Disclose:
• Financial conflicts of interest
• Include:
• Information about biological sample collection (if any)

12. CONTACT INFORMATION

• Provide:
• Investigator contact details
• Ethics Committee/Research Office contact

13. VOLUNTARY PARTICIPATION

• Clearly state:
• Participation is completely voluntary
• No penalty for refusal or withdrawal

14. SIGNATURES

Include:

• Participant
• Investigator
• Legally Authorized Representative (LAR) (if needed)
• Witness (in specific cases)
• For minors:
• Parent/guardian consent
• Assent (age 13–17)

⚖️ WAIVER OF WRITTEN INFORMED CONSENT

IRB may waive signed consent if:

✔ Condition 1:

• Only link to participant is consent document
• Main risk = breach of confidentiality
• Participant decides if documentation is needed

✔ Condition 2:

• Study involves minimal risk
• No procedures requiring written consent outside research

➡️ Participants may still receive an information sheet

⚖️ WAIVER / ALTERATION OF INFORMED CONSENT

IRB can waive or modify consent if:

• Study involves minimal risk
• Does not affect participant rights/welfare
• Not feasible without waiver
• Participants are informed later (if required)
• Not applicable to FDA-regulated clinical trials

🔑 EXAM QUICK POINTS

• Always written in 2nd person
• Use simple language
• Must include risks, benefits, confidentiality
• Voluntary participation is essential
• IRB approval required
• Waiver allowed only under strict conditions

 

 

Tuberculosis

Tuberculosis (TB)

1. Introduction

Tuberculosis (TB) is a chronic infectious disease caused mainly by the bacterium Mycobacterium tuberculosis. It primarily affects the lungs (pulmonary TB) but can also involve other organs such as lymph nodes, bones, kidneys, brain, and joints (extrapulmonary TB).

Several species belong to the genus Mycobacterium, including:

• Mycobacterium intracellulare
• Mycobacterium kansasii
• Mycobacterium bovis

However, Mycobacterium tuberculosis is the main pathogen responsible for TB in humans.

TB spreads from person to person through airborne droplets expelled when an infected person coughs, sneezes, laughs, or speaks.

In many healthy individuals, the immune system walls off the bacteria, resulting in latent TB infection, where bacteria remain inactive without symptoms. When immunity weakens (e.g., HIV infection, malnutrition, aging), the bacteria may become active and cause disease.

2. Epidemiology

Tuberculosis remains one of the most prevalent infectious diseases worldwide.

According to the World Health Organization:

• Millions of new TB cases occur each year globally.
• Developing countries carry the largest burden.
• India accounts for one of the highest numbers of TB cases in the world.

Factors contributing to high TB prevalence include:

• Poverty
• Malnutrition
• Overcrowding
• Poor living conditions
• Limited healthcare access

TB therefore remains a major public health problem, particularly in developing nations.

3. Etiology

Tuberculosis is caused by Mycobacterium tuberculosis.

Transmission occurs through airborne droplets released when a person with active TB:

• coughs
• sneezes
• speaks
• spits
• laughs
• sings

When these droplets are inhaled, the bacteria enter the lungs and initiate infection.

4. Risk Factors

Certain conditions increase the risk of TB infection or progression to active disease.

Major risk factors include:

• HIV/AIDS
• Frequent or prolonged contact with TB patients
• Malnutrition
• Poverty and overcrowded living conditions
• Immunocompromised states
• Diabetes mellitus
• Alcoholism
• Old age
• Chronic lung disease
• Smoking

5. Pathophysiology

Infection Process

1. TB bacteria enter the body through inhalation of droplet nuclei.
2. The bacteria reach the alveoli of the lungs.
3. Alveolar macrophages engulf the bacteria.
4. Instead of being destroyed, bacteria survive and multiply inside macrophages.
5. Infected macrophages release bacteria, triggering an immune response.
6. The immune system forms granulomas to contain the infection.

Granuloma Formation

Granulomas consist of:

• macrophages
• lymphocytes
• necrotic center (caseous necrosis)

The granuloma helps limit bacterial spread.

Latent TB Infection

In many individuals:

• Bacteria remain dormant
• Person has no symptoms
• Person is not infectious

However, the bacteria may reactivate later.

Active TB Disease

Active TB usually occurs when immunity weakens.

About 10% of people with latent TB develop active disease during their lifetime.

Risk is especially high in:

• HIV infection
• Patients receiving immunosuppressive therapy
• Those taking systemic corticosteroids or TNF-alpha inhibitors

6. Clinical Manifestations

Early Stage

During the initial infection, symptoms may be absent or mild.

Sometimes mild bronchial pneumonia may occur.

General Symptoms

Symptoms of chronic TB infection include:

• Loss of appetite (anorexia)
• Malaise (general feeling of illness)
• Weight loss
• Fatigue
• Low-grade fever
• Night sweats

Respiratory Symptoms

• Persistent cough lasting more than 2 weeks
• Sputum production (green, yellow, or blood-stained)
• Chest pain
• Shortness of breath
• Hemoptysis (coughing up blood)

Symptoms of Extrapulmonary TB

Symptoms depend on the organ involved.

Lymph nodes

• Swelling in neck or underarms

Bones and joints

• Pain and swelling, especially knee or hip

Genitourinary TB

• Flank pain
• Frequent urination
• Pain during urination
• Blood in urine

7. Diagnosis

Diagnosis involves clinical evaluation and laboratory tests.

Medical History and Physical Examination

Doctors assess symptoms such as:

• chronic cough
• fever
• fatigue
• night sweats
• weight loss

Laboratory Tests

Sputum Culture

• Confirms active TB infection
• Results may take 1–8 weeks

Sputum Microscopy

Examines sputum under a microscope to detect TB bacteria.

Mantoux Tuberculin Skin Test

A common test used to detect TB infection.

Procedure:

• Tuberculin is injected into the skin of the forearm.
• The reaction is checked after 48–72 hours.

A swelling at the site indicates possible infection.

TB Blood Test

Measures immune response to TB bacteria.

Useful when:

• Skin test results are uncertain
• Patient previously received TB vaccination

Chest X-Ray

Used to detect lung abnormalities such as:

• infiltrates
• nodules
• cavitation
• lesions

However, X-ray cannot confirm TB alone.

Rapid Molecular Tests

Rapid sputum tests can detect TB bacteria within 24 hours.

Diagnosis of Extrapulmonary TB

Additional tests may include:

Biopsy

• Tissue sample examined for TB bacteria

Urine culture

• Detects renal TB

Lumbar puncture

• Used to diagnose TB meningitis

CT scan

• Detects lung cavities or miliary TB

MRI scan

• Detects TB in brain or spine

Patients are also tested for:

• HIV infection
• Hepatitis

8. Anti-Tuberculosis Drugs

Treatment requires multiple drugs to prevent resistance.

First-Line Drugs

1. Isoniazid
2. Rifampicin
3. Ethambutol
4. Pyrazinamide
5. Streptomycin

These drugs are the most effective in TB treatment.

Second-Line Drugs

Used when resistance develops.

Examples include:

• Para-aminosalicylic acid
• Thiacetazone
• Ethionamide
• Cycloserine
• Kanamycin
• Rifabutin

New Drugs for Drug-Resistant TB

• Bedaquiline
• Delamanid
• Linezolid
• Sutezolid

Multidrug Resistant TB (MDR-TB)

Multidrug-resistant tuberculosis occurs when TB bacteria become resistant to isoniazid and rifampicin.

Treatment:

• Combination of second-line drugs
• Duration 18–24 months

9. Treatment Regimen

Short Course Therapy (6 Months)

Initiation Phase (First 2 Months)

• Isoniazid
• Rifampicin
• Pyrazinamide
• Ethambutol

Continuation Phase (Next 4 Months)

• Isoniazid
• Rifampicin

Long-Term Therapy (12 Months)

Used in complicated TB cases.

Initiation Phase

• Isoniazid
• Rifampicin
• Pyrazinamide
• Ethambutol

Glucocorticoids may be given for 2–3 weeks in severe inflammation.

Continuation Phase

• Isoniazid
• Rifampicin

for 10 months.

10. DOTS Strategy

The DOTS is recommended by the World Health Organization.

Five Components

1. Government commitment
2. Case detection by sputum microscopy
3. Standardized treatment under supervision
4. Continuous drug supply
5. Recording and reporting system

This strategy improves treatment success and prevents drug resistance.

11. Vaccination

BCG Vaccine

The BCG vaccine protects against severe TB in children.

Features:

• Given to newborn babies
• Common in countries with high TB prevalence
• Prevents severe childhood TB complications

12. Prevention

Health Education

• Encourage cough hygiene
• Use masks
• Improve ventilation
• Avoid crowded environments

Early Diagnosis and Treatment

Early treatment prevents:

• disease progression
• transmission to others

Healthy Lifestyle

• Balanced diet
• Regular exercise
• Adequate rest
• Avoid smoking and alcohol
• Maintain good ventilation

13. Spread of TB

TB spreads through air when infected individuals:

• cough
• sneeze
• laugh
• talk
• sing

Prolonged exposure in shared airspace increases infection risk.

14. TB Is NOT Spread By

TB does not spread through casual contact such as:

• shaking hands
• sharing utensils
• sharing food
• using public telephones
• brief contact on the street

Case Report Form Design

📘 CASE REPORT FORM (CRF) –

🔹 Definition

• A Case Report Form (CRF) is a data collection tool (paper or electronic) used in clinical trials.
• It records all protocol-required information for each trial subject.
• Ensures data accuracy, consistency, and regulatory compliance.

🔹 Types of CRF

1.     Paper CRF (pCRF)

• Traditional method
• Time-consuming, costly, risk of errors and duplication

2.     Electronic CRF (eCRF)

• Digital format (increasingly used)
• Advantages:
• Improved data quality
• Faster data entry and validation
• Online discrepancy management
• Faster database lock
• Reduced redundancy and errors

🔹 Importance of CRF

• Central to data collection, management, and analysis
• Ensures:
• Data integrity and quality
• Standardization across sites
• Validity of clinical trial results
• Supports:
• Investigators, coordinators, monitors, and statisticians

🔹 Elements of CRF

1. Header Information

• Study number
• Site/center number
• Subject ID
• Key identifying details

2. Safety Modules

Include:

• Demographics
• Adverse events
• Vital signs
• Medical history & physical examination
• Concomitant medications
• Patient disposition

3. Efficacy Modules

• Based on study protocol
• Include:
• Primary endpoints
• Secondary endpoints
• Additional efficacy tests
• Often custom-designed for each study

🔹 Data to be Collected

• Inclusion/exclusion criteria
• Baseline & demographic data
• Protocol-specific data
• Drug dosage and therapy details
• Adverse events & concomitant medications
• Missed visits or tests
• Withdrawals/dropouts (with reasons)
• Some data may be source data (no prior record)

🔹 CRF Design & Development Principles

• Follow protocol strictly
• Maintain uniform format, font, and layout
• Use:
• Clear, concise questions
• Minimal free text
• Separate answer fields
• Include:
• Units of measurement
• Standard date format (DD/MM/YYYY)
• Decimal precision
• Avoid:
• Duplication
• Ambiguity
• Ensure:
• Page numbering consistency
• Clear instructions
• Use NCR copies for paper CRFs

🔹 CRF Layout Types

1. Non-Time Dependent Data

• Collected once
• Example: Demographics, medical history

2. Time-Dependent Data

• Collected repeatedly over time
• Example: Vital signs
• Layout options:
• Per visit page
• Cumulative format

3. Cumulative Data

• Collected over time, not visit-specific
• Example:
• Adverse events
• Concomitant medications
• Uses cumulative log format

🔹 Checklist for Handling CRF

• Write legibly (block letters)
• Use appropriate units
• Correct errors:
• Strike with a single line
• Do not erase
• Add initials & date
• Use different ink for corrections
• Maintain source data availability
• Document all errors and changes with explanation

🔹 Responsibilities in CRF Design

• Collect only protocol-required data
• Include:
• Safety & efficacy parameters
• Align with:
• Study schedule (visit plan)
• Involves:
• CROs
• Data managers
• Investigators

🔹 Uses of CRF

• Subject tracking
• Data analysis & reporting
• Safety reporting to regulatory bodies (e.g., FDA)
• Support for:
• New Drug Application (NDA)
• Labeling claims
• Publication in journals

🧠 Exam Tip

👉 Most asked areas:

• Definition + Types
• eCRF advantages
• CRF elements (Safety vs Efficacy modules)
• Data types (Non-time, Time, Cumulative)
• Error correction rules