Download 01. Hepatitis(ABC)1432 - King Saud University Medical Student

14/2/2011
Dr. Salwa Tayel
1
Viral Hepatitis
Associate Professor
Family and Community Medicine Department
King Saud University
14/2/2011
21/2/2010
Dr. Salwa Tayel
2
Viral Hepatitis – Historical Perspective
“Infectious”
Viral
hepatitis
“Serum”
A
Enterically
E transmitted
“NANB”
C
Parenterally
transmitted
B D
other
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A, B, Cs of Viral Hepatitis
•
•
•
A
– fecal-oral spread: hygiene, drug use, men having
sex with men, travelers, day care, food
– vaccine-preventable
B
– sexually transmitted – 100x more infectious than
HIV
– blood-borne (sex, injection drug use, motherchild, and health care)
– vaccine-preventable
C
– blood borne (injection drug use primarily)
– 4-5 times more common than HIV
– NOT vaccine-preventable!
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Acute Hepatitis – Clinical Symptoms
Asymptomatic > Symptomatic > Fulminant Liver
Failure > Death
Symptoms (if present) are the same, regardless of
cause (e.g., A, B, C, other viruses, toxins)
• Nausea, vomiting
• Abdominal pain
• Loss of appetite
• Fever
• Diarrhea
• Light (clay) colored stools
• Dark urine
• Jaundice (yellowing of eyes, skin)
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Infectious hepatitis, epidemic hepatitis,
epidemic jaundice.
• Children are usually asymptomatic, adults symptomatic
• Onset is usually sudden with fever followed within few days
by jaundice.
• Complete recovery is the rule (no chronicity).
• The case-fatality rate among persons of all ages is
approximately 0.3%
• but is approximately 2% among persons > 40 years.
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It is worldwide
In developing countries, it occurs in endemic
and epidemic forms due to:
• Poor environmental sanitation
• Overcrowding
• Lack of personal hygiene.
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Geographic Distribution of HAV Infection
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Cycle of infection
Agent
Susceptible Host
IP
Reservoir
PC
Portal of Inlet
Portal of Exit
Mode of transmission
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
Hepatitis A Virus

Picornavirus (RNA)

Stable at low pH

Inactivated by high temperature,
formalin, chlorine
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• Human
 clinical
 sub-clinical cases
 incubating carriers
Through anal orifice with faeces.
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1. Fecal-oral route. Close personal contact;
house hold contact,, sex contact, day
care centers.
2.Common vehicle; contaminated water
and food; raw shellfish food handlers .
3. Rarely through blood transfusion and
contaminated syringes.
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Through the mouth.
• Susceptibility is general.
• Post infection immunity
probably lasts for life.
Dr. Salwa Tayel
after
the
attack
14
• Incubation period 28 days (range 15-50 days)
• The maximum infectivity is during the latter
half of the incubation period (2 weeks before
and 1 week after onset of jaundice).
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Prevention of Hepatitis A





Vaccination
Immune globulin
Good hygiene (hand washing)
Clean water systems; avoidance of food
contamination
Food sanitation especially shell fish and
raw eaten food.
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Hepatitis A Prevention – Immune Globulin

Pre-exposure
–

travelers to intermediate and high
HAV-endemic regions
Post-exposure (within 14 days)
Routine
–
household and other intimate contacts
Selected situations
–
institutions (e.g., day care centers)
–
common source exposure (e.g.,
food prepared by infected food handler)
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Hepatitis A Vaccine

Inactivated whole virus vaccine.

Licensed for persons 1 year of age and older.

Schedule 2 doses

First dose then booster dose 6-18 months after first.

Gives protection after 4 weeks of the fist dose.

The vaccine should be administered intramuscularly.

Site: deltoid muscle.
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Indications of Hepatitis A Vaccine

Persons at increased risk for infection:
– travelers to intermediate and high HAV-endemic
countries
(Individuals who will travel to high-risk areas <4 weeks
after the initial dose of vaccine should also be given IG)
– MSM (Men who have sex with men)
– illegal drug users
– Persons who have clotting factor disorders
– persons with chronic liver disease

For communities with historically high rates of hepatitis A:
-routine childhood vaccination
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Dr. Salwa Tayel
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Viral Hepatitis B (HBV)
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21/2/2010
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Serum hepatitis, serum jaundice.
 Clinical signs & symptoms occur more in adults.
 At least 50% of infections are asymptomatic
 Onset is usually gradual with anorexia, nausea and
vomiting, often progressing to jaundice.
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Hepatitis B – Clinical Features
• Incubation period:
Average 60-90 days
Range 45-180 days
• Clinical illness
(jaundice):
age <5 yrs, <10%
• Acute case-fatality rate:
0.5%-1%
• Chronic infection:
<5 yrs, 30%-90%
>5 yrs, 2%-10%
>5 yrs, 30%-50%
• Premature mortality from
chronic liver disease:
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Dr. Salwa Tayel
15%-25%
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Symptomatic Infection of Hepatitis B Virus by Age at Infection
Symptomatic Infection (%)
100
80
60
40
20
Symptomatic Infection
0
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Risk of Chronic HBV Carriage by Age of
Infection
100
Carrier risk (%)
90
80
70
60
50
40
30
20
10
0
Birth
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1-6 mo
7-12 mo
Age
infection
Dr. of
Salwa
Tayel
1-4 yrs
5+ yrs
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Outcome of Hepatitis B Virus Infection
by Age at Infection
Chronic Infection (%)
100
100
80
80
60
60
Chronic Infection
40
40
20
20
Symptomatic Infection
0
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0
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CHRONIC Hepatitis B Virus Infection
•Overall risk: 10% of all acute infections.
•About 15%-25% of persons with chronic HBV
infection might die from either cirrhosis or liver cancer
•Chronic infection occurs in:
~ 90% of infants infected with HBV at birth
~ 30% of children infected at age 1- 5 years
2- 6% of people infected after age 5 years
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Geographic Distribution of Chronic HBV Infection
HBsAg Prevalence
8% - High
2-7% - Intermediate
<2% - Low
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Global Patterns of
Chronic HBV Infection

High (>8%):
– 45% of global population
–

early childhood infections common
Intermediate (2%-7%):
– 43% of global population
–

infections occur in all age groups
Low (<2%):
– 12% of global population
–
most infections occur in adult risk groups
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Cycle of infection
Agent
Susceptible Host
IP
Reservoir
PC
Portal of Inlet
Portal of Exit
Mode of transmission
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Hepatitis B Virus
HBsAg
Double-Stranded
DNA
HBsAg
HBcAg
HBeAg
 The presence of HBsAg indicates active infection or chronic carrier.
 Antibody to HBsAg, from either disease or vaccine, indicates immunity.
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Human (cases and carriers).
Human blood and blood products can transmit
infection if not screened for HBs Ag.
Other body Fluids have the virus with varying
concentrations.
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Concentration of HBV
in Various Body Fluids
High
blood
serum
wound exudates
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Moderate
semen
vaginal fluid
saliva
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Low/Not
Detectable
urine
feces
sweat
tears
breast milk
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1.Parenteral: Unsafe injections and transfusions,
organ transplants, sharing needles,
haemodialysis, needle sticks, tattooing , razors
and toothbrushes.
2.Perinatal exposure, especially when HBs Ag
carrier mothers are also HBe Ag positive.
3.Sexual exposure.
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From 45-180 days, average 60-90 days.
• 1-2 months before the onset of symptoms
• during acute clinical course
• during the chronic carrier state which may persist
for life.
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Elimination of HBV Transmission
Strategy
 Prevent perinatal HBV transmission
 Routine vaccination of all infants
 Vaccination of children in high-risk
groups
 Vaccination of adolescents & all
children up through age 18
 Vaccination of adults in high-risk
groups
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Hepatitis B Vaccine
Currently, subunit recombinant HBs Ag
• given IM in the deltoid region.
• 3 dose series, typical schedule 0, 1-2, 4-6 months - no
maximum time between doses (no need to repeat missed
doses or restart)
• Protection
• ~30-50% dose 1
• 75% - dose 2
• 96% - dose 3
• lower protection in older, immunosuppressive
illnesses (e.g., HIV, chronic liver diseases, diabetes),
obese, smokers
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Indication of Hepatitis B Vaccination

Routine for infants.

Ages 11-15 “catch up”, and through age 18 years

Over 18 – high risk
– Occupational risk health care workers (HCWs)
– Hemodialysis patients
– All clinic clients of sexually transmitted diseases (STD)
– Multiple sex partners or prior STD
– MSM (Men having sex with men)
– IDU (injecting drug users)
– Institution for developmental disability (Staff & clients)
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Prevention of perinatal HBV transmission
Prevent perinatal HBV transmission by:
• screening all pregnant women for
hepatitis B surface antigen (HBsAg) &
• providing hepatitis B immune globulin
(HBIG) in combination with hepatitis B
vaccine to infants of HBsAg-positive
mothers
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Immunoglobulins (HBIG):
(HBIG) is indicated in combination with the
vaccine in:
accidental needle stick injury
sure sexual exposure
perinatal exposure
In blood banks:
screening of blood donors
And avoid donors from risky group.
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 Use of adequately sterilized syringes and needles or
preferably use disposal equipment.
 Discourage risky behaviors e.g. tattooing, drug abuse
and extramarital relations.
 Avoid transmission from persons with (e antigen),
especially medical and dental personnel who routinely
perform invasive procedures.
Health care personnel should follow the universal
precautions.
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Hepatitis D (Delta) Virus
d antigen
HBsAg
RNA
HDV is a defective single-stranded RNA virus (delta Ag)
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It requires HBV for synthesis of envelope protein composed of HBsAg.
45
Geographic Distribution of HDV Infection
Taiwan
Pacific Islands
HDV Prevalence
High
Intermediate
Low
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Very
Low
No Data
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Hepatitis D - Clinical Features
• Coinfection with HBV
–
–
severe acute disease
low risk of chronic infection
• Superinfection on top of chronic HBV
– usually develop chronic HDV infection
– high risk of severe chronic liver disease
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Hepatitis D Virus
Modes of Transmission
• Percutanous exposures
injecting
drug use
• Permucosal exposures
sex
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contact
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Prevention of Hepatitis D
• HBV-HDV Coinfection
– Pre or postexposure prophylaxis to prevent HBV
infection (HBIG and/or Hepatitis B vaccine)
• HBV-HDV Superinfection
– Education to reduce risk behaviors among persons
with chronic HBV infection
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Prevalence of HCV Infection Among Blood Donors
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Hepatitis C – Clinical Features

Incubation period:
Average 6 - 7 wks
Range 2 – 26 wks

Acute illness (jaundice)
Mild (≤20%)

Case fatality rate
Low

Chronic infection
60%-85%

Chronic hepatitis
70%

Cirrhosis
5%-20%

Mortality from CLD :
3%
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Natural History of HCV Infection
100 People
Time
15%
Resolve (15)
85%
Chronic (85)
80%
Stable (68)
20%
Cirrhosis (17)
75%
Stable (13)
25%
Mortality (4)
Leading Indication for Liver Transplant
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Chronic Hepatitis C Factors Promoting
Progression or Severity
• Increased alcohol intake
• Age > 40 years at time of infection
• HIV co-infection
• Others:
• Male gender
• Chronic HBV co-infection
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Risk Factors Associated with
Transmission of HCV
• Illegal injection drug use
• Transfusion or transplant from infected donor
• Occupational exposure to blood
– Mostly needle sticks
• Iatrogenic (unsafe injections)
• Birth to HCV-infected mother
• Sexual/household exposure to anti-HCV positive
contact
• Multiple sex partners
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Sources of Infection for
Persons With Hepatitis C
Injecting drug use 60%
Sexual 15%
Transfusion 10%
(before screening)
Occupational 4%
Other 1%*
Unknown 10%
* Nosocomial; iatrogenic; perinatal
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Source: Centers for Disease Control and Prevention
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Other modes of transmission:
percutaneous procedures using inadequately
sterilized equipment (e.g. ear and body piercing,
circumcision, tattooing)
HCV do not spread by sneezing, hugging,
coughing, food or water, sharing eating utensils, or
casual contact
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Prevention of HCV transmission
- Reduce or Eliminate Risks for Acquiring HCV Infection
- Preventing HCV Transmission from patients to Others
- HCV testing/ screening
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Prevention of HCV transmission

Screening and testing donors of blood, organs, and tissues

Virus inactivation of plasma-derived products

Risk-reduction counseling and services
– Obtain history of high-risk drug and sex behaviors
– Provide information on minimizing risky behavior,
including referral to other services

Infection control practices

Blood and body fluid precautions
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Public Health Service Guidelines for
Anti-HCV-Positive Persons
Anti-HCV-positive persons should:
• Be considered potentially infectious
• Keep cuts and skin lesions covered
• Be informed of the potential for sexual transmission
• Be informed of the potential for perinatal
transmission
– no evidence to advise against pregnancy or
breastfeeding
Anti-HCV-positive persons should not:
• Donate blood, organs, tissue, or semen
• Share household articles (e.g., toothbrushes,
razors)
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The End
Thank You
Website http://faculty.ksu.edu.sa/73234/default.aspx
[email protected]
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