Transcript types of viral hepatitis

Viral Hepatitis
Viral hepatitis is a major public health
problem, occurring endemically in all
areas of the world
TYPES OF VIRAL HEPATITIS
 TYPE A (HAV)
 TYPE B (HBV)
 TYPE C (HCV)
 TYPE DELTA (HDV)
 TYPE E (HEV)
THREE PHASES OF
“CLASSIC” HEPATITIS
 PRODROMAL PHASE
 Flu-like symptoms
 ICTERIC PHASE
 Jaundice
 CONVALESCENT PHASE
 Recovery
LAB TESTS
 Liver enzymes:
Alanine aminotransferase (ALT) and
aspartate aminotransferase (AST)
 10 TO 100 FOLD INCREASE CAN BE
EXPECTED
LAB TESTS
SERUM BILIRUBIN: hyperbilirubinemia
 LEVELS MUST APPROACH 3mg/100ml TO
MANIFEST AS JAUNDICE
JAUNDICE OFTEN FIRST MANIFESTS IN
SCLERA
LAB TESTS
 Prothrombin time:
HIGHER THE PROTHROMBIN TIME (PT),
THE
MORE SEVERE THE HEPATIC DAMAGE
HEPATITIS TYPE A
(HAV)
 SINGLE-STRANDED RNA
VIRUs
 SPREAD MAINLY BY ORAL-FECAL
ROUTE
INCUBATION PERIOD 15-50 DAYS
HAV
 Usually disease of young but can affect
adult.
 OFTEN ASYMPTOMATIC
ILLNESS USUALLY SELF-LIMITING
RECOVERY IS COMPLETE and does not
need any specific treatment
 NO EVIDENCE OF CHRONIC FORM OR
CARRIER STATE OF HAV
Prevention
 TWO-DOSE VACCINE
 6 MONTHS APART
 AVAILABLE SINCE 1994
 HEALTH CARE PROVIDERS RECOMMENDED
Hepatitis B virus
 Hepadnaviridae member
 100 times more infectious
than HIV
 10 times more infectious
than HCV
 The most common
carcinogen after tobacco in
man
Schaefer S. World J Gastroenterol. 2007;13:14–21. European Parliament. Hepatitis B: Revealing a Silent Killer. Workshop at the European Parliament, 2006.
Available at: http://www.ilcuk.org.uk/files/pdf_pdf_36.pdf. NIH 11th report on carcinogens 2004. Available at:
ntp.niehs.nih.gov/ntp/roc/eleventh/profiles/s092thpb.pdf.
HEPATITIS B (HBV)
CAN CAUSE ACUTE / AND A CHRONIC
HEPATITIS
Can also cause CARRIER STATE
40 - 180 DAY INCUBATION PERIOD
 MANY CASES ARE SUBCLINICAL
AND MOST ARE ANICTERIC
Concentration of Hepatitis B Virus in Various
Body Fluids
• High concentration
blood
serum
wound exudates
• Moderate concentration
semen
vaginal fluid
saliva
• Low/Not Detectable
urine
feces
sweat
tears
breast milk
Mode of spread
 Mainly by parenteral route
DIRECT PERCUTANEOUS INOCULATION
OF INFECTED SERUM OR PLASMA
 INDIRECTLY THROUGH CUTS OR
ABRASIONS
 ABSORPTION THROUGH MUCOSAL
SURFACES
 ABSORPTION OF OTHER INFECTIOUS
SECRETIONS (SALIVA OR SEMEN)
WHO IS AT GREATEST
RISK FOR HBV INFECTION?
 LAB PERSONNEL WORKING WITH
BLOOD PRODUCTS
 MEDICAL/DENTAL PERSONNEL
IV DRUG ABUSERS
 BLOOD PRODUCT RECIPIENTS
Clinical Features
 Can be asymptomatic (subclinical)
 Symptomatic case pass through 3 phases:
 Prodromal phase
 Icteric phase
 Recovery phase
 Persistence of infection beyond 6 months indicate
progression to chronic phase
Diagnosis
Serological:
Detection of HBV antigen and
antibodies.
Serological markers for hepatitis B
Name
Abbreviation
Definition/Comment
Hepatitis B surface
antigen
HBsAg
Antigen indicating infection
Hepatitis B e antigen
HBeAg
Antigen correlating with
hepatitis B replication and
infectivity
Hepatitis B surface
antibody
Anti-HBs
Usually indicates immunity
Hepatitis B e antibody
Anti-HBe
Presence in serum of persons
with chronic hepatitis B
infection indicates low titre of
hepatitis B
Hepatitis B core
antibody
Anti-HBc
Indicates previous or ongoing
infection with hepatitis B
Mahoney .Clin Microbiol Rev. 1999;12:351–366. http//www.ashm.org.au/uploads/B_Positive-Glossary_abbreviations.pdf.
Outcome of Infection
 COMPLETE RESOLUTION IN 6
MONTHS (95% of adults)
 Chronic infection
 5% ADULTS CHRONIC CARRIERS
 20% CHILDREN CHRONIC CARRIERS
 80-90% NEONATES AND INFANTS
BECOME CHRONIC CARRIERS
PREVENTION
 1. PASSIVE IMMUNITY:
 INJECTION OF IMMUNE GLOBULIN (HBIG)
TRANSFERRING PREFORMED ANTIBODIES FROM
AN IMMUNIZED HOST TO A PERSON IN NEED OF
IMMUNITY
 PROTECTION IS TRANSITORY, BUT ONSET IS
IMMEDIATE
2. ACTIVE IMMUNITY
 Using HBV vaccine
 Act BY STIMULATING OWN IMMUNE
RESPONSE using HBV vaccine
 PROTECTION AFTER LATENT PERIOD
 LONG-TERM IMMUNITY IS PROVIDED
The Hepatitis C Virus
Spherical, enveloped, single-stranded RNA
virus
Family Flaviviridae
HCV may produce ~ 1 trillion new viral
particles each day
Hepatitis C: Basic Facts
 Hepatitis
C is a global health problem
affecting over 170 million people worldwide.
 Hepatitis C is a leading cause of end-stage
liver disease and hepatocellular carcinoma.
HEPATITIS C (HCV)
SPREAD MAINLY BY
PARENTAL ROUTE
ACCOUNTS FOR 90-95% OF
POST TRANSFUSION
HEPATITIS
Sources of Infection for
Persons with Hepatitis C
Sexual 15%
Injecting
drug use
60%
Transfusion 10%
(before screening)
Other* 5%
Unknown 10%
* Hemodialysis; health-care work; perinatal
Source: Centers for Disease Control and Prevention
WHO IS AT GREATEST
RISK FOR HCV
INFECTION?
 LAB PERSONNEL WORKING WITH
BLOOD PRODUCTS
MEDICAL/DENTAL PERSONNEL (310% VIA NEEDLESTICK FROM
INFECTED PATIENT)
IV DRUG ABUSERS
 BLOOD PRODUCT RECIPIENTS
 HEMODIALYSIS PATIENTS
Clinical features
 30-180 DAY INCUBATION PERIOD
Acute infection can be asymptomatic.
Symptomatic cases present through 3
clinical phases
Outcome
 UP TO 90% = CHRONIC CARRIERS
Diagnosis
HCV antibody
HCV RNA (PCR)
A positive antibody test should be
repeated for confirmation
TREATMENT of Viral
Hepatitis
HAV and HEV- ACUTE: SYMPTOMATIC
HBV - ACUTE: SYMPTOMATIC
CHRONIC: Antiviral agents
HCV - ACUTE: SYMPTOMATIC
CHRONIC: COMBINATION INTERFERON ALPHA
and RIBAVIRIN
 SOURCE: RN December 1997
COMPLICATIONS
HAV - RELAPSE; IN RARE CASES - FULMINANT
HEPATITIS
HBV - CHRONIC LIVER DISEASE INCLUDING CIRRHOSIS,
PRIMARY HEPATOCELLULAR CARCINOMA AND
FULMINANT HEPATITIS
HCV - CHRONIC LIVER DISEASE INCLUDING CIRRHOSIS,
PRIMARY HEPATOCELLULAR CARCINOMA
Dental Management:
Difficult to identify all patient through history
Many acute cases of Hep B and C are mild
MUST use universal precautions for all
Screening recommended for patients from
high risk groups
Viral Hepatitis: A,B,C,D,E
Guidelines for blood exposure
From patients with Hepatitis B:
1. Determine the titrer of anti-HBs in the health
care professional
If adequate: no treatment is needed
If inadequate give Hepatitis B Immunoglobulin
Viral Hepatitis:
Guidelines for blood exposure
From patients with Hepatitis C
1. Exposed professional gets baseline and
follow up testing for anti-HCV and liver
enzymes
Viral Hepatitis:
Guidelines for blood exposure
From patients with Unknown
1. Ask for serological testing of the patient
(this can be ordered by the Medical
Officer)
The presence of HCV-RNA in saliva
provides a biological basis for saliva as
a possible source of HCV infection,
Dentists were in a high risk of
contracting this disease due to the
procedures and instruments of dental
treatment.