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Hepatitis A - Download as PDF - PDF

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Hepatitis A - Download as PDF - PDF Powered By Docstoc
					Inflammation of the liver
   Can have many causes
       viral infections specific to liver (A, B, C, D, E ..)
       drugs
       toxins
       alcohol
       other infections (viruses,parasites, bacteria)
Infection of the liver caused by group of viruses
  having a particular affinity for liver

   Hepatitis A
   Hepatitis B
   Hepatitis C
   Hepatitis D ( B + D )
   Hepatitis E
   Hepatitis G
A . Acute Asymptomatic infection
    serologic evidence only
B. Acute Viral Hepatitis
   Short-term hepatitis.
   Body’s immune system clears the virus from the body
    within 6months
C. Chronic hepatitis
    Long-term hepatitis.
    Infection lasts longer than 6 months
D. Fulminant Hepatitis
   hepatic failure in less then 2 weeks
         Acute Viral Hepatitis - 4 phases

1) Incubation period
2) asymptomatic pre icteric phase-
 non-specific constitutional symptoms - fever, malaise, weight loss,
   muscle and joint pains, diarrhoea
 Physical examination : mildly enlarged, tender liver

3) a symptomatic icteric phase
 Jaundice- conjugated and unconjugated hyperbilirubinemia
 Other symptoms abate
 Physical examination- liver mildly enlarged ,and tender
 urine- dark
 Serum Bilirubin ↑ ↑ , ALT, AST ↑ ↑
4) Convalescence
 Recovery
Evidence of continuing or relapsing hepatic disease for more
  than 6 months
Clinical features:
   The most common symptom is fatigue
   Malaise, loss of appetite, and bouts of mild jaundice.
Physical findings :
Mild hepatomegaly , hepatic tenderness
  Laboratory findings:
  Bilirubin 
  AST, ALT 
  Prothrombin time 
  Patients harbor replicating virus and therefore can transmit the
   infection
- Healthy carrier
- Chronic disease
    Severe hepatic insufficiency from onset of symptoms to
    hepatic encephalopathy within 2 to 3 weeks
   Jaundice, encephalopathy and fetor hepaticus.
   Life threatening complications – bleeding, hepatorenal syndrome
   Prognosis:
   Fulminant hepatitis carries a bad prognosis. Many patients die
    due to hepatic failure
   If the patient survives for more than a week secondary
    regenerative activity takes place and then the prognosis is more
    favourable.
Geographic Distribution of HAV Infection
    RNA virus ( picorna virus )
    Single stranded, Non enveloped
    27 nm in diameter



•
Mode of transmission :

 Feco-oral
 - ingestion of contaminated food and water
 - Close personal contact
   Consumption of raw oysters
   Cause for outbreaks
Acute asymptomatic infection or Acute
 symptomatic hepatitis
Protective antibodies develop in response
 to infection - confers lifelong immunity

NO CHRONIC INFECTION OR CARRIER STATE

RARELY FULMINANT HEPATITIS- 0.1%
   Incubation period from 15 - 45 days
   Fever, jaundice : main symptoms.
   99.9 % cases recover completely
                                                   ACUTE    CONVALESCENCE
      Serologic diagnosis :         INCUBATION               AND RECOVERY
                                    PERIOD        DISEASE


    HAVs                                         JAUNDICE
    Shed in feces 2-3 weeks                      SYMPTOMS
    before & 1 week after the
    onset of jaundice

    IgM antibody:                                IgM –anti-HAV

   Declines in a few months                                     IgG –anti-HAV
                                      Fecal
            IgG antibody              HAV
   Appears soon after IgM
    appears, persists for life.
    Provides immunity against re-
    infection.




                                    15-45 days                     Months
                                                 2-12 weeks
         Course of Hepatitis A



Recovery               Fulminant hepatitis
 99.9%                           0.1%

 Chronic Hepatitis                      NO

                                        NO
 CARRIER STATE
                                        NO
 ONCOGENIC POTENTIAL
   Prevention
   Vaccine – 2 doses
   questions?

				
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posted:12/1/2011
language:English
pages:17