Viral Hepatitis Flashcards
(36 cards)
Three main clinical presentations of Hepatitis
1) Acute
2) Chronic
3) Fulminant
Acute Viral Hepatitis Symptoms
1) Jaundice
2) Dark Urine
3) Acholic stool (light or clay-colored due to reduced bile production)
4) Prodrome (1-2 weeks prior to jaundice; Headache, myalgias, arthralgias, fatigue, nausea, vomiting, pharyngitis, mild fever)
Acute Viral Hepatitis Biochemistry
1) Bilirubin Levels
>3 mg/dL Jaundice
Commonly 5-20 mg/dL
Bilirubin in urine = liver disease
2) Liver Enzymes
- Alanine aminotransferase (ALT)
- Aspartate aminotransferase (AST)
- Elevation apparent as early as PRODROME PHASE
- Usually higher than that of other hepatitis causes
- May be up to 1000 U/L-ALT
Chronic Viral Hepatitis
- Hepatitis which DOES NOT resolve within 6 months
- Predisposes to hepatocellular carcinoma and cirrhosis
Fulminant Viral Hepatitis
- RAPID, SEVERE hepatitis
- Massive hepatic NECROSIS
- Encephalopathy (CNS EFFECTS): confusion, disorientation, coma
- Edema
- Complications: cerebral edema, brainstem compression, GI bleeding, sepsis, organ failure
- LIVER TRANSPLANT can be lifesaving
Hepatitis A (Virus Family, Transmission, Chronic Infection)
Picornavirus, Fecal-Oral, No
Hepatitis B (Virus Family, Transmission, Chronic Infection)
Hepadnavirus, Body Fluids, Yes
Hepatitis C (Virus Family, Transmission, Chronic Infection)
Flavivirus, Body Fluids, Yes
Hepatitis D (Virus Family, Transmission, Chronic Infection)
Deltavirus, Body Fluids, Yes
Hepatitis E (Virus Family, Transmission, Chronic Infection)
Hepevirus, Fecal-Oral, No
Hepatitis A
Picornavirus Family \+ssRNA Fecal oral transmission Seroprevalence 30% All age groups susceptible, children usually ASYMPTOMATIC Incubation period ~28 days Resolution usually within 2 months ***DOES NOT cause chronic hepatitis*** Very rarely causes fulminant hepatitis
Hepatitis A (Diagnosis)
Acute Infection = IgM antibodies against HAV
Anti-HAV IgG antibodies protective immunity (will be present in patients who were PREVIOUSLY exposed)
Hepatitis A (Prevention)
- HAVRIX and VAQTA
- IM injection (2 dose schedule)
- Since 2005, ACIP recommends universal vaccination for all infants (12-23 months), as well as high risk adult groups
- Post-exposure Prophylaxis* (Vaccine or anti-HAV IgG antibodies)
Hepatitis B (Appearance)
Tubes and Spheres: Incomplete, Noninfectious particles (Hepatitis B Surface Antigen - HBsAg)
Dane Particles: Complete Virions (HBsAg, Hepatitis B Core Antigen - HBcAg, and HBeAg)
Hepatitis B (Characteristics)
Hepadnavirus Family
Partially dsDNA genome
REVERSE TRANSCRIPTION (via reverse transcriptase) is part of life cycle
NOT a Retrovirus
Hepatitis B (Acute vs Chronic)
Acute:
- HBsAg is cleared PRIOR TO 6 months
- After this will see Anti-HBs
- Early–> will see IgM
- Late–> will see IgG
Chronic:
- HBsAg is maintained for a long period of time
- **DO NOT have Anti-HBs in this type because it is seen in RECOVERY and you are not having recovery in chronic infections
Hepatitis B (Diagnosis)
- Viral antigens and anti-HBV antibodies used for diagnosis
- Presence of HBsAg within the blood is a marker of ACTIVE INFECTION
Hepatitis B (Acute vs Chronic Lab Tests)
Acute: Anti-HBc Total and IgM are POSITIVE
Chronic: Anti-HBc Total is POSITIVE and IgM is NEGATIVE
How do you know if a patient is susceptible to HBV?
They will have a NEGATIVE Anti-HBc Total test
How do you know if a patient has been previously infected with HBV?
Positive Anti-HBsAg and Positive Anti-HBc Total test
How do you know if a patient has been vaccinated against HBV?
Will have Positive Anti-HBsAg
Hepatitis B (Characteristics)
- Incubation period median 90 days
- Transmission route = Bodily Fluids (e.g. sexual transmission, percutaneous needle stick (6-30%), perinatal transmission at birth (10-90%)
- Half of infected adults are ASYMPTOMATIC
- Acute symptoms are often MILDER than HAV
Younger you are, the more likely you are to develop a chronic HBV infection
Birth = 90% ; Over 5 years old = 10%
Hepatitis B (Treatment)
- None for acute infections
-
Chronic infections
a) Lamivudine —> REVERSE TRANSCRIPTION INHIBITOR
b) Famcyclovir/Adefovir dipivoxil: NUCLEOSIDE INHIBITOR
c) Interferon alpha
Usually a combo of either A and C or B and C
Hepatitis B (Vaccine)
IM injection - 3 dose schedule
Currently use Recombinant HBV vaccine produce in YEAST CELLS (Recombinvax HB and Engerix B)
-Recommended for all infants (1st dose soon after delivery)