Viral Hepatitis Flashcards
Hepatitis Definition
general term for inflammation of the liver
Detection of liver inflammation
liver enzymes elevated from damaged or dying liver cells
ALT & AST
Causes of Hepatitis
viruses, alcohol, drugs, toxins, autoimmunity
Viral agents of acute hepatitis can be divided into 2 major groups
primary hepatitis virus: A, B, C, D, E & G
secondary hepatitis virus: Epstein-Barr virus (EBV) & CMV etc
Acute Hepatitis symptoms
general flu like symptoms etc etc
Chronic Hepatitis symptoms
liver tenderness, JAUNDICE, dark urine, and light or clay colored feces
Hyperbilirubinemia
Jaundice - yellowing of the skin & whites of the eyes
unless increased RBC lysis, jaundice indicates livery injury
Hepatitis A General Characteristics
small RNA containing picornavirus, nonenveloped, single stranded RNA
produces an acute hepatitis NOT CHRONIC
Hepatitis A epidemiology & transmission
HAV is primarily a disease of young children in developing countries
fecal- oral route!
can be blood borne
HAV markers
HAV Ag- shed in the feces & normally not tested for
IgM Ab- detectable in serum indicates acute infection
IgG Ab- indicates immunity to the virus
Vaccine available for HAV?
yes for children & high risk adults
Hepatitis B General Characteristics
major cause of morbidity & mortality throughout the world mostly in China & Asia
DNA virus, enveloped, Double-shelled ‘ Dane Particle’
4 gene products of HBV
HBs, HBcore, HBpolymerase, HBX (transcription factor)
HBV epidemiology & transmission
LONG incubation period (45-90 days)
much more stable of a virus than retro viruses:
Percutaneous : contaminated needle stick etc
Permucosal: sexual intercourse & perinatal
HBV Surface Antigen
protein present on surface of virus, initial detectable marker found in serum
persence indicats active HBV infection (acute & chronic)
HBV Surface Antibody
develops during the recovery from HBV infeciton
serologic marker of recovery & immunity
HBV core antigen
only present in infected liver cells & is not detected in the blood
HBV acute infection
1st to appear is HBsAg then anti HBs antibody
HBV chronic infection
HBsAG is positive, virus remains in body after acute infection is over
NO presence of anti-HBsAg antibody
risk of progressing to chronic is age dependent (90% in infants)
HDV General Characteristics
parentally transmitted infection that can only occur in the presence of HBV!
uses HBsAg to assemble into new particles & attach and enter new cells
circular RNA & a single protein, delta antigen, surrounded by HBV viral envelop
HDV epidemiology & transmission
uncommon in the US, predominantly IV drug users & sexual partners
high mortality rate
co-infection w/ HBV or superinfection
Co-infection with HBV
in which infection of HDV & HBV occurs simultaneously
Superinfection
in which HDV infects individuals who are already chronic HBV carriers
HDV serological markers
antibodies to HDV antigens:
IgM HDV Ab - acute infection
IgG HDV Ab -indicates recovery from HDV
HDV RNA- indicates active infection
Hepatitis C Virus General Characteristics
small, enveloped, single stranded RNA virus w/ 6 different genotypes
HCV Acute & Chronic
Acute: 70% are asymptomatic Chronic: 75%-85% develop chronic infection 60%-70% will progress to chronic liver disease if untreated
HCV transmission
transmitted mainly by exposure to contaminated blood
IV drug use
prior to 1992- blood transfusions were a large risk
HCV serological Markers
Anti-HCV antibody- indicates current or past HCV infection
CONFIRMATION TEST:
RIBA test (recombinant immunoblot assay)
HCV vaccine?
no vaccine exists
ribaverin results in a ‘cure’ in 80% of patients
HCV genotyping assays
each different genotype presents a different clinical profile, different severity of liver disease & response to alpha interferon therapy
Hepatitis E General Characteristics
Fecal-oral transmission
self limiting / acute
