Lec. 9 UNFINISHED

Lecture 9

Hepatitis

Inflammation of the liver

classic symptom of hepatitis

jaundice

what is hep. usually caused by 

viruses, drugs, alcohol

where was hep. transmitted

war bc of crowding and unsanitary conditions 

primary hepatitis

occurs immediately after an initial infection by a hep. virus

secondary hep

symptoms follow after another type of infection, disease, treatment

torque teno virus 

TTV

Sentinel viruses

SEN

hep A

HAV

Hep B 

HBV

hep C

HCV

hep D

HDV

hep E

HEV

hep G

HGV

hep A genome

+ssRNA

enveloped or naked hep A

naked

hep B genome

DNA partially ds

hep B enveloped or naked

enveloped

hep C genome 

+ssRNA

hep C enveloped or naked

enveloped

hep D genome

-ssRNA

hep D enveloped or naked

enveloped 

hep E genome

+ssRNA

hep E enveloped or naked

naked

what are most HAV outbreaks associated with

contaminated food or water supplies 

major mode of transmission HAV

fecal-oral

average incubation period HAV

30 days

more often symptomatic in adults or children HAV

adul

symptoms of HAV

fatigue

ab pain

loss of apetite

nausea

dark urine

jaundice

jaundice

yellow color in skin, mucus membranes, or eyes

where is the yellow pigment in jaundice from 

bilirubin, byproduct of old red blood cells 

Is HBV endemic

yes

major spread model for HBV

mother to infant

high risk groups HBV

IV drug users

hemodyalisis

multiple sex. partners

institutionalized patients

healthcare workers 

average incubation period of HBV

80 days

how many people dont have symptoms HBV

30%

symptoms of HBV

similar to HAv + joint pain 

chronic HBV cases

5-10%

what do chronic infections of HBV cause

cirrhosis of liver

hepatocellular carcinoma cancer (HCC)

how was HCV discovered 

ruled out HAV and HBV and cloned. named HCV

symptoms of HCV

silent

what pop. of US is infected with HCV

1.8%

incubation period of HCV

6-7 weeks 

how is HCV spread

blood contact

when did screening for HCV begin

1992

how many HCV experience chronic infection 

bw 55% and 85%

what does HDV require

presence of HBV

symptoms HDV

undistinguishable from HBV

highest risk factor HDV

intravenous drug use

how many IV drug addicts test positive from HDV

39-90%

HEV mode of transmission 

similar to HAV fecal-oral route 

person-to-person transmission HEV

rare

incubation period of HEV

40 days

what are epidemics of HEV associated with 

fecally contaminated water supplies 

mortality HEV

1-3%

mortality in pregnant HEV

15-25%

HEV might be a 

zoonotic pathogen 

HGV

first cloned in plasma 1996

TTV

found in 1997 using RDA

SEN-V

Identified in 2000 with little known about clinical significance 

what is diagnosis of hep. based on

symptoms and physical

blood test for elevated liver enzymes

elevated antibodies against a virus (ELISA)

detection of viral genomes

liver enzymes that will be elevated

AST/ALT

which hepatitis viruses are typically transmitted via fecal-oral route

hep A and E

HBV can be transmitted through

sharing needles and syringes

which hep. virus is a satellite virys that requires co-infection with HBV

HDv

which hep. has no vaccine

HCV

primary mode of transmission HCV

exposure to infected blood, especially via injection drug use

what is used to diagnose HBV

serology 

why is chronic hep. harder to diagnose

patients have no symptoms until damage is severe

how is chronic hep. detectable

increased ALT levels

how long will inflammation be active for chronic hep.

more than 6m

how many familie are hep. viruses in

5

what hep. has no assigned family

HDV

hep. A-E shape 

spherical, icosahedral symm.

hep A-E size

28-50nm

enveloped hep.

BCD

naked hep. 

AE

which hep. is acid and bile resistant

HAV

hep. rep. cycle

blood —> liver —> hepatocytes —> disease

HAV stability, enveloped, family

very stable, naked, picornavirus 

HAV genome length

+ssRNA 7.5kb

where are the viral genome and poly(A) tail at HAV

3’ terminus of the genome

what does the 5’ end of HAV contain 

nontranslated region of hairpins and pseudoknots 

HAV replication integration

hairpin structure acts as an internal ribosomal entry site (IRES) necessary for cap-independent translation of the viral mRNA