hepatitis

Question 1

what is viral hepatitis?

Answer 1

Systemic disease caused by viral agents whose primary tissue tropism is the liver

5 well recognized HEPATOTROPIC VIRUSES:

A,b,c,d,e

can happen with other viruses includin :

CMV, Epstein barr virus , Yellow fever virus

Question 2

describe hepatitis viruses ?

Answer 2

5 types : A,B,C,D,E

Target organ for these viruses is the LIVER ( Tropism )

Basic hepatitis symptoms are similar

Viruses Differ greatly in structure, mode of Replication , mode of transmission, duration of ILLNESS and disease outcome

Question 3

which hepatitis virus is transmitted enterically ?

Answer 3

A –> mildest and most common

E

FECA/ORAL

Question 4

which hepatitis viruses are Parentally transmitted ?

Answer 4

B–> serious and live threating

C—> chronicity

D

Either by sex or blood

Question 5

describe HAV?

Answer 5

Causes about 25-50% of acute hepatitis worldwide –> Cause infectious hepatitis/ epidemic hepatitis

RNA virus

NON-ENVELOPED

Only one stable serotype of HAV –> Difficult to grow in cell culture

Question 6

how is HAV transmitted?

Answer 6

Fecal-oral route

Contaminated food or water ( INFECTED FOOD HANDLERS - RAAW SHELLFISH )

Close personal contact ( Household contact, childday care centers

Inactivated by BOILING FOR 1 MINUTE

Survive prolonged storage at 4 C or below ( survive cold temp )

Question 7

describe pathogenesis of HAV?

Answer 7

Incubation period 2-6 weeks = mean 1 month

Replicate in the alimentary tract and spread to the LIVER where it multiplies HEPATOCYTRES

Viraemia is transient = ( virus in blood )

ASYMPTOMATIC INFECTIONS ( very common in children )

Severe disease in adults ( pregnant women )

NO CHRONIC FORM ( ONLY ACUTE )

Complications –> Fulminant hepatitis ( RARE 0.1 )

AGGRESSIVE IN IMMUNODEFICIENT PATIENTS

SELF LIMITING

Question 8

Describe prodromal/ pre icteric phase of HAV?

Answer 8

symptoms include :

Fatigue, joint, abdominal pain, malaise , vomitting, lack of appetite, hepatomegaly

its in the initial viral replication stage

Question 9

describe icteric phase of HAV?

Answer 9

Jaundice–> SKIN , sclera, mucous membrane

Caused by elevated biliruib lvl, bilirubinuria , dark urine, pale stool

Classical presentation of HAV is scleral icterus

Question 10

Diagnosis of HAV?

Answer 10

Signs and Symptoms of acute hepatitis

Elevated LIVER enzymes ( LFTS )

AntiHAV igM antibodies –> APPEAR EARLY AND REMAIN DETECTABLE FOR 4-16 WEEKS

About 1/3 of asymptomatic population may also have anti HAV igG

DIAGNOSIS OF HAV BY IGM IS VERY SPECIFIC TO HEP A

igM then become igG which protect you throughout life

Question 11

HAV prevention ?

Answer 11

Killed vaccine

From children from age 2 years

Susceptible adults for high risk of infection

Travelers to endemic areas

Close personal contacts

Food handlers

We dont have treatment only supportive one but we use vaccines

Question 12

clues about HEP A?

Answer 12

no chronicity ( cuz its only acute and mild )

RNA VIRUS ( non enveloped )

Food handlers

Daycare

Acute onset

OUT BREAK

Asymptomatic management

Question 13

describe HBV?

Answer 13

mainly in serum hepatitis/post transfusional hepatitis ( blood or sex )

Small enveloped DNA virus ( hav was rna and non enveloped )

Hepandvirus group

Circular partially DOUBLE stranded DNA viruses ( the DNA strand is not complete )

Has reverse transcriptase ( To complete the DNA strand )

HAS NOT YET BEEN POSSIBLE TO PROPAGATE THE VIRUS IN THE CELL CULTURE

Question 14

HBV structure and Antigens ?

Answer 14

HbsAG = surface coat protein –> attachment–> virulence factor

HBcAg= Inner core protein

HbeAg= Secreted protein; Function unkown

HBsAg = comes out a lot to distract immune system

Question 15

How is HBV transmitted?

Answer 15

Virus present in blood , SEMEN, saliva , vaginal fluid

HIGHLY infectious- Remain on environmental surface for at least 7 days -> Sex workers, mother to son during birth when blood spills , IV drug abusers, Health workers

Urine, feces, vomitus, nasopharyngeal washing, sputum, sweat, , are not efficient vehicles of transmission unless they CONTAIN BLOOD

HBsAg –> found in breast milk –> unlikely to lead transmission - not a contraindication to breastfeeding

Question 16

Clinical features of HBV?

Answer 16

from asympotmatic infection to FULMINANT HEPATITIS

Average incubation period is 60 days ( 40-90 ) during this time its asymptomatic

Infant, children aged less than 5 years and immunosuppressed adults with newly acquired HBV infection typically are ASYMPTOMATIC

Symptomatic illness is noted in 30-50% of older children, adolscents and adults

When present –> Nausea, vomiting, abdominal pain, fever, dark urine, changes in stool color, hepatomegaly , splenomegaly, jaundice ( when jaundice occur this is icteric phase )

Fullminant HBV infection is uncommon less than 1% but often results in death or liver failure, necessiltating liver transplant

Extrahepatic manifestation –> Skin rash, arthrraglias, arthritis

Fatality rate among persons with reported cases of acute HBV infections is less than 1.5% with highest rates in adults aged older than 55 years

CASUALLY ASSOCIATED WITH HEPATOCELLULARLY CARCINOMA ( PHC )

Question 17

diagnosis of HBV?

Answer 17

Signs and Symptoms

Elevated LFT

CONFIRMED BY SEROLOGY :

HBsAg –> surface antigen
HBsAb/antiHBs –> antibody to surface antigen
HBcAb/anti HBc–> antibody to core antigen
HBeAg—> E antigen
HBeAb/anti HBe—> antibody to E antigen

CAN SEE C ANTIGEN CUZ ITS CORE

PCR to detect infectious virion nad estimate viral load

Question 18

Describe HBV serology?

Answer 18

HBsAg –> general marker for infection

HBsAb(body)- document recovery and or immunity to HBV

Anti-HBc IgM —> Acute infection

anti-HBc igG —-> Past or chronic infection

HBeAg —> indicates active replication of virus

AntiHBe–> virus no longer replicating but PERSISTING

Question 19

panel of someone immune du to natural infection?

Answer 19

Negative surface antigen

Positive antibody for core antigen ( igG)

Positive antibody for surface antigen

Question 20

panel of someone whos immune to vaccination ?

Answer 20

Negative surface antigen

Negative antibody for core antigen ( cuz never encountered the virus )

Positive antibody for surface antigen

when you have antibody for surface urs immune

Question 20

panel of someone acutely infected?

Answer 20

Positive surface antigen

Positive/negative igG for core antigen

Positive igM for core antigen

Negative antibody for surface antigen

Question 21

panel for chronic infectionn?

Answer 21

Positive surface antigen

Positive igG for core antigen

Negative for igM for core antigen ( cuz it goes down )

Negative antibody for surface antigen

Question 22

describe HBV acute infection?

Answer 22

Detection of both surface antigen and igM for core antigen and antigen E in blood

indicates ongoing infection

Question 23

describe chronic hepatitis ?

Answer 23

Marked by presence of surface antigen for 6 month or more and antibody for CORE antigen

Question 24

describe chronic infection ?

Answer 24

80-90% of persons infected during infancy 30% persons infected before 5 years less than 1%-12% of person infected as older child or adult

Question 25

Treatment of HBV? chronic

Answer 25

interferons nucleoside/nucleotide analogues

Question 26

prevention of HBV?

Answer 26

vaccine --> pre-exposure or active immunity Education HBIG--> post exposure, passive immunity

Question 27

describe HBV vaccines?

Answer 27

first vaccines consisted of Plasma derived surface antigen Recombinant HBV vaccines containing YEAST derived surface antigen 3 dose series ( day 0, day 30, 6 monnth ) If dose is missed continue where with the next scheduled dose if someone has titer antibody more than 10 = immune if its less u need booster the vaccines give u more than 10 antibody titer

Question 28

Post exposure prophylaxis ?

Answer 28

Would and skin sites that have been contact with blood or body fluits should be washed with soap or water For people who are vaccinated as has more than 10 titer no need for post exposure prophylaxis IF person has the less than 10 titer and the source of the surface antigen is UNKNOWN = passive immunity = give antibodies and revaccinate later ( 2 doses 1 month apart )

Question 29

describe hepatitis C?

Answer 29

Positive strand RNA enveloped virus Endemic world-wide -- high incidence in japan, italy, spain, classified into a total of six geno types 1-6 Genotype 1 and 4 has poorer prognosis and response to interferone therapy Transmission similar to hepatitis B Usually ASYMPTOAMTIC or MILD DISEASE Chronic infection is very common 70% ( C for chronicity ) Complications : Chronic liver disease , Hepatocellular carcinoma

Question 30

how is hepatitis C diagnosed ?

Answer 30

HCV antibody --> at least 4 weeks after infection b4 antibody appears HCV RNA --> PCR and branched DNA used to diagnose HCV infection in acute phase HCV antigen --> EIA for HCV antigen is available

Question 31

treatment of HCV?

Answer 31

Ribavirin + IFN alpha Ribavirin is guanosine analong/inhibit nucleoside synthesis/inhibit RNA synthesis INF alpha or pegylated interferon enhance its biologic lifetime NEWER DRUGS --> Sovaldi, Harvoni Genotyping --> 1 and 4 have wors prognosis and poor to treatment

Question 32

Prevention of HCV?

Answer 32

Screening of blood, organ , tissue bonors Blood and body fluid precautions Education risk factors from good to worse BLOOD > SEX > PERINATAL ( same as hep B) NO VACCINES AVAILABLE