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Hepatitis B: Disease and prevention. 3rd June , 2011. LAYOUT OF PRESENTATION. The virus/ es Epidemiology/Statistics HBV disease complications and Transmission Risk groups Prevention, Vaccination. Hepatitis A and B: overview. Hepatitis A and B are inflammatory diseases of the liver 1

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Hepatitis b disease and prevention

Hepatitis B:Disease and prevention

3rd June, 2011


Layout of presentation
LAYOUT OF PRESENTATION

  • The virus/es

  • Epidemiology/Statistics

  • HBV disease complications and Transmission

  • Risk groups

  • Prevention, Vaccination


Hepatitis a and b overview
Hepatitis A and B: overview

Hepatitis A and B are inflammatory diseases of the liver1

Caused by different viruses with different modes of transmission1,2

Both HAV and HBV provoke liver damage1,3

Both diseases have similar signs and symptoms1,3

A chronic carrier state may develop

only after hepatitis B2

HAV

HBV

1. WHO, Hepatitis A, WHO/CDS/CSR/EDC/2000.7

2. CDC, Hepatitis B, Pink book, 2007

3. WHO, WHO/CS/CSR/LYO/2002.2: Hepatitis B


Epidemiology
Epidemiology

Despite the differences in their modes of transmission and clinical outcome, the geographical distribution of HAV and HBV are similar


Geographical distribution of hepatitis a 2005
Geographical distribution of hepatitis A, 2005

Anti-hepatitis A virus prevalence

High

Intermediate

Low

1.5 million cases per yr

CDC, Travelers’ health: yellow book, 2007


Geographical distribution of hepatitis b
Geographical distribution of hepatitis B

Hepatitis B surfaceantigen (HBsAg)prevalence

High

Intermediate

Low

Mast, et al. MMWR Recomm Rep 2006; 55 (RR16): 1–25


Hbv statistics in kenya
HBV Statistics in Kenya

  • Prevalence in General Population – 7-10%

  • Prevalence in Pregnant Women – 9.3%

    (2001 KPA study) and HBeAg - 8.8%

  • HBV Markers of Kenyans by early teens – 70%-90%

  • Prevalence in Blood Donors 5 – 7%

  • HBeAg in child bearing age women +ve

    for HBsAg –8 -23.6%

  • HBeAg higher in children – 60%

    Wankya et al EAMJ 1979

    Okoth et al 1990

    EAMJ Sept. 2006 KPA study


What does hepatitis b cause
What does Hepatitis B cause?

  • Acute infection with jaundice

  • Acute infection, (can last for long) asymptomatic or subclinical

  • Chronic infection

    - Chronic Liver Disease

    - Liver cirrhosis

    - HCC


Typical serological course acute hepatitis b
Typical serological course:acute hepatitis B

Symptoms

HBeAg

anti-HBe

Total anti-HBc

Antibody titre

IgM anti-HBc

anti-HBs

HBsAg

0

4

8

12

16

24

28

32

52

100

20

36

Weeks after exposure

CDC, Hepatitis B slide set, 2007


Typical serological course chronic hepatitis b
Typical serological course:chronic hepatitis B

Antibody titre

0

4

8

12

16

24

28

32

52

20

36

Weeks after exposure

Acute

(6 months)

Chronic

(years)

anti-HBe

HBeAg

HBsAg

Total anti-HBc

IgM anti-HBc

CDC, Hepatitis B slide set, 2007


Hepatitis b outcome according to age at infection
Hepatitis B: outcome according to age at infection

100

100

80

80

60

60

Chronic infection

Symptomatic infection (%)

Chronic infection (%)

40

40

20

20

Symptomatic infection

0

0

1–6 months

7–12 months

Older children

and adults

Birth

1–4 years

Age at infection

CDC, Hepatitis B slide set, 2007


Concentration of hepatitis b virus in body fluids
Concentration of hepatitis B virus in body fluids

CDC, Hepatitis B slide set, 2007


Hbv transmission
HBV transmission

100-times more infectious than the human immunodeficiency virus (HIV)

Transmitted by exposure to infected body fluids (e.g. blood, semen, vaginal secretions):

WHO, WHO/CS/CSR/LYO/2002.2: Hepatitis B


Transmission of hbv in kenya
Transmission of HBV in Kenya

  • Horizontal

    - Most important than vertical

    - Intrafamilial spread important,

    (between siblings and btw spouses)

    - Intrafamilial more important than school

    spread

    - high infection rate in infants & children with

    highest prevalence reached by age ten (may

    be due to higher HBeAg rate)

    (Greenfield1986 & Wankya 1979)

    (Okoth et al 1983 &1990)

    (Bowry 1983)


Hepatitis b perinatal transmission
Hepatitis B Perinatal Transmission

  • If mother positive for HBsAg and HBeAg

    • 70%-90% of infants infected

    • 90% of infected infants become chronically infected

  • If positive for HBsAg only

    • 5%-20% of infants infected

    • 90% of infected infants become chronically infected


Perinatal transmission
Perinatal Transmission

In Asia the rate of HBeAg is highest at 40% hence high PT

PT is present in Kenya but less common than horizontal

Sexual transmission exists but no studies yet

Parenteral transmission less



Hepatitis a b
Hepatitis A & B

Hepatitis A Hepatitis B

Isolation of

Pathogen 1973 1965

FDA vaccine

Licensure 1995 1981

Efficacy 94-100% 80-100%


Prevention of hav hbv
PREVENTION OF HAV & HBV

  • NO SPECIFIC ANTIVIRAL TREATMENT AVAILABLE FOR BOTH

  • Improved Sanitation and Hygiene

  • Safe Sex

  • Screening of pregnant mothers

  • Vaccination for all, newborns, children, travellers


Hbv immunization
HBV IMMUNIZATION

  • Two types of HBV immunization:

    - HBV specific immunoglobulin injection

    - Short term protection

    - Cab be used at birth to reduce perinatal

    transmission in HBsAg + mothers

  • Active Immunization:

    - Current HBV vaccines are based on synthetically

    Recombinant HBsA

    - Contain sections of HBV protein to stimulate a

    natural immune response

    - available locally: Euvax B and Engerix B

  • ;


Hepatitis b risk groups in general
Hepatitis B risk groups in general

Babies born to infected mothers1

Persons living in countries where hepatitis B is endemic1

Family members and sexual contacts of a person infected with hepatitis B1

Healthcare workers (e.g. surgeons, dentists)1

Institutionalised people (developmentally disabled)2

Public safety workers (e.g. police force, fire service, prison service)3

Travellers1

People who have multiple sex partners and men who have sex with men3

Patients on haemodialysis3

Injecting drug users1

Patients with chronic liver disease4

1. WHO, WHO/CS/CSR/LYO/2002.2: Hepatitis B2. Mast, et al. MMWR Recomm Rep 2006; 55 (RR16): 1–253. CDC, Viral hepatitis B fact sheet, 20074. Oldfield & Keefe, Rev Gastroenterol Disord 2007; 7: 1–21


At risk groups requiring dual protection against hepatitis a and b
At-risk groups requiring dual protection against hepatitis A and B

Travellers to areas endemic for both hepatitis A and B

People at occupational risk

Institutionalised individuals

Sexually active homosexual men

Patients with chronic liver disease

Van Damme & Van Herck, Expert Rev Vaccines 2004;3: 249–67


Hepatitis b vaccination
Hepatitis B Vaccination and B

Hepatitis B is the most important Vaccine-preventable communicable disease

Vaccine:

One of the most widely used vaccine in the world

Safe, used for >25 yrs

95% effective in preventing children and adults from developing chronic infection

Reports of success in reducing carrier rates in children generally from 8-15% to <1%

Effective 70-90% in preventing PT given alone within 12 hrs of birth or with Immunoglobulins

Co administration with other vaccines together or separatelyVaccines: targeting 2000, 2nd WSIPD

Advances in Vaccinology, (1)2007

CKiire Gutt 1996; 38: S5-S12


Cont…. and B

  • Taiwan: seroprevalence decreased from 9.8% in 1984 to 0.7% in 1999 and incidence decreased from 0.7:100,000 in 1981/1986 to 0.36:100,000 in 1990-1994 in children.

    Chan CY. Et al. Legend of hepatitis B vaccination: Taiwan experience. J. Gastroenterol. Hepatol. 2004; 19;: 121-126.


Hepatitis b vaccination1
Hepatitis B vaccination and B

  • 1992 WHO recommendation for universal Hep B

    vaccination in all highly endemic (HBsAg carriage rate>8%)countries by 1995 and all other countries by 1997

  • Min age of vaccination - birth (monovalent)Schedules

    – 0,1, 6-12 months - 0,1,2 months for rapid schedule

    No need for a booster dose in routine vaccination

    SAGE Recommendation:

    - In all regions of the world, Perinatal transmission

    is responsible for a sizable proportion of CHB

    infections. Hence all infants should receive the first

    dose of Hep B vaccine as soon as possible after

    birth.


Hepatitis a vaccination recommendations
Hepatitis A vaccination recommendations and B

World Health Organization:1

consider in areas of intermediate endemicity

supplements health education and improved sanitation

persons at increased risk of hepatitis A virus infection should also be vaccinated

Schedule: First dose: 12–23 months:

a booster 6- 12m later

1. WHO, Wkly Epidemiol Rec 2000; 5: 38–44

2. Fiore, et al. MMWR Recomm Rep 2006; 55 (RR07: 1–23


Hib vaccination
HIB Vaccination and B

  • Mass vaccination has dramatically reduced the incidence of Hib infections in children under the age of 5

  • Vaccine in now used in routine immunization schedule in more than 100 countries worldwide

  • Vaccines available in Combination with DPT - Pentavalent, Pentaxim, and with HepB - Titanrix

    www.paho.org/English/HVP/hvp_hib_text.htm


Schedules
Schedules and B

  • Options:

    I. Birth, 6 wks, 6m

    II. Birth, 6wks, 6-9m

    III. 6wks, 10w, 6-9m

    IV. 6wks, 10wk, 14wk

  • For HBsAg mothers use the

    Birth, 6wk, 6mo schedule (birth dose given within 4-12hrs)


Kepi vaccination schedule
KEPI VACCINATION SCHEDULE and B

  • Birth

  • 6 Wks

  • 1O Wks

  • 14 Wks

  • 9 Months

  • BCG, OPV

  • OPV, DPT/Hib/HepB

  • OPV/DPT/Hib/HepB

  • OPV/DPT/Hib/HepB

  • Measles, Yellow Fever

    Mother & Child Health Booklet MOH 216


Efficacy of hepatitis b vaccination in kenya 1988 89
Efficacy of Hepatitis B vaccination in Kenya 1988/89 and B

  • Maragua study, high risk group

  • Plasma derived HB vaccine – 90.2%

  • Recombinant HB vaccine – 99.1%

  • Difference significant

  • Presently vaccine in use is Recombinant

    Okoth et al 1990


Hbv vaccination studies in sub sahara africa
HBV vaccination studies in Sub-Sahara Africa and B

  • Senegal - 93% - 95% seroconversion,

    - no effect on age, maternal Ab,

    pregnancy,

  • SA, Good seroconversion in babies- 93%

  • Im administration not sc

  • Booster doses at 5-10 yrs

  • Mass hepatitis B Vaccination programmes: Kenya,

    Gambia, Cameroon

    CKiireGutt 1996; 38: S5-S12


Hepatitis vaccine and hiv
Hepatitis vaccine and HIV and B

  • The serological response to hepatitis B vaccines is lower for HIV-infected children and adults than for uninfected persons of similar age. Serological response rates have varied, but most studies have reported that only 25–50% of HIV-infected children have developed protective antibodies.


GAVI and BHas helped to increase significantly the number of children who have access to immunization worldwide By 2006:

  • 126M – Hep B

  • 20M- Hib

  • 17m – Yellow fever

  • 1.2 B single use syringes distributed for

    safe vaccination

    http://www.gavialliance.org


Summary
SUMMARY and B

  • Hepatitis B is a serious disease with serious complications and Chronicity

  • Its a major contributing factor to HCC

  • Has a variable prevalence with high endemicity in the developing world

  • It is effectively preventable by the use of Vaccination


Thank you
THANK YOU and B


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