Presentation on theme: "MODERATOR : DR. ABHISHEK RAUT"— Presentation transcript:
1MODERATOR : DR. ABHISHEK RAUT HEPATITIS BEPIDEMIOLOGY AND WHO POSITION ON VACCINEVIKASH KESHRIMODERATOR : DR. ABHISHEK RAUT
2INTRODUCTIONPROBLEM STATEMENTEPIDEMIOLOGYPREVENTION AND CONTROLHEPATITIS B VACCINEWHO POSITION ON HEPATITIS B VACCINE
3INTRODUTIONHepatitis b initially called as serum hepatits is an acute systemic illness with major pathology in liver.Besides 2 billion infected cases world wide approximately 36 millions live with chronic infection.These chronically infected people are at increased risk of death from cirrhosis of liver or hepatocellular carcinoma.
4PROBLEM STATEMENT Hepatitis B is endemic in almost all part of world 60% of world population live in endemic areaEstimated 2 billion people infected360 million live with chronic infection600,000 person dies annually as result of consequence of hepatitis B every yearEstimated 25% child dies in later life as a consequence of hepatitis B infection.Vaccine coverage estimated is 69%
7Problem statement cont….. SEAR:Estimated one third population in the region infected80 million carrierEstimated 200,000 death occur annuallyvaccine coverage 41% according to WHO-UNICEF antigen studyINDIA:fall in intermediate endemicity groupHBsAg prevalence between 2% to 7%.Estimated million cases per year.40 million carriers.100,000 death annually by disease related to HBV infection.Of 25 million newborn annually, 1 milion runs lifetime risk of HBV infection
8EPIDEMIOLOGY AGENT FACTOR: Agent : Hepatitis B virus belongs to hepadenavirdae family.Complex 42 nm. Double stranded enveloped DNA virus.Also known as “Dane” particle.Has affinity for liver and hepatocytes
9Reservoir of infection Human being only reservoirInfection spread by cases and carrierCarrier defined as persistence of HBsAg > 6 monthsResistance of virus:quite stable , can survive for days in environmental condition.Can be destroyed by sodium hypochloriteAlso by autoclaving for 30 to 60 minutes.Period of communicability:from incubation period upto disappearnce of HBsAg and upto appearance of antibody.But can be years.
10HOST FACTOR outcome age independent For acute Hepatitis B occurs in 1% perinatal, 10% early childhood (1-5 yrs.) and 30% in older children (>5 yrs. Age)Development of Chronic hepatitis is inversely proportional to age
11HIGH RISK GROUPS Health care workers High risk sexual behavior Commercial sex workerFrequent blood transfusion reciepientInjectable drug usersImmunocompromised individualsInfant of HBV carrier
12Routes of transmission: Modes of transmissionInfective materials:Blood and blood products, serous exudates, saliva, seminal and vaginal fluids, etc.Routes of transmission:1. Percutaneous 2. sexual 3. perinatal4. Others routes
13Percutaneous routes injectable drug users Nonsexual contacts between individualsContact with intimate objectsContact of open skin or mucous membrane with infected materials.Occupational exposure: needlestick injury, surgical procedure, handling infected materials.Rituals: circumcision, tatooing, nose and ear piercing.
14Sexual routes perinatal route: Sexual contact with infected person Favourable factors:-Contact with a person during active infection- H/O sexually transmitted disease- promiscuosity- Male homosexualsperinatal route:important contributor of high prevalence of infectionMostly around perinatal period.
15Other routes: Acute infection during third trimester increases risk. In utero transmission very rareNo evidence of transmission via breast feedingOther routes:Interpersonal contact specially childhood. May be because of skin to skin contact.INCUBATION PERIOD:Varies from 30 to 180 daysAverage 75 daysHBsAg can be detected as early as 30 days and may persist for several months to years.
16Clinical features Insidious onset Early symptom : malaise, weakness , anorexiaRanges from mild asymptomatic infection to fulminant hepatitis to hepatocellular carcinoma to death.
17Subclinical infection Acute hepatitis B infection EXPOSUREClinical infection-jaundice-flu like symptomAsymptomaticOrSubclinical infectionAcute hepatitis B infectionRecoveryOrImmunityFulminant hepatitisChronicCarrierMinimal liverDiseaseChronic HepatitisDeathPrimary hepatocellular carcinomacirrhosisDEATH
18PREVENTION AND CONTROL GOALS OF PREVENTION:to decrease prevalence of chronic carrier and chronic liver diseaseprevention of acute hepatitis B infectionStrategies:Hepatitis B vaccination.Screening of blood, plasma, organ and semen donor.Universal precautions.
19HEPATITIS B VACCINATION Active immunizationPassive immunizationACTIVE IMMUNIZATIONTwo types of vaccine available1. Plasma derived vaccine2. Recombinant DNA vaccinePLASMA DERIVED VACCINE:Based on HBsAg derived from plasma of human carrier.Formalin inactivatedIntramuscularly administeredDose = 1 ml. (contains > 20 mcg. HBsAg.)costlier
20Recombinant DNA vaccine Introduced in in USA.Has replaced plasma derived vaccine.Cost effective and equally effectiveAvailable as monovalent or combined vaccineActive substance:-HBsAg derived from culture of yeast or mammalian cellsAdjuvant:- Alum or thiomersalStorage:-2 to 8°c- freezing avoided-vaccine survive for 7 day at 45°C and for 1 month at 37°c
21Administration Age : No. Of doses: no need of booster dose. Ideal first dose at birth ( within 24 hours)Next 2 or 3 dose according to immunization scheduleCan be given at any ageNo. Of doses:3 or 4First at birth , second and third with DPT1 and DPT3.First at birth, second, third and fourth with DPT and OPV routineOlder child and adults 3 doses at day o, 1 month, 2 monthno need of booster dose.
22Hepatitis B vaccine in immunocompromised state: Dose :- 0.5 ml. for child < 10 years- 1 ml. For adultsRoute :- intramuscularlySite :- left upper arm for adults- anterolateral thigh for young infantsHepatitis B vaccine in immunocompromised state:- not contraindicated but special attention required
23Immunogenicity and Duration of protection Usually life long immunityHepatitis B or even chronic carrier stage rarely occur.Role of natural booster by sub- clinical infection is yet to be provedAdverse reaction:infrequent and rareMyalgia , transient fever , local painNo serious adverse effectVery rarely anaphylactic reactionNo relation with G.B. syndrome or multiple myelomaGACVS recommends excellent safety profile
24Contraindications: H/O allergic reaction to component of vaccine. Pregnancy and lactation no contraindication.HIV positive individual and premature babies can be given vaccineCATCH UP STRATEGY:Vaccinate older children and adults in low and intermediate endemicity area for population immunityTarget age specific cohort and high risk individualStrategy may be mandatory vaccination at school and college entry and before joining job.Target strategic point i.e. STD clinics, centre for IDUs.Continuous surveillance.
25PASSIVE IMMUNIZATIONHepatitis B immunoglobulin used for temporary post-exposure prophylaxis.Combined active and passive vaccination better in following cases:- Newborn of HBsAg +ve mother specially if baby +ve- Percutaneous exposure-Sexual exposure- After liver transplant in case of recurrent HBV infectionTime :within 6 hours of exposure and maximum upto 48 hours.Dose: to ml. / kg. body weight.Provides short term passive immunity for 3 months.
26WHO POSITIONAll newborn should receive birth dose of hepatitis B within 24 hours of birth, in all countries irrespective of their immunity status.Immunization programme must include HBV.Proper Reporting and monitoringMCH care needs to be strenghthenedSchedule include :- First birth dose within 24 hours of birth , followed by either-2 dose schedule with 2 nd and 3rd dose with -DPT 1 and DPT3-Or 3 dose schedule with routine DPT 1 , 2 and 3.
27No need of booster doseCatch up compaign for older age group is important in intermediate and low endemicity area.Catch up compaign for infants and young children is important in high endemicity area.Other target group for catch up strategy can be high risk group.GACVs confirms excellent safety profile.WHO recommends all countries should develop goal for HBV control according to their epidemiological situation
28ReferencesPark k., text book of preventive and social medicine, 20th edition page noManson’ text book tropical diseaseMaxcy- rosaneu- last text book of public healthheahttp://www.who.int/immunization/topics/hepatitis_b/ en/index.htmllth/index.html