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Epidemiology of hepatitis

Epidemiology of hepatitis. Presenter : Dr.L.Karthiyayini Moderator: Dr. Abhishek V Raut. Framework. Introduction Hepatitis A,E,B,C,D&G Magnitude Natural history of the disease Epidemiological determinants Mode of transmission Clinical feature Sero epidemiology Prevention & control

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Epidemiology of hepatitis

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  1. Epidemiology of hepatitis Presenter : Dr.L.Karthiyayini Moderator: Dr. Abhishek V Raut

  2. Framework • Introduction • Hepatitis A,E,B,C,D&G • Magnitude • Natural history of the disease • Epidemiological determinants • Mode of transmission • Clinical feature • Sero epidemiology • Prevention & control • Hepatitis & HIV • Global policy report on hepatitis-status of India • WHO position of hepatitis vaccine

  3. Introduction • VIRAL HEPATITIS IS A MAJOR PUBLIC HEALTH PROBLEM • Hepatitis A & E - 0.5-4 % mortality • World wide 500 million people have chronic HBV & HCV infection • In India, 45 million people with HBV 500,000 to 1,000,000 people die every year of HBV-related chronic Hepatitis, cirrhosis or liver cancer • Out of nearly 22.6 million children born in India every year, over 9 million will acquire the infection in their lifetime.

  4. Hepatitis is the inflammation of liver by any cause • Viral hepatitis is mainly caused by • Hepatitis A & E virus - Faeco-oral route - Acute & self limiting • Hepatitis B,C & D virus- Parenteral route -Acute & chronic • Other viruses- cytomegalovirus, rubella virus, epsteinbarr virus, yellow fever virus ,herpes zoster virus,etc. • Other hepatitis- • Alcoholic hepatitis (50% of CLD)(mortality : M-11/100000 & F-6/10000) • Auto immune hepatitis, • toxic & drug induced hepatitis,

  5. Natural history of acute hepatits

  6. HEPATITIS A

  7. Source:CDC

  8. MAGNITUDE • GLOBAL: • Prevalence of anti-HAV antibodies in general population -15%-100% • Worldwide 1.5 million clinical cases yearly • Outbreaks • INDIA: • seroprevalence of anti-HAV: • 54.5%- high socio-economic status • 85% in low socio-economic status

  9. EPIDEMIOLOGICAL DETERMINANTS • AGENT: • Picarnovirus family • 4 human genotypes • 1 serophytype • HOST: • Low endemic area • Adolescents & adults(homosexual, IV drug users) • Travellers • Intermediate endemic area • Late childhood(faeco oral route) • Early adult hood • High endemic area • Early childhood

  10. ENVIRONMENTAL FACTORS: • Water borne & food borne epidemics • Sanitation & overcrowding • MODE OF TRANSMISSION: • Faeco-oral route • Parentral route – stage of viremia • Sexual transmission-homosexual due to ano-oral contact • Secondary attack rate among household contacts is 30% • INCUBATION PERIOD • 28 days

  11. CLINICALFEATURES Symptoms & signs • Fever • Anorexia • Malaise • Nausea • Abdominal discomfort • Dark urine • Jaundice Complications: • Relapsing hepatitis • Cholestatic hepatitis • Fulminant hepatitis(0.1%)

  12. SERO EPIDEMIOLOGY • IgM- Detectable from 5 days prior to onset of symptoms & declines to undetectable levels within 6 months. • IgG-Detect previous infection, persists life long • Elevated levels of serum bilirubin • Elevated hepatic enzymes(AST,ALT)

  13. HAV INFECTION-TYPICAL SEROLOGICAL COURSE Source: Yim, H. J., et al., (2006). Hepatology.

  14. PREVENTION & CONTROL • Control of reservoir: • Complete bed rest • Disinfection of faeces & fomites • 0.5% sodium hypochlorite • Control of transmission: • promoting personnel & community hygiene • Purification of community water supplies • Proper sanitation & waste disposal • During epidemics, boiling of water is preferred

  15. Active immunization • Inactivated vaccines & live attenuated vaccines • Parenterally (IM), 2 dose,6-18 months apart. • Combined vaccine(inactivated hepatitis A & recombinant hepatitis B) -0,1,6 mths. Passive immunization HAV IG –Pre & Post exposure prophylaxis -single I.M dose,0.02 ml/kg within 2 weeks

  16. HEPATITIS E

  17. MAGNITUDE • GLOBAL • SEAR • INDIA • MAHARASHTRA Source:CDC

  18. MAGNITUDE • GLOBAL: • Overall attack rates during hepatitis E outbreaks - 1% to 15%. • The rates are highest among young adults (3%-30% • Case-fatality rates - 0.5% to 4% • During outbreaks mortality rates - 0.07–0.6% • INDIA: • Proportion- 10% • Seroprevalence of anti-HEV antibodies-upto 50%

  19. EPIDEMIOLOGICALDETERMINANTS • AGENT • Hepatitis E like virus • HOST • 15-40yrs • Pregnant mothers-20% fulminant(0.5% mortality) • MODE OF TRANSMISSION: • Faeco oral route • Water borne disease • Ingestion of raw or uncooked shell fish- sporodic cases • Vertical transmission • Secondary attack rates 0.7-2.2% • INCUBATION PERIOD: 2-9 weeks

  20. CLINICAL FEATURES Symptoms • Abdominal pain • Nausea • Vomiting • Anorexia Signs • Jaundice • Hepatomegaly

  21. SERO EPIDEMIOLOGY • Elevated antibody levels-RT-PCR

  22. Hepatitis E Virus Infection Typical Serologic Course Symptoms IgG anti-HEV ALT Titer IgM anti-HEV Virus in stool 0 1 2 3 4 5 6 7 8 9 10 11 12 13 Source: Yim, H. J., et al., (2006). Hepatology. Weeks after Exposure

  23. PREVENTION & CONTROL • Good personnel hygiene • High quality standards of public water supply • Proper disposal of sanitary waste • Vaccines – undergoing clinical trails

  24. HEPATITIS B

  25. Source:CDC

  26. MAGNITUDE • GLOBAL: • 2million • 240 billion carriers • 60-80% of all primary liver cancer • High endemicity, intermediate endemicity & low endemicity • INDIA: • Point prevalence of hepatitis B is 2.1% • chronic carrier rate 1.7% • HCC 1.6% of all cancers • High carrier state among health workers 11% & in general population 5%

  27. Global Patterns of Chronic HBV Infection • High (>8%): 45% of global population • lifetime risk of infection >60% • early childhood infections common • Intermediate (2%-7%): 43% of global population • lifetime risk of infection 20%-60% • infections occur in all age groups • Low (<2%): 12% of global population • lifetime risk of infection <20% • most infections occur in adult risk groups

  28. NATURAL HISTORY OF DISEASE

  29. NATURAL HISTORY OF CHRONIC HBV INFECTION - seroepidemiology Source: Yim, H. J., et al., (2006). Hepatology.

  30. EPIDEMIOLOGICALDETERMINANTS • AGENT: • DNA virus- hepadnaviridae family • 3 morphological forms-small spherical particles, tubules & Dane particle(infectious) • HBsAg, HBcAg, HBeAg(Viral replication) • Only reservoir - Man • Infective material-contaminated blood, saliva, vaginal secretions, semen • Resistance – stable for 7 days in environmental surface, destroyed by sodium hypochlorite & by heat sterilization 30-60 mins

  31. HOST: • Age: • Acute hepatitis - 1% of perinatal cases,10% of early chidhood, 30% of late childhood • Chronic hepatitis – 80-90% -perinatally, 30% in early chilhood, 5% infected after 6 yrs • High risk groups: • Surgeons have 50% more chance • Others- recipients of blood transfusion, health care & laboratory care personnels,percutaneous IV drug abusers, homosexuals, infants of HBV carrier mothers,immunocompromised patients.

  32. MODE OF TRANSMISSION • Parenteral route -Blood borne disease • Perinatal route • Sexual transmission • Horizontal transmission • INCUBATION PERIOD 30-180 days(75 days)

  33. COURSE OF SYMPTOMS IN ACUTE HEPATITIS

  34. SEROEPIDEMIOLOGY • HBsAg: • Appears first & persists throughout the illness • Indicates infectivity • Anti-HBs: • Signal recovery, non-infectivity & immunity • Anti-HBc: • Appears shortly after HBsAg is detected • Indicates a diagnosis of acute hepatitis • IgM anti-HBc persists for 3-6 mths. Reappears during the flares of previously inactive chronic hepatitis B • IgG anti-HBc also appears Persists indefinitely

  35. SEROEPIDEMIOLOGY • HBeAg: • Appears in the incubation period shortly after HBsAg • Indicates viral replication & infectivity • Persistence beyoun 3 mths – chronic hepatitis B • HBV DNA: • Parellels the presence of HBeAg • Senisitve & precise marker • PCR

  36. Acute Hepatitis B Virus Infection with Recovery Source: Yim, H. J., et al., (2006). Hepatology.

  37. Progression to Chronic Hepatitis B Virus Infection Source: Yim, H. J., et al., (2006). Hepatology.

  38. PREVENTION & CONTROL • Hepatitis B vaccine • Hepatitis B immunoglobulin • Passive active immunization • Other measures

  39. HEPATITIS B VACCINE • Recombinant hepatitis B vaccine-1986 • Monovalent & Fixed combination(DPT, Hib, hepatitisA, inactivated polio) • Storage : 2-8˙C (avoid freezing) • Dose: • Adults: • 10-20 micrograms • Deltoid • Children : • Half the dose • Antero lateral aspect of thigh • Schedule: 0,1,6 mths

  40. National immunization schedule: • 3 dose schedule :At birth, along with 1st & 3rd dose of DPT • 4 dose schedule: At birth, 6,10,& 14 weeks • Monovalent or combined • Minimum interval between the doses are 4 weeks • If prevalence is > 8%- within 24 hrs of birth • Duration of protection: 15 yrs • Protective antibody levels-> 95% (infants, children & young adults) • More than 40yrs – protection <90% • More than 60yrs- protection 65-75% • Low birth weight babies

  41. Reduced immunogenicity: • Diabetes • Chronic renal failure • Chronic liver disease • HIV infection • If interrupted ? • as soon as possible • restarting not required • Recommnended for: • < 18 yrs of age • High risk group • International travellers • Contraindicated: • H/O allergy to vaccine components

  42. Hepatitis B immunoglobulin • Immediate protection • Used for acutely exposed: surgeons, lab workers, nurses, newborns of carrier mothers, sexual contacts of hepatitis B patients, liver transplanted patients • Within 6 hrs-48 hrs • Recommended dose: 0.05-0.07 ml/kg (2 doses,30 days apart) • Short term passive protection – 3 mths • No long term prophylaxis • limited availability • High cost • Risk complications

  43. Passive-active immunization • Combined HBIG & hepatitis B vaccine more efficacious • Recommended: • newborn babies of carrier mothers • Accidental exposure • Dose: 0.05-0.07 ml/kg within24 hrs • Hepatitis B vaccine 1.0ml, IM within 7 days of exposure, 2nd & 3rd dose at 1 & 6 months after 1st dose Other measures • Screening of blood donors • Adequate sterilization • Practice simple hygiene measures • Carriers- no sharing, barrier contraception, no blood donation

  44. HEPATITIS C

  45. MAGNITUDE • GLOBAL: • worldwide 3% infected • 3-4 million persons newly infected every year • 70% among newly infected- chronic hepatitis • INDIA: • 1/4th of all chronic liver cases • 12.5 million carriers • Seroprevalence among donors- 0.48%(Vellore) – 1.85%(Delhi)

  46. NATURAL HISTORY OF DISEASE

  47. EPIDEMIOLOGICAL DETERMINANTS • AGENT: • Flaviviridae family • 6 genotypes & 100 sub types • HOST: • High risk group - recipients of blood transfusion, health care personnel, homosexuals, drug abusers & infants of carriers • MODE OF TRANSMISSION: • Parenteral route • Perinatal route • Sexual transmission • INCUBATION PERIOD: • 15-150 days

  48. CLINICAL FEATURES • 80% -asymptomatic • 15-30% - develop jaundice • 80% of newly infected develop chronic hepatitis • Cirrhosis-10-20% • Liver cancer-5-10% (in 20-30 yrs)

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