1 / 76

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

walda
Download Presentation

Epidemiology of hepatitis

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  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)

More Related