1 / 55

Epidemiology of Viral Hepatitis

Epidemiology of Viral Hepatitis. Ashry Gad Mohamed Prof. of Epidemiology Consultant Medical Epidemiologist. Hepatitis A. Abrupt onset. Fever Malaise Anorexia Abdominal discomfort Jaundice. More than 90% are asymptomatic Seroprevalence increases with age.

leon
Download Presentation

Epidemiology of Viral 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 Viral Hepatitis Ashry Gad Mohamed Prof. of Epidemiology Consultant Medical Epidemiologist

  2. Hepatitis A • Abrupt onset. • Fever • Malaise • Anorexia • Abdominal discomfort • Jaundice

  3. More than 90% are asymptomatic • Seroprevalence increases with age. • At age 15, 95% are seropositive. • Case fatality rate (CFR)= 0.3%. • If age > 40 years CFR=2%. • Studies in KSA: 1997 25% 1999 25% Taif 10-82% Jazan (1-12 years)

  4. Agent: RNA virus • Reservior : Human (Clinical & subclinical cases) • Incubation period: 15-35 days ( median one month).

  5. Period of communicability : Last twoweeks of I.P. + one week of illness. • Modes of transmission: Fecal-oral route. Common source outbreaks. Blood transfusion (rare).

  6. Prevention and Control • Good sanitation & personal hygiene. “Careful hand washing” • Day- Care centers Hand washing after every diaper change and before eating. • Shellfish heat 85-90C 4 minutes. steam 90 seconds.

  7. Inactivated hepatitis A vaccine 0 -1 -6 months. Protection after one month. Lasting immunity at least 10 years. • Hepatitis A patient: Enteric precaution for the PC

  8. Hepatitis B • Incidous onset. • Anorexia. • Abdominal discomfort. • Nausia. • Vomiting. • Arthralgia. • Jaundice.

  9. Carriage rates: Sudan 13-19% Pakistan 10-16% Egypt 2.7-15% Saudi Arabia 8.5% Jordan 7-10. Syria 4-6% Iraq 4-5% Morocco 3-6% Yemen 5-6%

  10. More than 500,000 death/year 2 billion people infected 360 million CHB

  11. OVERALL PREVALENCE OF HBsAg AMONG SAUDIS IN THE 80’S ACCORDING TO REGIONS Positivity (%) Al-Faleh. Annals of Saudi Medicine, 1988

  12. COMPARISON OF PREVALENCE OF HBsAg AMONG SAUDI CHILDREN IN 1989 (n=4575) AND 1997 (n=5355) – ACCORDING TO AGE Al Faleh, J Infect 1999

  13. PREVALENCE OF HBsAg POSITIVITY AMONG BLOOD DONORS IN KKUH FROM 1987 TO 2000 Positivity (%)

  14. Natural History • Gow, BMJ2001

  15. Agent: Double strand DNA. Serotypes adw, ayw, adr, ayr. • Reservior: Human (case + carrier). • I.P. 2-3 months. • P.C. One week of I.P. + illness period + carriage. • Carriage depends on age.

  16. Modes of transmission: • Percutaneous and permucosal exposure to infective body fluids. Blood transfusion. Organs transplants. Sharing needles. Haemodialysis. Needlestick. Tattooing. Razors & toothbrushes.

  17. Sexual transmission. • Perinatal transmission.

  18. Prevention and control • Wide scale immunization of infants. • Immunization of high risk persons. Haemodialysis patients. Bleeding disorders. Susceptible households. Health care personnels. • Blood banks: avoid donors from risky groups.

  19. Education & history taking. Testing for HBs Ag. • Discourage: Tattooing, Drug abuse, Extramarital sexual relations. • Needle stick Single dose of HBIG (24 hours). Vaccine series.

  20. Sexual exposure Single dose of HBIG (14 days). Vaccination. • Infants to HBsAg +ve mothers. 0.5 ml HBIG im. First dose of the vaccine. 2nd & 3rd doses at 1 & 6 months later. • Health care personnel. Universal precautions

  21. Hepatitis C

  22. WESTERN EUROPE 9 M FAR EAST/ASIA 60 M EASTERN MEDITERRANEAN 20M USA 4 M SOUTH EAST ASIA 30 M AFRICA 32 M SOUTH AMERICA 10 M AUSTRALIA 0.2 M 170 Million Hepatitis C virus (HCV) carriers 3-4 MM new cases / year WHO, 1999

  23. AGE SPECIFIC PREVALENCE OF ANTIBODY TO HCV/ANTI-HCV AMONG HEALTHY SAUDIS Al-Faleh et al, Hepatology Vol. 14(2), 1991

  24. COMPARISON OF PREVALENCE OF ANTI-HCV IN SAUDI CHILDREN BETWEEN THE STUDIES CARRIED OUT IN 1989 AND 1997

  25. PREVALENCE OF ANTIBODY TO HCV TO SAUDI HIGH RISK GROUPS 2nd-generation anti-HCV tests and confirmation were only done in this study.

  26. ANTI-HCV IN HAEMODYLYSIS PATIENTS IN SAUDI POPULATION

  27. Hepatitis C Virus Genotypes • 11( 6 major) with many subtypes and quasispecies • The predominate genotype in Saudi is Genotype 4 (62.9% ) • Europe & America Genotype 1 75 (24.8) %  severe disease • Genotype 2 = 10.8 (7.4) % • Genotype 3 = 5.8 (5.9) % • Genotype 1 & 4  Poor response to therapy

  28. Natural History of HCV Infection Exposure (Acute phase) 15% (15) 85% (85) HIV and Alcohol Resolved Chronic 80% (68) 20% (17) Stable Cirrhosis 75% (13) 25% (4) Slowly Progressive HCC Transplant Death MJ Semin Liver Dis 1995; 15: Management of Hepatitis C NIH Consensus Statement 1997; March 24-26:15(3).

  29. Important HCV Transmission Modes Blood transfusion IV drug abuse 80% infected in first year 1:100,000 in US

  30. Uncommon HCV Transmission Modes Household transmission Vertical transmission mother - Child ? 1-5% Needle stick injury 3%

  31. Features of Hepatitis C Virus Infection Incubation periodAverage 6-7 weeks Range 2-26 weeks Acute illness (jaundice)Mild (<20%) Case fatality rate Low Chronic infection60%-85% Chronic hepatitis10%-70% Cirrhosis<5%-20% Mortality from CLD 1%-5% Age- related

  32. Chronic Hepatitis C Factors Promoting Progression or Severity • Increased alcohol intake • Age > 40 years at time of infection • HIV co-infection • Other • Male gender • Chronic HBV co-infection

  33. Serologic Pattern of Acute HCV Infection with Progression to Chronic Infection anti-HCV Symptoms +/- HCV RNA Titer ALT Normal 6 1 2 3 4 0 1 2 3 4 5 Years Months Time after Exposure

  34. Exposures Known to Be Associated With HCV Infection in the United States • Injecting drug use • Transfusion, transplant from infected donor • Occupational exposure to blood • Mostly needle sticks • Iatrogenic (unsafe injections) • Birth to HCV-infected mother • Sex with infected partner • Multiple sex partners

  35. Injecting Drug Use and HCV Transmission • Highly efficient • Contamination of drug paraphernalia, not just needles and syringes • Rapidly acquired after initiation • 30% prevalence after 3 years • >50% after 5 years • Four times more common than HIV

  36. Occupational Transmission of HCV • Average incidence 1.8% following needle stick from HCV-positive source • Associated with hollow-bore needles • Prevalence 1-2% among health care workers • Lower than adults in the general population • 10 times lower than for HBV infection

  37. HCV Related to Health Care Procedures • Recognized primarily in context of outbreaks • Chronic hemodialysis • Hospital inpatient setting • Private practice setting • Home therapy • Unsafe injection practices • Reuse of syringes and needles • Contaminated multiple dose medication vials

  38. HCW to Patient Transmission of HCV • Rare • In U.S., none related to performing invasive procedures • Most appear related to HCW substance abuse • Reuse of needles or sharing narcotics used for self-injection • No restrictions routinely recommended for HCV-infected HCWs

  39. Perinatal Transmission of HCV • Transmission only from women HCV-RNA positive at delivery • Average rate of infection 6% • Higher (17%) if woman co-infected with HIV • Role of viral titer unclear • No association with • Delivery method • Breastfeeding • Infected infants do well • Severe hepatitis is rare

  40. Sexual Transmission of HCV • Case-control, cross sectional studies • Infected partner, multiple partners, early sex, non-use of condoms, other STDs, sex with trauma, Partner studies • Low prevalence (1.5%) among long-term partners • infections might be due to common percutaneous exposures (e.g., drug use), BUT • Male to female transmission more efficient • more indicative of sexual transmission

  41. Household Transmission of HCV • Rare but not absent • Could occur through percutaneous/mucosal exposures to blood • Contaminated equipment used for home therapies • IV therapy, injections • Theoretically through sharing of contaminated personal articles (razors, toothbrushes)

  42. Reduce or Eliminate Risks for Acquiring HCV Infection • Screen and test donors • Virus inactivation of plasma-derived products • Risk-reduction counseling and services • Obtain history of high-risk drug and sex behaviors • Provide information on minimizing risky behavior, including referral to other services • Vaccinate against hepatitis A and/or hepatitis B • Safe injection and infection control practices

  43. Reduce Risks for Disease Progressionand Further Transmission • Identify persons at risk for HCV and test to determine infection status • Routinely identify at risk persons through history, record review • Provide HCV-positive persons • Medical evaluation and management • Counseling • Prevent further liver damage • Prevent transmission to others MMWR 1998;47 (No. RR-19)

  44. HCV Prevalence by Selected GroupsUnited States Hemophilia Injecting drug users Hemodialysis STD clients Gen population adults Surgeons, PSWs Pregnant women Military personnel Average Percent Anti-HCV Positive

  45. HCV Testing Routinely Recommended • Ever injected illegal drugs • Received clotting factors made before 1987 • Received blood/organs before July 1992 • Ever on chronic hemodialysis • Evidence of liver disease • Healthcare, emergency, public safety workers after needle stick/mucosal exposures to HCV-positive blood • Children born to HCV-positive women Based on increased risk for infection Based on need for exposure management

More Related