Hepatitis B: Epidemiology and Public Health Issues Perinatal Hepatitis B Prevention Program 2 nd Bi-Annual State Conference May 11, 2010 Austin, Texas Gary Heseltine MD MPH Epidemiologist - Infectious Disease Control Unit Chronic Illnesses Demand Chronic Attention
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Hepatitis B: Epidemiology and Public Health Issues
Hepatitis B: Epidemiology and Public Health Issues. Perinatal Hepatitis B Prevention Program 2 nd Bi-Annual State Conference May 11, 2010 Austin, Texas Gary Heseltine MD MPH Epidemiologist - Infectious Disease Control Unit. Chronic Illnesses Demand Chronic Attention. Topics. - PowerPoint PPT Presentation
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Hepatitis B: Epidemiology and Public Health Issues
Perinatal Hepatitis B Prevention Program2nd Bi-Annual State Conference
May 11, 2010Austin, Texas
Gary Heseltine MD MPHEpidemiologist - Infectious Disease Control Unit
Chronic Illnesses Demand Chronic Attention
Topics• Hepatitis what is it?• Hepatitis B acute
– Basic epidemiology, risks, transmission
• Hepatitis B chronic– Disease burden and sequelae– A health disparity
• Global burden of hepatitis B– Modes of transmission, including injection safety
• Perinatal hepatitis B– Efficacy of prevention strategies
• Patient safety culture and process improvement
Liver
• Located upper right side abdomen• Largest gland in body; 1.3 - 1.6kg• Receives most nutrients absorbed by
GI tract• Essential role in metabolism of fats,
sugars, and proteins• Produces bile, clotting substances,
proteins, stores sugar• Detoxifies compounds• Processes old erythrocytes
Hepatitis: Inflammation of the Liver• Disease process characterized by
– diffuse inflammatory infiltrate– with or without necrosis and local fibrosis.
Chronicity – continuing disease, no improvement– greater than 6 months duration
Hepatitis - inflammation of the liver– Causes
• Viral, drug, toxin, autoimmune, idiopathic
– Characterized by necrosis and inflammation • Cirrhosis – end stage liver disease, fibrosis, diffuse
parenchymal damage, nodular regeneration
Sequelae - 10 to 20 years – Cirrhosis and hepatocellular carcinoma
Progression of Liver Disease
BC Hepatitis Services, 2003
Time frame: years to decades
Cirrhosis
Fibrosis
Cancer
The Golden Fleece and the HeroesWho Lived before Achilles Prometheus Bound
For Prometheus to be set free:•An Immortal would have to give up his life for Prometheus – Chiron (centaur)•A mortal would have to slay the liver-eating eagle - Hercules
– 50-70% of these persons born outside U.S. – 2,000-4,000 deaths per year
• HCV estimated 3.2-3.7M persons– 70% of these persons age 35-54 years– 8,000-10,000 deaths per year– Elevated ALT, history IDU, and history blood transfusion
identified 85% persons 20-59 years
• Chronic liver disease and cirrhosis 12th leading cause of death nationally, 6th for Hispanics
Sorrell et al, Ann Int Med, 2009 150(2):104, Armstrong et al , Ann Int Med 2006;144(10):705, www.cdc.gov/hepatitis/
What proportion of these persons know their sero-status?
• Highest mortality rates with lower CD4 nadir counts
Thio et al, NEJM 2002;360:1921
Hepatitis C 57%
Alcohol 25%
Hepatitis B
Oth
er
NASH 10%
National Cancer Institute – Surveillance Epidemiology and End Results 2006. http://seer.cancer.gov/resources/
HBV 4.4%
Cause of Newly Diagnosed Chronic Liver Disease
Bell et al 2001
HBV Prevalence and Genotype Distribution 1998
A, C, B, D
A
A
D
B, C
E
F
D
G, H not determined
8% and above = High
2% - 8% = Intermediate
Below 2% = Low
F
D
A, B,C,D
F
C
B
Global Burden of Hepatitis B Disease
• 2 billion with markers of current or past infection• 350 million chronic carriers
– 130 million Chinese (1 in 10) have chronic HBV – 15%-25% will die from cirrhosis or liver cancer
• 10th leading cause of death– 600,000 to 1 million preventable deaths / year– Second only to tobacco in cause of cancer deaths
• Risk of dying from liver cancer 100 greater for carriers than non-carriers
Lavanchy D., J Viral Hepat. 2004 Mar;11(2):97-107.WHO. www.who.int/csr/disease/hepatitis/en/
Un homme enceinte s’accouche dans son tombeau*
*A pregnant man delivers in his grave
Cancer rates, Gambian males 1986-96
0
20
40
60
80
100
120
140
all cancerliver cancer
Incidenceper 100,000
Age GHIS Site Review Report 2004
40-44
0-14
15-19
20-24
25-29
30-34
35-39
45-49
50-54
55-59
60-64
65+
UNIJECT
Indonesia: 80–90% home births
•Vaccinate all babies within 7 days of birth
•70,000 midwives
Hepatitis B Carrier Prevalence Before and After Immunization
0
2
4
6
8
10
12
14
16
%
TAIWAN SHANGHAI RURALCHINA
GAMBIA
PRE
POST
Safe Injection Global Network• ~16 billion injections/year / 12 billion syringes sold
~33% unsafe in developing countries~12 million HBV infections ~3 million HCV infections~ 120,000 HIV infections
• Estimated 1 billion injections for childhood immunizations • Little change until Global Alliance for Vaccine and
Immunizations (GAVI) and SIGN were formed– Eligible countries get auto-disable syringes for 3 years. 200 million
already distributed
• Countries responsible for national plan, training, waste management
Kane A, et al, Bulletin of WHO, 1999, 77:801-807
SIGN Pakistan 2001
SIGN Pakistan 2001
Coalition for Safe Community Needle Disposal
800-643-1648
HBV Childhood Exposure Routes
• In Asia, HBV infection is vertical, mother-to-child– 30-40% mothers HBeAg+
• In Africa, horizontal transmission is predominant– About 10% mothers HBeAg+, mothers may be HBsAg-
• Studies in two Gambian villages have shown– infection uncommon first year of life– 50% of the children infected by age of 5– By the age of 10, almost everybody infected, 15 to 20%
chronic carriers.
• Significant associations, but no predominant route of exposure– Number of siblings– Tropical ulcer scars– E antigen positive household member
GHIS Site Review Report 2004
Estimated Births to HBsAg-Positive Mothers United States, 2002
Race/Ethnicity
2002 Births
HBsAg prevalence (%)
Births to HBsAg positive mothers
White 3,174,760 (0.13) 4,127
African American
593,691 (0.50) 2,968
Asian/Pacific Islander
210,907 (7.50) 15,818
Other 42,368 (0.50) 212
Total
4,021,726 23,125
Perinatal HBV Transmission Efficacy
• If mother positive for HBsAg and HBeAg– 70%-90% of infants infected
– 90% of infected infants become chronic carriers
• If positive for HBsAg only– 20-30% of infants infected
– 90% of infected infants become chronic carriers
• In utero transmission rare - accounts for <5% of perinatal infections
HBV Vaccine and HBIG
• HBIG only ~ 75% effective in preventing carriage– Protection wanes
• HBIG not cost effective developing countries– Little value added
Are Three Doses Needed?
“Thus, protection against chronic carriage does not depend on the number of doses received as originally assumed…results from GHIS follow-up of vaccinated subjects, more than 95% of children that received at least one dose are protected against the acquisition of chronic carriage early in life.”
Fortuin, M. et al Lancet 1993; 341:1129-31
Unapparent exposures as “boosters”?
Biologic Processes and Bureaucratic Processes
Success
Hepatitis B
• Hepatitis B virus (1970 Dane particle) - Hepadnaviridae• Enveloped, spherical 42 nm• Partial ds circular DNA genome, about 3.2 kb
• Partial + strand, full length - strand, 5’ RT• Four overlapping open reading frames
• 9 serotypes, 8 genotypes worldwide– Genotype B milder disease than C
• Resistant to environmental stress• 44º C for 7 days, room temperature 6 months, years at -20 º C
“serum hepatitis”
HBV: Gene Products and Mutants
Genome encodes 4 groups of proteins:
• C gene - HBcAg (nucleocapsid protein), HBeAg (soluble protein circulates in serum) – ?Associated fulminant hepatitis and severe liver disease– Pre-core mutants lack HBeAg production, 20%-30% US patients
• P gene - Polymerase (DNA synthesis) – Associated with resistance to treatment with nucleoside analogs
(e.g., lamivudine)• S gene - HBsAg (surface protein)
– Concern that these variants may allow replication in the presence of vaccine-induced anti-HBsAg
– No evidence to date that variants spread in immunized populations
• X gene - X protein (regulates gene transcription)– Associated with hepatocellular carcinoma
HBV S-gene mutants
•Emergence of HBV variant able to escape the vaccine-
induced response suggested in Italy 20 years ago (Zanetti et al, Lancet 1988)
•Evidence indicates that amino acid substitution lead to
conformational changes which allows mutated HBV to
escape vaccine-induced antibodies (G145R)
•44 of 1590 (2.8%) vaccinated people, including babies
born to HBsAg mothers, became HBV infected despite
immunization. All cases showed co-existence of HBsAg
and anti-HBs.
•At present there is no evidence that S-gene mutants
pose a threat to the established PH program of
vaccination
Hepatitis D Virus• Tiny single stranded RNA virus• A “defective” virus that requires HBVsAg for
replication. • Coinfection produces severe disease• Sperinfection often produces chronic disease• Exposure risks same as HBV• Preventing HBV infection prevents HDV
infection, why?
• Licensed in 1981; currently recombinant (in US)• 3 dose series, 0, 1-2, 4-6 months - no maximum time between
doses (no need to repeat missed doses or restart)• 2 dose series (using adult dose) for 11-15 year olds (Merk)• Protection ~50% dose 1; 85% - 2; 96% - 3
Twinrix• Combination adult A and B vaccine• Schedule: 0, 1, 6-12 months• Approved for persons >18 years
Hepatitis B Vaccines
Recommended for Hepatitis B Vaccination(Adults)
• High-risk heterosexual men and women • MSM• Injection drug users• Inmates of correctional facilities• Health care workers• Household and sex partners of persons with chronic infection• Hemodialysis patients• Recipients of blood products• Clients and employees of institution for developmentally disabled• Families of adoptees from endemic countries• Persons with chronic liver disease• Persons who are immunocompromised - HIV
Routine vaccine for all children
Missed Opportunities for Adult Hepatitis B Vaccination
Of all persons with reported acute hepatitis B:
• 37% reported prior treatment for an STD
• 29% reported prior incarceration
• 56% had been treated for an STD and/or incarcerated in a prison or jail prior to their illness
Source:Goldstein ST et.al., JID 2002;185:713-9
•Problem: Failure to screen motherFailure to give birth doseFailure to give prophylaxis
•Root Cause: Too much to doToo many people involvedToo complex a processToo few resources???
•Solutions: Put into delivery check-list (simplify)Put into publicly reported quality measuresPut development of patient safety culture first
Improving Hospital Compliance
Perinatal HBV infections are healthcare-associated infections.
Resources
• Texas Liver Coalition 800-72-LIVER– www.TexasLiver.org– Affiliated St. Luke’s Episcopal Health System, Houston