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HEPATITIS B C D AND G

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HEPATITIS B C D AND G Powered By Docstoc
					Hepatitis A-E November 2nd, 2006 duffuswa@dhec.sc.gov HEPATITIS A
BASICS • RNA picornoviruse, SS RNA • Single serotype worldwide • Humans only reservoir TRANSMISSION

• Fecal-oral • Contaminated raw seafood- e.g oysters • Day-care center outbreaks

EPIDEMIOLOGY

• Over 100,000 infections/ year in US • 31% sero-prevalence in US
rd

• Much higher prevalence in 3 world PATHOGENESIS

• Incubation 4 weeks (2-6wk range) • Oral cavity-GI tractliver • Virus in stool 2 weeks after infection, usually shed in stool prior

to symptoms
• Symptoms related to immune response and not direct cytopathic

effect of virus
SIGNS & SYMPTOMS Adults will have signs and symptoms more often than children.

70-80% of adults develop symptoms, <10% of kids (<6 years) develop symptoms
• jaundice • fatigue • abdominal pain • loss of appetite • Elevated ALT/AST • nausea • diarrhea • fever • Complete recovery in 99%

HEPATITIS A CONTINUED
LONG-TERM EFFECTS • There is no chronic (long-term) infection. • Lifelong immunity after infection- ie no repeat infection

DIAGNOSIS

• Hep A IgM antibody usually present when symptoms occur • IgG suggests prior infection or vaccination

TREATMENT PREVENTION

• Supportive- no antiviral therapy • Hepatitis A vaccine is the best protection. • Vaccine dosed at 0, 6-12m • Protection begins 4 weeks post vaccine • Protection probably at least 20 years (likely lifelong)-no

need for repeating
• Short-term protection against hepatitis A is available from immune globulin. It can be given before and within 2 weeks after coming in contact with HAV. • Good hygiene- hand washing, etc

VACCINE RECOMMENDATIONS

Vaccine is recommended for the following persons 2 years of age and older: • Travelers to areas with increased rates of hepatitis A • Men who have sex with men • Injecting and non-injecting drug users • Persons with clotting-factor disorders (e.g. hemophilia) • Persons with chronic liver disease • Children living in areas with increased rates of hepatitis A during the baseline period from 1987-1997 (mainly

West Coast US)

HEPATITIS B
STRUCTURE/BASICS DS DNA Virus Hepadnavirus. May exist in multiple formsDane particle, and 22nm spheres and filaments which do not contain DNA Humans only reservoir • Blood-borne (almost never through transfusion) • Sexual • Perinatal Persons at risk for HBV infection might also be at risk for infection with hepatitis C virus (HCV) or HIV. EPIDEMIOLOGY • 100,000 infections/ year • Higher seroprevalence among Asian-Americans • World-wide- high rates in SE Asia, Alaska, Africa • Estimated 1.25 million chronically infected Americans, of whom 20-30% acquired their infection in childhood.

TRANSMISSION

PATHOGENESIS

• Illness is immune mediated • 5% chronic carriers (in adults) • Higher rate of hepatocellular ca in chronic carriers- especially

“e” antigen positive
• Surface ab likely confers lifelong immunity • Antibody to “e” antigen indicates low transmissibility • Incubation 60-90 d (range 45-180d) SIGNS & SYMPTOMS About 1/3 of persons have no signs or symptoms. Signs and symptoms are less common in children than adults.

Chronic infection more common when infected at younger age and more likely in asymptomatic infection.
• jaundice • fatigue • abdominal pain • loss of appetite • nausea, vomiting

• joint pain

HEPATITIS B (CONT)
LONG-TERM EFFECTS WITHOUT VACCINATION Chronic infection occurs in: • 90% of infants infected at birth • 30% of children infected at age 1 - 5 years • 6% of persons infected after age 5 years Death from chronic liver disease occurs in: • 15-25% of chronically infected persons

SEROLOGY RISK GROUPS

See below • Persons with multiple sex partners or diagnosis of a sexually transmitted disease • Men who have sex with men • Sex contacts of infected persons • Injection drug users • Household contacts of chronically infected persons

VACCINE RECOMMENDATIONS

• Hepatitis B vaccine available since 1982 • Routine vaccination of 0-18 year olds • Vaccination of risk groups of all ages

PASSIVE IMMUNIZATION

• See attached schedule (last page) • Hep B immune globulin should be given in addition to

vaccine in exposures to known HepB infected patients/sources (surface antigen positive) when the individual exposed is uncertain about vaccination, unvaccinated or never responded to vaccine
• Give immune globulin ASAP (preferably within 24

hours of exposure)
TREATMENT & MEDICAL MANAGEMENT

• Adefovir dipivoxil, alpha interferon, and lamivudine are three drugs licensed for the treatment of persons with chronic hepatitis B.

• These drugs should not be used by pregnant women.

HEPATITIS D

• Caused by delta agent- cannot infect without HepB • Transmission risks same as Hep B • Co-infection: acquire infection at same time as Hep B- usually more severe • Superinfection: acquisition of D in chronic Hep B

Interpretation of the Hepatitis B Panel
Tests
HBsAg anti-HBc anti-HBs HBsAg anti-HBc anti-HBs HBsAg anti-HBc anti-HBs HBsAg anti-HBc IgM anti-HBc anti-HBs HBsAg anti-HBc IgM anti-HBc anti-HBs HBsAg anti-HBc anti-HBs

Results
negative negative negative negative positive positive negative negative positive positive positive positive negative positive positive negative negative negative positive negative

Interpretation
susceptible

immune due to natural infection

immune due to hepatitis B vaccination acutely infected

chronically infected

four interpretations possible *

*

1. May be recovering from acute HBV infection. 2. May be distantly immune and test not sensitive enough to to detect very low level of anti-HBs in serum. 3. May be susceptible with a false positive anti-HBc. 4. May be undetectable level of HBsAg present in the serum and the person is actually a carrier.

HEPATITIS C
STRUCTURE/ CLASSIFICATION TRANSMISSION Flavivirus Enveloped SS RNA virus 6 serotypes (genotypes) and multiple subtypes Humans (and chimps) only reservoir • Occurs when blood or body fluids from an infected person

enters the body of a person who is not infected.
• Persons at risk for HCV infection might also be at risk for Recommendations for infection with hepatitis B virus (HBV) or HIV. testing based on risk for HCV infection

Recommendations for Testing Based on Risk for HCV Infection PERSONS RISK OF TESTING INFECTION RECOMMENDED? High Yes

Injecting drug users Recipients of clotting factors made before 1987 Hemodialysis patients Recipients of blood and/or solid organs before 1992 People with undiagnosed liver problems Infants born to infected mothers Healthcare/public safety workers People having sex with multiple partners People having sex with an infected steady partner

High Intermediate

Yes Yes

Intermediate

Yes

Intermediate Intermediate Low Low

Yes After 12-18 mos. old Only after known exposure No*

Low

No*

*Anyone who wants to get tested should ask their doctor.
EPIDEMIOLOGY • Number of new infections per year has declined from an average of 240,000 in the 1980s to about 25,000 in 2001. • Most infections are due to illegal injection drug use. • Transfusion-associated cases occurred prior to blood donor screening; now occurs in less than one per million transfused unit of blood. • Estimated 3.9 million (1.8%) Americans have been

infected with HCV, of whom 2.7 million are chronically infected.

PATHOGENESIS

• Damage and illness immune mediated • Can lead to HCC

SIGNS & SYMPTOMS

80% of persons have no signs or symptoms. Those who do

may develop:

• jaundice • fatigue • dark urine • abdominal pain • loss of appetite • nausea

• Chronic infection: 75-85% of infected persons • Chronic liver disease: 70% of chronically infected persons LONG-TERM EFFECTS • Deaths from chronic liver disease: 1-5% • Leading indication for liver transplant • Extrahepatic manifestations may also be present and are due to immune complex deposition.

TREATMENT & MEDICAL MANAGEMENT

• HCV positive persons should be evaluated by their doctor for liver disease. • Interferon and ribavirin are two drugs licensed for the treatment of persons with chronic hepatitis C. • Interferon can be taken alone or in combination with ribavirin. Combination therapy, using pegylated interferon and ribavirin, is currently the treatment of choice. • Combination therapy can get rid of the virus in up to 50% of genotype 1 and in up to 80% for genotype 2 and 3.

DIAGNOSIS

• Hepatitis C ELISA or EIA 99% sensitive and specific • Usually positive 2-5 months after infection • RIBA and PCR used to confirm diagnosis

Hepatitis E

• RNA virus- calicivirus • Similar syndrome to Hep A • Fecal-oral transmission • Higher mortality in pregnant women

Public Health Responsibilities There are a few diseases that must be reported to the health department once the healthcare provider has diagnosed them. Hepatitis infection is an example. In South Carolina, Urgently Reportable conditions are Hepatitis A, acute (IgM Ab + only) and Hepatitis B, acute (IgM core Ab + only). Routine reporting (within 7 business days) is required for chronic Hepatitis B, Hepatitis B Surface Ag + with each pregnancy, and all Hepatitis C, D and E. The reporting of these diagnoses are essential for the health department to initiate an outbreak investigation and thus protect the health of the community at large, if at risk based on likely contact with the index patient. Good surveillance practices also ensure that limited resources are appropriately targeted. Failure to report is a criminal offense punishable by a fine/jail time.

SUMMARY (From Murray text)

Recommended dosages and schedules of hepatitis B vaccines
Vaccine Engerix-B (GlaxoSmithKline) Age group 0–19 years 20 years & older Dose 10µg 20µg Volume 0.5 ml 1.0 ml # Doses 3 3 Schedule* Infants: birth, 1–4, 6–18 mos. of age Alternative for older children: 0, 1–2, 4 mos. 0, 1, 6 mos. Infants: birth, 1–4, 6–18 mos. of age Alternative for older children: 0, 1–2, 4 mos. 0, 4–6 mos. 0, 1, 6 mos.

0–19 years Recombivax HB (Merck & Co.)

5µg

0.5 ml

3

11 thru 15 yrs. 20 years & older

10µg 10µg

1.0 ml 1.0 ml

2 3

* The schedule for hepatitis B vaccination is flexible and varies. Consult the ACIP statement on hepatitis B (11/91), AAP's 2003 Red Book, or the package insert for details. Note: For adult dialysis patients, the Engerix-B dose required is 40µg/2.0ml (use the adult 20µg/ml formulation) on a schedule of 0, 1, 2, and 6 months. For Recombivax HB, a special formulation for dialysis patients is available. The dose is 40µg/1.0ml and it is given on a schedule of 0, 1, and 6 months


				
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