HEPATITIS
C INFECTION
FACTS, DIAGNOSIS, AND INTERPRETATION
Dr.T.V.Rao MD
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WHAT IS HEPATITIS?
• “Hepatitis” means inflammation of the liver
• Can be caused by: • Genetic diseases • Medications (including over-the-counter) • Alcohol
• Hepatitis viruses (A,B,C,D,E)
HEPATITIS C
• Identified in 1989
• Blood test became available in 1992 • Used to be known as “nonA, non-B” hepatitis • Spread through blood-toblood contact
• No vaccine available to prevent hepatitis C
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STRUCTURE OF HEPATITIS C
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HEPATITIS CA GLOBAL INFECTION
• About 3 million Americans infected • About 170 million infected worldwide • Many do not experience symptoms
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SOURCES OF INFECTION FOR PERSONS WITH HEPATITIS C
Injecting drug use 60% Sexual 15%
Transfusion 10% (before screening) Other* 5% Unknown 10%
*Nosocomial; Health-care work; Perinatal
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Source: Centers for Disease Control and Prevention
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WHAT IS HEPATITIS C INFECTION
• Hepatitis C is a contagious liver disease that results from infection with the Hepatitis C virus. It can range in severity from a mild illness lasting a few weeks to a serious, lifelong illness. Hepatitis C is usually spread when blood from a person infected with the Hepatitis C virus enters
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the body of someone who is not infected
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HEPATITIS C - EPIDEMIOLOGY
Before 1985
Illegal Drug Use Transfusion Sexual Other Unknown
1999
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HEPATITIS C INFECTION NATURAL HISTORY
Acute infection
Resolve 15%
Chronic infection 85%
Stable 80%
Cirrhosis 20%
Stable 75%
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Mortality 25%
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WHAT HAPPENS TO PEOPLE WITH HEPATITIS C VIRUS?
100
Infected With Hepatitis C
15
No Chronic Disease
85
17
Cirrhosis
2
Liver Cancer
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Chronic Disease
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CHRONIC HEPATITIS C FACTORS PROMOTING PROGRESSION OR SEVERITY
• Increased alcohol intake • Age > 40 years at time of infection • HIV co-infection ? Other • Male gender • Other coinfections (e.g., HBV)
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ALCOHOL MAJOR CONTRIBUTOR FOR PROGRESS OF DISEASE
Chance Of Getting Cirrhosis
Non-Drinker
Hepatitis C Non-Drinker
Drinker Without Hepatitis C Drinker With Hepatitis C
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HEPATITIS C CAN PRESENT AS ACUTE OR CHRONIC INFECTION
• Hepatitis C can be either “acute” or “chronic.” Acute Hepatitis C virus infection is a short-term illness that occurs within the first 6 months after someone is exposed to the Hepatitis C virus. For most people, acute infection leads to chronic infection. Chronic Hepatitis C is a serious disease than can result in longterm health problems, or even death.
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TRANSMISSION / EXPOSURE
• Hepatitis C is spread when blood from a person infected with the Hepatitis C virus enters the body of someone who is not infected. Today, most people become infected with the Hepatitis C virus by sharing needles or other equipment to inject drugs. Before 1992, when widespread screening of the blood supply began in the United States, Hepatitis C was also commonly spread through blood transfusions and organ transplants. • People can become infected with the Hepatitis C virus during such activities as Sharing needles, syringes, or other equipment to inject drugs Needle stick injuries in health care settings • Being born to a mother who has Hepatitis C
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LESS COMMONLY TRANSMITTED THROUGH …
• Less commonly, a person can also get Hepatitis C virus infection through Sharing personal care items that may have come in contact with another person‟s blood, such as razors or toothbrushes • Having sexual contact with a person infected with the Hepatitis C viru s
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WHO SHOULD BE TESTED FOR HEPATITIS C?
• •
People with risk factors for hepatitis C Those who wish to be tested
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WHO SHOULD GET TESTED FOR HEPATITIS C?
• You are a current or former injection drug user, even if you injected only one time or many years ago. • You were treated for a blood clotting problem before 1987. • You received a blood transfusion or organ transplant before July 1992.
• You are on long-term hemodialysis treatment.
• You have abnormal liver tests or liver disease. • You work in health care or public safety and were exposed to blood through a needle stick or other sharp object injury. • You are infected with HIV.
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• • • • •
Based on increased risk for infection
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
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ROUTINE HCV TESTING NOT RECOMMENDED
(UNLESS RISK FACTOR IDENTIFIED)
• Health-care, emergency medical, and public safety workers • Pregnant women
• Household (non-sexual) contacts of HCVpositive persons • General population
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HCV INFECTION TESTING ALGORITHM FOR DIAGNOSIS OF ASYMPTOMATIC PERSONS
EIA for Anti-HCV
Positive (repeat reactive) Negative (non-reactive)
STOP
OR RIBA for Anti-HCV
Negative STOP Negative
RT-PCR for HCV RNA
Positive Positive
Indeterminate
Additional Laboratory Evaluation (e.g. PCR, ALT) Negative PCR, Normal ALT Positive PCR, Abnormal ALT
Medical Evaluation
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Source: MMWR 1998;47 (No. RR 19)
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HOW IS HEPATITIS C DIAGNOSED?
• Blood testing 1. Hepatitis C antibody test 2. Hepatitis C PCR test to find virus in blood • Liver function tests
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LABORATORY DIAGNOSIS
• Serologic tests to detect HCV antibodies:
enzyme immunoassay (EIA). False negative in pts on HD, immunodeficiency; false positive in autoimmune disorder. recombinant immunoblot assay (RIBA) • Target amplification technique to detect HCV RNA (molecular assay) -
polymerase chain reaction (PCR). A positive test confirms HCV infection.
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CURRENTLY PERFORMED TESTES FOR
HEPATITIS C INFECTION
• Currently, the secondgeneration enzyme immunoassay (EIA-2) for antibodies to HCV (anti-HCV) is the most practical screening test for HCV infection. The diagnosis of HCV infection can be supported or confirmed by the recombinant immunoblots assay (RIBA) or tests for HCV RNA. RIBA detects antibodies to individual HCV antigens and confers increased specificity compared to EIA-2.
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MOLECULAR METHODS IN DIAGNOSIS OF
HEPATITIS C INFECTION
• Qualitative reverse transcriptionpolymerase chain reaction (RT-PCR) assays for HCV RNA are simpler than quantitative tests and sufficient for confirmation of the diagnosis of HCV infection.
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ALANINE AMINOTRANSFERASE
• Serum ALT testing is inexpensive and noninvasive.
• Insensitive means of monitoring disease activity.
• A single determination gives limited information, and serial measurements recommended.
• Weak association between the degree of ALT elevation and severity of histopathological findings on liver biopsy.
• Resolution of ALT elevation with antiviral therapy appears to indicate disease response.
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Serologic Pattern of Acute HCV Infection with Recovery anti-HCV
Symptoms +/HCV RNA
Titer
ALT
Normal 0
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1
2
3 4 Months
5
6
1
2 3 Years
4
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Time after Exposure
Serologic Pattern of Acute HCV Infection with Progression to Chronic Infection
anti-HCV
Symptoms +/HCV RNA
Titer
ALT
Normal 0
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1
2
3 4 Months
5
6
1
2 3 Years
4
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Time after Exposure
LIVER BIOPSY
• Provides useful information about the degree of fibrosis in HCV infected patients. This information is important in management decisions. • Is not used for diagnosis of HCV infection. • Used for assessment of severity of inflammation, presence of fibrosis, evaluate possible concomitant disease processes, assess therapeutic intervention.
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LIVER HISTOLOGY
• Activity (necro-inflammation) – severity and progress. May fluctuate with disease activity or therapeutic intervention. • Fibrosis implies possible progression to cirrhosis. In mild cases, is limited to portal and periportal area. More advanced changes defined by „bridging fibrosis‟.
• Cirrhosis
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DIAGNOSTIC ASSESSMENT OF INFECTED PATIENTS
• In summary, the diagnostic algorithm of Hepatitis C depends on the clinical context. In asymptomatic, low-risk subjects, who are found to be anti-HCVpositive by EIA-2, the diagnosis of HCV infection needs to be confirmed, especially if the initial biochemical tests reveal normal ALT levels.
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CAN WE PREVENT HEPATITIS C INFECTION
• There is no vaccine for Hepatitis C. The best way to prevent Hepatitis C is by avoiding behaviors that can spread the disease, especially injection drug use.
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REFERENCES
• Centre for Disease Control (CDC) Atlanta USA, guidelines on basis of disease Diagnosis, and consequences of Hepatitis C Infection
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• Created by Dr.T.V.Rao MD for Medical and Health Care workers in the Developing world
• Email •
[email protected]
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