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Viral Hepatitis Viral hepatitis is a major public health problem, occurring endemically in all areas of the world TYPES OF VIRAL HEPATITIS TYPE A (HAV) TYPE B (HBV) TYPE C (HCV) TYPE DELTA (HDV) TYPE E (HEV) THREE PHASES OF “CLASSIC” HEPATITIS PRODROMAL PHASE Flu-like symptoms ICTERIC PHASE Jaundice CONVALESCENT PHASE Recovery LAB TESTS Liver enzymes: Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) 10 TO 100 FOLD INCREASE CAN BE EXPECTED LAB TESTS SERUM BILIRUBIN: hyperbilirubinemia LEVELS MUST APPROACH 3mg/100ml TO MANIFEST AS JAUNDICE JAUNDICE OFTEN FIRST MANIFESTS IN SCLERA LAB TESTS Prothrombin time: HIGHER THE PROTHROMBIN TIME (PT), THE MORE SEVERE THE HEPATIC DAMAGE HEPATITIS TYPE A (HAV) SINGLE-STRANDED RNA VIRUs SPREAD MAINLY BY ORAL-FECAL ROUTE INCUBATION PERIOD 15-50 DAYS HAV Usually disease of young but can affect adult. OFTEN ASYMPTOMATIC ILLNESS USUALLY SELF-LIMITING RECOVERY IS COMPLETE and does not need any specific treatment NO EVIDENCE OF CHRONIC FORM OR CARRIER STATE OF HAV Prevention TWO-DOSE VACCINE 6 MONTHS APART AVAILABLE SINCE 1994 HEALTH CARE PROVIDERS RECOMMENDED Hepatitis B virus Hepadnaviridae member 100 times more infectious than HIV 10 times more infectious than HCV The most common carcinogen after tobacco in man Schaefer S. World J Gastroenterol. 2007;13:14–21. European Parliament. Hepatitis B: Revealing a Silent Killer. Workshop at the European Parliament, 2006. Available at: http://www.ilcuk.org.uk/files/pdf_pdf_36.pdf. NIH 11th report on carcinogens 2004. Available at: ntp.niehs.nih.gov/ntp/roc/eleventh/profiles/s092thpb.pdf. HEPATITIS B (HBV) CAN CAUSE ACUTE / AND A CHRONIC HEPATITIS Can also cause CARRIER STATE 40 - 180 DAY INCUBATION PERIOD MANY CASES ARE SUBCLINICAL AND MOST ARE ANICTERIC Concentration of Hepatitis B Virus in Various Body Fluids • High concentration blood serum wound exudates • Moderate concentration semen vaginal fluid saliva • Low/Not Detectable urine feces sweat tears breast milk Mode of spread Mainly by parenteral route DIRECT PERCUTANEOUS INOCULATION OF INFECTED SERUM OR PLASMA INDIRECTLY THROUGH CUTS OR ABRASIONS ABSORPTION THROUGH MUCOSAL SURFACES ABSORPTION OF OTHER INFECTIOUS SECRETIONS (SALIVA OR SEMEN) WHO IS AT GREATEST RISK FOR HBV INFECTION? LAB PERSONNEL WORKING WITH BLOOD PRODUCTS MEDICAL/DENTAL PERSONNEL IV DRUG ABUSERS BLOOD PRODUCT RECIPIENTS Clinical Features Can be asymptomatic (subclinical) Symptomatic case pass through 3 phases: Prodromal phase Icteric phase Recovery phase Persistence of infection beyond 6 months indicate progression to chronic phase Diagnosis Serological: Detection of HBV antigen and antibodies. Serological markers for hepatitis B Name Abbreviation Definition/Comment Hepatitis B surface antigen HBsAg Antigen indicating infection Hepatitis B e antigen HBeAg Antigen correlating with hepatitis B replication and infectivity Hepatitis B surface antibody Anti-HBs Usually indicates immunity Hepatitis B e antibody Anti-HBe Presence in serum of persons with chronic hepatitis B infection indicates low titre of hepatitis B Hepatitis B core antibody Anti-HBc Indicates previous or ongoing infection with hepatitis B Mahoney .Clin Microbiol Rev. 1999;12:351–366. http//www.ashm.org.au/uploads/B_Positive-Glossary_abbreviations.pdf. Outcome of Infection COMPLETE RESOLUTION IN 6 MONTHS (95% of adults) Chronic infection 5% ADULTS CHRONIC CARRIERS 20% CHILDREN CHRONIC CARRIERS 80-90% NEONATES AND INFANTS BECOME CHRONIC CARRIERS PREVENTION 1. PASSIVE IMMUNITY: INJECTION OF IMMUNE GLOBULIN (HBIG) TRANSFERRING PREFORMED ANTIBODIES FROM AN IMMUNIZED HOST TO A PERSON IN NEED OF IMMUNITY PROTECTION IS TRANSITORY, BUT ONSET IS IMMEDIATE 2. ACTIVE IMMUNITY Using HBV vaccine Act BY STIMULATING OWN IMMUNE RESPONSE using HBV vaccine PROTECTION AFTER LATENT PERIOD LONG-TERM IMMUNITY IS PROVIDED The Hepatitis C Virus Spherical, enveloped, single-stranded RNA virus Family Flaviviridae HCV may produce ~ 1 trillion new viral particles each day Hepatitis C: Basic Facts Hepatitis C is a global health problem affecting over 170 million people worldwide. Hepatitis C is a leading cause of end-stage liver disease and hepatocellular carcinoma. HEPATITIS C (HCV) SPREAD MAINLY BY PARENTAL ROUTE ACCOUNTS FOR 90-95% OF POST TRANSFUSION HEPATITIS Sources of Infection for Persons with Hepatitis C Sexual 15% Injecting drug use 60% Transfusion 10% (before screening) Other* 5% Unknown 10% * Hemodialysis; health-care work; perinatal Source: Centers for Disease Control and Prevention WHO IS AT GREATEST RISK FOR HCV INFECTION? LAB PERSONNEL WORKING WITH BLOOD PRODUCTS MEDICAL/DENTAL PERSONNEL (310% VIA NEEDLESTICK FROM INFECTED PATIENT) IV DRUG ABUSERS BLOOD PRODUCT RECIPIENTS HEMODIALYSIS PATIENTS Clinical features 30-180 DAY INCUBATION PERIOD Acute infection can be asymptomatic. Symptomatic cases present through 3 clinical phases Outcome UP TO 90% = CHRONIC CARRIERS Diagnosis HCV antibody HCV RNA (PCR) A positive antibody test should be repeated for confirmation TREATMENT of Viral Hepatitis HAV and HEV- ACUTE: SYMPTOMATIC HBV - ACUTE: SYMPTOMATIC CHRONIC: Antiviral agents HCV - ACUTE: SYMPTOMATIC CHRONIC: COMBINATION INTERFERON ALPHA and RIBAVIRIN SOURCE: RN December 1997 COMPLICATIONS HAV - RELAPSE; IN RARE CASES - FULMINANT HEPATITIS HBV - CHRONIC LIVER DISEASE INCLUDING CIRRHOSIS, PRIMARY HEPATOCELLULAR CARCINOMA AND FULMINANT HEPATITIS HCV - CHRONIC LIVER DISEASE INCLUDING CIRRHOSIS, PRIMARY HEPATOCELLULAR CARCINOMA Dental Management: Difficult to identify all patient through history Many acute cases of Hep B and C are mild MUST use universal precautions for all Screening recommended for patients from high risk groups Viral Hepatitis: A,B,C,D,E Guidelines for blood exposure From patients with Hepatitis B: 1. Determine the titrer of anti-HBs in the health care professional If adequate: no treatment is needed If inadequate give Hepatitis B Immunoglobulin Viral Hepatitis: Guidelines for blood exposure From patients with Hepatitis C 1. Exposed professional gets baseline and follow up testing for anti-HCV and liver enzymes Viral Hepatitis: Guidelines for blood exposure From patients with Unknown 1. Ask for serological testing of the patient (this can be ordered by the Medical Officer) The presence of HCV-RNA in saliva provides a biological basis for saliva as a possible source of HCV infection, Dentists were in a high risk of contracting this disease due to the procedures and instruments of dental treatment.