ACUTE VIRAL HEPATITIS

Acute Viral Hepatitis I.Definition : Hepatitis = disease causing necrosis of the parenchymal cells of the liver II.Types and Incidence : A.Hepatitis A : RNA virus : 25,000 reported cases/yr in U.S. B.Hepatitis B : DNA virus : 25,000 reported cases/yr in U.S., probably 300,000 cases/yr in U.S. C.Non-A - Non-B hepatitis : 5,000 reported cases/yr in U.S. ; probably 2/3 of these cases caused by hepatitis C virus

More Causes of Acute Hepatitis D.Other viruses : Epstein-Barr (mononucleosis), CMV, Herpes simplex, Cosackie E.Parasitic : Entamoeba histolytica, liver flukes F.Toxic : most common is alcohol, also caused by organic halogen compounds G.Bacterial : usually cause liver abscesses H.Congestive : due to right-sided CHF

Acute Viral Hepatitis III.Hepatitis A : 1.Source : fecal / oral route, shellfish, rarely parenteral 2.Incubation period : 15 to 45 days 3.Infectivity : peak viral excretion in stool occurs prior to jaundice ; so maximal infectivity is during the prodrome 4.Risk factors : close personal contact with person with hepatitis, homosexuality, foreign travel, contact with kids at day care center, illicit drug use. No predisposing known factor in 40 % of cases. Most common in young adults.

Acute Viral Hepatitis III.Hepatitis A : 5.Sx : malaise, anorexia, RUQ pain, vomiting, only ? 20 % jaundiced, diarrhea in 60 % of kids 6.Clinical course : usually benign, self-limiting ; mortality ~ 1 % for age > 40, 0.3 % for age < 40. No progression to chronic hepatitis or carrier state. 7.Rx : supportive care only. Prophylaxis with 0.02 ml/kg immune serum globulin if : household contact, institution for handicapped, prison, day care center, travel in endemic country (Southeast Asia, China, tropical Africa, Pacific Islands, Brazil, Middle East). Consider vaccine also for close contacts.

Acute Viral Hepatitis IV.Hepatitis B : 1.Source : contact with infected blood, mucosal secretions, semen, saliva. Rarely fecal / oral route. 2.Incubation period : 30 to 180 days (mean : 50 days) 3.Infectivity : occurs as long as HB surface antigen present in serum ; precedes jaundice 4.Risk factors : parenteral drug use, homosexuality, patients and staff of hemodialysis units, other medical personnel with exposure to blood, sexual contact with index case, native of high incidence Asian / African countries (~ 10 % chronic carrier rate)

Acute Viral Hepatitis IV.Hepatitis B : 5.Sx : malaise, anorexia, vomiting, RUQ pain, loss of taste for cigarettes, jaundice, dark urine, if rapid  encephalopathy and bleeding disorder. Large (?) % anicteric. 5 to 10 % have prodromal serum-sickness-like syndrome (arthralgia, rash, angioedema). 6.Clinical course : 90 % recover without Rx, 10 % develop chronic carrier state, 4 % mortality age > 40, 1 % mortality age < 40. Chronic active hepatitis is most common cause of cirrhosis / hepatocellular cancer in some countries with resultant 250,000 deaths per year.

Acute Viral Hepatitis IV.Hepatitis B : 7.Rx : supportive care. Prophylaxis with 0.06 ml/kg IM HepB immune globulin for parenteral and sexual contacts of index case (if HepB surface antibody negative) and for newborn infant (0.5 ml IM) of HB surface antigen positive mother. Then start hepatitis vaccine (Heptavax B or Recombinvax – HB) 1cc IM with 2 nd dose at 1 month and 3 rd dose at 6 months in deltoid (not gluteus).

Acute Viral Hepatitis V.Non-A – Non-B Hepatitis : 1.Source : causes 90 % of transfusion-related hepatitis. May occur sporadically despite lack of overt parenteral exposure. 2.Incubation period : 15 to 160 days (mean 50 days) 3.Infectivity : not well characterized 4.Risk factors : hemodialysis patients and staff, renal transplant recipients, IV drug addicts, hemophiliacs, health care personnel

V.Non-A – Non-B Hepatitis: 5.Sx : same as hepatitis B but usually milder acute phase and lower incidence of jaundice 6.Clinical course : marked  chance of chronic hepatitis (? Up to 50 %) with its potential sequelae of cirrhosis and liver cancer 7.Rx : ? prophylaxis with immune serum globulin effective (0.06 ml/kg IM). No vaccine available yet. Acute Viral Hepatitis

VI.Criteria for Admission for Acute Viral Hepatitis : 1.Persistent vomiting / dehydration 2.Hypoglycemia 3.Protime  by 2 seconds or more, or overt coagulopathy 4.Encephalopathy 5.SGOT > 5,000 (?) 6.Age > 60 (?) 7.Dx unclear (if cannot R/O obstructive cause for jaundice without further tests)

Acute Viral Hepatitis VII.Needlestick (or other mucosal exposure to blood, etc.) protocol : Exposed Person SourceUnvaccinatedVaccinated Known HB surface AG + HBIG, HB vaccine (may check HepB surface antibody first if known prior episode of acute HepB)  HepB surface antibody If -  HBIG, vaccine booster Likely (high- risk) HB surface Ag+ HBIG, HB vaccine if unable to determine source HB Surface Antigen status Same as above Low-risk or unknown source ISG (optional) Start HB vaccine ISG (optional)  HepB surface antibody If -  booster vaccine dose If +  no Rx

Acute Viral Hepatitis VII.Needlestick (or other mucosal exposure to blood, etc.) protocol (cont.) : NOTE :ISG (0.06 ml/kg) optional for ? protection from Non-A – Non-B hepatitis transmission. Do not repeat ISG if given in previous 3 to 5 months. Repeat HepB surface antibody check only if > 1 year from previous known + HepB antibody. Remember routine wound care and tetanus prophylaxis also.