II. Epidemiology
- Endemic in underdeveloped countries
- More common in western United States
- Outbreaks
- Day-care centers
- Residential institutions
-
Incidence
- World: 1.4 Million/year
- U.S. (esp west): 60,000/year (only 7700 reported)
- Decreased >90% following Hepatitis A Vaccine introduction in 1995
III. Pathophysiology
- Picornavirus (enterovirus)
- Single stranded RNA genome
- Size: 27 nm
- Nonenveloped (resistant to bile lysis)
- Only replicates in hepatocytes, GI epithelial cells
- Hardy agent
- Resistant to acids, detergents, freezing Temperatures
- Survives in salt water and fresh water, soil, hands
- Inactivated by heat >185 F, formalin, Chlorine
IV. Pathophysiology: Timing
- Incubation: 15 to 50 days (mean 28 days)
- Duration: 2 weeks to 3 months
- Contagious status
- Infectivity peaks 2 weeks before and 1 week after symptom onset
- Stool virus concentration peaks 2 weeks before symptoms
- No longer contagious once significant symptoms occur
V. Pathophysiology: Transmission
- Oral-Fecal transmission
- Household or child care centers
- Sexual contact
-
Foodborne Illness epidemic
- Infected food handlers
- Raw shellfish
- Fresh produce (green onions, strawberries)
- Waterborne Illness epidemic
- Blood exposure can occur but is uncommon
VI. Symptoms
- Symptom occurence depends on age
- Adults: 70% have symptoms
- Children under age 6: 70% do not have symptoms
- Usually more mild in young children
- Common symptoms (onset 5-7 days before Jaundice)
- Other less common symptoms
VII. Signs: Pre-icteric (starting 5-7 days before Jaundice)
- Fever
- Enlarged and tender liver (Hepatomegaly)
- Splenomegaly
- Bradycardia
- Posterior cervical adenopathy
VIII. Signs: Icteric phase
- Pale, clay colored stool
- Dark Urine
-
Jaundice (Incidence increases with age)
- Under age 6: <10%
- Adults: Up to 80%
IX. Course
- Illness usually lasts 2 months
- Not uncommon to miss 1 month of school or work
- Usually complete recovery within 6-12 months
- No chronic carrier state
X. Labs
- Complete Blood Count (CBC)
-
Liver Transaminases elevated
- Transaminases are higher than in Alcoholic heptitis and similar or lower than toxic or ischemic hepatitis
- Alanine Aminotransferase (ALT) elevated (500 - 5000 U/L)
- Aspartate Aminotransferase (AST) elevated (500 - 5000 U/L)
- Typically lower than the ALT
-
Liver Function Tests and Cholestasis Labs elevated
- Bilirubin elevated (<10 mg/dl)
- Increase typically follows the transaminase increase
- Alkaline Phosphatase minimally increased
- Bilirubin elevated (<10 mg/dl)
XI. Diagnosis: Hepatitis A Serology
- Fecal HAV: present 2-6 weeks after exposure
-
xHAV IgM
- Present 4-12 weeks (up to 6 months) post-exposure
- Present 5-10 days before symptom onset
- Preferred first-line test (high Test Sensitivity >95%)
- Risk of False Positive in asymptomatic patients
-
xHAV IgG
- Present from 4 weeks after exposure
- Present life-long and confers Immunity
XII. Differential Diagnosis
XIII. Management
- Symptomatic relief
- Antiemetics
- Avoid Alcohol and other Hepatotoxins
- Diet as tolerated otherwise
- Rest
- Avoid return to work, school until fever and Jaundice resolve
XIV. Management: Post-exposure
- Indications
- Serologically confirmed case and
- Exposure during source patient's Incubation Period and extending until one week after Jaundice onset
- Administer Vaccine or Immunoglobulin within 2 weeks of exposure
-
Hepatitis A Vaccine (preferred in most cases)
- Offer to all outbreak exposures >age 1 years old
- Exceptions
- Isolated, single case exposures with casual contact (e.g. school, office)
- Controlled setting with barrier precautions (e.g. hospital)
-
Hepatitis A Immunoglobulin (0.02 ml/kg IM) indications
- Patient <1 year old
- Age over 40 years old
- Serious comorbidity
- Immunocompromised
- Chronic Liver Disease
- Severe allergy to Hepatitis A Vaccine
- Monitoring
- Hepatitis A Virus Antibody testing is optional
- References
XV. Prevention
-
General Hygiene Measures in endemic areas
- Meticulous Hand Washing
- Clean surfaces with 1:100 solution household bleach
- Careful food preparation
- See Prevention of Foodborne Illness
- Heat foods to 185 F for 1 minute
- Avoid uncooked foods
-
Hepatitis A Vaccine for high risk potential exposures
- Protective for 20 years or more after 2 doses
- Recommended as part of Primary Series for child age 1 year
-
Hepatitis A Immunoglobulin
- Preexposure for travel within 1 month
- Postexposure for close contacts of known case
XVI. Complications
- Most cases follow a benign, self limited course
- No increased risk of Cirrhosis and liver cancer
- No chronic form of Hepatitis A
- Uncommon complications
- Relapsing Hepatitis A infection (occurs in up to 15% at up to 6 months after the initial infection)
- Rare liver complications
- Biliary obstruction
- Fulminant Hepatitis (rare)
- Rare extra-hepatic complications
- Mortality
- Caused 100 U.S. deaths per year prior to routine Hepatitis A Vaccine
XVII. Prognosis: Risk factors for serious complications
- Age over 50 years
- Underlying liver disease (e.g. Hepatitis B, Hepatitis C)
- Pregnancy
XVIII. Resources
- CDC Hepatitis A faq
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Related Studies
Definition (MEDLINEPLUS) |
Hepatitis A is one type of hepatitis - a liver disease - caused by the hepatitis A virus (HAV). The disease is spread primarily through food or water contaminated by stool from an infected person. You can get HAV from
HAV can cause swelling of the liver, but it rarely causes lasting damage. You may feel as if you have the flu, or you may have no symptoms at all. It usually gets better on its own after several weeks. The hepatitis A vaccine can prevent HAV. Healthy habits also make a difference. Wash your hands thoroughly before preparing food, after using the toilet or after changing a diaper. International travelers should be careful about drinking tap water. NIH: National Institute of Diabetes and Digestive and Kidney Diseases |
Definition (NCI) | Acute inflammation of the liver caused by the hepatitis A virus. It is highly contagious and usually contracted through close contact with an infected individual or their feces, contaminated food or water. |
Definition (CSP) | inflammation of the liver due to microorganism infection. |
Definition (MSH) | INFLAMMATION of the LIVER in humans caused by a member of the HEPATOVIRUS genus, HUMAN HEPATITIS A VIRUS. It can be transmitted through fecal contamination of food or water. |
Definition (CSP) | hepatitis caused by Hepatovirus (Hepatitis A virus); it can be transmitted through fecal contamination of food or water. |
Concepts | Disease or Syndrome (T047) |
MSH | D006506 |
SnomedCT | 154347003, 40468003 |
LNC | LA7442-2 |
English | Hepatitides, Infectious, Hepatitis A, Hepatitis, Infectious, Infectious Hepatitides, Infectious Hepatitis, HEPATITIS A, HEPATITIS INFECTIOUS, INFECT HEPATITIS, HEPATITIS INFECT, hepatitis A infection, hepatitis A infection (diagnosis), hepatitis, A virus, hepatitis A viral infection, Hepatitis A Infection, Hep A, Viral hepatitis A, Hepatitis infectious NOS, Hepatitis A [Disease/Finding], infectious hepatitis (hepatitis A), hepatitis, Hepatitis;infectious, a hepatitis, hep a, hepatitis a, infectious hepatitis a, infectious hepatitis, hepatitis viral, HAV, Infectious hepatitis (disorder), Hepatitis, Hepatitis infectious, Viral hepatitis, type A, Infectious hepatitis, IH - Infectious hepatitis, Viral hepatitis, type A (disorder), epidemic; hepatitis, hepatitis; epidemic, hepatitis; infectious, hepatitis; virus, type, A, infectious; hepatitis, virus; hepatitis, type, A, hepatitis A |
French | HEPATITE INFECTIEUSE, Hépatite infectieuse SAI, Hép A, HEPATITIE VIRALE A, Hépatite A, Hépatite infectieuse, Hépatite virale A |
Portuguese | HEPATITE A, HEPATITE INFECCIOSA, Hepatite a vírus A, Hepatite infecciosa NE, Hepatite Viral A, Hepatite infecciosa, Hepatite A, Hepatite Infecciosa |
Spanish | HEPATITIS A, HEPATITIS INFECCIOSA, Hepatitis infecciosa NEOM, Hepatitis vírica A, hepatitis A, hepatitis infecciosa, hepatitis viral, tipo A (trastorno), hepatitis viral, tipo A, Hepatitis infecciosa, Hepatitis A, Hepatitis Infecciosa |
Dutch | hepatitis infectiosa NAO, infectieuze hepatitis, virale hepatitis A, epidemisch; hepatitis, hepatitis; epidemisch, hepatitis; infectieus, hepatitis; virus, type, A, infectieus; hepatitis, virus; hepatitis, type, A, hepatitis A, hepatitis infectieus, Hepatitis A, Hepatitis, infectieuze |
German | Hepatitis infektioes NNB, Hep A, virale Hepatitis A, HEPATITIS INFEKTIOES, infektioese Hepatitis, Hepatitis A, Hepatitis, infektiöse |
Italian | Epatite infettiva NAS, Epatite virale A, Epatite infettiva, Epatite A |
Japanese | 感染性肝炎, A型肝炎, 感染性肝炎NOS, カンセンセイカンエンNOS, カンセンセイカンエン, Aガタカンエン, A型ウイルス性肝炎, Aガタウイルスセイカンエン, 肝炎-A型, A型肝炎, 流行性肝炎, 肝炎-流行性, 伝染性肝炎, 肝炎-伝染性 |
Swedish | Hepatit A |
Czech | hepatitida A, Infekční hepatitis NOS, Hepatitida A, Infekční hepatitis, Virová hepatitida A, infekční hepatitida |
Finnish | Maksatulehdus A |
Russian | GEPATIT INFEKTSIONNYI, GEPATIT A, ГЕПАТИТ A, ГЕПАТИТ ИНФЕКЦИОННЫЙ |
Croatian | HEPATITIS A |
Polish | Zapalenie wątroby epidemiczne, Żółtaczka zakaźna, Zapalenie wątroby nagminne, Zapalenie wątroby A |
Hungarian | Hepatitis A, Fertőző májgyulladás, hepatitis infectiosa k.m.n., hepatitis A, hepatitis infectiosa, Viralis hepatitis A |
Norwegian | Hepatitt A, Epidemisk hepatitt, Infeksiøs hepatitt |