Hepatitis A

Hepatitis A is a viral hepatitis without a chronic phase, but 15% of cases may be prolonged or relapsing, lasting as long as a year. Transmission is by the fecal-oral route. Risky foods include raw oysters, clams, other shellfish, and contaminated, raw fruits and vegetables.

13,980 (US); 1,400,000 (Global)
Infectious hepatitis;
2-7 weeks; average 1 month; [CCDM]
Fever, nausea, abdominal pain, and jaundice; [CCDM]
Standard; "Provide hepatitis A vaccine post-exposure as recommended." For diapered or incontinent patients: Contact; "Maintain Contact Precautions in infants and children <3 years of age for duration of hospitalization; for children 3-14 yrs. of age for 2 weeks after onset of symptoms; >14 yrs. of age for 1 week after onset of symptoms." [CDC 2007 Guideline for Isolation Precautions]
Many cases are mild and without jaundice. Chronic infections do not occur, but 15% of cases may be prolonged or relapsing, lasting as long as a year. [CCDM, p. 253] Recovery usually occurs within 6-12 months. There is no carrier state. Fulminant hepatitis occurs in only 0.1% of cases. [Harrisons, p. 841-2] Usually, symptoms are self-limited within about 3 weeks, and ALT returns to normal in about 7 weeks. [ABX Guide] In acute viral hepatitis, aminotransferase levels are generally >10 times the upper limit of normal. [Cecil, p. 959] Jaundice occurs in about 7% of children 5 years old and younger, in about 37% of children aged 5-9, and in more than 70% among adolescents and adults. 2/3 of patients recover completely within 2 months. [PPID, p. 2254] About 70% of infected children <6 years are asymptomatic. About 10% of infected people have a prolonged or relapsing illness lasting 6-9 months. [CDC Travel, p. 219]

Transmission is by the fecal-oral route. Children with subclinical infections are sources of infection for others. Risky foods include raw oysters, clams, other shellfish, and contaminated, raw fruits and vegetables. Humans are the primary reservoirs, rarely primates. Case-fatality is less than 1% in most populations, but can reach 1.8% in older adults. [CCDM, p. 252-7] Men who have sex with men are at increased risk. [Cecil, p. 960] Transmission by transfusion has been reported. Virus is excreted in the stool from 14-21 days before the onset of jaundice to 8 days after the onset of jaundice. [PPID, p. 2248-9]

OTHER FINDINGS: Complications include pancreatitis, renal failure, encephalitis, Guillain-Barre syndrome, hemolysis, anemia, cholecystitis, thrombocytopenic purpura, and pancytopenia. Several cases have been reported of arthritis, vasculitis, and cryoglobulinemia. Confusion and severe vomiting may be seen in cases of fulminant hepatitis. [PPID, p. 2254] Other common symptoms are loss of appetite, dark urine, and light-colored stools. Symptoms occurring in less than 30% of patients include headache, myalgia, arthralgia, diarrhea, and constipation. About 0.14 % of hospitalized patients develop fulminant hepatitis with bleeding diathesis (GI bleeding) and coma. [ID, p. 761] In acute viral hepatitis, constitutional symptoms (nausea, fatigue, arthralgias, myalgias, headache, pharyngitis, cough, rhinitis, cervical adenopathy) may precede jaundice by 1-2 weeks. [Harrison ID, p. 889] Patients with acute viral hepatitis may have leukopenia, relative lymphocytosis, and immune-mediated symptoms (rash, hives, arthralgias, and fever) in the preicteric phase. [Cecil, p. 959] The CBC may show mild leukocytosis and thrombocytopenia may be present in severe cases. [5MCC-2020]

"Nosocomial hepatitis A occurs infrequently, and transmission to personnel usually occurs when the source patient has unrecognized hepatitis and is fecally incontinent or has diarrhea. . . . Serologic surveys among health care personnel have not shown greater prevalence of HAV infection than in control populations; therefore, routine administration of vaccine in health care personnel is not recommended. . . . Immune globulin given within 2 weeks after an HAV exposure is more than 85% effective in preventing HAV infection and may be advisable in some outbreak situations. Restriction from patient care areas or food handling is indicated for personnel with HAV infection. They may return to regular duties 1 week after onset of illness." [Guidelines for Infection Control in Health Care Personnel. CDC. 1998] "HCP have not been demonstrated to be at increased risk for hepatitis A virus infection because of occupational exposure, including persons exposed to sewage." [ACIP, 2011]
IgM antibodies (anti-HAV) become detectable 5-10 days after exposure. [CCDM, p. 253] IgM antibodies remain positive for 3-12 months; IgG elevated lifelong following infection; [ABX Guide]
Global; "Hepatitis A is one of the most common vaccine-preventable infections acquired during travel." [CDC Travel, p. 219]
  • >arthralgia
  • >fatigue, weakness
  • >fever
  • >myalgia
  • E pharyngitis
  • E rhinitis
  • G abdominal pain
  • G diarrhea
  • G hepatomegaly
  • G jaundice
  • G liver function test, abnormal
  • G nausea, vomiting
  • H anemia
  • H hemolysis
  • H leukocytosis
  • H leukopenia
  • H lymphadenopathy
  • H splenomegaly
  • H thrombocytopenia
  • N confusion, delirium
  • N headache
  • R cough
  • S urticaria
  • *acute renal failure
  • *arthritis
  • *bleeding tendency
  • *encephalitis
  • *hepatitis
  • *myelitis
  • *pancreatitis
  • *paralysis
  • *stupor, coma
  • *weight loss




Ingestion, Needle (Includes Drug Abuse), Scalpel or Transfusion, Swimming, Sexual Contact
Person-to-Person, Human Fecal-Oral, Eating Contaminated Food, Eating Contaminated Mollusks or Crustacean, Eating Contaminated Produce, Waterborne (Ingesting, Inhaling, or Swimming)
Fish and Shellfish, Monkeys, Human
  • Care for children or primates infected with hepatitis A
  • Care for patients (fecal-oral pathogens)
  • Eat undercooked meat or fish
  • Fail to complete immunizations
  • Have a blood transfusion
  • Ingest infectious agents in food/water
  • Injection drug users
  • Swim in contaminated water (ingestion or inhalation)
  • Travel to endemic area
1. (US) Published in MMWR 2011 = 1398; Use correction factor of 10 for reported diseases: 1398 X 10 = 13980;
2. (Global) Fact sheets from WHO 2013;