HAV

Question 1

General findings

HAV has no known chronic carrier state and does not cause chronic hepatitis or cirrhosis.💥

Answer 1

Hepatitis A is caused by an enterically transmitted RNA virus that, in older children and adults, causes typical symptoms of viral hepatitis, including anorexia, malaise, and jaundice. Young children may be asymptomatic. Fulminant hepatitis and death are rare in developed countries. Chronic hepatitis does not occur. Diagnosis is by antibody testing. Treatment is supportive. Vaccination and previous infection are protective.

Question 2

Trasmission

Answer 2

HAV spreads primarily by fecal-oral contact and thus may occur in areas of poor hygiene. Waterborne and food-borne epidemics occur, especially in developing countries. Eating contaminated raw shellfish is sometimes responsible. Sporadic cases are also common, usually as a result of person-to-person contact.

Fecal shedding of the virus occurs before symptoms develop and usually ceases a few days after symptoms begin; thus, infectivity often has already ceased when hepatitis becomes clinically evident.

Question 3

Clinica

Answer 3

In children < 6 years old, 70% of hepatitis A infections are asymptomatic, and in children with symptoms, jaundice is rare!👓

In contrast, most older children and adults have typical manifestations of viral hepatitis, including anorexia, malaise, fever, nausea, and vomiting; jaundice occurs in over 70%.

Manifestations typically resolve after about 2 months🧨, but in some patients, symptoms continue or recur for up to 6 months.

Recovery from acute hepatitis A is usually complete. Fulminant hepatitis rarely occurs.

Question 4

Diagnosis

Answer 4

If acute viral hepatitis is suspected, the following tests are done to screen for hepatitis viruses A, B, and C:

IgM antibody to HAV (IgM anti-HAV)
Hepatitis B surface antigen (HBsAg)
IgM antibody to hepatitis B core (IgM anti-HBc)
Antibody to hepatitis C virus (anti-HCV) and hepatitis C RNA (HCV-RNA)
If the IgM anti-HAV test is positive, acute hepatitis A is diagnosed. The IgG antibody to HAV (IgG anti-HAV) test is done (see table Hepatitis A Serology) to help distinguish acute from prior infection. A positive IgG anti-HAV test suggests prior HAV infection or acquired immunity. There is no further testing for hepatitis A.

HAV is present in serum only during acute infection and cannot be detected by clinically available tests!

IgM antibody typically develops early in the infection and peaks about 1 to 2 weeks after the development of jaundice. It diminishes within several weeks, followed by the development of protective IgG antibody (IgG anti-HAV), which persists usually for life. Thus, IgM antibody is a marker of acute infection, whereas IgG anti-HAV indicates only previous exposure to HAV and immunity to recurrent infection.

Question 5

Enzimi epatici

Answer 5

1. ALT>AST

2. nella variante colestatica, aumento di AP

Question 6

Treatment

Answer 6

Supportive care
No treatments attenuate acute viral hepatitis, including hepatitis A. Alcohol should be avoided because it can increase liver damage. Restrictions on diet or activity, including commonly prescribed bed rest, have no scientific basis.

For cholestatic hepatitis, cholestyramine 8 g orally once or twice a day can relieve itching.

Viral hepatitis should be reported to the local or state health department!🧨

Question 7

Prevention

Answer 7

The hepatitis A vaccine is recommended for all children beginning at age 1 year, with a 2nd dose 6 to 18 months after the first

✔Preexposure HAV vaccination (see Adult Immunization Schedule) should be provided for

Travelers to countries with high or intermediate HAV endemicity
Diagnostic laboratory workers
Men who have sex with men
People who use injection or noninjection illicit drugs
People with chronic liver disorders (including chronic hepatitis C) because they have an increased risk of developing fulminant hepatitis due to HAV
People who receive clotting factor concentrates
People who anticipate close contact with an international adoptee during the first 60 days after arrival from a country with high or intermediate HAV endemicity
People who do not have stable housing or who are homeless
!Travelers were advised to get the hepatitis A vaccine ≥ 2 weeks before travel; those leaving in < 2 weeks should also be given standard immune globulin.

✔Postexposure prophylaxis should be given to family members and close contacts of patients with hepatitis A.

• For healthy, unvaccinated patients aged 1 to 40 years, a single dose of hepatitis A vaccine is given.
• For other patients, particularly those > 75 years old, those with chronic liver disease, and immunocompromised patients, standard immune globulin (formerly immune serum globulin) prevents or decreases the severity of hepatitis A. A dose 0.02 mL/kg IM is generally recommended, but some experts advise 0.06 mL/kg (3 to 5 mL for adults). It can be given up to 2 weeks after exposure, but the earlier, the better.