Hepatitis A-

Q.What is the case definition for acute hepatitis A?
A.The clinical case definition for acute viral hepatitis is 1) discrete onset of symptoms    (e.g., nausea, anorexia, fever, malaise, or abdominal pain) and 2) jaundice or    elevated serum aminotransferase levels. Because the clinical characteristics are the    same for all types of acute viral hepatitis, hepatitis A diagnosis must be confirmed by    a positive serologic test for immunoglobulin M (IgM) antibody to hepatitis A virus.

Q.Who is at increased risk for acquiring hepatitis A virus infection?
A.Travelers to countries with high or intermediate endemicity of hepatitis A virus    infection
   Men who have sex with men
   Users of injection and non-injection illegal drugs
   Persons with clotting factor disorders
   Persons working with nonhuman primates susceptible to hepatitis A virus infection

Q.What are the signs and symptoms of hepatitis A virus infection?
A.Some persons, particularly young children, are asymptomatic. When symptoms are    present, they usually occur abruptly and can include the following:
      Fever
      Tiredness
      Loss of appetite
      Nausea
      Abdominal discomfort
      Dark urine
      Jaundice
   In children aged <6 years, 70% of infections are asymptomatic; if illness does occur,    it is typically not accompanied by jaundice. Among older children and adults, infection    is typically symptomatic, with jaundice occurring in >70% of patients.

Q.When symptoms occur, how long do they usually last?
A.Symptoms usually last less than 2 months, although 10%-15% of symptomatic    persons have prolonged or relapsing disease for up to 6 months.

Q.What is the incubation period for hepatitis A?
A.The average incubation period for hepatitis A is 28 days (range: 15-50 days).

Q.Can hepatitis A become chronic?
A. No. Hepatitis A does not become chronic.

Q.Can persons become reinfected with hepatitis A virus after recovering from    hepatitis A?
A.No. IgG antibodies to hepatitis A virus, which appear early in the course of infection,    provide lifelong protection against the disease.

Q.How is hepatitis A virus infection prevented?
A.Vaccination with the full, two-dose series of hepatitis A vaccine is the best way to    prevent hepatitis A virus infection. Immune globulin is available for short-term    protection (approximately 3 months) against hepatitis A. Immune globulin must be    administered within 2 weeks after exposure for maximum protection.
   Good hygiene - including handwashing or use of hand sanitizer after using the    bathroom, changing diapers, and before preparing or eating food - is also integral to    hepatitis A prevention, given that the virus is transmitted through the fecal-oral    route.

Q.Who should be vaccinated routinely against hepatitis A?
A.The following groups are recommended to receive hepatitis A vaccination:
   All children at age 1 year (i.e., 12-23 months)
   Children and adolescents ages 2-18 who live in states or communities where routine    hepatitis A vaccination has been implemented because of high disease incidence
   Persons traveling to or working in countries that have high or intermediate rates of    hepatitis A.
   Users of illegal injection and noninjection drugs.
   Persons who have chronic liver disease. Persons with chronic liver disease who have    never had hepatitis A should be vaccinated, as they have a higher rate of fulminant    hepatitis A. Persons who are either awaiting or have received liver transplants also    should be vaccinated.

Q.Which hepatitis A vaccines are licensed for use?
A.Two single-antigen hepatitis A vaccines, HAVRIX® (manufactured by GlaxoSmithKline)    and VAQTA® (manufactured by Merck & Co., Inc), are currently licensed. A    combination vaccine, TWINRIX® (manufactured by GlaxoSmithKline), contains both    hepatitis A virus (in a lower dosage) and hepatitis B virus antigens. All are inactivated    vaccines.

Q.Can hepatitis A vaccine be given during pregnancy?
A.The safety of hepatitis A vaccination during pregnancy has not been determined;    however, because vaccine is produced from inactivated hepatitis A virus, the    theoretical risk to the developing fetus is expected to be low. The risk associated    with vaccination, however, should be weighed against the risk for hepatitis A in    women who might be at high risk for exposure to hepatitis A virus.

Hepatitis B-

Q.How is HBV transmitted?
A.HBV is transmitted through activities that involve percutaneous (i.e., puncture    through the skin) or mucosal contact with infectious blood or body fluids (e.g.,    semen, saliva), including
   Sex with an infected partner
   Injection drug use that involves sharing needles, syringes, or drug-preparation    equipment
   Birth to an infected mother
   Contact with blood or open sores of an infected person
   Needle sticks or sharp instrument exposures
   Sharing items such as razors or toothbrushes with an infected person
   HBV is not spread through food or water, sharing eating utensils, breastfeeding,    hugging, kissing, hand holding, coughing, or sneezing.

Q.How long does HBV survive outside the body?
A.HBV can survive outside the body at least 7 days and still be capable of causing    infection.

Q.Who is at risk for HBV infection?
A.The following populations are at increased risk of becoming infected with HBV:
   Infants born to infected mothers.
   Sex partners of infected persons.
   Injection drug users.
   Healthcare and public safety workers at risk for occupational exposure to blood or    blood-contaminated body fluids.
   Hemodialysis patients

Q.How serious is acute HBV infection?
A.Acute infection ranges from asymptomatic or mild disease to - rarely - fulminant    hepatitis. Disease is more severe among adults aged >60 years. The fatality rate    among acute cases reported to CDC is 0.5%-1%.

Q.How likely is HBV infection to become chronic?
A.The risk for chronic infection varies according to the age at infection and is greatest    among young children. Approximately 90% of infants and 30% of children aged <5    years will remain chronically infected with HBV. By contrast, approximately 95% of    adults recover completely from HBV infection and do not become chronically infected.

Q.How is HBV infection treated?
A.For acute infection, no medication is available; treatment is supportive.
   For chronic infection, several antiviral drugs (adefovir dipivoxil, interferon alfa-2b,    pegylated interferon alfa-2a, lamivudine, entecavir, and telbivudine) are available.
   Persons with chronic HBV infection require medical evaluation and regular monitoring    to determine whether disease is progressing and to identify liver damage or    hepatocellular carcinoma.

Hepatitis C-

Q.What is hepatitis C?
A.Hepatitis C is a liver disease caused by the hepatitis C virus (HCV), which is found in    the blood of persons who have this disease. HCV is spread by contact with the blood    of an infected person.

Q.Is there a vaccine for the prevention of HCV infection?
A.No.

Q.What blood tests are available to check for hepatitis C?
A.There are several blood tests that can be done to determine if you have been    infected with HCV. Your doctor may order just one or a combination of these tests.
   The following are the types of tests your doctor may order and the purpose for each:
   a) Anti-HCV (antibody to HCV)
   EIA (enzyme immunoassay) or CIA (enhanced chemiluminescence immunoassay)
   Test is usually done first. If positive, it should be confirmed
   RIBA (recombinant immunoblot assay)
   A supplemental test used to confirm a positive EIA test
   Anti-HCV does not tell whether the infection is new (acute), chronic (long-term) or is    no longer present.
   b) Qualitative tests to detect presence or absence of virus (HCV RNA)
   c) Quantitative tests to detect amount (titer) of virus (HCV RNA)
   A single positive PCR test indicates infection with HCV. A single negative test does    not prove that a person is not infected. Virus may be present in the blood and just    not found by PCR. Also, a person infected in the past who has recovered may have a    negative test. When hepatitis C is suspected and PCR is negative, PCR should be    repeated.

Q.Who should get tested for hepatitis C?
A.Persons who ever injected illegal drugs, including those who injected once or a few    times many years ago
   Persons who were treated for clotting problems with a blood product made before    1987 when more advanced methods for manufacturing the products were developed
   Persons who were notified that they received blood from a donor who later tested    positive for hepatitis C
   Persons who received a blood transfusion or solid organ transplant before July 1992    when better testing of blood donors became available
   long-term hemodialysis patients
   Persons who have signs or symptoms of liver disease (e.g., abnormal liver enzyme    tests)
   Healthcare workers after exposures (e.g., needle sticks or splashes to the eye) to    HCV-positive blood on the job
vchildren born to HCV-positive women

Hepatitis D-

Q.What causes the disease?
A.Hepatitis D or delta hepatitis is caused by the hepatitis delta virus (HDV), a defective    RNA virus. HDV requires the help of a hepadnavirus like hepatitis B virus (HBV) for its    own replication.

Q.How is HDV spread?
A.HDV is transmitted percutaneously or sexually through contact with infected blood or    blood products.
   Blood is potentially infectious during all phases of active hepatitis D infection. Peak    infectivity probably occurs just before the onset of acute disease.

Q.Who is at risk for infection?
A.Chronic HBV carriers are at risk for infection with HDV.
   Individuals who are not infected with HBV, and have not been immunized against HBV,    are at risk of infection with HBV with simultaneous or subsequent infection with HDV.
   Since HDV absolutely requires the support of a hepadnavirus for its own replication,    inoculation with HDV in the absence of HBV will not cause hepatitis D. Alone, the viral    genome indeed replicates in a helper-independent manner, but virus particles are not    released.

Q.Where is HDV a problem globally?
A.The hepatitis delta virus is present worldwide and in all age groups.14, 21
   Its distribution parallels that of HBV infection, although with different prevalence    rates (highest in parts of Russia, Romania, Southern Italy and the Mediterranean    countries, Africa and South America). In some HBV-prevalent countries such as    China, HDV infection is disproportionately low.14
   The natural reservoir is man, but HDV can be experimentally transmitted to    chimpanzees and woodchucks that are infected with HBV and woodchuck hepatitis    virus, respectively.19, 21, 24

Q.When is a HDV infection life-threatening?
A.HDV infection of chronically infected HBV-carriers may lead to fulminant acute    hepatitis or severe chronic active hepatitis, often progressing to cirrhosis.
   Chronic hepatitis D may also lead to the development of hepatocellular carcinoma.11

Q.Why is there no treatment for the disease?
A.Hepatitis D is a viral disease, and as such, antibiotics are of no value in the treatment    of the infection.
   There is no hyperimmune D globulin available for pre- or postexposure prophylaxis.
   Disease conditions may occasionally improve with administration of a-interferon.15,    21, 25
   Since no effective antiviral therapy is currently available for treatment of type D    hepatitis, liver transplantation may be considered for cases of fulminant acute and    end-stage chronic hepatitis D.