Global Alert and Response (GAR)

Hepatitis A


Prevention and Treatment

- Guidelines for epidemic measures
- Future considerations

Since antivirals have never been as successful for the treatment of viral infections as antibiotics have been for the treatment of bacterial infections, prevention of viral diseases remains the most important weapon for their control.

Prevention
As almost all HAV infections are spread by the faecal - oral route, good personal hygiene, high quality standards for public water supplies and proper disposal of sanitary waste have resulted in a low prevalence of HAV infections in many well developed societies.18, 22

Within households, good personal hygiene, including frequent and proper hand washing after bowel movement and before food preparation, are important measures to reduce the risk of transmission from infected individuals before and after their clinical disease becomes apparent.18

For preexposure protection, the use of hepatitis A vaccines instead of IG is now highly recommended. Immunization should be a priority for persons at increased risk of acquiring hepatitis A.

For postexposure prophylaxis of non-vaccinated people, the passive administration of IG can modify the symptoms of infection, provided it is given within 2 weeks of exposure.21, 40

No special precautions are demanded for vaccinated persons.

Universal immunization would successfully control hepatitis A, although at present, high costs and limited availability of vaccines preclude such a recommendation.17, 21, 23

Eradication, however, can only be achieved through universal vaccination policies as long as HAV is not endemic in primates.

Treatment
As no specific treatment exists for hepatitis A, prevention is the most effective approach against the disease.4, 40

Therapy should be supportive and aimed at maintaining adequate nutritional balance (1 g/kg protein, 30-35 cal/kg). There is no good evidence that restriction of fats has any beneficial effect on the course of the disease. Eggs, milk and butter may actually help provide a correct caloric intake. Alcoholic beverages should not be consumed during acute hepatitis because of the direct hepatotoxic effect of alcohol. On the other hand, a modest consumption of alcohol during convalescence does not seem to be harmful. Hospitalization is usually not required.18, 40

Adrenocortical steroids (corticosteroids) and IG are of no value in acute, uncomplicated hepatitis A, since they have no effect on the resolution of the underlying disease.18

Antiviral agents have no beneficial clinical effect because a specific antiviral agent is not available and hepatic injury appears to be immunopathologically mediated.40

Patients who are taking oral contraceptives do not need to discontinue their use during the course of the disease.

Referral to a liver transplant centre is appropriate for patients with fulminant hepatitis A, although the identification of patients requiring liver transplantation is difficult. A good proportion of patients (60%) with grade 4 encephalopathy will still survive without transplantation. Temporary auxiliary liver transplantation for subacute liver failure may be a way to promote native liver regeneration.6, 18, 40

Guidelines for epidemic measures

  1. Determination of mode of transmission, whether person-to-person or by common vector (vehicle).

  2. Identification of the population exposed to increased risk of infection. Elimination of common sources of infection.

  3. Improvement of sanitary and hygienic practices to eliminate faecal contamination of food and water.

  4. Hepatitis A vaccination has been shown to be effective in controlling outbreaks of infection in communities that have high or intermediate rates of infection, provided a sufficient percent of the target population is reached.30, 45

  5. Passive immunization provides temporary protection, but it is not effective in controlling HAV on a community level.

Future considerations
Appropriate vaccine doses and schedules in the first two years of life need to be determined to overcome the reduced immune response observed among infants who have passively acquired maternal anti-HAV.

The duration of protection following a single dose of vaccine should be investigated.

Combination vaccines that integrate hepatitis A vaccine into existing childhood vaccination schedules need to be determined.

Most effective vaccination strategies for interrupting and preventing community wide outbreaks need to be defined.

Countries are encouraged to carry out studies addressing the cost-effectiveness of HAV prevention strategies to determine the feasibility of vaccination programmes.7, 34

The development of attenuated HAV vaccines capable of offering cost, production and administration advantages should be considered.

An assay to detect antibody to nonstructural proteins may serve, in future, to distinguish between natural infection and vaccine-induced antibody formation.23, 35, 39

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