Recommendations for Postexposure Prophylaxis to Hepatitis A Virus

 

Use of immune globulin:

(1) It should be administered as soon as possible after the exposure.

(2) The efficacy is greatest when administered early in the HAV incubation period.

(3) If given within 2 weeks of exposure it is > 85% effective in preventing viral hepatitis A.

(4) Do not administer if > 2 weeks since exposure.

(5) Do not administer if previously vaccinated with hepatitis A vaccine >=1 one month prior to exposure.

(6) Hepatitis A vaccine is usually employed now for pre-exposure prophylaxis but immune globulin may be warranted if a significant unpreventable exposure is likely to occur less than one month after vaccine administration.

 

Dose and administration of hepatitis A immune globulin:

(1) 0.02 mL/kg is administered intramuscularly.

(2) A dose of 0.02 mL/kg provides protection for < 3 months; a dose of 0.06 mL/kg provides protection for <= 5 months

(3) The preferred injection sites include the deltoid or gluteal muscles.

(4) If the gluteal muscle is used (1) only the upper outer quadrant should be used, avoiding the central buttock region and (2) the needle should be directed anteriorly to minimize possibility of injury to the sciatic nerve.

(5) If hepatitis A vaccine is also administered, it can be given concurrently but at a separate and remote anatomic site.

 

Laboratory testing:

(1) Laboratory confirmation of the index case with detection of IgM anti-HAV antibodies is usually recommended before administration of post-exposure immune globulin to contacts.

(2) Screening contacts for immunity to hepatitis A (presence of anti-HAV IgG) is not recommended, as (1) screening is more costly than immune globulin, (2) screening delays administration of the immune globulin.

 

Candidates for immune globulin administration:

(1) Close personal contacts:

(1a) Household contacts of persons with confirmed hepatitis A.

(1b) Sexual contacts of persons with confirmed hepatitis A.

(1c) Household contacts of day care center attendees and employees during outbreaks (>= 3 families involved).

(2) Day care center staff and attendees:

(2a) If one or more cases of hepatitis A are recognized in children or employees.

(2b) If cases of hepatitis A are noted in >= 2 household of center attendees.

(2c) If the day care center cares only for children beyond diapers, only classroom contacts of the index patient need vaccination.

(3) Common source exposure from food handler:

(3a) If a food handler is diagnosed with hepatitis A, all food handlers at the same location should receive immune globulin.

(3b) Patrons of restaurants usually are not given immune globulin, but may be considered if the affected food handler (a) had diarrhea or poor hygienic practices, and (b) processed uncooked food or food after it was cooked.

(3c) Patrons of institutional cafeterias may be given immune globulin if there was evidence of repeated exposures to the affected worker.

(3d) Immune globulin is not given in a common source outbreak after cases have begun to occur, since this usually indicates that too much time has passed for the immune globulin to be effective.

(4) Other common source exposures:

(4a) Students if epidemiologic investigation indicates HAV transmission occurred at school.

(4b) Workers if epidemiologic investigation indicates HAV transmission occurred at a workplace.

(4c) In health care settings if epidemiologic investigation indicates HAV transmission occurred at a workplace.

 

Immune globulin is not routinely administered:

(1) when a single case occurs in an elementary or secondary school, office or other work setting, and the likely source of the infection is outside of the school or work setting.

(2) when a patient is admitted to the hospital and careful hygienic practices are used.