HAV vaccination is the preferred method for controlling outbreaks, or for post-exposure prophylaxis. HAV vaccine may be used for post-exposure prevention of infection if given within two weeks of exposure.11 The US Advisory Committee on Immunization Practices (ACIP) recommends HAV vaccine for post-exposure prophylaxis in healthy persons aged 12 months t0 40 years.12 Human IG may be given to infants aged under 12 months and adults aged 41 years and older, and to other vulnerable groups. IG is not usually offered if more than two weeks have elapsed since the onset of exposure to the index case.
See Table 7.3 below for immunoprophylaxis recommendations.
Perinatal transmission is rare. If the mother develops symptoms two weeks before to one week after delivery, the infant may be given IG (0.02 mL/kg), although its efficacy in these circumstances has not been established. The mother may breastfeed. Specific advice should be sought from a paediatrician or infectious diseases physician.
Prevention of spread in these circumstances requires educating people about the modes of spread. For example, HAV can survive on objects in the environment for up to several weeks.
Immunisation should be considered for unimmunised children aged 12 months and older and unimmunised adult workers aged 40 years and under in the same room as the index case. In addition, new workers appointed or children admitted up to six weeks after the outbreak should be vaccinated prior to entry. Infants aged under 12 months and workers aged 41 years and older may be offered IG. Household contacts of confirmed cases should also be protected. Minimal contact in schools is not considered a high-risk situation.
HAV vaccine is effective in controlling community-wide epidemics and common-source outbreaks of HAV infection.13 Before the vaccine is used for outbreak control, consideration should be given to the current epidemiology in the community, the population at risk should be defined, and the feasibility and cost of delivering a programme should be assessed.
|Time since exposure||Age of patient||Recommended prophylaxis|
|2 weeks or less||Younger than 12 months||IG, 0.02 mL/kga|
|12 months through 40 years||HAV vaccineb|
|41 years or older||IG, 0.02 mL/kga but HAV vaccineb can be used if IG is unavailablea|
|People of any age who are immune compromised or have chronic liver disease||IG, 0.02 mL/kga|
|More than 2 weeks||Younger than 12 months||No prophylaxis|
|12 months or older||No prophylaxis, but HAV vaccine may be indicated for ongoing exposureb|
Source: Adapted from: American Academy of Pediatrics. 2012. Hepatitis A. In: Pickering LK, Baker CJ, Kimberlin DW, et al (eds). Red Book: 2012 report of the Committee on Infectious Diseases (29th edition). Elk Grove Village IL: American Academy of Pediatrics, Table 3.13.