Appendices for Prevention of Hepatitis A Virus Infection in the United States: Recommendations of the Advisory Committee on Immunization Practices, 2020

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Appendix A: Provider Guidance for Preexposure Protection for International Travelers Aged ≥12 Months

Hepatitis A (HepA) vaccination administered with the appropriate dose and schedule is preferred to immune globulin (IG) for preexposure protection for travelers aged ≥12 months. One dose of single-antigen HepA vaccine administered at any time before departure might provide adequate protection for most healthy persons (1). However, single-dose long-term protection data are limited, and limited data are available for other populations (e.g., immunocompromised) or other HepA vaccine formulations (i.e., Twinrix). For unvaccinated persons, the first dose of HepA vaccine should be administered as soon as travel is considered. The second dose should be administered according to the licensed schedule to complete the series. Travelers who have received a single dose of single-antigen HepA vaccine ≥6 months previously can receive a second dose of HepA vaccine to complete the vaccine series. Travelers who have received a single dose of single-antigen HepA vaccine within the previous 6 months do not need an additional dose for travel (1). Travelers may be administered Twinrix before travel, consisting of 3 doses administered on a 0-, 1-, and 6-month schedule. An alternate, accelerated schedule is also available for Twinrix: 3 doses at 0, 7, and 21–30 days, followed by a booster dose at 12 months that provides long-term protection (2).

For travelers aged >40 years, immunocompromised persons, and persons with chronic liver disease, the ability of the person to develop a protective antibody level after receipt of HepA vaccine, the magnitude of the risk for hepatitis A virus (HAV) transmission from the exposure (e.g., endemicity of hepatitis A in the area of travel), and availability of IG and vaccine should be considered in decisions to use IG in addition to vaccine (1). In addition, because of the complexity of determining HAV endemicity globally and limited data on subpopulation variation of HAV antibody (anti-HAV) seroprevalence within regions (3,4), preexposure protection against HAV infection can be considered for persons aged ≥12 months who are traveling to any area.


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Appendix B: Provider Guidance on Risk Assessment for Hepatitis A Postexposure Prophylaxis

Postexposure Prophylaxis for Persons Exposed to Hepatitis A Virus

Healthy persons who have completed the hepatitis A (HepA) vaccination series at any time do not need additional postexposure prophylaxis (PEP) if they are exposed to hepatitis A virus (HAV). The effectiveness of PEP is greater when administered soon after exposure. Therefore, if only immune globulin (IG) (1) or only vaccine is available for a person who has been exposed, either available product should be administered as soon as possible; the person may return for the other product if it becomes available within 2 weeks of exposure. If administered simultaneously, HepA vaccine and IG should be administered in a different anatomic site (i.e., separate limbs) (2). The HepA vaccine series should be completed with a second dose at least 6 months after the first dose for long-term protection.

PEP should be administered to all persons who have not previously completed the HepA vaccine series who have been exposed or are at risk for exposure through close personal contact with a person who has serologically confirmed HAV infection (e.g., household and sexual contacts, persons using injection or noninjection drugs with the HAV-infected person, or caregivers not using appropriate personal protective equipment) (3).

Risk for HAV Transmission in Various Settings and for Various Groups

For persons exposed to HAV, considerations regarding decisions to use IG, vaccine, or both should include the ability of the person to develop a protective level of antibodies after receipt of HepA vaccine, the magnitude of the risk for HAV transmission from the exposure, and the availability of IG and vaccine (4). The severity of HAV infection and the time to develop protective antibodies increase with age (4). In general, the risk for infection after a household or sexual exposure is likely to be greater than the risk associated with a common source exposure (e.g., exposure to a contaminated food product or restaurant exposure) (5). The risk for transmission of HAV is influenced by host and environmental factors and varies considerably in different settings. For example, without PEP, secondary attack rates of 20%–50% have been reported in households, with higher rates of transmission occurring from infected young children than from infected adolescents and adults (68). In contrast, attack rates among patrons of food service establishments who have been exposed to HAV-infected food handlers are generally low (5,912). Given the difficulty in determining precise timing and extent of exposure and potential repeated exposures, as well as concerns over the administration and availability of IG (1,11), risk-based provider guidance is provided below.

Child care centers. PEP should be administered to all previously unvaccinated staff members and attendees of child care centers or institutions if 1) one or more cases of HAV infection are recognized in children or 2) cases are recognized in two or more households of center attendees. If one or more cases of HAV infection occur among employees, PEP for other staff and attendees should be considered based on the duties, hygienic practices, and presence of symptoms at work. In centers that do not provide care to children who wear diapers, PEP can be considered only for care center contacts of the index patient (3).

Common-source food exposure and food handlers. Because common-source transmission to patrons is unlikely (5,9,11,12), administering PEP to patrons of food establishments staffed by an HAV-infected person typically is not indicated. If, during the time when the food handler was likely to be infectious, the food handler both directly handled uncooked or cooked foods without gloves and had diarrhea or poor hygienic practices, the risk for an individual patron remains low; however, PEP may be considered for persons who have potentially been exposed (patrons or co-workers of the infected food handler during the time the food handler was symptomatic and worked) (5,11). PEP in this scenario should generally consist of vaccination for persons aged ≥12 months, although IG may be considered in addition to vaccine for exposed persons who are immunocompromised or have chronic liver disease. In settings in which repeated exposures to HAV might have occurred (e.g., institutional cafeterias), consideration of HepA vaccine, IG, or both is warranted.

Settings providing services to children and adults. PEP is not routinely indicated when a single case occurs in an elementary or secondary school or an office or other work setting and the source of infection is outside of the setting. PEP should be administered to persons who have close contact with index patients if an epidemiologic investigation indicates HAV transmission has occurred (e.g., among students in a school). PEP should be considered for all previously unvaccinated residents and employees when a confirmed hepatitis A case occurs in a setting where close personal contact occurs regularly and hygiene standards are difficult to maintain (e.g., correctional facility, homeless shelter, psychiatric facility, or group home or residential facility for persons with developmental disabilities). In a setting containing multiple enclosed units or sections (e.g., prison ward), PEP administration should be limited only to persons in the area with risk for exposure (3).

Health care institutions. Because health care personnel do not have an increased prevalence of HAV infection, HepA vaccination is not routinely recommended for health care personnel in the United States (3). When a person who has HAV infection is admitted to a hospital, staff members should not routinely be administered PEP; instead, appropriate infection control practices should be emphasized (i.e., contact precautions for diapered or incontinent patients) (13). PEP within the health care setting may be considered on a case-by-case basis if the risk for exposure to HAV is considered high. Outbreaks have been observed in neonatal intensive care units because of infants acquiring infection from transfused blood and subsequently transmitting HAV to other infants and staff (14,15). Outbreaks of hepatitis A caused by transmission from patients to health care personnel are typically associated with fecal incontinence and inadequate hand hygiene (16), although most hospitalized patients who have HAV infection are admitted after onset of jaundice, when they are beyond the point of peak infectivity (17,18). In hospitals, sharing food or beverages between patients, families, and health care personnel has been associated with HAV transmission (19,20).

Host-specific factors to consider when assessing for increased risk for HAV transmission in the health care setting include health care personnel with hepatitis A working during the infectious period or working with symptoms including diarrhea, and patients with hepatitis A who are diapered or incontinent and symptomatic, including diarrhea. Infection control considerations include poor compliance with hand hygiene, poor adherence to recommended standard and transmission-based precautions (e.g., contact precautions when caring for patients with hepatitis A who are diapered or incontinent, standard precautions for all others []) and suboptimal cleaning and disinfection of the environment. When perceived risk for HAV exposure is high, PEP for patients or health care personnel may be considered. In a health care setting with multiple enclosed units or sections (e.g., a hospital or psychiatric facility), PEP administration may be limited to areas where potential exposures may have occurred (e.g., cardiology ward or intensive care unit).


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  16. Foster MA, Weil LM, Jin S, et al. Transmission of hepatitis A virus through combined liver-small intestine-pancreas transplantation. Emerg Infect Dis 2017;23:590–6. CrossRefexternal icon PubMedexternal icon
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