Update: Widespread Outbreaks of Hepatitis A among People Who Use Drugs and People Experiencing Homelessness across the United States

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This is an official CDC Health Update

Distributed via the CDC Health Alert Network
March 25, 2019 1330 ET (1:30 PM ET)


Multiple states across the country have reported outbreaks of hepatitis A, primarily among people who use drugs and people experiencing homelessness. Since the hepatitis A outbreaks were first identified in 2016, more than 15,000 cases, 8,500 (57%) hospitalizations, and 140 deaths as a result of hepatitis A virus (HAV) infection have been reported. This Health Alert Network (HAN) update recommends that public health departments, healthcare facilities, and partners and programs providing services to affected populations vaccinate at-risk groups against hepatitis A, applying the updated recommendations of the Advisory Committee on Immunization Practices (ACIP).

This is an update to the Health Alert Network (HAN) advisory released on June 11, 2018 titled Outbreak of Hepatitis A Virus (HAV) Infections among Persons Who Use Drugs and Persons Experiencing Homelessness (https://emergency.cdc.gov/han/han00412.asp).



Multiple states across the country have reported outbreaks of hepatitis A, primarily among people who use drugs and people experiencing homelessness. Since these outbreaks were first identified in 2016, more than 15,000 cases and 8,500 (57%) hospitalizations have been reported. Hospitalization rates have been higher than typically associated with HAV infection.1, 2 Severe complications have also been reported, sometimes leading to liver transplantation or death; at least 140 deaths have occurred nationwide.

HAV is highly transmissible from person-to-person. States experiencing large-scale outbreaks have reported widespread transmission soon after their jurisdictions first recognized hepatitis A cases among populations being affected by these outbreaks. For many states, this has resulted in an unprecedented number of hepatitis A cases among unvaccinated adults since hepatitis A vaccine became available in 1996, and has led to prolonged community outbreaks that have been challenging and costly to control.

CDC recommends that public health departments, healthcare providers, and other partners serving affected populations launch a rapid and effective public health response with the following strategies.



Offer Vaccination to the Following Groups to Prevent or Control an Outbreak

The best way to prevent HAV infection is through vaccination with the hepatitis A vaccine. The following groups are at highest risk for acquiring HAV infection or developing serious complications from HAV infection in these outbreaks and should be offered the hepatitis A vaccine:

    • People who use drugs (injection or non-injection)
    • People experiencing homelessness
    • Men who have sex with men (MSM)
    • People who are, or were recently, incarcerated
    • People with chronic liver disease, including cirrhosis, hepatitis B, or hepatitis C

One dose of single-antigen hepatitis A vaccine has been shown to control outbreaks of hepatitis A and provides up to 95% seroprotection in healthy individuals for up to 11 years.3, 4

Pre-vaccination serologic testing is not required to administer hepatitis A vaccine. Vaccinations should not be postponed if vaccination history cannot be obtained or records are unavailable.

New ACIP Recommendations since the June 2018 HAN00412 (https://emergency.cdc.gov/han/han00412.asp)

  1. As of November 2, 2018, ACIP recommends hepatitis A vaccine for post-exposure prophylaxis (PEP) for people 12 months of age and older. Providers may also administer immunoglobulin to adults older than 40 years of age, if indicated, and persons who are immunocompromised or have chronic liver disease.5
  2. As of February 15, 2019, ACIP recommends hepatitis A vaccination for people experiencing homelessness.6

Health Departments


  1. Identify venues serving populations at-risk for HAV infection, including correctional facilities, syringe service programs, medication-assisted treatment (MAT) facilities, substance use disorder treatment facilities, homeless shelters, emergency departments, and sexually transmitted diseases (STD) clinics. Where ongoing relationships with these facilities and services providers do not exist, engage with partners serving these populations to promote education and vaccination efforts.
  2. Employ novel approaches to improve vaccine delivery to hard-to-reach populations (e.g., Point of Dispensing sites (PODs), mobile outreach teams).
  3. Include hepatitis A vaccination for ACIP-recommended risk groups in routine clinical services to increase vaccination coverage.
  4. Engage multidisciplinary stakeholders (e.g., viral hepatitis or communicable disease experts, epidemiologists, immunization program staff, emergency preparedness staff, disease investigator specialists, health educators, behavioral scientists, harm reduction partners), which is critical for effective response efforts.

Case investigation, contact tracing, and outbreak response monitoring

  1. Implement the new 2019 Acute Hepatitis A Case Definition from the Council of State and Territorial Epidemiologists (CSTE).7
  2. Follow established procedures to interview cases and perform contact tracing for all new hepatitis A diagnoses.
  3. Provide or encourage PEP of previously unvaccinated contacts as soon as possible, within 2 weeks after exposure.5
  4. Track vaccine delivery and administration to at-risk populations to monitor the outbreak response efforts and improve vaccine coverage among at-risk populations.

Preventing outbreaks

  1. States that are not currently experiencing hepatitis A outbreaks should remain vigilant for hepatitis A cases and proactively develop and implement prevention strategies. This includes outreach to and vaccination of ACIP-recommended risk groups, particularly people who use drugs (injection or non-injection), people experiencing homelessness, MSM, and people with chronic liver disease.6, 8
  2. As soon as a hepatitis A case is identified in the at-risk populations, states should rapidly mobilize a response to mitigate the threat of HAV transmission.

Healthcare Providers

  1. Screen patients for risk factors (e.g., drug use, homelessness, incarceration, MSM, and chronic liver disease).
  2. Recommend and administer hepatitis A vaccine to at-risk patients, regardless of the original presenting complaint or the type of clinical facility. In particular, the emergency department may be an individual’s only interaction with the healthcare system and is an important opportunity for prevention.
  3. Record immunizations in the state immunization information system (registry).
  4. Consider hepatitis A as a diagnosis in anyone with jaundice or clinically compatible symptoms.
  5. Rapidly report all persons diagnosed with hepatitis A to the health department to ensure timely case investigation and follow-up of contacts.


For More Information

  1. CSTE’s 2019 Acute Hepatitis A Case Definition. https://wwwn.cdc.gov/nndss/conditions/hepatitis-a-acute/case-definition/2019/
  2. Hepatitis A Virus Outbreaks Associated with Drug Use and Homelessness – California, Kentucky, Michigan, and Utah, 2017. https://www.cdc.gov/mmwr/volumes/67/wr/mm6743a3.htm
  3. CDC’s Hepatitis A Outbreak website. https://www.cdc.gov/hepatitis/outbreaks/2017March-HepatitisA.htm
  4. Outbreak specific considerations for hepatitis A vaccine administration. https://www.cdc.gov/hepatitis/outbreaks/InterimOutbreakGuidance-HAV-VaccineAdmin.htm
  5. CDC’s Hepatitis A Virus website. https://www.cdc.gov/hepatitis/hav/index.htm
  6. Viral Hepatitis Surveillance – United States, 2016. https://www.cdc.gov/hepatitis/statistics/2016surveillance/pdfs/2016HepSurveillanceRpt.pdf
  7. Hepatitis A General Information Fact Sheet. https://www.cdc.gov/hepatitis/hav/pdfs/hepageneralfactsheet.pdf
  8. CDC’s The Pink Book. Chapter 9: Hepatitis A. https://www.cdc.gov/vaccines/pubs/pinkbook/downloads/hepa.pdf



  1. Ly K and Klevens RM. Trends in disease and complications of hepatitis A virus infection in the United States, 1999-2011: A new concern for adults. J Infect Dis 2015;212:176-182.
  2. Viral hepatitis surveillance, United States, 2016. Atlanta, GA: CDC. https://www.cdc.gov/hepatitis/statistics/2016surveillance/pdfs/2016HepSurveillanceRpt.pdf
  3. McMahon BJ, Beller M, Williams J, Schloss M, Tanttila H, Bulkow L. A program to control an outbreak of hepatitis A in Alaska by using an inactivated hepatitis A vaccine. Arch Pediatr Adolesc Med 1996;150(7):733-739.
  4. Ott JJ, Wiersma ST. Single-dose administration of inactivated hepatitis A vaccination in the context of hepatitis A vaccine recommendations. Int J Infect Dis 2013;17(11):e939-944.
  5. Nelson NP, Link-Gelles R, Hofmeister MG, et al. Update: Recommendations of the Advisory Committee on Immunization Practices for use of hepatitis A vaccine for post exposure prophylaxis and for preexposure prophylaxis for international travel. MMWR Morb Mortal Wkly Rep 2018;67(43):1216-1220. https://www.cdc.gov/mmwr/volumes/67/wr/mm6743a5.htm?s_cid=mm6743a5_w
  6. Doshani M, Weng M, Moore K, Romero J, Nelson NP. Recommendations of the Advisory Committee on Immunization Practices for Use of Hepatitis A Vaccine for Persons Experiencing Homelessness. MMWR Morb Mortal Wkly Rep 2019;68:153-156. https://www.cdc.gov/mmwr/volumes/68/wr/mm6806a6.htm
  7. National Notifiable Diseases Surveillance System. Hepatitis A, Acute 2019 Case Definition. https://wwwn.cdc.gov/nndss/conditions/hepatitis-a-acute/case-definition/2019/
  8. Fiore AE, Wasley A, Bell BP; Advisory Committee on Immunization Practices (ACIP). Prevention of hepatitis A through active or passive immunization: Recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR Recomm Rep 2006;55(No. RR-7). https://www.cdc.gov/mmwr/preview/mmwrhtml/rr5507a1.htm

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