Hepatitis A Outbreak Linked to Person-to-Person Contact

Update

Investigation status: Open
Recall issued: No

In 2016, hepatitis A outbreaks began spreading across the United States through person-to-person transmission. The outbreaks peaked in 2019.

Fast Facts

United States
  • Confirmed cases: 44,937
  • Hospitalizations: 27,461
  • Deaths: 424
  • States: 37 states (Active in IN, MD, and PA; declared over in AL, AZ, AR, CA, CO, DE, FL, GA, ID, IL, KS, KY, LA, ME, MA, MI, MN, MS, MO, NV, NH, NJ, NM, NY, NC, OH, SC, TN, TX, UT, VT, VA, WA, and WV)

In 2016, hepatitis A outbreaks began spreading across the United States through person-to-person transmission. The outbreaks peaked in 2019.

Situation summary

Many people think hepatitis A is only connected to contaminated food and water. However, in the US, hepatitis A is more commonly spread from person to person. Since outbreak cases were first identified in 2016, 37 states have publicly reported cases.

A doctor giving a man a shot in the arm in a doctor's office
CDC helped contain a widespread outbreak of hepatitis A to only a couple states.

Hepatitis A outbreak cases and clinical outcomes

Since the hepatitis A outbreaks began in 2016, affected states have publicly reported 44,937 cases across the US. More than half of the people who got sick were hospitalized.

State-reported hepatitis A outbreak cases and clinical outcomes, 2016 - 2023

The table below shares more data about what happened to the people who got sick. Scroll to the right to see the full table below.

Table details in footnotes AA, BB, and CC below.

Outbreak investigation summary

Since March 2017, CDC has been helping multiple state and local health departments with hepatitis A outbreaks spread through person-to-person contact.

CDC can provide support anytime states or jurisdictions request it. In some cases, CDC sends "disease detectives" to help local health officials trace an outbreak. CDC also makes sure that affected areas have access to hepatitis A testing and vaccination.

In some cases, states and jurisdictions handle occasional outbreaks independent of CDC.

Source of the outbreak

The hepatitis A virus (HAV) is found in the stool and blood of a person who is infected. In these outbreaks, HAV spread from person to person, especially among people who use drugs and people experiencing homelessness.

What you should do

If you think you’ve been exposed to hepatitis A, contact a health professional as soon as possible. Getting hepatitis A vaccine within 2 weeks after exposure could prevent you from getting sick. After that time, the vaccine does not prevent illness from your recent exposure but can still prevent you from getting hepatitis A in the future.

Preventing hepatitis A

Some groups of people have a higher risk of getting hepatitis A during these outbreaks. If you use or inject drugs, are experiencing homelessness, have recently been in jail or prison, or are a man who has sex with other men, talk to your doctor about getting vaccinated as soon as possible. People with liver diseases like cirrhosis, hepatitis B, or hepatitis C should also get vaccinated since they are at higher risk for developing serious complications from HAV infection during these outbreaks.

Get vaccinated‎

Hepatitis A vaccine is the best way to prevent HAV infection.

Practice good hand hygiene‎

Thoroughly wash your hands with soap and warm water to prevent the spread of many illnesses, including hepatitis A.

Post-exposure prophylaxis

If you think you've been exposed to HAV and haven't previously received hepatitis A vaccine, talk to your doctor about a prevention measure called post-exposure prophylaxis (PEP). PEP should be administered as soon as possible within 2 weeks of exposure to HAV. This prevention measure includes hepatitis A vaccine, and, for some people, another medicine called immune globulin.

If you have been around someone diagnosed with hepatitis A and aren't sure whether you have had the vaccine, talk to your doctor right away. Getting treated within 2 weeks after exposure can prevent you from getting sick.

About Hepatitis A

Hepatitis A is a liver infection caused by HAV. It is very contagious, and people can spread the virus even before they start showing symptoms.

The virus is found in the stool and blood of people who are infected. It can also live on surfaces for several months. You can also get sick by ingesting the virus. This usually happens through close personal contact with a person who is infected.

Most people who get hepatitis A don't get very sick. In some cases, the virus can cause severe illness that lasts several months.

Although uncommon, hepatitis A can cause death. People who are older have a higher risk of dying from hepatitis A.

Outbreaks increase the prevalence of hepatitis A

Hepatitis A declined dramatically after 1996 when health officials first recommended hepatitis A vaccine in the US.

In 2015, there were 1,390 reported cases of hepatitis A in the nation. The widespread outbreaks associated with person-to-person transmission started in 2016.

Since then, CDC has reported more than 44,000 cases nationwide. The outbreaks have caused severe health issues, putting many in the hospital and killing more than 400 people.

Get vaccinated‎

Hepatitis A is easily prevented with a safe and effective vaccine.

Resources for the public

Outbreak fact sheets for:

Public health and health care provider resources

CDC developed educational materials to help state and local health officials dealing with an outbreak.

Most materials below can be customized. To customize, type your organization's contact information into the blue-colored rectangle. To upload your logo, click on the white space below the blue-colored rectangle. In the pop-up box, select "browse" and upload a PDF version of your logo.

Pocket cards

These cards should be printed double-sided on business card templates that print six double-sided cards per page. Settings must be set to “actual size” or “custom scale 100%” to ensure accurate alignment.

Posters

The collection below contains posters encouraging high-risk audiences to get vaccinated for Hepatitis A.

Posters encouraging men who have sex with men to get vaccinated:

Poster outlining what Emergency Departments can do to help stop hepatitis A outbreaks:

Symptoms of Hepatitis A

Most people get symptoms anywhere between 2–7 weeks after being exposed. Even if you don’t have symptoms, you can still spread the virus to others. Common symptoms include:

  • Dark urine or clay-colored stools
  • Diarrhea
  • Feeling tired
  • Fever
  • Joint pain
  • Loss of appetite
  • Nausea, stomach pain, throwing up
  • Yellow skin or eyes (jaundice)

If you develop symptoms‎

If you develop any hepatitis A symptoms, contact your doctor. For more information on hepatitis A symptoms, see Hepatitis A Symptoms.
Health Care Providers: Clinical Signs and Symptoms of Hepatitis A
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Content Source:
Division of Viral Hepatitis
  1. "Outbreak-associated" status is currently determined at the state level in accordance with each state's respective outbreak case definition.
  2. Outbreak-related hepatitis A deaths are defined at the state level in accordance with each state's respective hepatitis A-related death definition. Some states are reviewing death certificates on a regular basis to actively find hepatitis A-related deaths, while other states are utilizing passive surveillance.
  3. Outbreak start date is defined at the state level and may represent the earliest onset date of an outbreak case (AZ, AR, KS, UT), the left censor date for which cases are considered part of the outbreak based on the state outbreak case definition (AL, CA, CO, DE, FL, GA, ID, IL, IN, KY, LA, ME, MD, MA, MI, MN, MS, MO, NV, NH, NJ, NC, OH, PA, SC, TN, TX, VA, WA), or when a state declared a hepatitis A outbreak (NM, WV).
  • 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 Nov;17(11):e939-44. doi: 10.1016/j.ijid.2013.04.012. Epub 2013 Jun 21. Review. PubMed PMID: 23791857.
  • 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 Jul;150(7):733-9. PubMed PMID: 8673200.