The number of hepatitis A cases reported in the U.S. has changed significantly over the past two decades

The Centers for Disease Control and Prevention (CDC) reported approximately 4,000 to 5,000 cases of hepatitis A per year in recent years, though this number fluctuates. In 2016 and 2017, cases dropped to around 3,000 annually. Starting in 2018, reported cases began climbing again, reaching over 12,000 in 2019 during a multistate outbreak. The number varies year to year depending on outbreaks, vaccination rates, and food safety incidents.

These are reported cases — the actual number of infections is likely higher because some people with hepatitis A have no symptoms or mild symptoms they don't report to a doctor. The CDC estimates that for every reported case, there may be additional unreported infections, particularly in children under age 5, who often have no symptoms at all.

Key Takeaways

  • The CDC reported between 4,000 and 5,000 hepatitis A cases per year in the early 2010s, with numbers rising to over 12,000 during the 2018–2019 outbreak period.
  • Reported case numbers do not capture all infections, since many people with hepatitis A have no symptoms or mild symptoms they never report.
  • Outbreaks tied to contaminated food, water, or person-to-person spread can cause case numbers to spike in specific regions or populations.
  • Vaccination rates and access to the hepatitis A vaccine affect how many cases occur in a given year.

Why reported numbers don't match actual infections

A person with hepatitis A may never see a doctor, especially if their symptoms are mild or they recover on their own. Young children often have no symptoms at all, so their infections go undetected. Healthcare providers report confirmed cases to state health departments, which report to the CDC — but this chain depends on someone seeking care and getting tested.

The CDC uses statistical models to estimate the true burden of hepatitis A, accounting for unreported cases. These estimates suggest the actual number of infections is substantially higher than the reported count, though the exact multiplier varies by year and population.

How outbreaks change the yearly count

Hepatitis A spreads through contaminated food or water, or through close contact with an infected person. When a single source — such as contaminated produce, a restaurant, or a childcare facility — infects many people at once, case numbers spike. The 2018–2019 outbreak, which affected multiple states, was linked to contaminated food and person-to-person transmission in homeless and drug-using populations.

Between outbreaks, case numbers tend to be lower and more stable. A year with no major outbreak may see 4,000 to 5,000 reported cases; a year with a significant outbreak can see double or triple that number. This is why looking at a single year's count can be misleading — trends over several years give a clearer picture.

Regional variation in hepatitis A cases

Hepatitis A cases are not evenly distributed across the country. Some states and regions report higher rates than others, depending on vaccination coverage, sanitation infrastructure, and the presence of outbreaks. Rural areas and areas with lower vaccination rates may see higher case counts.

During the 2018–2019 outbreak, certain states were hit much harder than others. The CDC tracks cases by state and publishes this information regularly, so you can see whether your area has had recent cases or outbreaks.

Who gets hepatitis A most often

Hepatitis A can infect anyone, but certain groups have higher rates. Young children, people living in crowded conditions, people experiencing homelessness, and people who use drugs have higher infection rates. International travelers to areas where hepatitis A is common also face increased risk.

Vaccination has reduced hepatitis A rates dramatically in vaccinated populations. The hepatitis A vaccine became available in the mid-1990s and was added to the routine childhood vaccination schedule in 2006. States and regions with high vaccination coverage report fewer cases than areas with lower vaccination rates.

How case counts are tracked and reported

The CDC collects hepatitis A case reports from state and local health departments through the National Notifiable Diseases Surveillance System (NNDSS). Healthcare providers and laboratories report confirmed cases to their state health department, which then reports to the CDC. This system captures cases that are diagnosed and reported, but misses infections that are never diagnosed or reported.

The CDC publishes case counts and trends on its website, updated regularly. You can find current-year data and historical comparisons by state and region. These reports also note ongoing outbreaks and their sources when they are identified.

What the trend means for prevention

The rise in hepatitis A cases from 2018 onward highlighted gaps in vaccination coverage and sanitation in certain populations. Public health responses have focused on increasing vaccination rates, improving food safety oversight, and providing prevention education in high-risk communities.

If case counts are rising in your area, it may mean an outbreak is underway or vaccination coverage is lower than it should be. The hepatitis A vaccine is highly effective at preventing infection and is recommended for all children and for adults at higher risk. Checking your own vaccination status and that of your family is a practical step if you live in or travel to an area with reported cases.

Frequently Asked Questions

Is hepatitis A getting more common?

Case numbers rose significantly from 2018 to 2019 during a multistate outbreak, but this does not mean hepatitis A is becoming endemic in the U.S. The increase was tied to specific outbreaks in specific populations. Long-term trends show that vaccination has reduced hepatitis A rates compared to the pre-vaccine era.

Why are some states reporting more cases than others?

Variation depends on vaccination rates, sanitation infrastructure, population density, and whether an outbreak is occurring in that state. States with lower vaccination coverage or ongoing outbreaks report higher case counts. The CDC website shows case counts by state so you can see your own region's numbers.

Can I learn about there's a hepatitis A outbreak near me?

Yes. The CDC publishes information about active hepatitis A outbreaks on its website, including which states are affected and the source when known. Your state or local health department also posts outbreak alerts. Checking these sources regularly is the best way to stay informed about your area.

Does the reported case count include people who had no symptoms?

No. Reported cases are people who were diagnosed and tested, usually because they had symptoms and sought care. People with no symptoms are not counted in the official numbers, which is why the true number of infections is higher than reported cases.

What should I do if hepatitis A cases are rising in my area?

Check your vaccination status and that of your family members. The hepatitis A vaccine is highly effective and is recommended for all children and for adults at higher risk. If you are unvaccinated and live in or travel to an area with reported cases, talk to your doctor about getting vaccinated.