Hepatitis A: How Food Spreads the Virus and What to Do After Exposure

One bite of a contaminated salad. A handshake with someone who didn’t wash their hands after using the bathroom. A plate of oysters from a polluted bay. These aren’t just risky behaviors-they’re real ways hepatitis A spreads. And it’s not rare. Around 1.4 million people get hepatitis A every year worldwide. In the U.S., outbreaks still happen-not because of dirty water in poor countries, but because of food handled by someone who doesn’t know they’re sick.

How Hepatitis A Moves Through Food

Food handlers are the most common link in this chain. Studies show a single infected worker can contaminate dozens, even hundreds, of meals during a shift. The virus sticks to fingers, then transfers to lettuce, sandwiches, sushi, or cooked shrimp. One study found that nearly 10% of the virus on a contaminated finger moves to a piece of lettuce with just a light touch. That’s enough to start an outbreak.

It doesn’t need to be raw food. The virus survives cooking. It can live at 60°C (140°F) for a full hour. You need 85°C (185°F) for one minute to kill it. That means undercooked shellfish, like clams or oysters, are high-risk. So are salads, fruits, and sandwiches-anything handled bare-handed after the person has used the bathroom.

And the virus doesn’t die quickly. On stainless steel surfaces, it can survive for 30 days. In dried form, up to four weeks. In frozen food? It can last for years. That’s why outbreaks can pop up months after the original source was handled.

Who’s at Risk-and Why It’s Silent

Between 30% and 50% of adults with hepatitis A have no symptoms. Kids? Almost always symptom-free. But they can still spread the virus. An infected person becomes contagious one to two weeks before they feel sick. That means they’re working the grill, slicing bread, or serving coffee while shedding the virus in their stool. By the time they get jaundice (yellow skin), they’ve already passed it to others.

Outbreaks often go unnoticed until multiple people get sick. Then health departments scramble. A single outbreak can cost $100,000 to $500,000 to investigate. That’s not just lost wages-it’s restaurant closures, public panic, and lawsuits.

What Happens After Exposure

There are two options for PEP:

1. Hepatitis A vaccine (for people aged 1 to 40). One shot gives you protection for at least 25 years. It’s cheaper-$50 to $75 per dose-and builds long-term immunity.
2. Immune globulin (IG) (for everyone else, including kids under 1 and adults over 40). This is a shot of antibodies that gives you immediate, but temporary, protection-lasting only 2 to 5 months. It costs $150 to $300 per dose.

Neither option instantly stops the virus. You still need to wash your hands like your life depends on it-for at least six weeks. And if you’re a food worker? You can’t go back to handling food until at least 7 days after jaundice starts-or two weeks after symptoms begin, depending on your state’s rules.

California requires 14 days from symptom onset before returning to work. Iowa says 7 days after jaundice. There’s no national standard. That’s a problem.

Why Vaccines Aren’t Enough-Yet

Turnover. In quick-service restaurants, staff turn over 150% a year. Someone gets hired, works two weeks, gets sick, and leaves. No one tracks their vaccination status. Language barriers make training hard. Many workers don’t even know the symptoms of hepatitis A. Surveys show only 35% can name them.

And handwashing? It’s supposed to be basic. But 78% of food establishments don’t enforce bare-hand contact rules. Only 42% use gloves or tongs for ready-to-eat food. And even when they do, 22% of kitchens don’t have enough handwashing stations. One station for every 15 employees? That’s the rule. Most places fall short.

Training matters. Hands-on demos improve compliance by 65%. But only 31% of restaurants use them. Most just hand out a pamphlet.

What’s Changing-And What Could Work

More states are stepping in. As of January 2024, 14 U.S. states require hepatitis A vaccination for food handlers. California’s 2022 law prevented an estimated 120 infections and saved $1.2 million in outbreak costs. That’s a win.

New tools are coming. Researchers are testing wastewater monitoring in restaurants. They can detect the virus in sewage before anyone gets sick-89% accurate. Point-of-care blood tests are in Phase 3 trials and are 94% specific. If you could test a food worker in 10 minutes, you could stop outbreaks before they start.

Some places are trying financial incentives. Giving workers a $50 bonus for getting vaccinated increased uptake by 38 percentage points. That’s huge. For every $1 spent on prevention, you save $3.20 in outbreak costs.

What You Can Do

• Get vaccinated. Even if your employer doesn’t require it.
• Wash your hands with soap and water for 20 seconds-every time after the bathroom, before eating, before handling food. Water alone cuts risk by 30%. Soap cuts it by 70%.
• Use gloves or utensils. Never touch ready-to-eat food with bare hands.
• If you feel sick-nausea, fever, dark urine, yellow eyes-stay home. Don’t wait for a diagnosis.

If you eat out:

• Pay attention to hygiene. Are workers using gloves? Are there handwashing signs?
• Be cautious with raw shellfish, salads, and street food in places with poor sanitation.
• If you hear about an outbreak, check if you were there in the past two weeks. If yes, call your doctor. You may still have time for PEP.

What’s Next

Right now, we’re treating outbreaks like accidents. But they’re not. They’re preventable. Every time a food handler gets vaccinated, every time someone washes their hands properly, every time a restaurant uses gloves-we’re not just protecting one person. We’re protecting a whole community.

Stopping hepatitis A isn’t about fear. It’s about action. Clean hands. Vaccines. Gloves. Training. Systems that work. We know how to stop it. Now we just need to do it-consistently, everywhere.