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

Every year, hepatitis A sickens over a million people worldwide-not from dirty water in faraway countries, but from your sandwich, your sushi, or the salad you bought at the grocery store. It doesn’t need to be a dirty kitchen. Just one infected person handling food without washing their hands properly can set off a chain reaction that leaves dozens sick. And here’s the scary part: you won’t know they’re contagious until it’s too late.

How Hepatitis A Spreads Through Food

Hepatitis A is caused by a virus that lives in human poop. It doesn’t need blood or needles to spread. All it needs is a few viral particles-sometimes as few as 100-to get from someone’s hands to your food. The virus survives on surfaces for weeks. It laughs at cold temperatures. It shrugs off chlorine. Even if you cook food to 60°C, it can still survive. Only when you hit 85°C for a full minute does it finally die.

That’s why shellfish are risky. They filter water. If that water has even a tiny bit of sewage, the virus gets trapped in their flesh. A 2023 study found that 92% of shellfish outbreaks happened because the harvest area had more than 14 fecal coliforms per 100 milliliters of water-the FDA’s safety limit. But shellfish aren’t the only problem. Produce like lettuce, herbs, and strawberries are just as dangerous. A 2007 study showed that 10% of the virus on a contaminated fingerpad transfers to a leaf of lettuce in just 10 seconds of casual contact. No cooking. No heat. Just a handshake with your food.

Food handlers are the hidden link. Many don’t even know they’re infected. About 30-50% of hepatitis A cases show no symptoms, especially in kids. But they’re still shedding the virus in their stool. They wash their hands after using the bathroom-or they don’t. They touch raw chicken, then grab a roll. They wipe their nose, then serve a burrito. And because symptoms take 15 to 50 days to show up, the outbreak doesn’t even make sense until people start getting sick weeks later.

Who’s at Risk-and Why It’s Not Just Travelers

If you think hepatitis A is only a problem for people who travel overseas, you’re wrong. In the U.S., routine childhood vaccination since 1996 has cut endemic cases by over 90%. But outbreaks still happen-every year. And they’re almost always tied to food.

Recent CDC data shows that 73% of outbreaks since 2020 happened in places with high staff turnover: fast-casual restaurants, food trucks, seasonal farms, and catering services. Why? Because vaccine coverage among food workers is below 30%. In some places, it’s as low as 7%. And when someone gets sick, they don’t just miss work-they bring the virus with them to the next job. One food handler in Iowa infected 87 people during a single shift. No one knew they were contagious until three weeks later, when the first case of jaundice appeared.

It’s not just the handler. It’s the environment. A 2023 survey in Washington State found that 78% of restaurants don’t use gloves or tongs for ready-to-eat food. They use bare hands. And 45% of kitchen staff speak a language other than English, making training harder. Many don’t even know what hepatitis A is. Only 35% could name the symptoms. Only 28% knew the window for post-exposure prophylaxis is 14 days.

Post-Exposure Prophylaxis: What to Do After You’ve Been Exposed

If you’ve eaten at a restaurant where a worker later tested positive for hepatitis A, or if you’ve handled food with someone who’s now sick, time matters. You have 14 days-no more-to get protected. After that, it’s too late.

There are two options:

• Hepatitis A vaccine (for ages 1 to 40)
• Immune globulin (IG) (for anyone outside that age range, or if you’re immunocompromised)

The vaccine is a single shot. It costs $50-$75. It gives you protection for at least 25 years. The immune globulin is an injection of antibodies. It costs $150-$300. It only protects you for 2-5 months. But it works faster.

Here’s the catch: neither option gives you instant immunity. The vaccine takes two weeks to build protection. IG works faster, but it’s temporary. So even if you get PEP, you still need to be careful. You must avoid bare-hand contact with food. You must wash your hands with soap and water for at least 20 seconds-every time you use the bathroom, before you eat, before you touch anything someone else might eat. The CDC says this reduces transmission risk by 70%. But without gloves or utensils, you’re still at risk.

And if you’re a food handler yourself? You can’t go back to work until at least 7 days after jaundice starts-or 14 days after symptoms begin. California requires 14 days. Iowa says 7 days after jaundice. Rules vary. But the science doesn’t: you’re still contagious long after you feel fine.

Why Handwashing Alone Isn’t Enough

You’ve heard it a thousand times: wash your hands. But washing with water alone? That’s almost useless. Studies show soap and water for 20 seconds cuts transmission risk by 70%. But in many kitchens, handwashing stations are broken, or there aren’t enough. One in five inspected restaurants fail to meet the minimum standard of one sink per 15 workers.

And soap isn’t magic. You need to scrub. You need to rinse. You need to dry. Most people don’t. A Penn State study found that even in restaurants with good signage, only 31% of workers wash long enough. And when they do, they often skip the fingernails, the thumbs, the backs of the hands. That’s where the virus hides.

What’s worse? Many food workers think they’re safe if they wear gloves. But gloves get contaminated too. If you touch your phone, your face, your hair, then put on gloves-you’re just moving the virus around. Gloves need to be changed like socks: after every task, after every bathroom break. And they need to be disposed of properly. Most places don’t.

What’s Changing-and What Still Isn’t

Things are starting to shift. As of January 2024, 14 U.S. states now require hepatitis A vaccination for food handlers. California’s 2022 law prevented 120 infections and saved $1.2 million in outbreak costs. In places that tried it, vaccine uptake jumped from 18% to 62% in just two years.

Some restaurants are now offering $50 bonuses to staff who get vaccinated. Early results show a 38-percentage-point increase in uptake. That’s huge. And pilot programs are testing wastewater in restaurant drains to detect the virus before anyone gets sick. One study got 89% accuracy-meaning they could spot an outbreak before the first person even felt sick.

But the gaps are still massive. Fast-food chains, food trucks, seasonal farms-these are the places where outbreaks explode. Staff turnover is over 150% a year. Training is a PowerPoint slide. No hands-on demos. No practice. Just words. And without practice, behavior doesn’t change.

Dr. Michael Chen, lead author of a major 2025 review, says this: “Every dollar spent on vaccinating food workers saves $3.20 in outbreak response.” That’s not a guess. That’s math from real outbreaks. The average investigation costs $100,000 to $500,000. The vaccine? $75. The IG? $300. The cost of closing a restaurant? Priceless.

What You Can Do

If you’re a customer: If you hear about an outbreak linked to a restaurant, don’t panic. But do ask: Did they notify customers? Did they offer PEP? If they didn’t, that’s a red flag.

If you work with food: Get vaccinated. Even if your employer doesn’t require it. Even if it’s out of pocket. One shot now saves you from weeks of fever, vomiting, jaundice, and missing work. It protects your coworkers. It protects your customers.

If you’re exposed: Go to a clinic within 14 days. Don’t wait. Don’t hope it goes away. Get the vaccine or IG. Wash your hands like your life depends on it-for the next six weeks. And if you’re sick, stay home. Even if you feel okay. Even if you think you’re not contagious. You are.

Hepatitis A isn’t a disease of the past. It’s a disease of silence. Of dirty hands. Of missed shots. Of systems that assume people will do the right thing. But we know better now. We have the tools. We just have to use them.